Preparation of a supported catalyst system

Abstract

The disclosure relates to a process for preparation of a supported catalyst system, wherein the supported catalyst system comprises: (i) a metallocene complex of formula (I); (ii) a cocatalyst system comprising an aluminoxane cocatalyst; and (iii) a porous inorganic support; wherein the process comprises: - a) reacting the porous inorganic support with the aluminoxane cocatalyst in a first hydrocarbon solvent to obtain an aluminoxane cocatalyst treated support; - b) contacting the aluminoxane cocatalyst treated support with a solution to obtain the supported catalyst system, wherein the solution comprises the metallocene complex of formula (I) and a second hydrocarbon solvent, and the solution does not include an aluminoxane cocatalyst; wherein the metallocene complex of formula (I) is (I).

Description

[0001] PREPARATION OF CATALYST SYSTEM FIELD OF THE DISCLOSURE The present disclosure relates to a process for the preparation of a supported catalyst system, particularly a silica supported catalyst system, for use in propylene polymerization, especially for the production of isotactic polypropylene. The invention also relates to the supported catalyst system and the use of the supported catalyst system. 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. Metallocene catalysts have been used in propylene polymerization in order to achieve some desired polymer properties. Suitable metallocene catalysts should have high activity and high productivity. WO2018 / 122134 describes, inter alia the complex rac-anti-dimethylsilanediyl[2-methyl-4- (3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s-indacen-1-yl][2-methyl-4-(3’,5’-dimethyl- phenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride, which is activated with MAO and is supported on silica. WO2019 / 179959 describes bisindenyl ligand complexes and catalysts comprising those complexes. It is directed to improving the manufacturing of specific C1-symmetric bisindenyl complexes by modifying one of the indenyl ligands in order to improve the selectivity of the complex synthesis towards the desired anti-isomer, increase the yield and simplify the purification of the complex. It also relates to the use of the new bisindenyl metallocene catalysts for the production of polypropylene homopolymers or propylene copolymers. Although a lot of work has been done in the field of metallocene catalysts for polypropylene, there remains some problems, which relate mainly to the productivity or activity of the catalysts. In addition, straightforward and cost-efficient catalyst preparation procedures are desired. It is of paramount importance to improve the production efficiency of the metallocene component itself, which is the component having the highest cost impact on the overall manufacturing cost of the catalyst.

[0002] Sensitivity: Internal Thus, it is still desirable to find metallocene-based catalyst systems, which, while providing high activity and productivity, especially in the case of copolymerization between propylene and alpha-olefins of 4 to 8 C atoms and / or ethylene to form propylene copolymers, have also a more favorable production economics and are stable for longer times. The desired catalysts should also have improved performance in the production of high molecular weight polypropylene polymers, especially homopolymers. BRIEF DESCRIPTION OF THE DISCLOSURE An object of the present disclosure is to provide an improved process for preparation of a supported catalyst system, which is characterized by what is stated in the independent claim. The preferred embodiments are discloses in the dependent claims. The supported catalyst system for olefin polymerization may alleviate the above disadvantages. The supported catalyst system is characterized by what is stated in the independent claim. An advantage of the preparation process is that the supported catalyst system can be produced by a simpler method and uses a lower total amount of the aluminoxane cocatalyst, thereby reducing production cost. The supported catalyst system of the disclosure obtained from the process surprisingly has improved shelf life. Use of the supported catalyst system of the disclosure unexpectedly leads to higher catalyst productivity and improved performance in the production of high molecular weight polymers derived from propylene, such as a propylene homopolymer or a propylene copolymer. The purity of the propylene polymers produced with the supported catalyst system of the disclosure is higher because the polymers contain a lower content of catalyst residues. BRIEF DESCRIPTION OF THE DRAWINGS In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which: Figures 1 to 3 show the kinetic profiles of the catalysts tested in the examples using two different H2 concentrations (the profiles for each concentration are labelled A. and B. in each figure). Figure 4 shows the 40 minute productivities of the catalysts tested in the examples at two MFR values. Figure 5 shows the productivity of a catalyst versus its age. Figure 6 shows the melting point of hPP produced by a catalyst against the catalyst’s age.

