Metallocenes for the manufacture of polypropylene

Abstract

The disclosure relates to a metallocene complex of formula (I), wherein Mt is Zr or Hf: X is a sigma ligand; R1 are each independently, same or different from each other, C1-C20 hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8 ring; R2 and R2' are each independently, same or different from each other, C1-C10- hydrocarbyl; n are each independently an integer from 1 to 5; R3 and R4 are each independently H, C1-C10 hydrocarbyl group, or a –OR31, -SR31 or -N R31 2 group in which R31 is a C1-C10 hydrocarbyl, whereby at least on R3 per phenyl group and at least one R4 is not hydrogen.; R51' is C1-C10-hydrocarbyl; and R6' is C(R61)3, with R61 being linear or branched C1-C6-alkyl.

Description

[0001] METALLOCENES FOR THE MANUFACTURE OF POLYPROPYLENE FIELD OF THE DISCLOSURE The present disclosure relates to new bisindenyl ligands, complexes thereof, and catalysts comprising those complexes. The present disclosure also relates to the use of the new bisindenyl metallocene catalysts for the production of polypropylene homopolymers or propylene copolymers, with high activity levels, high molecular weight, and hence low MFR, and with ideal melting points. BACKGROUND OF THE DISCLOSURE Metallocene catalysts have been used to manufacture polyolefins for many years. Countless academic and patent publications describe the use of these catalysts in olefin polymerization. Metallocenes are now used industrially and polyethylenes and polypropylenes in particular are often produced using cyclopentadienyl based catalyst systems with different substitution patterns. WO2001048034 describes C1-symmetric bisindenyl complexes bearing 5-methoxy substituents and 6-tert-butyl substituents, but the 2-substituents are linear. Such catalysts produce relatively low melting hPP (148-150 °C). WO2018091684 describes C2-symmetric rac-Me2Si(2-Me-4-(3,5-Me2Ph)-ind)2ZrCl2 complex, that produces hPP with low Tm of 150-151 °C. WO2005058916 describes a series of C1-symmetric bisindenyl complexes combining one 2-iso-propyl-4-aryl-indenyl ligand and one 2-methyl-4-aryl-indacenyl ligand. While Tm of hPP is somewhat high varying from 152 to 160°C, catalyst activities are invariably low. WO2019179959 describes C1-symmetric bisindenyl complexes comprising indenyl moiety bearing 5-methoxy substituents and 6-tert-butyl substituents and an indacenyl moiety. The catalysts provide somewhat high Tm of hPP varying from 154 to 156 °C in the presence of borate containing cocatalyst. While these prior art catalyst have their advantages, they lack in isoselectivity, in particular in the absence of borate containing cocatalyst, generating hPP with a relatively low melting and crystallisation temperature due to the formation of insertion regiodefects in the PP chains. The present inventors sought new metallocenes, which ligands have been designed in order to provide a higher synthesis efficiency and higher isoselectivity without compromising productivity, especially in the case of the production of high melting temperature and high molecular weight polypropylene homopolymers (hPP). BRIEF DESCRIPTION OF THE DISCLOSURE An object of the present disclosure is to provide new metallocene complexes, and hence catalysts which overcome the above problems. The object of the disclosure is achieved by metallocene complexes of formula (I), polymerization catalyst comprising said metallocene complex of formula (I), and process for polymerization of polypropylene optionally with comonomers which are characterized by what is stated in the independent claims. The preferred embodiments of the disclosure are disclosed in the dependent claims. It was surprisingly found that specific modification of C2-symmetric, metallocenes incorporating bulky aryl substituent at 4- and 7-position of indene ligand with no substitution at 5- and 6-positions in combination with specific substitution of indenyl ligand provide desired properties. The inventors have identified a supported catalyst system composed of a specific class of metallocene catalysts in combination with an aluminium containing cocatalyst having improved polymerization behavior, higher catalyst productivity, improved performance in the production of propylene polymers, in particular, homopolymers compared to systems known in the art. The specific catalyst system gives a higher flexibility / freedom in the design of propylene polymers than prior art catalyst systems. The present disclosure also provides a polymerization catalyst, comprising, preferably consisting of (i) a metallocene complex of formula (I) as described herein; (ii) a cocatalyst comprising a group 13 element; and (iii) optionally a support. The present disclosure provides a process for the polymerization of propylene, comprising polymerizing propylene in the presence of the polymerization catalyst described herein. In one example, the process may be process for the preparation of a heterophasic polypropylene copolymer. This process may comprise (I) polymerizing propylene in bulk in the presence of the polymerization catalyst as described herein to form a polypropylene homopolymer matrix; (II) in the presence of said matrix and said polymerizationcatalyst and in the gas phase, polymerizing propylene and ethylene to form a heterophasic polypropylene copolymer comprising a homopolymer matrix and an ethylene propylene rubber. An advantage of the disclosure is that these metallocene allow production propylene polymers with high isoselectivity, in particular upon MAO activation producing homopolymer polypropylene (hPP) with higher Tm. DEFINITIONS Throughout the description, the following definitions are employed: The term “C1-20-hydrocarbyl” includes C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C20-cycloalkyl, C3-C20-cycloalkenyl, C6-C20-aryl, C7-C20-alkylaryl, and C7-C20-arylalkyl groups or of course mixtures of these groups such as cycloalkyl substituted by alkyl. Unless otherwise stated, preferred C1-C20-hydrocarbyl groups are C1-C20-alkyl, C4-C20-cycloalkyl, C5-C20-cycloalkyl-alkyl groups, C7-C20-alkylaryl groups, C7-C20-arylalkyl groups, and C6-20-aryl groups, especially C1-C10alkyl groups, C6-C10aryl groups, and C7-C12arylalkyl groups, e.g. C1-C8alkyl groups. Most especially preferred hydrocarbyl groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C5-C6-cycloalkyl, cyclohexylmethyl, phenyl, and benzyl. It is to be noted that linear and branched hydrocarbyl groups cannot contain cyclic units. Aliphatic hydrocarbyl groups cannot contain aryl rings. The term “heteroatoms of Group 14-16 of the Periodic Table” includes for example Si, N, O or S. The term “C4-C8 ring” as used herein in connection to -R'2Si-, refers to cyclic groups containing 4 to 8 carbon atoms and a Si atom and includes for example silacycloalkanediyls, such as silacyclobutane, silacyclopentane, or 9-silafluorene The term “halogen” includes fluoro, chloro, bromo, and iodo groups, especially chloro or fluoro groups, when relating to the complex definition. The oxidation state of the metal ion is governed primarily by the nature of the metal ion in question and the stability of the individual oxidation states of each metal ion. It is appreciated that in the complexes of the invention, the metal ion is coordinated by ligands X to satisfy the valency of the metal ion and to fill its available coordination sites. The nature of these sigma-ligands can vary greatly. The numbering of these rings will be evident from the structures indicated herein. Catalyst activity is defined in this application to be the amount of polymer produced / g catalyst / h. Catalyst metal activity is defined here to be the amount of polymer produced / g Metal / h. The term productivity is also sometimes used to indicate the catalyst activity although herein it designates the amount of polymer produced per unit weight of catalyst. The term “molecular weight” is used herein to refer to weight average molecular weight Mw unless otherwise stated. DETAILED DESCRIPTION OF THE DISCLOSURE This invention relates to a series of new ligands, metallocene catalyst complexes and hence catalysts that are ideal for the polymerization of propylene. Metallocene catalyst complex The metallocene catalyst complexes of the invention are asymmetrical. Asymmetrical means simply that the two ligands forming the metallocene are different, that is, each ligand bears a set of substituents that are chemically different. The metallocene complexes of the invention are preferably chiral, racemic, bridged bisindenyl C1-symmetric metallocenes in their anti-configuration. Although the complexes of the invention are formally C1-symmetric, the complexes ideally retain a pseudo-C2- symmetry since they maintain C2-symmetry in close proximity of the metal center although not at the ligand periphery. By nature of their chemistry both anti and syn enantiomer pairs (in case of C1-symmetric complexes) are formed during the synthesis of the complexes. For the purpose of this invention, racemic-anti means that the two indenyl ligands are oriented in opposite directions with respect to the cyclopentadienyl- metal-cyclopentadienyl plane, while racemic-syn means that the two indenyl ligands are oriented in the same direction with respect to the cyclopentadienyl-metal- cyclopentadienyl plane, as shown in the scheme below. Racemic Anti Racemic Syn Formula (I), and any sub formulae, are intended to cover both syn- and anti- configurations. Preferred metallocene catalyst complexes are in the anti-configuration. The metallocene complexes of the invention are preferably employed as the racemic- anti-isomers. Ideally, therefore at least 95% mol, such as at least 98 %mol, especially at least 99 %mol of the metallocene catalyst complex is in the racemic anti-isomeric form. For the purpose of this invention, the numbering scheme of the indenyl ligands is the following: The present invention accordingly relates to compounds of formula (I): wherein Mt is Zr or Hf: X is a sigma ligand; R1are each independently, same or different from each other, C1-C20hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8ring; R2and R2’are each independently, same or different from each other, C1-C10- hydrocarbyl; n are each independently an integer from 1 to 5; R3and R4are each independently H, C1-C10hydrocarbyl group, or a –OR31, -SR31or -N R312group in which R31is a C1-C10hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen.; R51’ is C1-C10-hydrocarbyl; and R6’ is C(R61)3, with R61being linear or branched C1-C6-alkyl. Advantageously, one of the indenyl ligands is unsubstituted at the 5 and 6 positions. For the above-defined compound of formula (I), the following represent preferable embodiments, which can be selected alone or in combination: In a complex of formula (I) it is preferred if Mt is Zr or Hf, preferably Zr. Each X is a sigma ligand. Preferably, each X is independently, same or different from each other, H, halogen, C1-C6alkoxy, or R´ group, where R´ is a C1-C6alkyl, phenyl, or benzyl group. More preferably, each X is independently, same or different from each other, chlorine, benzyl, or a methyl group. It is preferred that both X groups are the same. Most preferably both X are Cl, methyl, or benzyl, especially Cl. Preferably R1are each independently, same or different from each other, C1-C10- hydrocarbyl, more preferably C1-C10-alkyl, C4-C10-cycloalkyl, C5-C10-cycloalkyl-alkyl, C7- C10-arylalkyl, C6-C10-aryl, or C7-C10-alkylaryl, such as methyl, ethyl, propyl, isopropyl, tert- butyl, isobutyl, C3-C8-cycloalkyl, cyclohexylmethyl, phenyl, or benzyl, even more preferably both C1-C6-alkyl, C5-C6-cycloalkyl or C6-aryl group. In an embodiment each R1is independently, same or different from each other, C1-C10-alkyl, optionally substituted with C1-C10-alkoxy. It is preferred that both R1groups are the same. Most preferably, both R1are methyl. As mentioned above, R2and R2’are each independently, same or different from each other, C1-C10-hydrocarbyl, for example, linear or branched C1-C10-hydrocarbyl. Preferably R2and R2’are each independently, same or different from each other, alpha-branched C3-C10-hydrocarbyl or CH2-R21, with R21being H, linear or branched C1-C6-alkyl, C3-C8 cycloalkyl, or C6-C10 aryl, such as R21being methyl, ethyl, n-propyl, i-propyl, n-butyl, i- butyl, sec-butyl, tert-butyl, cyclohexyl, or phenyl; more preferably R2and R2’are each independently, same or different from each other, alpha-branched C3-C6-alkyl or CH2- R21, with R21being H, linear or branched C1-6-alkyl, preferably R21being H or linear or branched C1-C3-alkyl. Preferably R2is CH2-R21, with R21being H, linear or branched C1-C6-alkyl, C3-C8cycloalkyl, or C6-10aryl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, cyclohexyl, or phenyl, more preferably R21being H or linear or branched C1-C3- alkyl group, even more preferably, R2is methyl or ethyl. Preferably R2’is alpha-branched C3-C10-hydrocarbyl or CH2-R21, with R21being H, a linear or branched C1-C6-alkyl, a C3-C8cycloalkyl, or a C6-10aryl; more preferably R2’is alpha- branched C3-C6-alkyl or CH2-R21, with R21being H, linear or branched C1-6-alkyl, preferably R21being H or linear or branched C1-C3-alkyl, even more preferably R2’is C(CH3)2, methyl, ethyl or n-propyl; It is preferred that R2is methyl and R2’is alpha-branched C3-C6-alkyl or CH2-R21, with R21being H or linear or branched C1-C6-alkyl, more preferably, R2is methyl and R2’is CH2- R21, with R21being H or linear or branched C1-C3-alkyl. Most preferably, R2is methyl and R2’is either methyl, ethyl or propyl (e.g. iso-propyl or n-propyl). It is preferred that each n is independently, same or different from each other, an integer from 1 to 3, such as 1, 2 or 3. Preferably, the R3and R4substituents of the respective phenyl ring are in the 3-, 4-, and / or 5-position of the ring, whereby the 1-position is attached to the indenyl ring. It is for example possible that the phenyl ring is substituted in the para position i.e. 4´ position only, like 4´-tert-butyl phenyl, or di-substituted in the meta positions, i.e. 3´ and 5´ position, like 3´,5´-dimethylphenyl or 3´,5´-ditert-butylphenyl. Furthermore, it is possible that each of the phenyl rings have the same substitution pattern or that the phenyl rings have different substitution patterns. It is therefore preferred when n is 1, the only R3and / or R4group, respectively, is preferably in the para position. If n is 2, then the two R3and / or R4groups, respectively are preferably in the meta positions. Preferably R3and R4are each independently, same or different from each other, H, linear or branched C1-C6-alkyl, or C6-10 aryl group, more preferably H, a linear or branched C1-C4-alkyl, or -OR31, wherein R31 is a C1-4 hydrocarbyl, even more preferably, each R3and R4are each independently, same or different from each other, H, methyl, ethyl, isopropyl, tert-butyl, or methoxy, especially hydrogen, methyl, or tert-butyl, whereby at least one R3per phenyl group and at least one R4is not H. As noted above, R51’ is C1-C10-hydrocarbyl, for example, linear or branched C1-C10- hydrocarbyl. Preferably R51’ is linear or branched C1-C6-alkyl, such as methyl, ethyl, n- propyl, i-propyl, n-butyl, i-butyl, sec-butyl, or tert-butyl, C7-C10-arylalkyl, C7-C10-alkylaryl, or C6-C10-aryl, more preferably a linear or branched C1-C6alkyl or C6-aryl, even more preferably linear C1-C4alkyl, yet even more preferably methyl or ethyl, and most preferably methyl. Preferably R6’ is C(R61)3, with R61being a linear C1-C3alkyl group; more preferably methyl. Thus advantageously, R6’ is tert-butyl. Viewed from another aspect the invention provides a metallocene catalyst complex of formula (I-a) wherein Mt is Zr or Hf; each X is independently a sigma ligand; R1are each independently, same or different from each other, C1-C20 hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8 ring; R2and R2’are each independently, same or different from each other, C1-C10- hydrocarbyl; R3and R4are each independently H, C1-C10 hydrocarbyl group, or a –OR31, -SR31or -N R312 group in which R31is a C1-C10 hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen.; R51’ is C1-C10-hydrocarbyl; and R6’ is C(R61)3, with R61being linear or branched C1-C6-alkyl. The substituents on the phenyl rings R3and R4, same or different from each other, may be H or C1-C10hydrocarbyl. whereby at least on R3per phenyl group and at least one R4is not hydrogen.. For the above-defined compound of formula (I-a), the following represent preferable embodiments, which can be selected alone or in combination: In a complex of formula (I-a) it is preferred if Mt is Zr or Hf, preferably Zr. Each X is a sigma ligand. Preferably, each X is independently, same or different from each other, H, halogen, C1-C6alkoxy, or R´ group, where R´ is a C1-C6alkyl, phenyl, or benzyl group. More preferably, each X is independently, same or different from each other, chlorine, benzyl, or a methyl group. It is preferred that both X groups are the same. Most preferably both X are Cl, methyl, or benzyl, especially Cl. Preferably R1are each independently, same or different from each other, C1-C10- hydrocarbyl, more preferably C1-C10-alkyl, C4-C10-cycloalkyl, C5-C10-cycloalkyl-alkyl, C7- C10-arylalkyl, C6-C10-aryl, or C7-C10-alkylaryl, such as methyl, ethyl, propyl, isopropyl, tert- butyl, isobutyl, C3-C8-cycloalkyl, cyclohexylmethyl, phenyl, or benzyl, even more preferably both C 1 1-C6-alkyl, C5-C6-cycloalkyl or C6-aryl group. In an embodiment each R is independently, same or different from each other, C1-C10-alkyl, optionally substituted with C1-C10-alkoxy. It is preferred that both R1groups are the same. Most preferably, both R1are methyl. As mentioned above, R2and R2’are each independently, same or different from each other, C1-C10-hydrocarbyl, for example, linear or branched C1-C10-hydrocarbyl. Preferably R2and R2’are each independently, same or different from each other, alpha-branched C3-C10-hydrocarbyl or CH2-R21, with R21being H, linear or branched C1-C6-alkyl, C3-C8 cycloalkyl, or C6-C10 aryl, such as R21being methyl, ethyl, n-propyl, i-propyl, n-butyl, i- butyl, sec-butyl, tert-butyl, cyclohexyl, or phenyl; more preferably R2and R2’are each independently, same or different from each other, alpha-branched C3-C6-alkyl or CH2- R21, with R21being H, linear or branched C1-6-alkyl, preferably R21being H or linear or branched C1-C3-alkyl. Preferably R2is CH2-R21, with R21being H, linear or branched C1-C6-alkyl, C3-C8 cycloalkyl, or C6-10 aryl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, cyclohexyl, or phenyl, more preferably R21being H or linear or branched C1-C3- alkyl group, even more preferably, R2is methyl or ethyl. Preferably R2’is alpha-branched C3-C10-hydrocarbyl or CH2-R21, with R21being H, a linear or branched C1-C6-alkyl, a C3-C8cycloalkyl, or a C6-10aryl; more preferably R2’is alpha- branched C3-C6-alkyl or CH2-R21, with R21being H, linear or branched C1-6-alkyl, preferably R21being H or linear or branched C1-C3-alkyl, even more preferably R2’is C(CH3)2, methyl, ethyl or n-propyl; It is preferred that R2is methyl and R2’is alpha-branched C3-C6-alkyl or CH2-R21, with R21being H or linear or branched C1-C6-alkyl, more preferably, R2is methyl and R2’is CH2- R21, with R21being H or linear or branched C1-C3-alkyl. Most preferably, R2is methyl and R2’is either methyl, ethyl or propyl (e.g. iso-propyl or n-propyl). Preferably R3and R4are each independently, same or different from each other, H, linear or branched C1-C6-alkyl, or C6-10aryl group, more preferably H, a linear or branched C1-C4-alkyl, or -OR31, wherein R31is a C1-4hydrocarbyl. Even more preferably, each R3and R4are each independently, same or different from each other, H, methyl, ethyl, isopropyl, tert-butyl, or methoxy, especially hydrogen, methyl, or tert-butyl. Preferably, the R3and R4substituents of the respective phenyl ring are in the 3-, 4-, and / or 5-position of the ring, whereby the 1-position is attached to the indenyl ring. It is for example possible that the phenyl ring substituted in the para position i.e. 4´ position only, like 4´-tert.-butyl phenyl, or di-substituted in the meta positions, i.e.3´ and 5´ position, like 3´,5´-dimethylphenyl or 3´,5´-ditert.-butylphenyl. Furthermore, it is possible that each of the phenyl rings have the same substitution pattern or that the three phenyl rings have different substitution patterns. It is therefore preferred if one or two R3and / or R4groups is H. If two R3and / or R4groups are H then the remaining R3and / or R4group, respectively, is preferably in the para position. If one R3and / or R4group is H then the remaining R3and / or R4groups are preferably in the meta positions. Advantageously one or two R3on the phenyl group are not H, more preferably R3on both phenyl rings are the same, like 3´,5´-di-methyl or 4´- tert-butyl. For the indenyl moiety preferably one or two R4on the phenyl group are not H, more preferably two R4are not H, and most preferably these two R4are the same like 3´,5´-di- methyl or 3´,5´-di-tert-butyl. As noted above, R51’ is C1-C10-hydrocarbyl, for example, linear or branched C1-C10- hydrocarbyl. Preferably R51’ is linear or branched C1-C6-alkyl, such as methyl, ethyl, n- propyl, i-propyl, n-butyl, i-butyl, sec-butyl, or tert-butyl, C7-C10-arylalkyl, C7-C10-alkylaryl, or C6-C10-aryl, more preferably a linear or branched C1-C6alkyl or C6-aryl, even more preferably linear C1-C4alkyl, yet even more preferably methyl or ethyl, and most preferably methyl. Preferably R6’ is C(R61)3, with R61being a linear C1-C3alkyl group; more preferably methyl. Thus advantageously, R6’ is tert-butyl. Viewed from another aspect the invention provides a metallocene catalyst complex of formula (I-b) wherein Mt is Zr or Hf; each X is independently a sigma ligand; R1are each independently, same or different from each other, C1-C20hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8ring; R2’is a C1-C10-hydrocarbyl, preferably a linear or branched C1-C10-hydrocarbyl; R3and R4are each independently H, C1-C10 hydrocarbyl group, or a –OR31, -SR31or -N R312 group in which R31is a C1-C10 hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen.; R51’ is C1-C10-hydrocarbyl; and R6’ is C(R61)3, with R61being linear or branched C1-C6-alkyl. For the above-defined compound of formula (I-b), the following represent preferable embodiments, which can be selected alone or in combination: In a complex of formula (I-b) it is preferred if Mt is Zr or Hf, preferably Zr. Each X is a sigma ligand. Preferably, each X is independently, same or different from each other, H, halogen, C1-C6alkoxy, or R´ group, where R´ is a C1-C6alkyl, phenyl, or benzyl group. More preferably, each X is independently, same or different from each other, chlorine, benzyl, or a methyl group. It is preferred that both X groups are the same. Most preferably both X are Cl, methyl, or benzyl, especially Cl. Preferably R1are each independently, same or different from each other, C1-C10- hydrocarbyl, more preferably C1-C10-alkyl, C4-C10-cycloalkyl, C5-C10-cycloalkyl-alkyl, C7- C10-arylalkyl, C6-C10-aryl, or C7-C10-alkylaryl, such as methyl, ethyl, propyl, isopropyl, tert- butyl, isobutyl, C3-C8-cycloalkyl, cyclohexylmethyl, phenyl, or benzyl, even more preferably both C1-C6-alkyl, C5-C6-cycloalkyl or C6-aryl group. In an embodiment each R1is independently, same or different from each other, C1-C10-alkyl, optionally substituted with C1-C10-alkoxy. It is preferred that both R1groups are the same. Most preferably, both R1are methyl. Preferably R2’is alpha-branched C3-C10-hydrocarbyl or CH2-R21, with R21being H, linear or branched C1-C6-alkyl, C3-C8 cycloalkyl, or C6-C10 aryl, such as R21being methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, cyclohexyl, or phenyl; more preferably R2’is alpha-branched C3-C6-alkyl or CH2-R21, with R21being H, linear or branched C1-6-alkyl, preferably R21being H or linear or branched C1-C3-alkyl; even more preferably R2’is C(CH3)2, methyl, ethyl or n-propyl; Preferably R3and R4are each independently, same or different from each other, H, linear or branched C1-C6-alkyl, or C6-10 aryl group, more preferably H, a linear or branched C1-C4-alkyl, or -OR31, wherein R31is a C1-4 hydrocarbyl. Even more preferably, each R3and R4are each independently, same or different from each other, H, methyl, ethyl, isopropyl, tert-butyl, or methoxy, especially hydrogen, methyl, or tert-butyl. Preferably, the R3and R4substituents of the respective phenyl ring are in the 3-, 4-, and / or 5-position of the ring, whereby the 1-position is attached to the indenyl ring. It is for example possible that the phenyl ring substituted in the para position i.e. 4´ position only, like 4´-tert.-butyl phenyl, or di-substituted in the meta positions, i.e.3´ and 5´ position, like 3´,5´-dimethylphenyl or 3´,5´-ditert.-butylphenyl. Furthermore, it is possible that each of the phenyl rings have the same substitution pattern or that the three phenyl rings have different substitution patterns. It is therefore preferred if one or two R3and / or R4groups is H. If two R3and / or R4groups are H then the remaining R3and / or R4group, respectively, is preferably in the para position. If one R3and / or R4group is H then the remaining R3and / or R4groups are preferably in the meta positions. Advantageously one or two R3on the phenyl group are not H, more preferably R3on both phenyl groups are the same, like 3´,5´-di-methyl or 4´- tert-butyl. For the indenyl moiety preferably one or two R4on the phenyl group are not H, more preferably two R4are not H, and most preferably these two R4are the same like 3´,5´-di- methyl or 3´,5´-di-tert-butyl.As noted above, R51’ is C1-C10-hydrocarbyl, for example, linear or branched C1-C10- hydrocarbyl. Preferably R51’ is linear or branched C1-C6-alkyl, such as methyl, ethyl, n- propyl, i-propyl, n-butyl, i-butyl, sec-butyl, or tert-butyl, C7-C10-arylalkyl, C7-C10-alkylaryl, or C6-C10-aryl, more preferably a linear or branched C1-C6alkyl or C6-aryl, even more preferably linear C1-C4alkyl, yet even more preferably methyl or ethyl, and most preferably methyl. Preferably R6’ is C(R61)3, with R61being a linear C1-C3 alkyl group; more preferably methyl. Thus advantageously, R6’ is tert-butyl. Viewed from another aspect the invention provides a metallocene catalyst complex of formula (I-c) (I-c) wherein Mt is Zr or Hf; each X is independently a sigma ligand; R1are each independently, same or different from each other, C1-C20hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8ring; R2’is a C1-C10-hydrocarbyl, preferably a linear or branched C1-C10-hydrocarbyl; R3and R4are each independently H, C1-C10hydrocarbyl group, or a –OR31, -SR31or -N R312group in which R31is a C1-C10hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen. For the above-defined compound of formula (I-c), the following represent preferable embodiments, which can be selected alone or in combination: In a complex of formula (I-c) it is preferred if Mt is Zr or Hf, preferably Zr. Each X is a sigma ligand. Preferably, each X is independently, same or different from each other, H, halogen, C1-C6alkoxy, or R´ group, where R´ is a C1-C6alkyl, phenyl, or benzyl group. More preferably, each X is independently, same or different from each other, chlorine, benzyl, or a methyl group. It is preferred that both X groups are the same. Most preferably both X are Cl, methyl, or benzyl, especially Cl. Preferably R1are each independently, same or different from each other, C1-C10- hydrocarbyl, more preferably C1-C10-alkyl, C4-C10-cycloalkyl, C5-C10-cycloalkyl-alkyl, C7- C10-arylalkyl, C6-C10-aryl, or C7-C10-alkylaryl, such as methyl, ethyl, propyl, isopropyl, tert- butyl, isobutyl, C3-C8-cycloalkyl, cyclohexylmethyl, phenyl, or benzyl, even more preferably both C 1 1-C6-alkyl, C5-C6-cycloalkyl or C6-aryl group. In an embodiment each R is independently, same or different from each other, C1-C10-alkyl, optionally substituted with C1-C10-alkoxy. It is preferred that both R1groups are the same. Most preferably, both R1are methyl. Preferably R2’is alpha-branched C3-C10-hydrocarbyl or CH2-R21, with R21being H, linear or branched C1-C6-alkyl, C3-C8 cycloalkyl, or C6-C10 aryl, such as R21being methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, cyclohexyl, or phenyl; more preferably R2’is alpha-branched C3-C6-alkyl or CH2-R21, with R21being H, linear or branched C1-6-alkyl, preferably R21being H or linear or branched C1-C3-alkyl. Preferably R2’is alpha-branched C3-C10-hydrocarbyl or CH2-R21, with R21being H, a linear or branched C1-C6-alkyl, a C3-C8 cycloalkyl, or a C6-10 aryl; more preferably R2’is alpha- branched C3-C6-alkyl or CH2-R21, with R21being H, linear or branched C1-6-alkyl, preferably R21being H or linear or branched C1-C3-alkyl, even more preferably R2’is C(CH3)2, methyl, ethyl or n-propyl; It is preferred that R2’is alpha-branched C3-C6-alkyl or CH2-R21, with R21being H or linear or branched C1-C6-alkyl, more preferably, R2is methyl and R2’is CH2-R21, with R21being H or linear or branched C1-C3-alkyl. Most preferably, R2’is either methyl, ethyl or propyl (e.g. n-propyl or iso-propyl). Preferably R3and R4are each independently, same or different from each other, H, linear or branched C1-C6-alkyl, or C6-10aryl group, more preferably H, a linear or branched C1-C4-alkyl, or -OR31, wherein R31is a C1-4hydrocarbyl. Even more preferably, each R3and R4are each independently, same or different from each other, H, methyl, ethyl, isopropyl, tert-butyl, or methoxy, especially hydrogen, methyl, or tert-butyl. Furthermore, it is possible that each of the phenyl rings have the same substitution pattern or that the three phenyl rings have different substitution patterns. Advantageously R3on both rings are the same, like 3´,5´-di-methyl or 4´- tert-butyl. For the indenyl moiety preferably two R4on the phenyl ring are the same like 3´,5´-di- methyl or 3´,5´-di-tert-butyl.Synthesis The ligands required to form the complexes and hence catalysts of the invention can be synthesized by any process and the skilled organic chemist would be able to devise various synthetic protocols for the manufacture of the necessary ligand materials. For example, WO 2007 / 116034 discloses the necessary chemistry. Synthetic protocols can also generally be found in WO2002 / 02576, WO2011 / 135004, WO2012 / 084961, WO2012 / 001052, WO2011 / 076780, WO2015 / 158790, WO2018 / 122134, WO2019 / 179959, and WO2012 / 058740. The examples section also provides the skilled person with sufficient direction. Polymerization catalyst Viewed from a further aspect the invention provides a polymerization catalyst comprising (i) a metallocene complex of formula (I); (ii) a cocatalyst comprising a group 13 element; and (iii) optionally a support. Catalyst Manufacture The metallocene complex as described above is used in combination with a suitable cocatalyst combination as described below. The metallocene catalysts can be used in supported or unsupported form. The particulate support material used is preferably an organic or inorganic material, such as silica, alumina or zirconia or a mixed oxide such as silica-alumina, in particular silica, alumina or silica-alumina. The use of a silica support is preferred. The skilled person is aware of the procedures required to support a metallocene catalyst. Especially preferably the support is a porous material so that the complex may be loaded into the pores of the support, e.g. using a process analogous to those described in WO94 / 14856 (Mobil), WO95 / 12622 (Borealis) and WO2006 / 097497. The particle size is not critical but is preferably in the range 5 to 200 μm, more preferably 20 to 80 μm. The use of these supports is routine in the art. Especially preferred procedures for producing such supported catalysts are those described in EP1828266, WO 2020 / 239598 and WO 2020 / 239603. Alternatively, no support is used at all. Such a catalyst can be prepared in solution, for example in an aromatic solvent like toluene, by contacting the metallocene (as a solid or as a solution) with the cocatalyst, for example methylaluminoxane or a borane or a borate salt previously dissolved in an aromatic solvent, or can be prepared by sequentially adding the dissolved catalyst components to the polymerization medium. In one aspect, no external carrier is used but the catalyst is still presented in solid particulate form. Thus, no external support material, such as inert organic or inorganic carrier, for example silica as described above is employed, but the solid catalyst is prepared using an emulsion-solidification method. Such catalysts can be prepared as described for example in WO 2003 / 051934, WO 2014 / 060540 and WO 2019 / 179959. The catalyst system of the invention is preferably used in supported form. The particulate support material used is an inorganic porous support such as a silica, alumina or a mixed oxide such as silica-alumina, in particular silica. The use of a silica support is preferred. The complex may be loaded into the pores of the particulate support, e.g. using a process analogous to those described in W094 / 14856, W095 / 12622, W02006 / 097497 and EP18282666. The average particle size of the support such as silica support can be typically from 10 to 100 µm. However, it has turned out that special advantages can be obtained, if the support has an average particle size from 15 to 80 µm, preferably from 18 to 50 µm. The average pore size of the inorganic porous support such as silica support can be in the range from 10 to 100 nm and the pore volume from 1 to 3 mL / g. The pore diameter of the inorganic porous support such as silica support can be in the range from 20 to 40 nm. The surface area of the inorganic porous support such as silica support can be typically in the range from 100 to 400 m2 / g. Examples of suitable support materials are, for instance, ES757 produced and marketed by PQ Corporation, Sylopol 948 produced and marketed by Grace or SUNSPERA DM-L- 303 silica produced by AGC Si-Tech Co. Supports can be optionally calcined prior to the use in catalyst preparation in order to reach optimal silanol group content. The use of these supports is routine in the art. The catalyst can contain from 5 to 500 µmol, such as 10 to 100 µmol of transition metal of the metallocene per gram of support such as silica, and 3 to 15 mmol of Al per gram of support such as silica. The present polymerization catalyst may be produced by e.g. as described in WO2020239603 or WO2020239598. In an aspect of the present disclosure the process for the manufacture of the present polymerization catalyst includes P1-a) combining the porous inorganic support with aluminoxane cocatalyst in a hydrocarbon solvent to obtain aluminoxane cocatalyst treated support, optionally followed by thermal treatment of the aluminoxane treated support; P-1b) optionally combining the metallocene complex with aluminoxane cocatalyst in a hydrocarbon solvent, wherein the amount of aluminoxane cocatalyst added in step a) is 75.0 to 97.0 wt% of the total amount of aluminoxane cocatalyst and the amount of aluminoxane cocatalyst added in step b) is 3.0 to 25.0 wt% of the total amount of aluminoxane cocatalyst; P1-c) adding the boron containing cocatalyst to the solution obtained in step a) or b) to obtain a solution of metallocene complex, boron containing cocatalyst and aluminoxane cocatalyst whereby the boron containing cocatalyst is added in an amount that a boron / M molar ratio of feed amounts in the range of 0.1 :1 to 10:1 is reached; P1-d) adding the solution obtained in step c) to the aluminoxane cocatalyst treated support obtained in step a) and optionally P1-e) drying the so obtained supported catalyst system. In an alternative aspect of the present disclosure the said process comprises P2- a) treating a porous inorganic support with aluminoxane cocatalyst in a hydrocarbon solvent, optionally followed by thermal treatment of the aluminoxane treated support; P2-b) combining a metallocene complex with a boron containing cocatalyst and optionally with an aluminoxane cocatalyst in a hydrocarbon solvent; P2-c) loading the solution of step b) onto the treated support of step a); wherein the amount of aluminoxane cocatalyst added in step a) is 75.0 to 100.0 wt% of the total amount of aluminoxane cocatalyst and the amount of aluminoxane cocatalyst added in step b) is 0.0 to 25.0 wt% of the total amount of aluminoxane cocatalyst. In step P2-b) of the process, the components can be mixed in any order. The boron containing cocatalyst can be mixed with the metallocene complex followed by addition of a hydrocarbon and the optional aluminoxane, or the metallocene complex can be mixed with the optional aluminoxane and a hydrocarbon followed by addition of boron containing cocatalyst and so on. In some embodiments, all components might be combined simultaneously. Only one impregnation step is used, i.e. the treated support of step a) is loaded only in one step with the metallocene. In a preferred aspect of the present invention the said process comprises P3-a) combining the porous inorganic support with aluminoxane cocatalyst in a hydrocarbon solvent to obtain aluminoxane cocatalyst treated support, optionally followed by thermal treatment of the aluminoxane treated support, filtering off the hydrocarbon solvent, optionally washing with an aromatic solvent, repeating the filtration and washing steps to remove unreacted aluminium compounds; drying the final aluminoxane cocatalyst treated support; P3-b) adding the metallocene in a hydrocarbon solvent to the aluminoxane cocatalyst treated support obtained in step a) and optionally P3-c) drying the so obtained supported catalyst system. If desired, the obtained supported catalyst system may be provided as an oil slurry with a desired solid content. The solid catalyst content in the slurry may be e.g. up to 30 wt%, like up to 25 wt%. The amounts of support, aluminoxane, preferably MAO, boron containing cocatalyst and metallocene depend on the desired above defined ratios (boron / M, Al / M, Al / SiO2, M / SiO2). Cocatalyst To form an active catalytic species it is normally necessary to employ a cocatalyst as is well known in the art. Cocatalysts comprising one or more compounds of Group 13 metals, like organoaluminium, organoboron, and / or borate compounds used to activate metallocene catalysts are suitable for use in this invention. Preferably, only cocatalysts comprising aluminium, like organoaluminium compounds used to activate metallocene catalysts, are utilized in this invention. According to the present invention a cocatalyst system comprising a boron containing cocatalyst and / or an aluminoxane cocatalyst is advantageously used in combination with the above defined metallocene catalyst complex. In an aspect of the present invention a cocatalyst system comprising an aluminoxane cocatalyst is advantageously used in combination with the above defined metallocene catalyst complex. Thus, preferably no further cocatalysts comprising one or more compounds of Group 13 metals other than aluminium, like organoboron and / or borate compounds used to activate metallocene catalysts are suitable for use in this invention. Suitable amounts of cocatalyst will be well known to the person skilled in the art. Preferably, the amount of cocatalyst is chosen to reach below defined molar ratios. The molar ratio of Al from the aluminoxane to the metal ion (Mt) (preferably zirconium) of the metallocene Al / Mt may be in the range 10:1 to 2000:1 mol / mol, preferably 50:1 to 1000:1, and more preferably 100:1 to 600:1 mol / mol. The molar ratio of feed amounts of boron (B) to the metal ion (Mt) (preferably zirconium) of the metallocene B / Mt may be in the range 0.1:1 to 10:1 mol / mol, preferably 0.3:1 to 7:1, especially 0.5:1 to 3:1 mol / mol. Even more preferably, the molar ratio of feed amounts of boron (B) to metal ion (Mt), preferably zirconium, of the metallocene B / Mt is from 0.5:1 to 2:1 Aluminoxane cocatalyst The aluminoxane cocatalyst can be one of formula (A): where n is usually from 6 to 20 and R has the meaning below. Aluminoxanes are formed on partial hydrolysis of organoaluminum compounds, for example those of the formula AlR3, AlR2Y and Al2R3Y3 where R can be, for example, C1- C10-alkyl, preferably C1-C5-alkyl, or C3-C10-cycloalkyl, C7-C12-arylalkyl or -alkylaryl and / or phenyl or naphthyl, and where Y can be hydrogen, halogen, preferably chlorine or bromine, or C1-C10-alkoxy, preferably methoxy or ethoxy. The resulting oxygen- containing aluminoxanes are not in general pure compounds but mixtures of oligomers of the formula (A). The preferred aluminoxane is methylaluminoxane (MAO). Since the aluminoxanes used according to the invention as cocatalysts are not, owing to their mode of preparation, pure compounds, the molarity of aluminoxane solutions hereinafter is based on their aluminium content. Boron containing cocatalyst According to the present invention, also a boron containing cocatalyst can be used instead of the aluminoxane cocatalyst or the aluminoxane cocatalyst can be used in combination with a boron containing cocatalyst. It will be appreciated by the person skilled in the art that where boron based cocatalysts are employed, it is normal to pre-alkylate the complex by reaction thereof with an aluminium alkyl compound, such as TIBA. This procedure is well known and any suitable aluminium alkyl, e.g. Al(C1-C6alkyl)3can be used. Preferred aluminium alkyl compounds are triethylaluminium, tri-isobutylaluminium, tri-isohexylaluminium, tri-n-octylaluminium and tri-isooctylaluminium. Alternatively, when a borate cocatalyst is used, the metallocene complex is in its alkylated version, that is for example a dimethyl or dibenzyl metallocene complex can be used. Boron