[0003] Sensitivity: Internal Figure 7 shows the bulk density of hPP produced by a catalyst against the catalyst’s age. DEFINITIONS Throughout the description, the following definitions are employed: The term “C1-C20-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- C20-aryl groups, especially C1-C10-alkyl groups, C6-C10-aryl groups, and C7-C12-arylalkyl groups, e.g. C1-C8-alkyl groups. Most especially preferred hydrocarbyl groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C5-C6-cycloalkyl, cyclohexylmethyl, phenyl, and benzyl. The term “C1-C10-hydrocarbyl” includes C1-C10-alkyl, C2-C10-alkenyl, C2-C10-alkynyl, C3- C10-cycloalkyl, C3-C10-cycloalkenyl, C6-C10-aryl, C7-C10-alkylaryl, and C7-C10-arylalkyl groups or, of course, mixtures of these groups, such as cycloalkyl substituted by alkyl. Unless otherwise stated, preferred C1-C10-hydrocarbyl groups are C1-C10-alkyl, C4-C10- cycloalkyl, C5-C10-cycloalkyl-alkyl groups, C7-C10-alkylaryl groups, C7-C10-arylalkyl groups, and C6-C10-aryl groups, especially C1-C6-alkyl groups, C6-aryl groups, and C7-C10-arylalkyl groups, e.g. C1-C6-alkyl groups. Most especially preferred hydrocarbyl groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C5-C6-cycloalkyl, cyclohexylmethyl, phenyl, and benzyl. The term “C1-C8-hydrocarbyl” includes C1-C8-alkyl, C2-C8-alkenyl, C2-C8-alkynyl, C3-C8- cycloalkyl, C3-C8-cycloalkenyl, C6-C8-aryl, C7-C8-alkylaryl, and C7-C8-arylalkyl groups or, of course, mixtures of these groups, such as cycloalkyl substituted by alkyl. Unless otherwise stated, preferred C1-C8-hydrocarbyl groups are C1-C8-alkyl, C4-C8-cycloalkyl, C5- C8-cycloalkyl-alkyl groups, C7-C8-alkylaryl groups, C7-C8-arylalkyl groups, and C6-C8-aryl groups, especially C1-C6-alkyl groups, C6-aryl groups, and C7-C8-arylalkyl groups, e.g. C1- C6-alkyl groups. Most especially preferred hydrocarbyl groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C5-C6-cycloalkyl, cyclohexylmethyl, phenyl, and benzyl. The term “C1-C6-hydrocarbyl” includes C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, C3-C6- cycloalkyl, C3-C6-cycloalkenyl, and C6-aryl (e.g. phenyl) groups or, of course, mixtures of these groups, such as cycloalkyl substituted by alkyl. Unless otherwise stated, preferred C1-C6-hydrocarbyl groups are C1-C6-alkyl, C4-C6-cycloalkyl, C5-C6-cycloalkyl-alkyl groups, and a C6-aryl group, especially C1-C6-alkyl groups, and C6-aryl group, e.g. C1-C6-alkyl

[0004] Sensitivity: Internal groups. Most especially preferred hydrocarbyl groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C5-C6-cycloalkyl, and phenyl. The term “halo” or “halogen” includes fluoro, chloro, bromo, and iodo groups, especially chloro or fluoro groups, particularly when relating to the definition of the metallocene complex. 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 valence of the metal ion and to fill its available coordination sites. The nature of these sigma-ligands can vary greatly. Catalyst activity is defined in this application to be the amount of polymer produced / g catalyst / h. Metallocene activity is defined here to be the amount of polymer produced / g metallocene / 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. The term “consisting essentially of” is used herein to refer to that further components may be present namely those not materially affecting the essential characteristics of the compound or composition e.g. minor amounts of impurities. DETAILED DESCRIPTION OF THE DISCLOSURE The present disclosure relates to an improved process for preparation of a supported catalyst system. Provided herein is a process for the preparation of a supported catalyst system. The supported catalyst system comprises: (i) a metallocene complex of formula (I); (ii) a cocatalyst system comprising an aluminoxane cocatalyst; and (iii) a porous inorganic support.

[0005] Sensitivity: Internal The metallocene complex of formula (I) is wherein: Mt is Zr or Hf; X is a monoanionic ligand; R1are the same or different, with each R1independently selected from H and a C1- C8-hydrocarbyl group, wherein the C1-C8 hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms; R2and R2’ are each independently CH2-R21, with R21being H or a linear or branched C1-C6 alkyl group, C3-C8 cycloalkyl group or C6-C10 aryl group; R3are the same or different and R4are the same or different, wherein each R3and each R4is independently selected from H, a linear or branched C1-C6-alkyl group, a C7- C20-arylalkyl, a C7-C20-alkylaryl group, C6-C20-aryl group, an OY and a NY2group, wherein each Y is independently a C1-C10-hydrocarbyl group, and / or two adjacent R3or two adjacent R4form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded; each R5, R6and R7is independently selected from hydrogen and a C1-C20- hydrocarbyl group, wherein the C1-C20-hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10- hydrocarbyl group, and / or the C1-C20-hydrocarbyl group of R6and the C1-C20-hydrocarbyl group of one of R5and R7form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded, with the provisos that (i) when R7is H, then both R5and R6are not H, and (ii) R5and R6can be hydrogen only when R7is not H; R5’ and R6’ is each independently a C1-C20-hydrocarbyl group, wherein the C1-C20- hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1-

[0006] Sensitivity: Internal C20-hydrocarbyl group of R5’ and the C1-C20-hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded. The process for the preparation of a supported catalyst system comprises: a) reacting the porous inorganic support with the aluminoxane cocatalyst in a first hydrocarbon solvent to obtain an aluminoxane cocatalyst treated support; and b) contacting the aluminoxane cocatalyst treated support with a solution to obtain the supported catalyst system, wherein the solution comprises the metallocene complex of formula (I) and a second hydrocarbon solvent, and the solution does not include an aluminoxane cocatalyst. When preparing a supported catalyst system, the solution contacted with the aluminoxane cocatalyst treated support (see b) above) includes an additional amount of the aluminoxane cocatalyst (e.g. MAO). This second impregnation of the support can be problematic. Typically, the solution that is used to perform the second impregnation is chemically unstable. The components in the solution (e.g. MAO, TMA and the metallocene complex) can react with each other, possibly leading to deactivation of the metallocene over time and poor batch to batch repeatability. When the solution comprising the metallocene complex also contains a borate cocatalyst, then the additional presence of the aluminoxane cocatalyst can lead to loss of borate and leaching. Furthermore, in the situation when there is incomplete soaking into the carrier or pore overfilling, the solution leaves an active catalyst layer on the surface of the particles, possibly leading to poor morphology. It has unexpectedly been found that the second aliquot of the aluminoxane cocatalyst is unnecessary for the specific metallocene complexes of the present disclosure. One of the reasons for including the aluminoxane cocatalyst in the solution with the metallocene complex is to assist with solubilizing the metallocene. However, the metallocene complexes of the present disclosure have relatively high solubility in the second hydrocarbon solvent (e.g. toluene), which is part of the solution for contacting the aluminoxane cocatalyst treated support. Once the support has been initially treated with an aluminoxane cocatalyst, there are several advantages associated with avoiding further treatments that include an aluminoxane cocatalyst, such as when the treated supported is contacted with a metallocene complex. When the aluminoxane cocatalyst is used for a second time in a step of treating the support, then about 10% of the total amount of aluminoxane catalyst

[0007] Sensitivity: Internal used in the entire process is used in this second treatment step. By excluding the aluminoxane catalyst from the second treatment step, there is a cost saving by eliminating the 10% of the aluminoxane catalyst that would otherwise normally be used in catalyst production. Thus, the supported catalyst system has a lower content of aluminium. The process also avoids the potential negative effect associated with the presence of trimethylaluminium (TMA) in catalyst polymerisation. However, the biggest benefit is the simpler catalyst preparation procedure, since the metallocene-containing solution without the aluminoxane cocatalyst eliminates one step involving the sampling and handling of the aluminoxane cocatalyst. The present disclosure further provides a supported catalyst system obtained or obtainable from the process for the preparation of the supported catalyst system. By preparing the catalyst system according to the present invention, a supported catalyst system having high activity and productivity can be obtained. The supported catalyst system is stable at room temperature indefinitely, which is not the case when an aluminoxane cocatalyst is present. The present disclosure also provides a process for preparation of a polypropylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers. The process comprises polymerising propylene and optionally one or more C2 to 8 alpha olefin comonomers in the presence of the supported catalyst system of the present disclosure. The purity of the polypropylene homopolymer or copolymer produced with the supported catalyst system of the disclosure is high because the polymers contain a lower content of catalyst residues. Also provided by the present disclosure is the use of the supported catalyst system for producing a propylene polymer, such as a propylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers. Furthermore, the present disclosure provides a polypropylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers. The polypropylene homopolymer or the polypropylene copolymer is obtained from the process for preparation of a polypropylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers of the present disclosure. Supported catalyst system The supported catalyst system comprises, preferably consists essentially of, more preferably consists of: (i) a metallocene complex of formula (I) as discussed herein;

[0008] Sensitivity: Internal (ii) a cocatalyst system comprising an aluminoxane cocatalyst; and (iii) a porous inorganic support. Metallocene complex (i) The metallocenes that are suitable for the catalysts of the invention are bridged, asymmetric bisindenyl metallocenes in their racemic anti configuration. 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 In the present invention, the metallocene complex of formula (I), and any sub formulae, are intended to cover both syn- and anti-configurations. It is preferred that the metallocene complex of formula (I), and any sub formulae, is 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 complex is in the racemic anti-isomeric form. The metallocene complexes of the invention are preferably C1-symmetric.