containing cocatalysts of interest include those of formula (B) BY3(B) wherein Y is the same or different and is a hydrogen atom, C1-10-haloalkyl, or C6-C20- haloaryl, or fluorine, chlorine, bromine or iodine. Preferred examples for Y are fluorine, trifluoromethyl, unsaturated groups such as haloaryl like p-fluorophenyl, 3,5-difluorophenyl, pentachlorophenyl, pentafluorophenyl, 3,4,5- trifluorophenyl and 3,5-di(trifluoromethyl)phenyl. Most preferably, Y are fluorine, trifluoromethyl, aromatic fluorinated groups such as p- fluorophenyl, 3,5-difluorophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl and 3,5- di(trifluoromethyl)phenyl. Preferred boron containing cocatalysts of formula (B) are trifluoroborane, tris(4- fluorophenyl)borane, tris(3,5-difluorophenyl)borane, tris(2,4,6-trifluorophenyl)borane, tris(penta-fluorophenyl)borane, and / or tris(3,4,5-trifluorophenyl)borane. Particular preference is given to tris(pentafluorophenyl)borane. However it is preferred that borates are used, i.e. compounds containing a borate anion. These compounds have formula (C): Z4B–-W+(C) wherein Z is a substituted phenyl derivative, said substituent being halo-C1-C6-alkyl or halogen; and W+is a cationic counterion. Preferably the substituents of Z are are fluoro or trifluoromethyl. Most preferably, the phenyl group is perfluorinated. The borate anion Z4B–is preferably a weakly-coordinating anion such as tetrakis(pentafluorophenyl)borate. Suitable cationic counterions W+are triarylcarbenium such as triphenylcarbenium or protonated amine or aniline derivatives such as methylammonium, anilinium, dimethylammonium, diethylammonium, N- methylanilinium, diphenylammonium, N,N-dimethylanilinium, trimethylammonium, triethylammonium, tri-n- butylammonium, methyldiphenylammonium, pyridinium, p-bromo-N,N- dimethylanilinium or p-nitro-N,N-dimethylanilinium. Preferred ionic compounds which can be used according to the present invention include: tributylammoniumtetra(pentafluorophenyl)borate, tributylammoniumtetra(trifluoromethylphenyl)borate, tributylammoniumtetra(4-fluorophenyl)borate, N,N-dimethylcyclohexylammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, N,N-di(propyl)ammoniumtetrakis(pentafluorophenyl)borate, di(cyclohexyl)ammoniumtetrakist(pentafluorophenyl)borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, or ferroceniumtetrakis(pentafluorophenyl)borate. Preference is given to triphenylcarbeniumtetrakis(pentafluorophenyl) borate, N,N- dimethylcyclohexylammoniumtetrakis(pentafluorophenyl)borate or N,N- dimethylbenzylammoniumtetrakis(pentafluorophenyl)borate. Mostly preferred are triphenylcarbeniumtetrakis(pentafluorophenyl) borate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, N,N- dimethylcyclohexylammoniumtetrakis(pentafluorophenyl)borate, or N,N- dimethylbenzylammoniumtetrakis(pentafluorophenyl)borate. Polymerization The catalysts according to the invention are suitable for the production of propylene homopolymers, propylene-ethylene copolymers or propylene C4-C10 alpha olefin copolymers. Thus, the process comprises polymerizing propylene, propylene and ethylene or propylene and a C4-C10 alpha olefin. The ethylene content in such a propylene-ethylene polymer may vary depending on the desired properties of the polymer. Typically, ethylene content will range from 0.1 to 10 mol%. Especially, the catalysts of the present invention are used to manufacture propylene homopolymers or propylene copolymers with ethylene as comonomer and propylene copolymers with butene as a comonomer. Accordingly, the present disclosure relates in a further aspect to a process for producing a propylene homopolymer, a propylene random copolymer or a heterophasic propylene copolymer using the specific catalyst system, as defined before. Polymerization in the method of the invention may be effected in one or more, e.g.1, 2, or 3, polymerization reactors, using conventional polymerization techniques, e.g. gas phase, solution phase, slurry or bulk polymerization, or combinations thereof, like a combination of a slurry and at least one gas phase reactor. The process may also involve an in-line pre-polymerization step. This pre-polymerization step is a conventional step used routinely in polyolefin production plants and can be carried out in a CSTR or a loop reactor, from which the prepolymerized catalyst is then transferred together with the liquid monomer(s) into the main loop reactor. Prepolymerization can be carried out at temperatures between -10 °C and 50 °C, preferably between 10 °C and 40 °C. In case of propylene polymerization in slurry reactors, like a liquid loop reactor, the reaction temperature will generally be in the range 60 to 110 °C (e.g.60 to 90 °C), the reactor pressure will generally be in the range 5 to 80 bar (e.g. 20 to 60 bar), and the residence time will generally be in the range 0.3 to 5 hours (e.g. 0.5 to 2 hours). The liquefied monomer is usually used as reaction medium. It is a particular feature of the invention that polymerization takes place at temperatures of at least 60 °C. For gas phase reactors, the reaction temperature used will generally be in the range 60 to 115 °C (e.g.70 to 110 °C), the reactor pressure will generally be in the range 10 to 30 bar-g (e.g.15 to 25 bar-g), and the residence time will generally be 0,5 to 8 hours (e.g. 0,5 to 4 hours). The gas used will be the monomer optionally as mixture with a non- reactive gas such as nitrogen or propane. In addition to actual polymerization steps and reactors, the process can contain any additional polymerization steps, like a pre- polymerization step, and any further after reactor handling steps as known in the art. For solution polymerization, an aliphatic or aromatic solvent can be used to dissolve the monomer and the polymer, and the polymerization temperature will generally be in the range 80 to 200 °C (e.g.90 to 150 °C) Generally, the quantity of catalyst used will depend upon the nature of the catalyst, the reactor types and conditions and the properties desired for the polymer product. As is well known in the art hydrogen can be used for controlling the molecular weight of the polymer. The metallocene catalysts of the invention possess excellent catalyst activity and good comonomer response. The catalysts are also able to provide polymers of high weight average molecular weight Mw and narrow polydispersity Mw / Mn. Moreover, the random copolymerization behavior of metallocene catalysts of the invention shows a reduced tendency of chain transfer to ethylene. Polymers It is a feature of the invention that the claimed catalysts enable the formation of propylene polymers with high molecular weight. These features can be achieved at commercially interesting polymerization temperatures, e.g.60 °C or more, such as from 60 °C to 90 °C. The polydispersity index (Mw / Mn) of the polymers depend on the polymerization conditions in each reactor, and can be between 2.0 and 7.0. In a particular embodiment, the propylene polymers obtained using the catalysts of the invention have a narrow polydispersity index (Mw / Mn), between 2.0 and 4.0. Propylene homopolymers Propylene homopolymers made by catalyst system comprising the metallocenes of the invention can be made with Mw (weight average molecular weight) values in the range of 40 to 2000 kg / mol, preferably in the range of 50 to 1500 kg / mol depending on the use and amount of hydrogen used as Mw regulating agent. The catalysts of the invention enable the formation of polypropylene homopolymers with high melting points. In a preferred embodiment the propylene homopolymer formed by the process of the invention has a melting point of more than 155 °C, preferably more than 157 °C. Propylene homopolymers having melting points up to 158 °C, or even up to 160 °C, are possible. Propylene copolymers Propylene copolymers with ethylene or with C4-C10 alpha olefin comonomers made by the metallocenes of the invention can be made with high productivity and low solubles. The polymers made by the catalysts of the description are useful in all kinds of end articles such as pipes, films (cast, blown or BOPP films, such as for example BOPP for capacitor film), fibers, moulded articles (e.g. injection moulded, blow moulded, rotomoulded articles), extrusion coatings and so on. The invention will now be illustrated by reference to the following non-limiting Examples. EXPERIMENTAL Measurement methods Al, B and Zr determination (ICP-method) In a glovebox, an aliquot of the catalyst (ca. 40 mg) was weighed into glass weighting boat using analytical balance. The sample was then allowed to be exposed to air overnight while being placed in a steel secondary container equipped with an air intake. Then 5 mL of concentrated (65 %) nitric acid was used to rinse the content of the boat into the Xpress microwave oven vessel (20 mL). A sample was then subjected to a microwave-assisted digestion using MARS 6 laboratory microwave unit over 35 minutes at 150 °C. The digested sample was allowed to cool down for at least 4 h and then was transferred into a glass volumetric glass flask of 100 mL volume. Standard solutions containing 1000 mg / L Y and Rh (0.4 mL) were added. The flask was then filled up with distilled water and shaken well. The solution was filtered through 0.45 µm Nylon syringe filters and then subjected to analysis using Thermo iCAP 6300 ICP-OES and iTEVA software. The instrument was calibrated for Al, B, Hf, Mg, Ti and Zr using a blank (a solution of 5 % HNO3) and six standards of 0.005 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L and 100 mg / L of Al, B, Hf, Mg, Ti and Zr in solutions of 5 % HNO3distilled water. However, not every calibration point was used for each wavelength. Each calibration solution contained 4 mg / L of Y and Rh standards. Al 394.401 nm was calibrated using the following calibration points: blank, 0.1 mg / L, 1 mg / L, 10 mg / L and 100 mg / L. Al 167.079 nm was calibrated as Al 394.401 nm excluding 100 mg / L and Zr 339.198 nm using the standards of blank, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L and 100 mg / L. Curvilinear fitting and 1 / concentration weighting was used for the calibration curves. Immediately before analysis the calibration was verified and adjusted (instrument reslope function) using the blank and a 10 mg / L Al, B, Hf, Mg, Ti and Zr standard which had 4 mg / L Y and Rh. A quality control sample (QC: 1 mg / L Al, Au, Be, Hg & Se; 2 mg / L Hf & Zr, 2.5 mg / L As, B, Cd, Co, Cr, Mo, Ni, P, Sb, Sn & V; 4 mg / L Rh & Y; 5 mg / L Ca, K, Mg, Mn, Na & Ti; 10 mg / L Cu, Pb and Zn; 25 mg / L Fe and 37.5 mg / L Ca in a solution of 5 % HNO3 in distilled water) was run to confirm the reslope for Al, B, Hf, Mg, Ti and Zr. The QC sample was also run at the end of a scheduled analysis set. The content for Zr was monitored using Zr 339.198 nm {99} line. The content of aluminium was monitored via the 167.079 nm {502} line, when Al concentration in test portion was under 2 wt% and via the 394.401 nm {85} line for Al concentrations above 2 wt%. Y 371.030 nm {91} was used as internal standard for Zr 339.198 nm and Al 394.401 nm and Y 224.306 nm {450} for Al 167.079 nm. The content for B was monitored using B 249 nm line. The reported values were back calculated to the original catalyst sample using the original mass of the catalyst aliquot and the dilution volume. Catalyst Activity The catalyst activity was calculated on the basis of following formula: amount of polymer produced (kg) Catalyst Activity (kg-PP / g-Cat / h) = catalyst loading (g) × polymerization time (h) GPC: Molecular weight averages, molecular weight distribution, and polydispersity index (Mn, Mw, Mw / Mn) The MWD and the corresponded molecular weight averages Mn, Mw, Mvand Mzof the polymer sample were determined by using Gel Permeation Chromatography (GPC) at 160°C. All samples were integrated at the low Mwend up to the 3rdlast calibration point of the calibration curve (PS = 1820 g / mol ~ 1340 g / mol PP equivalent). A high temperature GPC equipped with a suitable concentration detector (like IR5 or IR4 from PolymerChar (Valencia, Spain), an online four capillary bridge viscometer (PL-BV 400-HT), and a dual light scattering detector (PL-LS 15 / 90 light scattering detector) with a 15° and 90° angle was used. 3x Olexis and 1x Olexis Guard columns from Agilent as stationary phase and 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg / L 2,6-Di tert butyl-4-methyl-phenol) as mobile phase at 160 °C and at a constant flow rate of 1 mL / min was applied.200 μL of sample solution were injected per analysis. All samples were prepared by dissolving 8.0 – 10.0 mg of polymer in 10 mL (at 160 °C) of stabilized TCB (same as mobile phase) for 2,5 hours at 160°C under continuous gentle shaking. The injected concentration of the polymer solution at 160 °C (c160°C) was determined in the following way. 0,8772 With: w25(polymer weight) and V25(Volume of TCB at 25°C). The column set was calibrated using universal calibration (according to ISO 16014- 2:2019) with 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg / mol to 11 500 kg / mol. The PS standards were dissolved at 160°C for 15 min or alternatively at room temperatures at a concentration of 0.2 mg / ml for molecular weight higher and equal 899 kg / mol and at a concentration of 1 mg / ml for molecular weight below 899 kg / mol. The conversion of the polystyrene peak molecular weight to polyethylene molecular weights is accomplished by using the Mark Houwink equation and the following Mark Houwink constants: KPS = 19 x 10-5ml / g, αPS = 0.655 KPP = 39 x 10-5ml / g, αPP = 0.725 A third order polynomial fit was used to fit the calibration data. All samples were prepared in the concentration range of 0.5 -1 mg / ml and dissolved at 160 °C for 3 hours under continuous gentle shaking Molecular weight averages (Mn, Mw, Mvand Mz), Molecular weight distribution (MWD) and its broadness, described by the polydispersity index PD= Mw / Mn(wherein Mnis the number average molecular weight and Mwis the weight average molecular weight) were determined using the following formulas: DSC The DSC curves and data have been produced on a DSC Q200 TA Instrument, by placing a 5-7 mg sample cut from the polymer MFR string, into a closed DSC aluminum pan, heating the sample from -10 °C to 225 °C at 10 °C / min, holding for 10 min at 225 °C, cooling from 225 °C to –30 °C, holding for 5 min at –30 °C, heating from –30 °C to 225 °C at 10 °C / min. The reported Tm values are those of the peak of the endothermic heat flow determined from the second heating scan. Melt Flow Rate The melt flow rate (MFR) was determined according to ISO 1133 and is indicated in g / 10 min. The MFR is an indication of the flowability, and hence the processability, of the polymer. The higher the melt flow rate, the lower the molecular weight of the polymer. The MFR is determined at 230 °C and may be determined at different loadings such as 2.16 kg (MFR2) or 21.6 kg (MFR21). Metallocene synthesis Synthesis of comparative metallocene CM1 Synthesis of this metallocene has been carried out as described in WO2019179959, MC- 2. Synthesis of comparative metallocene CM2 2,5,6-Trimethylindan-1-one 2-Bromo-2-methylpropanoyl bromide (144.8 g, 77.9 ml, 0.63 mol) was added dropwise over 15 min to a suspension of AlCl3 (222.7 g, 1.67 mol, 2.65 equiv) in 200 ml of dichloromethane cooled to –30 °C. The reaction mixture was stirred at –30 °C for 0.5 h, then the temperature was raised to –20 °C, and a solution of о-xylene (66.9 g, 76.9 ml, 0.63 mol) in 200 ml of dichloromethane was added dropwise over 30 min. The cooling bath was removed, the temperature was brought to room temperature, and the reaction mixture was stirred for 5 h at this temperature. The resulting mixture was poured onto 1 kg of ice, and 300 ml of 12 M HCl was added. The resulting mixture was extracted with 4 ^250 ml of dichloromethane. The combined organic extract was washed with an aqueous K2CO3, dried over K2CO3 and then evaporated to dryness. The residue was purified by vacuum distillation to give 103.45 g (94.2 %) of a mixture of linear 2,5,6- trimethylindan-1-one and angular 2,4,5-trimethylindanone in a ratio ca. 2:1 (in favor of the linear isomer) as a yellowish oil (bp 122-130oC / 5 mm Hg). The resulting mixture was dissolved in 400 ml of n-hexane and then crystallized overnight at –30 °C. The precipitate formed was crushed with a spatula, filtered off (G3), and then kept until the temperature of the precipitate reached room temperature, and the mother liquor dripping off practically stopped. The white, slightly oily mass that remained on the filter (ca.56 g) was dissolved in 55 ml of n-hexane and then recrystallized at 0°C to obtain 23.5 g (21%) of a white crystalline powder (free flowing, non-sticky) of 2,5,6-trimethylindan-1-one contaminated by ca.2-5% of the angular isomer.1H NMR (CDCl3): δ 7.49 (s, 1H), 7.20 (s, 1H), 3.36-3.22 (m, 1H), 2.73-2.56 (m, 2H), 2.32 (s, 3H), 2.28 (s, 3H), 1.28 (d, J = 7.2 Hz, 3H).13C NMR (CDCl3): δ 209.56, 152.02, 145.22, 136.57, 134.83, 127.63, 124.63, 42.54, 34.91, 21.07, 20.09, 16.86. 4,7-Dibromo-2,5,6-trimethylindan-1-one A solution of 2,5,6-trimethylindan-1-one (33.8 g, 194 mol) in 35 ml of dichloromethane was added dropwise for 0.5 h to a suspension of AlCl3(64 g, 480 mmol, 2.47 equiv.) in 250 ml of dichloromethane at –10 °C. The reaction mixture was stirred for 10 min at this temperature, then 0.35 g of iron powder was added. Further on, 20.3 ml (63.0 g, 394.0 mmol, 2.03 equiv) of bromine was added dropwise over 0.5 h. The resulting mixture was stirred overnight at room temperature and then poured onto 500 cm3of crushed ice. The organic layer was separated, and the aqueous layer was extracted with 2 ^250 ml of dichloromethane. The combined organic extract was washed with aqueous K2CO3, dried over K2CO3, passed through a short pad of silica gel 60 (40-63 µm), and then evaporated to dryness. The product was isolated by column chromatography on silica gel 60 (40-63 µm, d 50 mm, l 1000 mm, eluent: hexanes / CH2Cl2= 1:1). This procedure gave 49.6 g (77.0%) of pure 4,7-dibromo-2,5,6-trimethylindan-1-one.1H NMR (CDCl3): δ 3.25 (dd, J = 17.6 Hz, J = 8.1 Hz, 1H), 2.79-2.68 (m, 1H), 2.58 (dd, J = 17.6 Hz, J = 4.1 Hz, 1H), 2.55 (s, 3H), 2.51 (s, 3H), 1.32 (d, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 205.74, 153.37, 144.43, 138.42, 133.10, 123.90, 120.96, 42.66, 35.88, 21.70, 19.99, 16.40. 4,7-Bis(3,5-dimethylphenyl)-2,5,6-trimethylindan-1-one A mixture of 43.99 g (132.49 mmol) of 4,7-dibromo-2,5,6-trimethylindan-1-one, 49.68 g (331.24 mmol, 2.5 equiv.) of 3,5-dimethylphenylboronic acid, 2.0 g (3.91 mmol, 2.95 mol.%) of Pd(PtBu3)2, 84.4 g of Na2CO3, 545 ml of 2-methyltetrahydrofurane, and 380 ml of water was refluxed for 6 h. Further on, 500 ml of water was added, the organic layer was separated, and the aqueous layer was extracted with 300 ml of dichloromethane. The combined organic extract was dried over K2CO3 and then evaporated to dryness to give a brownish solid mass. The product was isolated by flash-chromatography on silica gel 60 (40-63 µm, eluent: hexanes / CH2Cl2 = 1:1 and then 1:3, vol.). Yield 52.42 g (ca. 100%) of a white solid mass.1H NMR (CDCl3): δ 7.03 (s, 1H), 7.01 (s, 1H), 6.86 (s, 1H), 6.84 (s, 1H), 6.81 (s, 1H), 6.78 (s, 1H), 2.98 (dd, J = 17.2 Hz, J = 8.1 Hz, 1H), 2.58-2.48 (m, 1H), 2.38 (s, 6H), 2.37 (s, 3H), 2.35 (s, 3H), 2.38-2.29 (dd, 1H), 2.14 (s, 3H), 2.06 (s, 3H), 1.15 (d, J = 7.3 Hz, 3H).13C NMR (CDCl3): δ 208.13, 149.86, 141.74, 139.20, 139.16, 138.29, 137.99, 137.98, 137.03, 136.96, 135.03, 130.91, 128.70, 128.60, 126.75, 126.72, 126.60, 42.47, 34.00, 21.52, 21.41, 21.38, 18.56, 16.96, 15.92. 