[0009] Sensitivity: Internal The present invention accordingly utilizes a metallocene complex of formula (I) wherein: Mt is Zr or Hf; X is a monoanionic ligand; R1are the same or different, with each R1is independently selected from H and a C1-C8-hydrocarbyl group, wherein the C1-C8hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms; R2and R2’ are each independently CH2-R21, with R21being H or a linear or branched C1-C6 alkyl group, C3-C8 cycloalkyl group or C6-C10 aryl group; R3are the same or different and R4are the same or different, wherein each R3and each R4is independently selected from H, a linear or branched C1-C6-alkyl group, a C7- C20-arylalkyl, a C7-C20-alkylaryl group, C6-C20-aryl group, an OY and a NY2 group, wherein each Y is independently a C1-C10-hydrocarbyl group, and / or two adjacent R3or two adjacent R4form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded; each R5, R6and R7is independently selected from hydrogen and a C1-C20- hydrocarbyl group, wherein the C1-C20-hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10- hydrocarbyl group, and / or the C1-C20-hydrocarbyl group of R6and the C1-C20-hydrocarbyl group of one of R5and R7form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded, with the provisos that (i) when R7is H, then both R5and R6are not H, and (ii) R5and R6can be hydrogen only when R7is not H; R5’ and R6’ is each independently a C1-C20-hydrocarbyl group, wherein the C1-C20- hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1-

[0010] Sensitivity: Internal C20-hydrocarbyl group of R5’ and the C1-C20-hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded. For the above-defined metallocene complexes 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 monoanionic ligand. Preferably, each X is independently, the same or different from each other, H, halogen or a C1-C10-hydrocarbyl group, wherein the C1-C10-hydrocarbyl group optionally contains up to two Si, O, S, N or P atoms, an OY’ group or an NY’2group in which each Y’ is independently, same or different, preferably the same, a C1-C10- hydrocarbyl group. In other words, each monoanionic ligand is selected from H, halogen and the C1-C10-hydrocarbyl group. The C1-C10hydrocarbyl group optionally contains up to two Si, O, S, N or P atoms, an OY’ group or an NY’2group is preferably C1-C6-alkoxy, or R´ group, where R´ is C1-C6-alkyl, phenyl, or benzyl. It is preferred that the C1-C10hydrocarbyl group does not contain a Si, O, S, N or P atom, an OY’ group or an NY’2group. More preferably, each X is independently, the same or different from each other, H, Cl, F, C1-C6-alkoxy, or an R´ group, where R´ is C1-C6-alkyl, phenyl, or benzyl. Even more preferably, each X is independently, the same or different from each other, Cl, benzyl, or methyl. Most preferably, each X is independently, the same or different from each other, Cl or methyl. In general, it is preferred that both X groups are the same. More preferably, both X groups are Cl or methyl. In some embodiments, both X groups are Cl. In some embodiments, both X groups are methyl. Advantageously, when both X groups are not halogen, then the metallocene complex is, and the resulting supported catalyst system may potentially be, halogen free. It is preferred that the supported catalyst system does not include a halogen, more preferably the supported catalyst system does not include fluorine and / or chlorine. A halogen is not intentionally added to the supported catalyst system. Halogens may be incorporated in the supported catalyst system when the X group on the metallocene complex is halogen. Fluorine may also be incorporated in the supported catalyst system when a boron cocatalyst is used (e.g. trityl tetrakispentafluoro-phenylborate). Sensitivity: Internal Preferably R1are each independently, the same or different from each other, H or C1-C8- hydrocarbyl group, wherein the C1-C8-hydrocarbyl group does not contain a heteroatom (e.g. up to two silicon, oxygen, sulphur or nitrogen atoms). More preferably, each R1is independently, the same or different from each other, H, C1-C8-alkyl, C4-C8-cycloalkyl, phenyl, or C7-C8-arylalkyl. Even more preferably, each R1is independently, the same or different from each other, H, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl or phenyl. Most preferably, one R1is selected from hydrogen, methyl, ethyl, n-propyl and i-propyl, and the other R1is selected from methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl and phenyl. In general, it is preferred that both R1groups are the same. More preferably, both R1groups are methyl. R2and R2’ are each independently CH2-R21, with each R21independently being H or a linear or branched C1-C6alkyl group, C3-C8cycloalkyl group or C6-C10aryl group. Preferably R2and R2’ are each independently, the same or different from each other, CH2- R21, with each R21being independently H or linear or branched C1-C6-alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl or tert-butyl. More preferably, each R21is independently, the same or different from each other, H, linear C1-C3-alkyl, or branched C3-alkyl. Even more preferably, each R21is independently, the same or different from each other, H or methyl. It is further preferred that R2is methyl or ethyl. Most preferably, R2is methyl or ethyl and R2’ is methyl or ethyl. In some embodiments, R2and R2’ are independently methyl or ethyl. Generally, it is preferred that R2and R2’ are the same. Thus, R2and R2’ are each CH2- R21, wherein R21is H or a linear or branched C1-C6-alkyl group (e.g. R21is the same for R2and R2’), preferably H or linear C1-C3-alkyl, more preferably H or methyl. Thus, R2and R2’ may be both methyl or both ethyl, more preferably both methyl. In some embodiments, one of R2and R2’ is methyl, and the other is of the formula CH2- R21, with R21being C1-C6-alkyl. In such embodiments, the R21of the R2and R2’ that is not methyl is preferably C1-C4-alkyl; more preferably linear C1-C4-alkyl, even more preferably methyl or ethyl. In some embodiments, R2is methyl, and R2’ is of the formula CH2-R21, with R21being C1-C6-alkyl. In such embodiments, the R21of R2’ is preferably C1-C4-alkyl; more preferably linear C1-C4-alkyl, even more preferably methyl or ethyl. Sensitivity: Internal In a preferred embodiment, R2is methyl or ethyl and R2’ is methyl or ethyl. In more preferred embodiments, R2and R2’ are independently methyl or ethyl. Most preferably, R2and R2’ are both methyl or both ethyl. R3are the same or different and R4are the same or different, wherein each R3and each R4is independently selected from H, a linear or branched C1-C6-alkyl group, a C7-C20- arylalkyl, a C7-C20-alkylaryl group, C6-C20-aryl group, an OY and a NY2group, wherein each Y is independently a C1-C10-hydrocarbyl group, and / or two adjacent R3or two adjacent R4form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded. Two adjacent R3or two adjacent R4may form a ring together with the two C atoms of the phenyl ring to which they are bonded. It is preferred that the two adjacent R3or the two adjacent R4form a 5 to 6 atom ring. When two adjacent R3or two adjacent R4form a 4 to 7 atom ring, it is preferred that the ring is a carbocylic ring. The ring is preferably a C4-C8-ring, more preferably a C5-C6-ring, even more preferably a C6-ring. Preferably each R3and R4is independently, the same or different from each other, H, C1-C6-alkyl, or C6-C20-aryl, more preferably H or C1-C4-alkyl. Even more preferably, each R3and each R4is independently, same or different from each other, H, methyl, ethyl, isopropyl or tert-butyl, especially H, methyl, or tert-butyl. It is preferred that at least one R3is not H and at least one R4is not H. More preferably, either (a) at least two R3are not H and at least one R4is not H or (b) at least one R3is not H and at least two R4are not H. Furthermore, it is possible that each of the phenyl rings (e.g. with R3and R4) have the same substitution pattern or that the phenyl rings have different substitution patterns. It is preferred that at least two R3and / or at least two R4groups are H. If three R3and / or three R4groups are H, then the remaining R3and / or R4groups are preferably in the meta positions. If four R3and / or four R4groups are H, then the remaining R3and / or R4group, respectively, is preferably in the para position. The meta positions or the para position refer to the position on the phenyl ring to which the R3or the R4group is attached. Advantageously at least two R3are H, more preferably, at least three R3are H. The remaining R3may be the same (e.g. the remaining R3are methyl), and may, for example, be 3´,5´-di-methyl. Alternatively, only one R3is not H, for example, 4´-tert-butyl. Sensitivity: Internal Advantageously, at least two R4are H, more preferably, at least three R4are H. The remaining R4may be the same (e.g. the remaining R4are methyl or tert-butyl), and may, for example, be 3´,5´-di-methyl or 3´,5´-di-tert-butyl. Each R5, R6and R7is independently selected from hydrogen and a C1-C20-hydrocarbyl group. The C1-C20-hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and / or the C1-C20-hydrocarbyl group of R6and the C1-C20-hydrocarbyl group of one of R5and R7form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded, with the provisos that (i) when R7is H, then both R5and R6are not H, and (ii) R5and R6can be hydrogen only when R7is not H. The 4 to 7 atom ring formed by the C1-C20-hydrocarbyl group of R6and the C1-C20- hydrocarbyl group of one of R5and R7together with the two C atoms of the phenyl ring may optionally contain up to two silicon, oxygen, sulphur or nitrogen atoms. It is preferred that the 4 to 7 atom ring is a 4 to 7 atom carbocyclic ring. The C1-C20-hydrocarbyl group of R6and the C1-C20-hydrocarbyl group of one of R5and R7may be attached to one another to form the ring. In other words, the C1-C20-hydrocarbyl group of R6may be covalently bonded to the C1-C20-hydrocarbyl group of one of R5and R7. When R6and one of R5and R7together with the two C atoms of the phenyl ring to which they are bonded form a 4 to 7 atom ring, it is preferred that R6is a C1-C3-hydrocarbyl group and the one of R5and R7that forms a 4 to 7 atom ring is a C1-C2-hydrocarbyl group. It is preferred that 4 to 7 atom ring formed by the hydrocarbyl group of R6and the hydrocarbyl group of one of R5and R7together with the two C atoms of the phenyl ring is a 5 or 6 atom ring, preferably a 5 atom ring. When (i) R7is H, then both R5and R6are not H, and (ii) R5and R6can be hydrogen only when R7is not H. In other words, there is at least one substituent on the phenyl ring at the R5and R7positions that is not hydrogen. When R7is not H, then each of R5and R6can independently be hydrogen and a C1-C20- hydrocarbyl group, as defined herein. It is preferred that each of R5, R6and R7is independently selected from hydrogen, a linear or branched C1-6 alkyl group, a C7-20 arylalkyl, a C7-20 alkylaryl group and a C6-20 aryl group, and / or R6is a C1-C3-hydrocarbyl group and one of R5and R7is a C1-C2-hydrocarbyl group, wherein the C1-C3-hydrocarbyl group of R6and the C1-C2-hydrocarbyl group of the one of Sensitivity: Internal R5and R7forms a 4 to 7 atom ring, preferably a 5 to 6 atom ring, together with the two C atoms of the phenyl ring to which they are bonded, with the provisos that (i) when R7is H, then both R5and R6are not H, and (ii) R5and R6can be hydrogen only when R7is not H. In one example, each of R5and R6is independently selected from hydrogen, a linear or branched C1-6alkyl group, a C7-20arylalkyl, a C7-20alkylaryl group and a C6-20aryl group, and / or R6is a C1-C3-hydrocarbyl group and R5is a C1-C2-hydrocarbyl group, wherein the C1-C3-hydrocarbyl group of R6and the C1-C2-hydrocarbyl group of R5forms a 4 to 7 atom ring, preferably a 5 to 6 atom ring, especially a 5 atom ring, together with the two C atoms of the phenyl ring to which they are bonded, and R7is a linear or branched C1-6alkyl group, a C7-20arylalkyl, a C7-20alkylaryl group or a C6-20aryl group. In this example, it is preferred that each of R5and R6is independently selected from hydrogen and a linear or branched C1-6alkyl group, and / or R6is a C1-C3-hydrocarbyl group and R5is a C1-C2-hydrocarbyl group, wherein the C1-C3-hydrocarbyl group of R6and the C1-C2-hydrocarbyl group of R5forms a 5 to 6 atom ring, preferably a 5 atom ring, together with the two C atoms of the phenyl ring to which they are bonded, and R7is a C7-20 alkylaryl group or a C6-20 aryl group. More preferably, R6is a C1-C3-hydrocarbyl group and R5is a C1-C2-hydrocarbyl group, wherein the C1-C3-hydrocarbyl group of R6and the C1-C2- hydrocarbyl group of R5form a 5 to 6 atom ring together with the two C atoms of the phenyl ring to which they are bonded, and R7is a C7-20 alkylaryl group. R5’ and R6’ is each independently a C1-C20-hydrocarbyl group, wherein the C1-C20- hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1- C20-hydrocarbyl group of R5’ and the C1-C20-hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded. The 4 to 7 atom ring formed by the C1-C20-hydrocarbyl group of R5’ and the C1-C20- hydrocarbyl group of R6’ together with the two C atoms of the phenyl ring may optionally contain up to two silicon, oxygen, sulphur or nitrogen atoms. The C1-C20-hydrocarbyl group of R5’ and the C1-C20-hydrocarbyl group of R6’ may be attached to one another to form the ring. In other words, the C1-C20-hydrocarbyl group of R5’ is covalently bonded to the C1-C20-hydrocarbyl group of R6’. When R5’ and R6’ together with the two C atoms of the phenyl ring to which they are bonded form a 4 to 7 atom ring, it is preferred that R5’ is a C1-C3-hydrocarbyl group and R6’ is a C1- C2-hydrocarbyl group, which form the 4 to 7 atom ring. The 4 to 7 atom ring may optionally Sensitivity: Internal contain up to two silicon, oxygen, sulphur or nitrogen atoms. It is preferred that the 4 to 7 atom ring is a 4 to 7 atom carbocyclic ring. It is preferred that 4 to 7 atom ring formed by the hydrocarbyl group of R5’ and the hydrocarbyl group of R6’ together with the two C atoms of the phenyl ring is a 5 or 6 atom ring, more preferably a 5 atom ring. Preferably, R5’ and R6’ is each independently a C1-C10-hydrocarbyl group, wherein the C1- C10-hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10-hydrocarbyl group. More preferably R5’ and R6’ is each independently a linear or branched C1-6alkyl group, a linear or branched C1-6alkoxy group, a C7-10arylalkyl group, a C7-10arylalkoxy group, a C7-10alkylaryl group, a C7-10alkylaryloxy group, a C6-10aryl group, or a C6-10aryloxy group. In one example, R5’ and R6’ is each independently a linear or branched C1-6alkyl group, a linear or branched C1-6alkoxy group, a phenyl-C1-4-alkyl group, a phenyl-C1-4-alkoxy group, a C1-4alkylphenyl group, a C1-4alkylphenoxy group, a phenyl group, or a phenoxy group. Preferably, R5’ and R6’ is each independently a linear or branched C1-6 alkyl group, a linear or branched C1-6 alkoxy group or a phenyl group. More preferably, R5’ is a linear or branched C1-6 alkoxy group and R6’ is a linear or branched C1-6 alkyl group. Viewed from another aspect the invention utilizes a metallocene complex of formula (II): wherein: Mt is Zr or Hf; X is a monoanionic ligand; R1are the same or different, with each R1independently selected from H and a C1- C8-hydrocarbyl group, wherein the C1-C8hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms; Sensitivity: Internal R2and R2’ are each independently CH2-R21, with R21being H or a linear or branched C1-C6alkyl group, C3-C8cycloalkyl group or C6-C10aryl group; R3are the same or different and R4are the same or different, wherein each R3and each R4is independently selected from H, a linear or branched C1-C6-alkyl group, a C7- C20-arylalkyl, a C7-C20-alkylaryl group, C6-C20-aryl group, an OY and a NY2group, wherein each Y is independently a C1-C10-hydrocarbyl group, and / or two adjacent R3or two adjacent R4form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded; each R5, R6and R7is independently selected from hydrogen and a C1-C20- hydrocarbyl group, wherein the C1-C20-hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10- hydrocarbyl group, and / or the C1-C20-hydrocarbyl group of R6and the C1-C20-hydrocarbyl group of one of R5and R7form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded, with the provisos that (i) when R7is H, then both R5and R6are not H, and (ii) R5and R6can be hydrogen only when R7is not H; R5” and R6’ is each independently a C1-C10-hydrocarbyl group, wherein the C1-C10- hydrocarbyl group optionally contains up to one silicon, oxygen, sulphur or nitrogen atom, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1- C10-hydrocarbyl group of R5”, the oxygen atom to which R5” is bonded and the C1-C10- hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded. Each of the definitions for Mt, X, R1, R2, R2’, R3, R4, R5, R6, R6’ and R7described herein for the metallocene complex of formula (I) also