4,7-Bis(3,5-dimethylphenyl)-2,5,6-trimethyl-1H-indene NaBH4 (7.8 g, 206.2 mmol, 1.51 equiv.) was added to a solution of 4,7-bis(3,5- dimethylphenyl)-2,5,6-trimethylindan-1-one (52.42 g, calc. 137.03 mmol) in 400 ml of THF cooled to 5 °C. MeOH (200 ml) was added dropwise over ca.5 h to this mixture at 5 °C, then the resulting mixture was stirred overnight at room temperature. The so obtained mixture was evaporated to dryness, 700 ml of dichloromethane and 700 ml water were added to the residue, and the so obtained mixture was acidified with 2 M HCl to pH~6.5. The organic layer was separated, the aqueous layer was additionally extracted with 2 ^300 ml of dichloromethane. The combined organic extract was passed through a pad (~30 ml) of silica gel 60 (40-63 µm; eluent: dichloromethane) to get rid of most of the palladium black. The obtained elute was evaporated to dryness to give a grey solid mass. TsOH (0.5 g) was added to a solution of this solid in 500 ml of toluene. This mixture was refluxed with Dean-Stark head for 10 min and then cooled to room temperature using a water bath. The formed solution was washed with 10% Na2CO3, the organic layer was separated, and the aqueous layer was extracted with 500 ml of dichloromethane. The combined organic extract was dried over K2CO3 and then evaporated to dryness. The product was purified by flash chromatography on silica gel 60 (40-63 µm, d 50 mm, l 250 mm, eluent: hexanes / CH2Cl2 = 3:1, vol.).The combined elute was evaporated to ca.100 ml, and the precipitated white solid was filtered off (G3). The mother liquor was evaporated to dryness, the residue was triturated with a small amount of hexane and filtered off (G3). The combined precipitate was dried under vacuum to give 47.29 g (yield 97.4% for two stages starting from 4,7-dibromo-2,5,6- trimethylindan-1-one) of 4,7-bis(3,5-dimethylphenyl)-2,5,6-trimethyl-1H-indene.1H NMR (CDCl3): δ 6.99 (s, 2H), 6.93 (s, 2H), 6.91 (s, 2H), 6.15 (m, 1H), 3.06 (s, 2H), 2.37 (s, 12H), 2.14 (s, 3H), 2.10 (s, 3H), 1.98 (s, 3H).13C NMR (CDCl3): δ 145.04, 141.77, 141.21, 140.71, 139.32, 137.58, 137.33, 136.99, 133.36, 132.30, 129.82, 128.14, 128.01, 127.78, 126.97, 126.72, 43.17, 21.41, 17.67, 17.50, 16.66. [4,7-Bis(3,5-dimethylphenyl)-2,5,6-trimethyl-1H-inden-1-yl][6-tert-butyl-4-(3,5- dimethylphenyl)-5-methoxy-2-methyl-1H-inden-1-yl]dimethylsilane nBuLi in hexanes (2.5 M, 7.4 ml, 18.5 mmol) was added in one portion to a suspension of 4,7-bis(3,5-dimethylphenyl)-2,5,6-trimethyl-1H-indene (6.75 g, 18.42 mmol) in a mixture of 100 ml of ether and 25 ml of THF cooled to –50 °C. The resulting mixture was stirred overnight at room temperature, then the so obtained yellow suspension was cooled to – 50 °C, then 150 mg of CuCN was added. The obtained mixture was stirred for 0.5 h at – 25 °C, then a solution of [6-tert-butyl-4-(3,5-dimethylphenyl)-2-methyl-5-methoxy-1H- inden-1-yl]chlorodimethylsilane (7.6 g, 18.4 mmol) in 150 ml of ether was added in one portion. This mixture was stirred for 5 h at room temperature, then filtered through a pad of silica gel 60 (40-63 µm), which was additionally washed with 2 ^50 ml of ether. The combined organic elute was evaporated to dryness, and the residue was dried under vacuum at elevated temperature to give 13.87 g (ca.100% of ca.85% purity) of the title product (as ca. 1:1 mixture of the stereoisomers) as a slightly yellowish glassy solid which was used without further purification. dimethylsilanediyl[2,5,6-trimethyl-4,7-bis(3,5-dimethylphenyl)-inden-1-yl][2-methyl-4- dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride nBuLi in hexanes (2.5 M, 8.0 ml, 20.0 mmol) was added in one portion to a yellowish solution of [4,7-bis(3,5-dimethylphenyl)-2,5,6-trimethyl-1H-inden-1-yl][6-tert-butyl-4-(3,5- dimethylphenyl)-5-methoxy-2-methyl-1H-inden-1-yl]dimethylsilane (7.43 g, ca. 10.0 mmol) in 50 ml ofnBu2O at room temperature. This mixture was stirred overnight at room temperature, then the resulting turbid yellow solution was cooled to 0 °C in an ice-bath, and ZrCl4 (2.33 g, 10.0 mmol) was added. The reaction mixture was stirred for 24 h at room temperature to give a light-orange suspension. This mixture was evaporated to dryness (to the state of orange foam). On the evidence of NMR spectroscopy, the resulting solid included a ca.85 / 15 mixture of anti- and syn-zirconocene dichlorides. This solid was extracted with 70 ml of boiling n-hexane, the resulting extract was evaporated to ca.15 ml, and 15 ml of n-pentane was added. The orange crystalline solid precipitated from this solution overnight at room temperature was collected and dried under vacuum. This procedure gave 3.2 g of anti-zirconocene dichloride as a solvate with ca. 0.5 molecule of n-pentane, so the adjusted net weight of the isolated anti-isomer was 3.05 g. Anal. calc. for C53H60Cl2OSiZr.(C5H12): C, 71.42; H, 7.44. Found: C, 71.59; H, 7.74.1H NMR (CDCl3): δ 7.60-6.95 (very br. s, 2H), 7.50 (s, 1H), 7.40 (s, 1H), 7.09 (s, 1H), 7.01 (s, 1H), 6.96 (s, 2H), 6.92 (s, 1H), 6.77 (s, 1H), 6.58 (s, 1H), 6.51 (s, 1H), 3.43 (s, 3H), 2.39 (s, 3H), 2.37 (s, 3H), 2.35 (s, 9H), 2.32 (s, 3H), 2.26 (s, 3H), 2.25 (s, 3H), 2.11 (s, 3H), 2.04 (s, 3H), 1.34 (s, 9H), 1.10 (s, 3H), -0.19 (s, 3H).13C NMR (CDCl3): δ 159.80, 143.89, 141.54, 139.15, 138.52, 137.93, 137.78, 137.09, 136.95, 136.05, 136.01, 135.18, 135.05, 134.89, 134.50, 134.47, 131.11, 130.85, 129.91, 129.45, 129.14, 128.71, 128.65, 127.81, 127.50, 127.22, 126.67, 125.17, 123.04, 121.17, 120.98, 82.76, 81.58, 62.78, 35.67, 30.39, 21.46, 21.41, 21.37, 21.24, 19.78, 18.86, 18.83, 18.79, 3.90, 0.88. Synthesis of inventive metallocene IM1 Synthesis of 6-tert-butyl-5-methoxy-2-methylindan-1-one Methacrylic acid (137.6 g, 1.6 mol) was added to Eaton's reagent obtained from 220 g of P4O10 and 1120 ml of MeSO3H at 50 °C. To this mixture, 1-tert-butyl-2-methoxybenzene (131.2 g, 0.8 mol) was added dropwise by vigorous stirring over ca. 1 h at 50-53 °C (water bath temperature). The resulting mixture was stirred for 1 h at this temperature, then cooled to room temperature, and poured onto a mixture of 1.5 liter of cold water and 3 kg of ice. The crude product was extracted with 3 ^600 ml of dichloromethane. The combined organic extract was washed by aqueous K2CO3, dried over K2CO3 and then evaporated to dryness. Fractional rectification of the residue gave 159.5 g of yellowish oil (bp 150-180oC / 5 mm Hg.) which crystallizes at room temperature. Further on, this product was dissolved in 300 ml of hot hexanes. Crystals precipitated from this solution overnight at room temperature were collected, washed with 50 ml of cold hexanes, and dried under vacuum. This procedure gave 127.0 g of the pure 6-tert-butyl-5-methoxy-2- methylindan-1-one. The mother liquor was evaporated to ca. 100 ml that resulted in formation of one portion of the crystalline product. This procedure gave additional 10.5 g of the title product. Thus, the total yield of the product was 137.5 g (74%). 2-methyl-4-bromo-5-methoxy-6-tert-butyl-indan-1-one Bromine (45.0 g, 0.282 mol) was added over ca. 5 min with vigorous stirring into a mixture of 60.0 g (0.258 mol) of 6-tert-butyl-5-methoxy-2-methylindan-1-one, 130 g of NaOAc(H2O)3, 1.5 g of Et4NI, 220 ml of dichloromethane, and 450 ml of water cooled to 5 °C. This mixture was stirred for 1 h at 5 °C, then a solution of 60.0 g of NaOAc(H2O)3in 200 ml of water was added. To the resulting mixture, bromine (23.5 g, 0.147 mmol) was added at 5 °C. The resulting solution was stirred for 30 min and then washed by aqueous Na2SO3. The crude product was extracted with 3 ^300 ml of dichloromethane. The combined organic extract was dried over K2CO3, passed through short layer of silica gel 60 (40-63 µm) and then evaporated to dryness. The residue was dried in vacuum to give 79.9 g (99%) of the target product which was used without further purification.1H NMR (CDCl3): δ 7.70 (s, 1H), 4.03 (s, 3H), 3.31 (dd, J = 17.4 Hz, J = 7.8 Hz, 1H), 2.72 (m, 1H), 2.62 (dd, J = 17.4 Hz, J = 3.8 Hz, 1H), 1.40 (s, 9H), 1.32 (d, J = 7.6 Hz, 3H).13C{1H} NMR (CDCl3): δ 208.0, 162.8, 154.0, 145.5, 132.7, 121.5, 116.7, 61.7, 42.2, 36.1, 35.7, 30.6, 16.4. 2-methyl-4-(3,5-dimethylphenyl)-5-methoxy-6-tert-butyl-indan-1-one A mixture of 49.14 g (157.9 mmol) of 2-methyl-4-bromo-5-methoxy-6-tert-butyl-indan-1- one, 29.6 g (197.4 mmol, 1.25 eq.) of (3,5-dimethylphenyl)boronic acid, 45.2 g (427 mmol) of Na2CO3, 1.87 g (8.3 mmol, 5 mol.%) of Pd(OAc)2, 4.36 g (16.6 mmol, 10 mol.%) of PPh3, 200 ml of water, and 500 ml of 1,2-dimethoxyethane was refluxed for 6.5 h. DME was evaporated on a rotary evaporator, 600 ml of water and 700 ml of dichloromethane were added to the residue. The organic layer was separated, and the aqueous one was additionally extracted with 200 ml of dichloromethane. The combined extract was dried over K2CO3 and then evaporated to dryness to give black oil. Crude product was purified by flash chromatography on silica gel 60 (40-63 µm, hexane- dichloromethane = 1:1, vol., then, 1:3, vol.) to give 48.43 g (91%) of 2-methyl-4-(3,5- dimethylphenyl)-5-methoxy-6-tert-butyl-indan-1-one as a brownish oil. Anal. calc. for C23H28O2: C, 82.10; H, 8.39. Found: C, 82.39; H, 8.52.1H NMR (CDCl3): δ 7.73 (s, 1H), 7.02 (s, 3H), 7.01 (s, 3H), 3.32 (s, 3H), 3.13 (dd, J = 17.5 Hz, J = 7.8 Hz, 1H), 2.68-2.57 (m, 1H), 2.44 (dd, J = 17.5 Hz, J = 3.9 Hz), 2.36 (s, 6H), 1.42 (s, 9H), 1.25 (d, J = 7.5 Hz, 3H).13C{1H} NMR (CDCl3): δ 208.90, 163.50, 152.90, 143.32, 138.08, 136.26, 132.68, 130.84, 129.08, 127.18, 121.30, 60.52, 42.17, 35.37, 34.34, 30.52, 21.38, 16.40. 2-methyl-5-tert-butyl-6-methoxy-7-(3,5-dimethylphenyl)-1H-indene NaBH4(8.2 g, 217 mmol) was added to a solution of 2-methyl-4-(3,5-dimethylphenyl)-5- methoxy-6-tert-butyl-indan-1-one (48.43 g, 143.9 mmol) in 300 ml of THF cooled to 5°C. Then, 150 ml of methanol was added dropwise to this mixture with vigorous stirring over ca. 7 h at 5°C. The resulting mixture was evaporated to dryness, and the residue wad partitioned between 500 ml of dichloromethane and 500 ml of 2 M HCl. The organic layer was separated, the aqueous layer was additionally extracted with 100 ml of dichloromethane. The combined organic extract was evaporated to dryness to give a slightly yellowish oil. To a solution of this oil in 600 ml of toluene, 400 mg of TsOH was added, then this mixture was refluxed with Dean-Stark head for 10 min and then cooled to room temperature using water bath. The formed solution was washed with 10% Na2CO3, the organic layer was separated, the aqueous layer was extracted with 150 ml of dichloromethane. The combined organic extract was dried over K2CO3 and then passed through a short layer of silica gel 60 (40-63 µm). The silica gel layer was additionally washed with 100 ml of dichloromethane. The combined organic elute was evaporated to dryness, and the resulting oil was dried under vacuum at elevated temperature. This procedure gave 45.34 g (98%) of 2-methyl-5-tert-butyl-6-methoxy-7- (3,5-dimethylphenyl)-1H-indene which was used without further purification. Anal. calc. for C23H28O: C, 86.20; H, 8.81. Found: C, 86.29; H, 9.07.1H NMR (CDCl3): δ 7.20 (s, 1H), 7.08 (br.s, 1H), 6.98 (br.s, 1H), 6.42 (m, 1H), 3.25 (s, 3H), 3.11 (s, 2H), 2.36 (s, 6H), 2.06 (s, 3H), 1.43 (s, 9H).13C{1H} NMR (CDCl3): δ 154.20, 145.22, 141.78, 140.82, 140.64, 138.30, 137.64, 131.80, 128.44, 127.18, 126.85, 116.98, 60.65, 42.80, 35.12, 31.01, 21.41, 16.65. [6-tert-butyl-4-(3,5-dimethylphenyl)-5-methoxy-2-methyl-1H-inden-1- yl]chlorodimethylsilane nBuLi in hexanes (2.43 M, 14.6 ml, 35.5 mmol) was added in one portion to a solution of 5-tert-butyl-7-(3,5-dimethylphenyl)-6-methoxy-2-methyl-1H-indene (11.3 g, 35.3 mmol) in 200 ml of ether cooled to –50 °C. The resulting orange solution was stirred overnight at room temperature, then the obtained orange solution containing a yellowish precipitate was cooled to –78 °C (the precipitate almost completely disappeared), and dichlorodimethylsilane (22.8 g, 177 mmol, 5 equiv) was added in one portion. The formed solution was warmed to room temperature and stirred overnight at room temperature. The resulting mixture was filtered through glass frit (G4). The precipitate was additionally washed with 2×10 ml of ether. The combined filtrate was evaporated to dryness to give the title material as slightly orange oil which was used without further purification. 1,4-Dibromo-2-(bromomethyl)benzene Bromine (15.5 ml, 47.9 g, 0.30 mmol) was added dropwise by vigorous stirring for 3 h to 2,5-dibromotoluene (74.9 g, 0.30 mol) at 200 °C. The resulting mixture was cooled to room temperature. Fractional distillation gave a colorless liquid, b.p.132°C - 135°C / 3 mm Hg. Yield 84.3 g (85%, ca.82% purity).1H NMR (CDCl3): δ 7.59 (s, 1H), 7.43 (d, J = 8.5 Hz, 1H), 7.29 (d, J = 8.5 Hz, 1H), 4.52 (s, 2H).13C NMR (CDCl3): δ 138.94, 134.64, 133.95, 133.04, 130.31, 121.44, 32.11. 4,7-Dibromo-2-methylindan-1-one Sodium metal (6.10 g, 0.27 mol) was dissolved in 200 ml of dry ethanol. To the resulting solution, 45.5 g (0.26 mol) of diethylmethylmalonate was added. This mixture was stirred for 15 min, then 84.3 g (0.26 mol) of 1,4-dibromo-2-(bromomethyl)benzene was added at a rate that allowed the reaction mixture to maintain a gentle reflux. Additionally, this mixture was refluxed for 4 h, then cooled to room temperature. A solution of 52.1 g of KOH in 140 ml of water was added. This mixture was refluxed for 6 h to saponificate the ester formed. Ethanol was distilled off. To the residue 200 ml of water and then 12 M HCl were added to pH=1. The substituted methylmalonic acid precipitated was filtered off, washed with 2x100 ml of cold water, and dried on air. Crude 3-(2,5-dibromophenyl)-2- methylpropanoic acid was obtained after decarboxylation of this substituted methylmalonic acid by heating the latter in a round bottom flask for 0.5 h at 180°C. The so obtained crude 3-(2,5-dibromophenyl)-2- methylpropanoic acid was used without further purification. A mixture of this acid, 70 ml (114.6 g, 0.96 mol) of SOCl2, and 100 ml of dichloromethane was stirred overnight at room temperature. Excess thionyl chloride and dichloromethane were distilled off. The residue was dried under vacuum and then dissolved in 95 ml of dichloromethane. The obtained solution was added dropwise for 1 h to a suspension of 47.0 g (0.35 mol) of AlCl3in 470 ml of dichloromethane at 0 °C. The formed mixture was refluxed for 3 h, cooled to ambient temperature, and then poured onto 1000 cm3of ice. The organic layer was separated. The aqueous layer was extracted with 3x200 ml of dichloromethane. The combined organic extract was dried over K2CO3and evaporated to dryness. The crude 4,7-dibromo-2-methylindan-1-one was purified by column chromatography on silica gel 60 (40-63 µm, d 50 mm, l 1250 mm, eluent: hexanes / CH2Cl2 = 1:1, vol.). Yield 54.1 g (70%).1H NMR (CDCl3): δ 7.52 (d, J= 8.4 Hz, 1H), 7.37 (d, J= 8.4 Hz, 1H), 3.27 (dd, J= 17.7 Hz, J= 8.0 Hz, 1H), 3.73 (m, 1H), 2.58 (dd, J= 17.7 Hz, J= 4.2 Hz, 1H), 1.31 (d, J= 7.3 Hz, 3H).13C NMR (CDCI3): δ 205.5, 155.4, 137.6, 135.3, 133.9, 121.0, 118.6, 42.6, 35.3, 16.1. 4,7-Dibromo-2-methyl-1H-indene NaBH4 (9.40 g, 0.248 mmol) was added to a solution of 4,7-dibromo-2-methyl-1- indanone (54.1 g, 0.178 mol) in 200 ml of THF cooled to 5 °C. Then, 80 ml of methanol was added dropwise to this mixture over ca. 3 h at 5 °C. The obtained mixture was stirred overnight at ambient temperature. The resulting mixture was evaporated to dryness, and the residue was partitioned between 500 ml of dichloromethane and 500 ml of 2 M HCl. The organic layer was separated, the aqueous layer was additionally extracted with 100 ml of dichloromethane. The combined organic extract was evaporated to dryness. To the residue 500 ml of toluene and 5.0 g TsOH were added. This toluene solution was refluxed with Dean-Stark head until elimination of water was complete. After cooling to room temperature the reaction mixture was washed with 200 ml of 10% NaHCO3. The organic layer was separated, and the aqueous layer was additionally extracted with 2 ^50 ml of toluene. The combined organic extract was dried over K2CO3 and evaporated to dryness. The product was purified by flash-chromatography on silica gel 60 (40-63 µm, d 50 mm, l 550 mm, eluent: hexanes / CH2Cl2= 10:1, vol.). Yield 47.2 g (92%).1H NMR (CDCl3): δ 7.18 (d, J= 8.4 Hz, 1H), 7.03 (d, J= 8.4 Hz, 1H), 6.55 (s, 1H), 3.29 (s, 2H), 2.14 (s, 3H).13C NMR (CDCI3): δ 148.17, 146.88, 144.28, 131.09, 127.88, 126.85, 116.93, 112.61, 45.38, 16.73. 4,7-Bis(3,5-dimethylphenyl)-2-methyl-1H-indene A mixture of 46.79 g (162.48 mmol) of 4,7-dibromo-2-methyl-1H-indene, 56.0 g (370 mmol) of (3,5-dimethylphenyl)boronic acid, 93.1 g (906 mmol) of Na2CO3, 1.3 g (2.54 mmol) of Pd(PtBu3)2, 420 ml of water, and 600 ml of 2-methyltetrahydrofuran was refluxed for 5 h. The organic layer was separated and evaporated to dryness. The crude 4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-indene was purified by column chromatography on silica gel 60 (40-63 µm, d 50 mm, l 1000 mm, eluent: hexanes / CH2Cl2 = 5:1, vol.). The elute was evaporated to dryness, and the residue was refluxed with 300 ml of hot n- hexane. White crystals precipitated at –5 °C were collected and dried under vacuum. This procedure gave 52.5 g (95%) of the title product.1H NMR (CDCl3): δ 7.31 (d, J= 7.8 Hz, 1H), 7.17-7.15 (m, 5H), 7.00 (s, 2H), 6.72-6.70 (m, 1H), 3.43 (s, 2H), 2.39-2.38 (m, 12H), 2.13 (s, 3H).13C NMR (CDCI3): δ 146.50, 143.78, 141.23, 141.19, 140.94, 137.82, 136.43, 133.20, 128.65, 128.40, 127.41, 126.74, 126.34, 126.32, 124.64, 43.06, 21.42, 16.82. [4,7-Bis(3,5-dimethylphenyl)-2-methyl-1H-inden-1-yl][6-tert-butyl-4-(3,5-dimethylphenyl)- 5-methoxy-2-methyl-1H-inden-1-yl]dimethylsilane nBuLi in hexane (2.5 M, 8.35 ml, 20.8 mmol) was added in one portion to a solution of 4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-indene (7.05 g, 20.8 mmol) in a mixture of 100 ml of ether and 25 ml of THF cooled to –50 °C. The resulting mixture was stirred overnight at room temperature, then the so obtained yellow suspension was cooled to – 50 °C, and 150 mg of CuCN was added. The obtained mixture was stirred for 0.5 h at – 25 °C, then a solution of [6-tert-butyl-4-(3,5-dimethylphenyl)-5-methoxy-2-methyl-1H- inden-1-yl]chlorodimethylsilane (8.6 g, 20.8 mmol) in a mixture of 125 ml of ether and 35 ml of THF was added in one portion. The resulting mixture was stirred overnight at room temperature, then filtered through a pad of silica gel 60 (40-63 µm) which was additionally washed with 2 ^50 ml of ether. The combined organic elute was evaporated to dryness. The crude product was purified by column chromatography on silica gel 60 (40-63 µm, d 50 mm, l 600 ml, eluent: hexanes / CH2Cl2= 10:1, then, 2:1, vol.). This procedure gave 12.9 g (18.0 mmol, ca.86.7%, purity ca.95%) of the title product (as a ca 55:45 mixture of the stereoisomers) as a slightly yellowish glassy solid which was used without further purification. dimethylsilanediyl[2-methyl-4,7-bis(3,5-dimethylphenyl)-inden-1-yl][2-methyl-4-(3,5- -5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride nBuLi in hexanes (2.5 M, 13.1 ml, 32.72 mmol) was added in one portion to a solution of [4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-inden-1-yl][6-tert-butyl-4-(3,5-dimethylphenyl)- 5-methoxy-2-methyl-1H-inden-1-yl]dimethylsilane (11.7 g, 16.35 mmol) in 100 ml of di-n- butyl ether at room temperature. This mixture was stirred overnight at room temperature, then the resulting red solution was cooled to 0 °C in an ice-bath, and then ZrCl4(3.81 g, 16.35 mmol) was added. The reaction mixture was stirred for 24 h at room temperature to give a yellow suspension. This suspension was evaporated to dryness. The solid residue was extracted with 150 ml of boiling toluene. On the evidence of NMR spectroscopy, the obtained extract included a ca. 83:17 mixture of anti- and syn- zirconocene dichlorides. The mother liquor was evaporated to ca. 80 ml. The orange solid precipitated from this solution at room temperature was collected and dried under vacuum. This procedure gave 8.20 g of anti-zirconocene dichloride containing ca. 0.8 mol of toluene, so the adjusted net weight of the isolated anti-isomer was 7.56 g. The mother liquor was evaporated to ca.25 ml, and 25 ml of hexane was added. The orange solid precipitated from this solution at room temperature was collected and dried under vacuum. This procedure gave 2.30 g of anti-zirconocene dichloride slightly contaminated with polymeric side products, so the adjusted net weight of the isolated anti-isomer was 2.12 g. Thus, the total yield of anti-zirconocene dichloride isolated in this synthesis was 9.68 g (67.7%). Anal. calc. for C51H56Cl2OSiZr*0.8(C7H8): C, 71.64; H, 6.62. Found: C, 71.75; H, 6.84.1H NMR (CDCl3): δ 7.44 (s, 1H), 7.39 (d, J =7.2 Hz, 1H), 7.37 (s, 2H), 7.30-7.10 (m, 5H), 6.99 (d, J =6.3 Hz, 2H), 6.96-6.91 (m, 2H), 6.61 (s, 1H), 3.44 (s, 3H), 2.39-2.32 (m, 21H), 1.96 (s, 3H), 1.38 (s, 9H), 1.19 (s, 3H), -0.04 (s, 3H).13C NMR (CDCl3): δ 160.01, 144.55, 143.27, 139.37, 139.08, 138.42, 137.96, 136.74, 135.78, 134.21, 134.12, 130.77, 130.41, 130.34, 129.34, 129.31, 128.82, 128.28, 127.38 (br. s.), 127.00, 126.72, 126.07, 125.10, 123.66, 123.56, 122.49, 121.01, 82.88, 82.41, 62.64, 35.72, 30.41, 21.44, 21.35, 21.22, 19.72, 18.43, 3.35, 2.76. Synthesis of inventive metallocene IM2 Ethylmalonic acid A solution of 196.4 g (3.5 mol) of potassium hydroxide in 1000 cm3of water was added to a solution of 188.2 g (1.0 mol) of diethyl ethylmalonate in 500 ml of methanol. The resulting mixture was refluxed for 5 h, then ethanol and methanol were distilled off. Then, 1000 cm3of water was added and the obtained mixture was acidified with 12 M HCl to pH 1.0. Ethylmalonic acid was extracted with 5 ^300 ml of ether. The combined extract was evaporated to dryness and the residue was dried under vacuum. This procedure gave 120.2 g (91.0%) of ethylmalonic acid as white solid.1H NMR (DMSO-d6): δ 4.28 (br.s, 2H), 3.12 (d, J = 7.4 Hz, 1H), 1.71 (quin, J = 7.40 Hz, 2H), 0.86 (t, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 171.12, 53.36, 22.01, 11.95. 2-Ethylacrylic acid Diethylamine (108.2 ml, 76.82 g, 1.05 mol) was added dropwise at 5 °C to a solution of ethylmalonic acid (118.8 g, 899.2 mmol) in 1300 ml of ethyl acetate. Paraform (38.4 g, 1.28 mol) was added to the obtained suspension. The resulting mixture was refluxed for 5 h, then cooled to 5 °C, then 600 ml of ether and 1700 cm3of 2 M HCl were added. After mixing, the organic layer was separated, the aqueous layer was additionally extracted with 2 ^700 ml of ether. The combined organic extract was dried over Na2SO4 and then carefully evaporated to dryness. The residue was purified by vacuum distillation to give 2-ethylacrylic acid, bp 75-77oC / 6 mm Hg. Yield 79.8 g (88.6%) of a colorless liquid.1H NMR (CDCl3): δ 12.55 (br.s, 1H), 6.28 (m, 1H), 5.64 (m, 1H), 2.32 (qm, J = 7.5 Hz, 2H), 1.08 (t, J = 7.5 Hz, 3H). 6-tert-Butyl-5-methoxy-2-ethylindan-1-one 2-ethylacrylic acid (47.6 g, 475.5 mmol, 1.27 equiv.) was added to Eaton's reagent obtained from 103.5 g of P4O10 and 520 ml of MeSO3H at 50 °C. To this rapidly stirred mixture, 1-tert-butyl-2-methoxybenzene (61.7 g, 375.7 mmol) was added dropwise over ca. 1 h at 50-53 °C (hot water bath). The resulting mixture was stirred for 1 h at this temperature, then cooled to room temperature, and poured on a mixture of 1.0 liter of cold water and 1 kg of ice. The crude product was extracted with 3x400 ml of dichloromethane. The combined organic extract was washed with aqueous K2CO3, dried over K2CO3, filtered through a short pad of silica gel 60 (40-63 µm) and then evaporated to dryness. The residue was purified by vacuum distillation to give 81.18 g (87.7 %, ca. 90% purity) of 6-tert-butyl-5-methoxy-2-ethylindan-1-one as a yellowish oil (bp 150- 170oC / 5 mm Hg).1H NMR (CDCl3): δ 7.65 (s, 1H), 6.85 (s, 1H), 3.90 (s, 3H), 3.20 (dd, J = 17.2 Hz, J = 7.7 Hz, 1H), 2.71 (dd, J = 17.2 Hz, J = 3.6 Hz, 1H), 2.59-2.51 (m, 1H), 1.99-1.87 (m, 1H), 1.54-1.41 (m, 1H), 1.35 (s, 9H), 0.97 (t, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 207.59, 164.52, 154.75, 138.65, 129.31, 121.87, 107.72, 55.15, 48.86, 35.00, 31.93, 29.54, 24.61, 11.56. 4-Bromo-6-tert-butyl-2-ethyl-5-methoxyindan-1-one Bromine (18.5 ml, 57.4 g, 359.1 mmol) was added dropwise over 5 min at 5 °C to a mixture of 6-tert-butyl-2-ethyl-5-methoxyindan-1-one (81.18 g, 329.5 mmol), 100.4 g of sodium acetate, 3.0 g ofnBu4NI, 280 ml of dichloromethane, and 570 ml of water. This mixture was stirred for 2 h at 5 °C, then a solution of 46.3 g of sodium acetate in 260 ml of water was added followed by addition of 9.7 ml (30.1 g, 188.3 mmol) of bromine. The resulting mixture was additionally stirred for 1 h at this temperature and then washed by aqueous Na2SO3 to remove excess bromine. The crude product was extracted with 3 ^250 ml of dichloromethane. The combined organic extract was dried over K2CO3, evaporated to dryness, and the residue was dried under vacuum. This procedure gave 105.3 g (98.1%, ca.90% purity) of 4-bromo-6-tert-butyl-2-ethyl-5-methoxyindan-1-one as a yellowish oil which was used without further purification.1H NMR (CDCl3): δ 7.69 (s, 1H), 4.03 (s, 3H), 3.21 (dd, J = 17.6 Hz, J = 7.8 Hz, 1H), 2.70 (dd, J = 17.6 Hz, J = 3.7 Hz, 1H), 2.66-2.58 (m, 1H), 2.03-1.91 (m, 1H), 1.60-1.47 (m, 1H), 1.40 (s, 9H), 1.03 (t, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 207.14, 162.57, 154.07, 145.20, 133.07, 121.13, 116.50, 61.45, 48.79, 35.46, 33.36, 30.45, 24.34, 11.43. 6-tert-Butyl-2-ethyl-5-methoxy-4-(3,5-dimethylphenyl)-indan-1-one A mixture of 64.08 g (197.0 mmol) of 4-bromo-6-tert-butyl-2-ethyl-5-methoxyindan-1-one, 37.32 g (248.8 mmol, 1.26 equiv.) of 3,5-dimethylphenylboronic acid, 1.02 g (2.0 mmol, 1 mol.%) of Pd(PtBu3)2, 63.4 g of Na2CO3, 325 ml of 2-methyltetrahydrofurane, and 290 ml of water was refluxed for 6 h. Then 500 ml of water was added, the organic layer was separated, and the aqueous layer was extracted with 200 ml of dichloromethane. The combined organic extract was dried over K2CO3 and then evaporated to dryness to give slightly yellowish oil. The product was isolated by flash-chromatography on silica gel 60 (40-63 µm, eluent: hexanes-dichloromethane = 1:1 and then 1:5, vol.). Yield 62.95 g (91.2%, purity ca.95%) of a slightly yellowish oil.1H NMR (CDCl3): δ 7.73 (s, 1H), 7.03 (s, 1H), 7.02 (s, 2H), 3.32 (s, 3H), 3.06 (dd, J = 18.3 Hz, J = 8.6 Hz, 1H), 2.57-2.47 (m, 2H), 2.39 (s, 6H), 2.00-1.87 (m, 1H), 1.54-1.40 (m, 1H), 1.42 (s, 9H), 0.95 (t, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 208.30, 163.42, 153.15, 143.21, 138.06, 136.27, 132.68, 131.42, 129.07, 127.17, 121.11, 60.47, 49.00, 35.33, 31.69, 30.49, 24.48, 21.36, 11.67. 5-tert-Butyl-2-ethyl-6-methoxy-7-(3,5-dimethylphenyl)-1H-indene NaBH4(10.2 g, 269.6 mmol, 1.5 equiv.) was added to a solution of 62.95 g (179.6 mmol) of 6-tert-butyl-2-ethyl-5-methoxy-4-(3,5-dimethylphenyl)-indan-1-one in 300 ml of THF cooled to 5 °C. To this mixture 150 ml of MeOH was added dropwise over ca.5 h at 5 °C, and the resulting mixture was stirred overnight at room temperature. Then, this mixture was evaporated to dryness, 700 ml of dichloromethane and 700 ml water were added to the residue, and the so obtained mixture was acidified with 2 M HCl to pH~6.5. The organic layer was separated, the aqueous layer was additionally extracted with 100 ml of dichloromethane. The combined organic extract was passed through a pad (~30 ml) of silica gel 60 (40-63 µm; eluent: dichloromethane) to get rid of most of the palladium black. The obtained elute was evaporated to dryness to give a grey oil. This oil was dissolved in 300 ml of toluene and TsOH (0.3 g) was added to it. This mixture was refluxed with Dean-Stark head for 10 min and then cooled to room temperature using a water bath. The formed solution was washed with 10% Na2CO3, the organic layer was separated, the aqueous layer was extracted with 150 ml of dichloromethane. The combined organic extract was dried over K2CO3and then evaporated to dryness. The crude product was purified by flash chromatography on silica gel 60 (40-63 µm, hexanes- dichloromethane = 10:1) followed by vacuum distillation to give 53.14 g (88.5%) of 5-tert- butyl-2-ethyl-6-methoxy-7-(3,5-dimethylphenyl)-1H-indene as a yellowish oil (bp 175- 195oC / 2 mm Hg).1H NMR (CDCl3): δ 7.22 (s, 1H), 7.09 (s, 2H), 6.99 (s, 1H), 6.45 (t, J = 1.4 Hz, 1H), 3.25 (s, 3H), 3.13 (s, 2H), 2.41 (q, J = 7.4 Hz, 2H), 2.37 (s, 6H), 1.44 (s, 9H), 1.14 (d, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 154.25, 151.76, 141.51, 140.88, 140.43, 138.31, 137.66, 131.91, 128.46, 127.20, 124.97, 117.17, 60.66, 41.00, 35.13, 31.01, 24.25, 21.43, 13.47. [6-tert-Butyl-4-(3,5-dimethylphenyl)-2-ethyl-5-methoxy-1H-inden-1- yl]chlorodimethylsilane nBuLi in hexanes (2.5 M, 10.9 ml, 27.25 mmol) was added in one portion to a solution of of 5-tert-butyl-7-(3,5-dimethylphenyl)-2-ethyl-6-methoxy-1H-indene (9.05 g, 27.06 mmol) in 200 ml of ether cooled to –50 °C. This mixture was stirred overnight at room temperature, then the resulting orange-yellow solution was cooled to –50 °C, then dichlorodimethylsilane (16.3 ml, 17.44 g, 135.1 mmol, 5.0 equiv.) was added to it in one portion. The resulting mixture was stirred overnight at room temperature, then filtered through a glass frit (G3), and the filter cake was washed with 2 ^50 ml of toluene. The combined filtrate was evaporated to dryness to give the title compound as a yellowish thick oil that was used without further purification.1H NMR (CDCl3): δ 7.39 (s, 1H), 7.09 (s, 2H), 6.99 (s, 1H), 6.45 (s, 1H), 3.65 (s, 1H), 3.24 (s, 3H), 2.67-2.46 (m, 2H), 2.38 (s, 6H), 1.43 (s, 9H), 1.15 (t, J = 7.5 Hz, 3H), 0.43 (s, 3H), 0.15 (s, 3H).13C NMR (CDCl3): δ 155.83, 152.58, 143.55, 137.96, 137.58, 137.55, 136.53, 128.33, 127.90, 127.74, 124.52, 121.00, 60.46, 48.34, 35.16, 31.17, 24.71, 21.44, 13.76, 1.21, -0.66. [4,7-Bis(3,5-dimethylphenyl)-2-methyl-1H-inden-1-yl][6-tert-butyl-4-(3,5-dimethyl phenyl)-2-ethyl-5-methoxy-1H-inden-1-yl]dimethylsilane nBuLi in hexane (2.5 M, 8.3 ml, 20.75 mmol) was added in one portion to a solution of 4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-indene (7.03 g, 20.77 mmol) in a mixture of 100 ml of ether and 70 ml of THF cooled to –50 °C. The resulting mixture was stirred overnight at room temperature, then the so obtained yellow suspension was cooled to – 50 °C, and 150 mg of CuCN was added. The obtained mixture was stirred for 0.5 h at – 20 °C, then a solution of [6-tert-butyl-4-(3,5-dimethylphenyl)-2-ethyl-5-methoxy-1H-inden- 1-yl]chlorodimethylsilane (8.87 g, 20.77 mmol) in 150 ml of ether was added in one portion. The resulting mixture was stirred overnight at room temperature, then filtered through a pad of silica gel 60 (40-63 µm) which was additionally washed with 2x50 ml of ether. The combined organic elute was evaporated to dryness. The product was purified by flash chromatography on silica gel 60 (40-63 µm, 600 ml, eluent: hexanes: dichloromethane = 5:1, vol.). The combined organic elute was evaporated to dryness, and the residue was dried under vacuum at elevated temperature to give 13.8 g (18.92 mmol, yield ca.91.1%, purity ca.98%) of the title product (as a ca 40:60 mixture of the stereoisomers) as a slightly yellowish glassy solid. dimethylsilanediyl[2-methyl-4,7-bis(3,5-dimethylphenyl)-inden-1-yl][2-ethyl-4-(3,5- -5-methoxy-6-tert-butyl-inden-1-yl]zirconium dichloride nBuLi in hexanes (2.5 M, 14.04 ml, 35.1 mmol) was added in one portion to a solution of [4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-inden-1-yl][6-tert-butyl-4-(3,5-dimethylphenyl)- 2-ethyl-5-methoxy-1H-inden-1-yl]dimethylsilane (12.8 g, 17.55 mmol) in 100 ml of di-n- butyl ether at room temperature. This mixture was stirred overnight at room temperature, then the resulting red solution was cooled to 0 °C in an ice bath, and ZrCl4(4.1 g, 17.6 mmol) was added. The reaction mixture was stirred for 24 h at room temperature to give a yellow suspension. This suspension was evaporated to dryness. The formed solid was extracted with 150 ml of hot toluene. The mother liquor was evaporated to ca.25 ml. The orange solid precipitated from this solution at room temperature was collected and dried under vacuum. This procedure gave 12.3 g of anti-zirconocene dichloride (as a solvate with ca.0.5 molecule of toluene) (78%). Synthesis of inventive metallocene IM3 Isopropylmalonic acid To a solution of 110.0 g (544 mmol) of diethyl isopropylmalonate in 500 ml of methanol a solution of 125 g of potassium hydroxide in 1000 cm3of water was added. The resulting mixture was refluxed for 5 h, then ethanol and methanol were distilled off. Further on, 1000 cm3of water was added, and the obtained mixture was acidified by 12 M HCl to pH 1.0. Isopropylmalonic acid was extracted with 4 x 500 ml of ether. The combined extract was evaporated to dryness, and the residue was dried in vacuum. This procedure gave 76.4 g (96.1%) of isopropylmalonic acid as white solid.1H NMR (CDCl3): δ 9.72 (br.s, 2H), 3.24 (d, J = 8.3 Hz, 1H), 2.48-2.34 (m, 1H), 1.07 (d, J = 6.8 Hz, 6H). 2-Isopropylacrylic acid 62.4 ml (44.3 g, 0.606 mol) of diethylamine was added dropwise to a solution of 76.4 g (523 mmol) of isopropylmalonic acid in 750 ml of ethyl acetate at 5 °C. Paraform (22.1 g, 0.736 mol) was added to the obtained suspension. The resulting mixture was refluxed for 5 h, then cooled to 5oC, and 350 ml of ether and 1000 cm3of 2 M HCl were added. After mixing, the organic layer was separated, the aqueous layer was additionally extracted with 2x500 ml of ether. The combined organic extract was dried over Na2SO4 and then evaporated to dryness. The residue was purified by vacuum distillation to give 2- isopropylacrylic acid, bp 65oC / 4 mm Hg. Yield 57.0 g (95.5%) of a colorless liquid.1H NMR (CDCl3): δ 12.45 (br.s, 1H), 6.30 (s, 1H), 5.65 (t, 1H), 2.81 (septd, J = 6.9 Hz, J = 0.9 Hz, 1H), 1.11 (d, J = 6.9 Hz, 6H).13C NMR (CDCl3): δ 173.30, 146.47, 124.31, 28.94, 21.76. 6-tert-Butyl-5-methoxy-2-isopropylindan-1-one 114.1 g (1.0 mol) of 2-isopropylacrylic acid was added to Eaton's reagent obtained from 220 g of P4O10and 1120 ml of MeSO3H at 50 °C. To this mixture 131.2 g (0.8 mol) of 1- tert-butyl-2-methoxybenzene was added dropwise by vigorous stirring for ca. 1 h at 50- 53 °C (water bath temperature). The resulting mixture was stirred for 1 h at this temperature, then cooled to room temperature, and poured on a mixture of 1.5 liter of cold water and 3 kg of ice. The crude product was extracted with 3 x 600 ml of dichloromethane. The combined organic extract was washed by aqueous K2CO3, dried over K2CO3, filtered through a short pad of silica gel 60 (40-63 µm) and then evaporated to dryness. The residue was purified by vacuum distillation to give 193.8 g (93.0 %, ca. 95% purity) of 6-tert-butyl-5-methoxy-2-isopropylindan-1-one as a yellowish oil (bp 150- 190oC / 4 mm Hg).1H NMR (CDCl3): δ 7.66 (s, 1H), 6.89 (s, 1H), 3.93 (s, 3H), 3.04 (dd, J = 17.4 Hz, J = 8.0 Hz, 1H), 2.84 (dd, J = 17.4 Hz, J = 3.8 Hz, 1H), 2.67-2.60 (m, 1H), 2.48-2.34 (m, 1H), 1.37 (s, 9H), 1.05 (d, J = 6.9 Hz, 3H), 0.77 (d, J = 6.9 Hz, 3H).13C NMR (CDCl3): δ 207.45, 164.44, 155.10, 138.54, 130.07, 121.69, 107.64, 55.14, 53.20, 35.00, 29.54, 28.87, 27.65, 20.96, 17.00. 4-Bromo-6-tert-butyl-2-isopropyl-5-methoxyindan-1-one 20.8 ml (64.9 g, 405.9 mmol) of bromine was added dropwise by vigorous stirring over 5 min to a mixture of 97.0 g (0.372 mol) of 6-tert-butyl-2-isopropyl-5-methoxyindan-1-one, 113.2 g of sodium acetate, 3.0 g ofnBu4NI, 310 ml of dichloromethane, and 645 ml of water at 5 °C. This mixture was stirred at 5 °C for 2 h, and then a solution of 52.2 g of sodium acetate in 290 ml of water was added followed by addition of 10.8 ml (33.7 g, 210.8 mmol) of bromine. The resulting mixture was additionally stirred for 1 h at this temperature and then washed by aqueous Na2SO3to remove excess bromine. The crude product was extracted with 3x250 ml of dichloromethane. The combined organic extract was dried over K2CO3, evaporated to dryness, and the residue was dried under vacuum. This procedure gave 124.84 g (98.9%, ca.95% purity) of a yellowish oil, which was used without further purification.1H NMR (CDCl3): δ 7.68 (s, 1H), 4.04 (s, 3H), 3.04 (dd, J = 17.9 Hz, J = 8.1 Hz, 1H), 2.80 (dd, J = 17.9 Hz, J = 3.9 Hz, 1H), 2.71-2.64 (m, 1H), 2.49-2.35 (m, 1H), 1.40 (s, 9H), 1.08 (d, J = 6.9 Hz, 3H), 0.80 (d, J = 6.8 Hz, 3H).13C NMR (CDCl3): δ 207.21, 162.59, 154.47, 145.24, 133.82, 121.03, 116.56, 61.54, 53.32, 35.56, 30.54, 29.41, 28.94, 20.78, 17.17. 6-tert-Butyl-2-isopropyl-5-methoxy-4-(3,5-dimethylphenyl)-indan-1-one A mixture of 124.84 g (368.0 mmol) of 4-bromo-6-tert-butyl-2-isopropyl-5-methoxyindan- 1-one, 69.7 g (464.7 mmol, 1.26 equiv.) of 3,5-Me2C6H3B(OH)2, 1.9 g (3.72 mmol, 1 mol. %) of Pd(PtBu3)2, 118.3 g of Na2CO3, 600 ml of 2-methyltetrahydrofurane and 540 ml of water was refluxed for 6 h. Further on, 500 ml of water was added, the organic layer was separated, and the aqueous layer was extracted with 300 ml of dichloromethane. The combined organic extract was dried over K2CO3and then evaporated to dryness to give slightly yellowish solid mass. The product was isolated by flash-chromatography on silica gel 60 (40-63 µm, eluent: hexanes-dichloromethane = 1:1 and then 1:5, vol.). Yield 121.55 g (90.6%, purity ca.95%) of a yellowish crystalline material.1H NMR (CDCl3): δ 7.71 (s, 1H), 7.04 (s, 1H), 7.03 (s, 2H), 3.31 (s, 3H), 2.87 (dd, J = 18.5 Hz, J = 8.8 Hz, 1H), 2.65-2.54 (dd and m, 2H), 2.43-2.34 (s and m, 7H), 1.42 (s, 9H), 0.99 (d, J = 6.9 Hz, 3H), 0.77 (d, J = 6.8 Hz, 3H).13C NMR (CDCl3): δ 208.19, 163.34, 153.44, 143.11, 138.08, 136.33, 132.64, 132.12, 129.08, 127.20, 120.93, 77.00, 60.46, 53.37, 35.33, 30.50, 28.88, 27.38, 21.39, 20.90, 17.25. 5-tert-Butyl-2-isopropyl-6-methoxy-7-(3,5-dimethylphenyl)-1H-indene 18.9 g (0.5 mol, 1.5 equiv.) of NaBH4 was added to a solution of 121.55 g (333.45 mmol) of 6-tert-butyl-2-isopropyl-5-methoxy-4-(3,5-dimethylphenyl)-indan-1-one in 600 ml of THF cooled to 5 °C. To this mixture, 300 ml of MeOH was added dropwise over ca.5 h at 5 °C, and the resulting mixture was stirred overnight at room temperature. Then, this mixture was evaporated to dryness, 1000 ml of dichloromethane and 1000 ml water were added to the residue, and the so obtained mixture was acidified with 2 M HCl to pH~6.5. The organic layer was separated, the aqueous layer was additionally extracted with 100 ml of dichloromethane. The combined organic extract was passed through a pad (~30 ml) of silica gel 60 (40-63 mm; eluent: dichloromethane) to get rid of most of the palladium black. The obtained elute was evaporated to dryness to give a grey solid mass. 1.0 g of TsOH was added to a solution of this mass in 1000 ml of toluene. This mixture was refluxed with Dean-Stark head for 10 min and then cooled to room temperature using water bath. The formed solution was washed with 10% Na2CO3, the organic layer was separated, the aqueous layer was extracted with 300 ml of dichloromethane. The combined organic extract was dried over K2CO3 and then evaporated to dryness. The crude product was purified by flash chromatography on silica gel 60 (40-63 µm, hexanes-dichloromethane = 5:1) followed by recrystallization from n- hexane (hot→-30oC). This procedure gave 96.93 g (83.4%) of pure 5-tert-butyl-7-(3,5- dimethylphenyl)-2-isopropyl-6-methoxy-1H-indene.1H NMR (CDCl3): δ 7.24 (s, 1H), 7.09 (s, 2H), 6.99 (s, 1H), 6.46 (m, 1H), 3.24 (s, 3H), 3.15 (m, 2H), 2.68 (sept, J = 6.8 Hz, 1H), 2.37 (s, 6H), 1.43 (s, 9H), 1.14 (d, J = 6.8 Hz, 6H).13C NMR (CDCl3): δ 156.43, 154.33, 141.34, 140.95, 140.23, 138.29, 137.69, 131.99, 128.49, 127.22, 123.86, 117.32, 60.67, 39.15, 35.13, 31.00, 30.04, 22.64, 21.44. nBuLi in hexanes (2.5 M, 8.0 ml, 20.0 mmol) was added in one portion to a solution of 5- tert-butyl-7-(3,5-dimethylphenyl)-2-isopropyl-6-methoxy-1H-indene (6.97 g, 20.0 mmol) in 200 ml of ether cooled to –50 °C. This mixture was stirred overnight at room temperature, then the resulting yellow suspension was cooled to –50 °C, then dichlorodimethylsilane (12.1 ml, 12.95 g, 100.3 mmol, 5.02 equiv.) was added in one portion followed by 5 ml of THF. The resulting mixture was stirred overnight at room temperature, then filtered through a glass frit (G3), and the filter cake was washed with 2x50 ml of toluene. The combined filtrate was evaporated to dryness to give [6-tert-butyl- 4-(3,5-dimethylphenyl)-2-isopropyl-5-methoxy-1H-inden-1-yl]chlorodimethylsilane as a yellowish thick oil which was used without further purification.1H NMR (CDCl3): δ 7.40 (s, 1H), 7.10 (br.s, 2H), 7.00 (m, 1H), 6.44 (s, 1H), 3.76 (s, 1H), 3.23 (s, 3H), 2.89 (sept.d, J = 6.8 Hz, J = 1.3 Hz, 1H), 2.39 (s, 6H), 1.43 (s, 9H), 1.20 (d, J = 6.7 Hz, 3H), 1.12 (d, J = 6.9 Hz, 3H), 0.43 (s, 3H), 0.12 (s, 3H).13C NMR (CDCl3): δ 157.53, 155.85, 143.40, 137.91, 137.60, 136.43, 128.33, 127.92, 127.89, 122.52, 121.06, 60.45, 47.72, 35.16, 31.16, 29.45, 24.43, 21.45, 21.17, 1.35, -0.77. 2- 1H-inden-1- nBuLi in hexane (2.5 M, 8.0 ml, 20.0 mmol) was added in one portion to a solution of 4,7- bis(3,5-dimethylphenyl)-2-methyl-1H-indene (6.77 g, 20.0 mmol) in a mixture of 100 ml of ether and 65 ml of THF cooled to –50 °C. The resulting mixture was stirred overnight at room temperature, then the so obtained yellow suspension was cooled to –50 °C, and 150 mg of CuCN was added. The obtained mixture was stirred for 0.5 h at –15 °C, then a solution of [6-tert-butyl-4-(3,5-dimethylphenyl)-2-isopropyl-5-methoxy-1H-inden-1- yl]chlorodimethylsilane (8.7 g, 19.72 mmol) in 150 ml of ether was added in one portion. The resulting mixture was stirred overnight at room temperature, then filtered through a pad of silica gel 60 (40-63 µm) which was additionally washed with 2x50 ml of ether. The combined organic elute was evaporated to dryness. The product was purified by flash chromatography on silica gel 60 (40-63 µm, 600 ml, eluent: hexanes: dichloromethane = 5:1, vol.). The combined organic elute was evaporated to dryness, and the residue was dried under vacuum at elevated temperature to give 13.9 g (18.7 mmol, yield ca.93.5%, purity ca. 95%) of the title product (as a ca 35:65 mixture of the stereoisomers) as a slightly yellowish glassy solid. Anti-dimethylsilanediyl[2-methyl-4,7-bis(3,5-dimethylphenyl)-inden-1-yl][2-iso-propyl-4- nBuLi in hexanes (2.5 M, 3.64 ml, 34.1 mmol) was added in one portion to a solution of [4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-inden-1-yl][6-tert-butyl-4-(3,5-dimethylphenyl)- 2-isopropyl-5-methoxy-1H-inden-1-yl]dimethylsilane (12.67 g, 17.05 mmol) in 100 ml of di-n-butyl ether at room temperature. This mixture was stirred overnight at room temperature, then the resulting red solution was cooled to 0 °C in an ice bath, and ZrCl4(4.0 g, 17.1 mmol) was added. The reaction mixture was stirred for 24 h at room temperature to give a yellow suspension. This suspension was evaporated to dryness. The formed solid was extracted with 150 ml of hot toluene. On the evidence of NMR spectroscopy, the obtained extract included a ca. 80:20 mixture of anti- and syn- zirconocene dichlorides. The mother liquor was evaporated to ca. 35 ml. The orange solid precipitated from this solution at room temperature was collected and dried under vacuum. This procedure gave 8.8 g of anti-zirconocene dichloride (as a solvate with ca. 0.8 molecule of toluene) (57%). The mother liquor was evaporated to ca.5 ml, and 30 ml of hexane was added. The orange solid precipitated from this solution at room temperature was collected and dried under vacuum. This procedure gave 3.3 g of anti- zirconocene dichloride contaminated with some polymeric material. Synthesis of inventive metallocene IM4 n-Propylmalonic acid A solution of 99.7 g (1.78 mol) of potassium hydroxide in 500 cm3of water was added to a solution of 101.1 g (0.5 mol) of diethyl n-propylmalonate in 100 ml of methanol. The resulting mixture was refluxed for 5 h, then ethanol and methanol were distilled off. Then, 500 cm3of water was added, and the obtained mixture was acidified by 12 M HCl to pH 1.0. Propylmalonic acid was extracted with 4x400 ml of ether. The combined extract was evaporated to dryness, and the residue was dried in vacuum. This procedure gave 76.4 g (ca.100%) of n-propylmalonic acid which was used without further purification. 