applies to the metallocene complex of formula (II), unless the context indicates otherwise. The definition of R5’ applies to the R5”O group shown in formula (II) insofar as the definition of R5’ permits an oxygen atom to be present. For the above-defined metallocene complexes of formula (II), the following represent preferable embodiments, which can be selected alone or in combination. The 4 to 7 atom ring formed by the C1-C10-hydrocarbyl group of R5”, the oxygen atom to which R5” is bonded and the C1-C10-hydrocarbyl group of R6’ together with the two C atoms of the phenyl ring may optionally contain a further silicon, oxygen, sulphur or nitrogen atom. The 4 to 7 atom ring at least contains an oxygen at the R5’ position in formula (I). The C1-C10-hydrocarbyl group of R5” and the C1-C10-hydrocarbyl group of R6’ may be attached to one another to form the ring. In other words, the C1-C10-hydrocarbyl group of R5” is covalently bonded to the C1-C10-hydrocarbyl group of R6’. Sensitivity: Internal When R5”, the oxygen atom to which R5” is bonded and R6’ together with the two C atoms of the phenyl ring to which they are bonded form a 4 to 7 atom ring, it is preferred that R5” is a C1-C2-hydrocarbyl group and R6’ is a C1-C2-hydrocarbyl group, which form the 4 to 7 atom ring. The 4 to 7 atom ring may optionally contain a further silicon, oxygen, sulphur or nitrogen atom. It is preferred that the 4 to 7 atom ring contains a total of 1 or 2 oxygen atoms (e.g. R6’ is R6”O, where R6” is a covalent bond to R5” or is a C1-hydrocarbyl group). It is preferred that 4 to 7 atom ring formed by the hydrocarbyl group of R5”, the oxygen atom to which R5” is bonded and the hydrocarbyl group of R6’ together with the two C atoms of the phenyl ring is a 5 or 6 atom ring. Preferably, R5” is a linear or branched C1-6alkyl group, a C7-10arylalkyl group, a C7-10alkylaryl group, or a C6-10aryl group; and R6’ is a linear or branched C1-6alkyl group, a linear or branched C1-6alkoxy group, a C7-10arylalkyl group, a C7-10arylalkoxy group, a C7-10alkylaryl group, a C7-10alkylaryloxy group, a C6-10aryl group, or a C6-10aryloxy group. R6’ may be as defined for formula (I) above. In one example, R5” is a linear or branched C1-6 alkyl group, a phenyl-C1-4-alkyl group, a C1-4 alkylphenyl group, or a phenyl group. Preferably, R5”is a linear or branched C1-6 alkyl group, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, pentyl or hexyl, preferably methyl or ethyl, more preferably methyl. Viewed from another aspect the invention utilizes a metallocene complex of formula (III): wherein: each Y is independently H or a C1-C10-hydrocarbyl group; and n is 2, 3 or 4. Each of the definitions for Mt, X, R3, R4, R5”, R6’ and R7described herein for the metallocene complex of formulas (I) and (II) also apply to the metallocene complex of Sensitivity: Internal formula (III), unless the context indicates otherwise. The definition of R5’ applies to the R5”O group shown in formula (III) insofar as the definition of R5’ permits an oxygen atom to be present. For the above-defined metallocene complexes of formula (III), the following represent preferable embodiments, which can be selected alone or in combination. Preferably, n is 3 or 4. In one example, n is 3. In another example, n is 4. Preferably, each Y is independently H or a C1-C4-hydrocarbyl group. It is further preferred that the C1-C4-hydrocarbyl group may be methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl or t-butyl. More preferably, each Y is H. Preferred metallocene complexes are selected from: rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4-(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4-(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl zirconium; Sensitivity: Internal rac-anti-dimethylsilanediyl[2-methyl-4-(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl zirconium; rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl zirconium; rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl hafnium; rac-anti-dimethylsilanediyl[2-methyl-4-(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl hafnium; and rac-anti-dimethylsilanediyl[2-methyl-4-(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacen- 1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl hafnium. Viewed from another aspect the invention utilizes a metallocene complex of formula (IV): wherein: each Y is independently H or a C1-C10-hydrocarbyl group; and n is 2, 3 or 4. Each of the definitions for Mt, X, R3, R4, R5”, R6’, Y and n described herein for the metallocene complex of formulas (I) to (III) also apply to the metallocene complex of formula (III), unless the context indicates otherwise. The definition of R5’ applies to the R5”O group shown in formula (IV) insofar as the definition of R5’ permits an oxygen atom to be present. Sensitivity: Internal For the above-defined metallocene complexes of formula (IV), the following represent preferable embodiments, which can be selected alone or in combination. It is preferred that each R3and each R4is independently selected from H and a linear or branched C1-C6-alkyl group. Preferably, either (a) the R3at the para position (e.g.4’ position) is a linear or branched C1-C6-alkyl group and the R3groups at the meta positions (e.g.3’ and 5’ positions) are H or (b) the R3groups at the meta positions (e.g.3’ and 5’ positions) are a linear or branched C1-C6-alkyl group and the R3at the para position (e.g.4’ position) is H. It is preferred that either (a) the R4at the para position (e.g. 4’ position) is a linear or branched C1-C6-alkyl group and the R4groups at the meta positions (e.g. 3’ and 5’ positions) are H or (b) the