2-n-Propylacrylic acid Diethylamine (42.4 g, 0.58 mol) was added dropwise at 5 °C to a solution of ca.0.5 mol of n-propylmalonic acid in 650 ml of ethyl acetate. To the obtained suspension, 21.3 g (0.71 mol) of paraform was added. The resulting mixture was refluxed for 5 h, then cooled to 5oC, and 350 ml of ether and 1000 cm3of 2 M HCl were added. After mixing, the organic layer was separated, the aqueous layer was additionally extracted with 2x500 ml of ether. The combined organic extract was dried over Na2SO4and then evaporated to dryness. The residue was purified by vacuum distillation to give 2-n- propylacrylic acid, bp 67-70°C / 4 mm Hg. Yield 46.1 g (80%) of a colorless liquid.1H NMR (CDCl3): δ 12.54 (br.s, 1H), 6.30 (m, 1H), 5.65 (m, 1H), 2.29 (t, J = 7.3 Hz, 2H), 1.52 (sext, J = 7.4 Hz, 2H), 0.94 (t, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 173.24, 140.02, 127.04, 33.44, 21.48, 13.58. 6-tert-Butyl-5-methoxy-2-n-propylindan-1-one 46.1 g (0.4 mol) of 2-n-propylacrylic acid was added to the Eaton's reagent obtained from 55 g of P4O10 and 280 ml of MeSO3H at 50oC. To this mixture 52.5 g (0.32 mol) of 1-tert- butyl-2-methoxybenzene was added dropwise by vigorous stirring for ca.1 h at 50-53oC (water bath temperature). The resulting mixture was stirred for 1 h at this temperature, then cooled to room temperature and poured on a mixture of 0.5 liter of cold water and 1 kg of ice. The crude product was extracted with 3x300 ml of dichloromethane. The combined organic extract was washed by aqueous K2CO3, dried over K2CO3, filtered through a short pad of silica gel 60 (40-63 µm), and then evaporated to dryness. The residue was purified by vacuum distillation to give 62.6 g (75 %) of 6-tert-butyl-5- methoxy-2-n-propylindan-1-one as a yellowish oil (bp 155-170oC / 4 mm Hg).1H NMR (CDCl3): δ 7.67 (s, 1H), 6.87 (s, 1H), 3.93 (s, 3H), 3.23 (dd, J = 17.1 Hz, J = 7.6 Hz, 1H), 2.71 (dd, J = 17.1 Hz, J = 3.5 Hz, 1H), 2.66-2.60 (m, 1H), 1.94-1.88 (m, 1H), 1.51-1.39 (m, 3H), 1.37 (s, 9H), 0.95 (t, J = 7.4 Hz, 3H).13C NMR (CDCl3): δ 207.76, 164.51, 154.70, 138.64, 129.18, 121.89, 107.70, 55.15, 47.41, 34.99, 33.83, 32.47, 29.53, 20.63, 14.05. 4-Bromo-6-tert-butyl-2-n-propyl-5-methoxyindan-1-one To a mixture of 31.3 g (0.120 mol) of 6-tert-butyl-2-n-propyl-5-methoxyindan-1-one, 39.45 g of sodium acetate, 1.0 g ofnBu4NI, 100 ml of dichloromethane, and 200 ml of water 6.2 ml (19.2 g, 120 mmol) of bromine was added dropwise by vigorous stirring for 15 min at 5 °C. This mixture was stirred for 1 h at 5 °C, then a solution of 20 g of sodium acetate in 100 ml of water was added followed by addition of 3.1 ml (60 mmol) of bromine. The resulting mixture was additionally stirred for 1 h at this temperature and then washed by aqueous Na2SO3to remove an excess of bromine. The crude product was extracted by 3x100 ml of dichloromethane. The combined organic extract was dried over K2CO3, filtered through a pad of silica gel 60 (40-63 µm) and evaporated to dryness. Crystallization of the residue from ca.50 ml of n-pentane at -15 °C gave 33.2 g of the title product (81.6%).1H NMR (CDCl3): δ 7.69 (s, 1H), 4.03 (s, 3H), 3.22 (dd, J = 18.3 Hz, J = 8.4 Hz, 1H), 2.72-2.65 (m, 2H), 1.97-1.88 (m, 1H), 1.54-1.43 (m, 3H), 1.40 (s, 9H), 0.97 (t, J = 7.3 Hz, 3H).13C NMR (CDCl3): δ 207.70, 162.75, 154.24, 145.43, 133.15, 121.38, 116.66, 61.64, 47.52, 35.66, 34.04, 33.64, 30.62, 20.59, 14.03. 6-tert-Butyl-2-n-propyl-5-methoxy-4-(3,5-dimethylphenyl)-indan-1-one A mixture of 16.6 g (48.9 mmol) of 4-bromo-6-tert-butyl-2-n-propyl-5-methoxyindan-1- one, 9.45 g (63.0 mmol, 1.28 equiv.) of 3,5-Me2C6H3B(OH)2, 0.26 g (0.5 mmol, 1 mol.%) of Pd(PtBu3)2, 15.8 g of Na2CO3, 80 ml of 2-methyltetrahydrofurane, and 75 ml of water was refluxed for 6 h. Further on, 100 ml of water was added, the organic layer was separated, and the aqueous layer was extracted with 2x50 ml of dichloromethane. The combined organic extract was dried over K2CO3 and then evaporated to dryness. The product was purified by flash-chromatography on silica gel 60 (40-63 µm, eluent: dichloromethane-hexane = 2:1, vol.). The combined elute was evaporated to dryness, the residue was washed by 30 ml of n-pentane and dried under vacuum. This procedure gave 15.7 g (88.0%) of title product.1H NMR (CDCl3): δ 7.73 (s, 1H), 7.03 (s, 1H), 7.02 (s, 2H), 3.31 (s, 3H), 3.06 (dd, J = 17.3 Hz, J = 7.6 Hz, 1H), 2.58 (m, 1H), 2.49 (dd, J = 17.3 Hz, J = 3.8 Hz, 1H), 2.39 (s, 6H), 1.94-1.84 (m, 1H), 1.42 (s, 9H), 1.40-1.34 (m, 3H), 0.91 (t, J = 7.3 Hz, 3H).13C NMR (CDCl3): δ 208.45, 163.41, 153.09, 143.21, 138.06, 136.28, 132.67, 131.33, 129.07, 127.17, 121.14, 60.48, 47.51, 35.33, 33.67, 32.20, 30.50, 21.37, 20.62, 14.02. 5-tert-Butyl-2-n-propyl-6-methoxy-7-(3,5-dimethylphenyl)-1H-indene 2.44 g (64.6 mmol) of NaBH4was added to a solution of 15.7 g (43 mmol) of 6-tert-butyl- 2-n-propyl-5-methoxy-4-(3,5-dimethylphenyl)-indan-1-one in 180 ml of THF cooled to 5 °C. To this mixture, 70 ml of MeOH was added dropwise over ca.5 h at 5 °C, and the resulting mixture was stirred overnight at room temperature. Then, this mixture was evaporated to dryness, 200 ml of dichloromethane and 200 ml water were added to the residue, and the so obtained mixture was acidified with 2 M HCl to pH~6.5. The organic layer was separated, the aqueous layer was additionally extracted with 2x50 ml of dichloromethane. The combined organic extract was evaporated to dryness. 300 mg of TsOH was added to a solution of this residue in 300 ml of toluene. This mixture was refluxed with Dean-Stark head for 10 min and then cooled to room temperature using a water bath. The formed solution was washed with 10% Na2CO3, the organic layer was separated, the aqueous layer was extracted with 2x50 ml of dichloromethane. The combined organic extract was dried over K2CO3 and then evaporated to dryness. The product was purified by flash-chromatography on silica gel 60 (40-63 µm, eluent: dichloromethane-hexane = 1:1, vol.) and dried in vacuum to give 14.0 g (93.4%) of pure product as a mixture of two isomeric indenes.1H NMR (CDCl3): δ 7.34 (s), 7.23 (s), 7.10 (s), 7.09 (s), 6.98 (s), 6.45 (m), 6.34 (s), 3.30 (s), 3.25 (s), 3.12 (s), 2.38-2.34 (m), 1.55 (sextet, J = 7.4 Hz), 1.44 (s), 0.91 (t, J = 7.3 Hz).13C NMR (CDCl3): δ 156.08, 154.24, 151.14, 149.97, 144.16, 141.56, 140.85, 140.44, 138.30, 137.87, 137.72, 137.65, 137.53, 137.43, 131.87, 128.46, 128.28, 127.84, 127.20, 126.05, 125.40, 120.81, 117.13, 60.65, 60.44, 41.13, 41.04, 35.12, 35.04, 33.52, 33.29, 31.11, 31.00, 22.44, 22.29, 21.42, 14.01, 13.94. [6-tert-Butyl-4-(3,5-dimethylphenyl)-5-methoxy-2-propyl-1H-inden-1- yl]chlorodimethylsilane nBuLi in hexanes (2.5 M, 6.3 ml, 16.0 mmol) was added in one portion to a solution of 5- tert-butyl-7-(3,5-dimethylphenyl)-6-methoxy-2-propyl-1H-indene (5.5 g, 15.78 mmol) in a mixture of 120 ml of ether and 10 ml of THF cooled to –50 °C. This mixture was stirred overnight at room temperature, then the resulting yellow solution was cooled to –50 °C, and dichlorodimethylsilane (9.5 ml, 10.07 g, 78.0 mmol, 5.0 equiv.) was added in one portion. The resulting mixture was stirred overnight at room temperature, then filtered through a glass frit (G3), and the filter cake was washed with 2x50 ml of toluene. The combined filtrate was evaporated to dryness to give the title product which was used without further purification.1H NMR (CDCl3): δ 7.39 (s, 1H), 7.09 (br. s, 2H), 6.99 (s, 1H), 6.45 (s, 1H), 3.64 (s, 1H), 3.25 (s, 3H), 2.54-2.49 (m, 2H), 2.38 (s, 6H), 1.68-1.48 (m, 2H), 1.43 (s, 9H), 0.91 (t, J = 7.3 Hz, 3H), 0.42 (s, 3H), 0.15 (s, 3H).13C NMR (CDCl3): δ 155.79, 150.92, 143.54, 137.95, 137.56, 137.49, 136.54, 128.31, 127.89, 127.65, 125.43, 120.99, 60.46, 48.22, 35.16, 33.72, 31.16, 22.75, 21.44, 14.06, 1.19, -0.64. [4,7-Bis(3,5-dimethylphenyl)-2-methyl-1H-inden-1-yl][6-tert-butyl-4-(3,5-dimethylphenyl)- 5-methoxy-2-propyl-1H-inden-1-yl]dimethylsilane nBuLi in hexanes (2.5 M, 3.0 ml, 7.5 mmol) was added in one portion to a solution of 2.53 g (7.47 mmol) of 4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-indene in a mixture of 40 ml of ether and 20 ml of THF cooled to –50 °C. The resulting mixture was stirred overnight at room temperature, then thus obtained yellow suspension was cooled to –50 °C, and 75 mg of CuCN was added. The obtained mixture was stirred for 0.5 h at –20 °C, then a solution of 3.3 g (7.48 mmol) of [6-tert-butyl-4-(3,5-dimethylphenyl)-5-methoxy-2-propyl- 1H-inden-1-yl]chlorodimethylsilane in 50 ml of THF was added in one portion. The resulting mixture was stirred overnight at room temperature, then filtered through a pad of silica gel 60 (40-63 µm) which was additionally washed with 2x50 ml of ether. The combined organic elute was evaporated to dryness. The crude product was purified by flash chromatography on silica gel 60 (40-63 µm, 600 ml, eluent: hexanes: dichloromethane = 5:1, vol.). This procedure gave 3.3 g (60%, purity ca.98%) of the title product (as a ca.2:3 mixture of two stereoisomers) as a slightly yellowish glassy solid. Anti-dimethylsilanediyl[2-methyl-4,7-bis(3,5-dimethylphenyl)-inden-1-yl][2-propyl-4-(3,5- dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride nBuLi in hexanes (2.5 M, 3.54 ml, 8.75 mmol) was added in one portion to a solution of 3.3 g (4.4 mmol) of [4,7-bis(3,5-dimethylphenyl)-2-methyl-1H-inden-1-yl][6-tert-butyl-4- (3,5-dimethylphenyl)-2-propyl-5-methoxy-1H-inden-1-yl]dimethylsilane in 40 ml of di-n- butyl ether at room temperature. This mixture was stirred overnight at room temperature, then the resulting red solution was cooled to 0 °C in an ice-bath, and ZrCl4 (1.03 g, 4.45 mmol) was added. The reaction mixture was stirred for 24 h at room temperature to give a yellow suspension. This suspension was evaporated to dryness. The formed solid was extracted with 50 ml of hot toluene. On the evidence of NMR spectroscopy, the obtained extract included a ca.80:20 mixture of anti- and syn-zirconocene dichlorides. The mother liquor was evaporated to ca. 10 ml. The orange solid precipitated from this solution at room temperature was collected and dried under vacuum. This procedure gave 2.4 g of anti-zirconocene dichloride which was further recrystallized from a mixture of 10 ml of toluene and 20 ml of hexane to give 2.00 g of yellow powder of anti-zirconocene dichloride containing 0.4 mol of toluene per mol of the complex, so the adjusted net weight of the isolated complex was 1.92 g (48%). Anal. calc. for C53H60Cl2OSiZr*0.4(C7H8): C, 71.29; H, 6.78. Found: C, 71.43; H, 6.97.1H NMR (CDCl3): δ 7.46 (s, 1H), 7.39 (d, J = 7.3 Hz, 1H), 7.36 (s, 2H), 7.25 (very br. s, 2H), 7.22 (s, 1H), 7.15 (s, 2H), 7.01 (s, 1H), 6.98 (s, 1H), 6.96 (s, 1H), 6.93 (d, J = 7.3 Hz, 1H), 6.61 (s, 1H), 3.42 (s, 3H), 2.46-2.33 (m, 22H), 2.11-2.03 (m, 1H), 1.38 (s, 9H), 1.27-1.15 (m, 5H), 0.80 (t, J = 7.3 Hz, 3H), -0.03 (s, 3H).13C NMR (CDCl3): δ 160.05, 144.67, 143.25, 139.82, 139.40, 138.90, 138.48, 137.97, 137.82, 137.77, 136.71, 135.90, 134.18, 130.79, 130.48, 129.75, 129.39, 129.34, 128.79, 128.35, 127.46 (br. s), 127.16, 126.73, 126.06, 125.40, 123.95, 123.66, 121.29, 121.09, 82.60, 81.75, 62.63, 35.74, 34.11, 30.43, 27.19, 21.45, 21.36, 21.24, 19.83, 13.85, 3.58, 3.35. Catalyst synthesis, used chemicals All catalysts have been prepared using silica Sunspera AGC DM-L-303, calcined at 600 °C. MAO Axion CA1330 was used as received and stored at –20 °C for not longer than 6 months. Catalyst preparations The catalysts were prepared by following a two-step preparation method. First step is the preparation of SiO2 / MAO (activated carrier), followed by a second step where a toluene solution of the metallocene complex is impregnated on the dry support from the first step. Only in case the metallocene is not enough soluble in toluene (metallocene C), a second aliquot of MAO is added to the metallocene / toluene slurry in order to promote the full dissolution of the metallocene. Preparation of SiO2 / MAO activated carrier A steel reactor equipped with a mechanical stirrer and a filter net was flushed with nitrogen. 10 kg of SiO2 carrier was first added from a feeding drum into the reactor, followed by careful pressurizing and depressurizing with nitrogen. Then, toluene (43.5 kg) was added. The SiO2 / toluene slurry was stirred for 25 min at 22 °C. Then, 18 kg of 30 wt% MAO in toluene (Axion CA 1330) was added slowly (140 min) through a 12 mm line on the top of the reactor keeping the temperature around 22 °C. After MAO addition, the reactor temperature was quickly increased to 90 °C and the mixture was stirred at this temperature for 120 min. Then the hot toluene was filtered out and the solid cake was washed twice with hot toluene while stirring (43.5 kg, 90 °C, 30 min, 40 rpm). Each time the hot toluene was filtered out. Finally the solid cake was dried with slow stirring (5 rpm) under vacuum for 9 h at 80 °C. Synthesis of SiO2 / MAO / CM1 (Comparison catalyst 1, CC1) In a nitrogen filled glovebox, dry toluene (2.5 mL) was added to an aliquot of metallocene CM1 (32.3 mg). The mixture was stirred for 30 minutes at room temperature. Next, 2.000 g of the silica / MAO carrier was placed in a glass vial. The solution of metallocene in toluene was added dropwise by means of a syringe to the SiO2 / MAO carrier over the course of 5 minutes with gentle mixing. The resulting mixture was shaken well and allowed to stay for 1 hour. The resulting solid was dried under vacuum for 1 hour at 60°C to yield the catalyst as a red free flowing powder. Synthesis of SiO2 / MAO / CM2 (comparison catalyst 2, CC2) In a nitrogen filled glovebox, dry toluene (2.5 mL) was added to 28.1 mg of metallocene CM2. The mixture was stirred for 30 minutes at room temperature to give a clear yellow solution. Next, 2.000 g of SiO2 / MAO was placed in a septum bottle. The solution of metallocene in toluene was added dropwise by means of a syringe to the SiO2 / MAO carrier over the course of 5 minutes with gentle mixing. The resulting powder was allowed to rest for 1 hour, then it was transferred into a Schlenk flask and dried under vacuum for 1 hour at 60 °C to yield the catalyst as a salmon-red free-flowing powder. Synthesis of SiO2 / MAO / IM1 (Inventive catalyst 1, IC1) In a nitrogen filled glovebox, dry toluene (2.5 mL) was added to 26.3 mg of metallocene IM1. The mixture was stirred for 30 minutes at room temperature to give a clear yellow solution. Next, 2.000 g of SiO2 / MAO was placed in a septum bottle. The solution of metallocene in toluene was added dropwise by means of a syringe to the SiO2 / MAO carrier over the course of 5 minutes with gentle mixing. The resulting powder was allowed to rest for 1 hour, then it was transferred into a Schlenk flask and dried under vacuum for 1 hour at 60 °C to yield the catalyst as a salmon-red free-flowing powder. Synthesis of SiO2 / MAO / IM2 (Inventive catalyst 2, IC2) In a nitrogen filled glovebox, dry toluene (2.5 mL) was added to 27.0 mg of metallocene IM2 in a septum bottle. Next, 2.004 g of SiO2 / MAO was placed in a septum bottle. The solution of metallocene in toluene was added dropwise by means of a syringe to the SiO2 / MAO carrier over the course of 5 minutes with gentle mixing. The resulting powder was allowed to rest for 1 hour, then it was transferred into a Schlenk flask and dried under vacuum for 1 hour at 60 °C to yield the catalyst as salmon red free-flowing powder. Synthesis of SiO2 / MAO / IM3 (Inventive catalyst 3, IC3) In a nitrogen filled glovebox, dry toluene (2.5 mL) was added to 27.3 mg of metallocene IM3 in a septum bottle. Next, 2.000 g of SiO2 / MAO was placed in a septum bottle. The solution of metallocene in toluene was added dropwise by means of a syringe to the SiO2 / MAO carrier over the course of 5 minutes with gentle mixing. The resulting powder was allowed to rest for 1 hour, then it was transferred into a Schlenk flask and dried under vacuum for 1 hour at 60 °C to yield the catalyst as beige free-flowing powder. Synthesis of SiO2 / MAO / IM4 (Inventive catalyst 4, IC4) In a nitrogen filled glovebox, dry toluene (2.5 mL) was added to 27.0 mg of metallocene IM4 in a septum bottle. Next, 2.001 g of SiO2 / MAO was placed in a septum bottle. The solution of metallocene in toluene was added dropwise by means of a syringe to the SiO2 / MAO carrier over the course of 5 minutes with gentle mixing. The resulting powder was allowed to rest for 1 hour, then it was transferred into a Schlenk flask and dried under vacuum for 1 hour at 60 °C to yield the catalyst as a beige-reddish free-flowing powder. The metallocene content in each catalyst is calculated by mass balance. The values are listed in Table 1. Table 1: Catalysts tested and their metallocene content. Catalyst Al in SiO2 / MAO MC in catalyst wt% Al wt% CC1 15,2 1,59 CC2 12,7 1,38 IC1 12,3 1,30 IC2 12,6 1,33 IC3 12,6 1,35 IC4 12,3 1,33 Polymerization examples Propylene homopolymerization procedure (bulk, 20-L reactor) A stainless-steel reactor equipped with a ribbon stirrer, with a total volume of 20.9 dm³ containing 0.2 bar-g propylene, was filled with additional 3.95 kg propylene. Triethylaluminium (0.8 ml of 0.62 molar solution in n-heptane) was added using a stream of 250 g propylene, then 0.5 NL of H2 was added via mass flow controller in one minute. The reactor temperature was stabilized at 25 °C (HB-Therm) and the solution was stirred and 250 rpm for at least 20 min. Then the catalyst was injected as described in the following. The desired amount of solid catalyst was loaded into a 5 ml stainless steel vial. This feeder system was mounted on a port on the lid of the autoclave. Then the catalyst was flushed into the reactor with 350 g propylene. Stirring speed is kept at 250 rpm and pre- polymerization was run for 10 minutes at 25 °C or 30 °C. Then the polymerization temperature was increased to 75 °C. The second aliquot of H2 was added at 60 °C over 1 min. The reactor temperature was kept constant throughout the polymerization. The polymerization time was measured starting when the temperature is 2 °C below the set polymerization temperature. When the set polymerization time lapsed, the reaction was stopped by injecting 5 ml ethanol, cooling the reactor and simultaneously flashing the volatile components. After purging the reactor 3 times with N2 and one vacuum / N2 cycle, the reactor was opened, the polymer powder was taken out and dried overnight in a fume hood.100 g of the polymer was additivated with 0.5 wt% Irganox B225 (dissolved in acetone) and then dried overnight in a fume hood and additionally one hour in a vacuum drying oven at 60 °C. Analysis of the results 1. Metallocene synthesis Comparing the synthesis efficiency of the four metallocenes IM1-IM4 to the two metallocenes CM1 and CM2 (Table 2) one can see that the syntheses of IM1, IM2 and IM3 are much more efficient (higher isolated yield of the targeted anti isomer) than those of CM1 and CM2. Table 2: synthesis results isolated anti % anti / syn in crude relative solubility CM1 55 85:15 anti<syn CM2 34 85:15 anti<syn IM1 68 81:19 anti<<syn IM2 79 n.d. anti<syn IM3 76 80:20 anti<<syn IM4 48 80:20 anti<<syn 2. Propylene polymerization results Comparing the performance of the four catalysts IC1-IC4 based on the inventive metallocenes IM1-IM4 to the two catalysts CC1 and CC2 based on the comparative metallocenes CM1 and CM2 in liquid propylene polymerization, one can see that all the inventive catalysts produce polypropylene homopolymer with higher melting point than the comparison catalysts (Table 3).

[0002] E E E E E E E E T8 7 6 5 4 3 2 1 a Example bICICICICICC C Cle34 3 2 1 1 C C C C 2 1 1 Catalyst a:ta li5 7 5 4 mylqs u 7 9 77 89 59 72 0 , 1 7,1g catalyst amount tidp3 3ro0 0 30 30 25 25 25 25 °C temperature P p rey 10 1 m ple0 10 10 10 10 10 10ino n res. timeyle s 0,050,0 5 0,0 5 0,0 5 0,0 5t1,0 5 1,0 5 0,5Ne po p 0 L H2lym e 2,2 2 0 252,52,52,2 0 2 5 0,52,52,50,5N H Tr0 L 2ria zn a st60 60 60 60 60 60 60 60 °C Initial temperature oftobii ti oon n r N H2 feeding ufe1,1 1 1 1 1 1 1 Lklros5,5,5,0,5,5,5,5 / mH2 dosing rate inst m u intransitionepplt rse16 17 16 17 18 1 m p 8 18 18 o niTime transition fromlyprepoly to bulk 75 75 75 75 75 75 75 75 °C B Temperature u klms60 60 60 60 60 60 40 40tin etime p 86 6 1 6 2 99 6 5 5 5 5 3 33 7 09 90 84 14 g Yield 63 1 1 1 1 k 5 8,6 1 0 8 11 12 g2,4,0,2,3,2,5,5c / ga Overall productivity t 11 6 1 4 2 2 86 7 5 9 10 kg 1 1 0 9 9 4 2 / MC productivity (mass , 4 1 , 4 , 3 4 5 Mg,0 7,0 7 0,8,2,1C balance) g 56 1 4 / ,81 2 0 34 4 0 9210 3,2,4,785,5,0m MFR2 powder in15 15 15 15 1 1 1 1 4 5 6 1 52 30 4 5 °C T,7,0,2,6,5,9 9,0 7,5m 1 1 1 5 1 kg 4 1 5 5 6 7 47 12 / mM 6 4 0 1 2 7 8 3 o w l 3,3 , 3 , 2 , 3 , 2 , 2 , 32 1 1 7 2 2 8,6Mw / Mn Therefore, fully removing the indacenyl cyclopentane ring of CM1 provides for a more efficient metallocene synthesis while removing only one C of that ring (as done in CM2) worsens both synthesis efficiency and catalyst performance.

Claims

CLAIMS 1. A metallocene complex of formula (I)wherein Mt is Zr or Hf: X is a sigma ligand; R1are each independently, same or different from each other, C1-C20hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8ring; R2and R2’are each independently, same or different from each other, C1-C10- hydrocarbyl; n are each independently an integer from 1 to 5; R3and R4are each independently H, C1-C10 hydrocarbyl group, or a –OR31, -SR31or -NR312 group in which R31is a C1-C10 hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen.; R51’ is C1-C10-hydrocarbyl; and R6’ is C(R61)3, with R61being linear or branched C1-C6-alkyl.

2. A metallocene complex of formula (I) as claimed in claim 1 having formula (I-a)wherein Mt is Zr or Hf; each X is independently a sigma ligand; R1are each independently, same or different from each other, C1-C20hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8 ring; R2and R2’are each independently, same or different from each other, a C1-C10- hydrocarbyl; R3and R4are each independently H, C1-C10 hydrocarbyl group, or a –OR31, -SR31or -N R312 group in which R31is a C1-C10 hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen.; R51’ is C1-C10-hydrocarbyl; and R6’ is C(R61)3, with R61being linear or branched C1-C6-alkyl.

3. A metallocene complex of formula (I) as claimed in claim 1 or 2 having formula (I-b)wherein Mt is Zr or Hf; each X is independently a sigma ligand; R1are each independently, same or different from each other, C1-C20hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8ring; R2’is a C1-C10-hydrocarbyl; R3and R4are each independently H, C1-C10hydrocarbyl group, or a –OR31, -SR31or -N R312group in which R31is a C1-C10hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen.; R51’ is C1-C10-hydrocarbyl; and R6’ is C(R61)3, with R61being linear or branched C1-C6-alkyl.

4. A metallocene complex of formula (I) as claimed in any one of claims 1 to 3 having formula (I-c)(I-c) wherein Mt is Zr or Hf; each X is independently a sigma ligand; R1are each independently, same or different from each other, C1-C20 hydrocarbyl, optionally containing up to two heteroatoms of Group 14-16 of the Periodic Table, or form together with the Si atom they are attached to a C4-C8ring; R2’is a C1-C10-hydrocarbyl;R3and R4are each independently H, C1-C10hydrocarbyl group, or a –OR31, -SR31or -N R312group in which R31is a C1-C10hydrocarbyl, whereby at least on R3per phenyl group and at least one R4is not hydrogen.

5. A metallocene complex as claimed in any one of claims 1 to 4, wherein one or two R3per phenyl group are not H and on both phenyl groups the R3are the same, and two R4on the phenyl group are not H and these two R4are the same.

6. A polymerization catalyst, comprising, preferably consisting of (i) a metallocene complex of formula (I) as claimed in any one of claim 1 to 5; (ii) a cocatalyst comprising a group 13 element; and (iii) optionally a support.

7. The polymerization catalyst according to claim 6, wherein cocatalyst (ii) is an aluminoxane cocatalyst, preferably in the absence of any further cocatalysts.

8. The catalyst as claimed in claim 6 or 7, supported on silica.

9. A process for the polymerization of propylene, comprising polymerizing propylene in the presence of the catalyst claimed in any one of claim 6 to 8.

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