R4groups at the meta positions (e.g.3’ and 5’ positions) are a linear or branched C1-C6-alkyl group and the R4at the para position (e.g.4’ position) is H. Viewed from another aspect the invention utilizes a metallocene complex of formula (V): (V). Each of the definitions for Mt, X, R3and R4described herein for the metallocene complex of formulas (I) to (IV) also apply to the metallocene complex of formula (V), unless the context indicates otherwise. Preferred metallocene complexes are selected from: rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; Sensitivity: Internal rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; Sensitivity: Internal rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; Sensitivity: Internal rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl hafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethyl hafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl hafnium; Sensitivity: Internal rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl hafnium; and rac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1-yl]dimethyl hafnium. The metallocene complexes of the present disclosure can be prepared as described in WO2018 / 122134 or WO2019 / 179959. Cocatalyst system (ii) To form active catalytic species it is normally necessary to employ a cocatalyst as is well known in the art. Cocatalysts comprising one or more organoaluminium compounds are able to activate metallocene catalysts are suitable for use in this invention. According to the present invention, a cocatalyst system comprising an aluminoxane cocatalyst is advantageously used in combination with the above defined metallocene complex. It is preferred that the cocatalyst system comprises an aluminoxane cocatalyst as the only cocatalyst of the supported catalyst system. The cocatalyst system may therefore consist essentially of, or consist of, the aluminoxane cocatalyst. Thus, other than the aluminoxane cocatalyst, no further cocatalysts comprising one or more compounds of Group 13 metals, like organoboron and / or borate compounds (e.g. a boron cocatalyst), is used to activate the metallocene complex in the supported catalyst system. An advantage of using only the aluminoxane cocatalyst is that there is no fluorine in the supported catalyst system. Thus, any propylene polymer that is produced using the supported catalyst system will be free from fluorine and fluorinated derivatives. Suitable amounts of cocatalyst are 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 cocatalyst to the metal ion (Mt) (preferably zirconium) of the metallocene complex, 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. Sensitivity: Internal 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). It is preferred that the aluminoxane cocatalyst 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. Porous inorganic support (iii) The supported catalyst system of the invention includes a porous inorganic support. The porous inorganic support is a particulate, porous inorganic support material. It is preferred that the porous inorganic support is silica, alumina or a mixed oxide, such as silica-alumina. More preferably, the porous inorganic support is silica. The inorganic support is a porous material so that 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, EP18282666 and US6,043,180. The average particle size of the porous inorganic support, such as a 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 porous inorganic support, such as a 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 Sensitivity: Internal the porous inorganic support, such as a silica support, can be in the range from 20 to 40 nm. The surface area of the porous inorganic support, such as a 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 supported catalyst system can contain from 5 to 500 pmol, such as 10 to 100 pmol, of transition metal per gram of support, such as silica, and 3 to 15 mmol of Al per gram of support, such as silica. Process for preparation of the supported catalyst system The process for preparation of the supported catalyst system comprises, preferably consists essentially of, more preferably consists of: a) reacting the porous inorganic support with aluminoxane cocatalyst in a first hydrocarbon solvent to obtain an aluminoxane cocatalyst treated support; and b) contacting the aluminoxane cocatalyst treated support with a composition to obtain a supported catalyst system, wherein the composition comprises a metallocene complex of formula (I) in a second hydrocarbon solvent and does not include an aluminoxane cocatalyst. In step a), the porous inorganic support (iii) is reacted, preferably treated, with the aluminoxane cocatalyst (ii). Preferably, the porous inorganic support (iii) is silica. Preferably, the reaction between the porous inorganic support and the aluminoxane cocatalyst is performed with a stoichiometry of Al in the aluminoxane cocatalyst to the porous inorganic support in the range of 3 to 12 mmol Al / g support. The porous inorganic support (iii) is preferably calcined before step a) for removing moisture from the surface thereof. The calcination temperature is normally in the range of from 200 to 800 °C, preferably in the range of from 400 to 650 °C. The porous inorganic support, preferably silica support, is then suspended in a suitable hydrocarbon solvent, referred to herein as the first hydrocarbon solvent. Suspending may Sensitivity: Internal be done under inert gas atmosphere, e.g. under nitrogen, at a temperature of from 15 °C to 25 °C. It is preferred that the first hydrocarbon solvent is toluene. The porous inorganic support and first hydrocarbon solvent (e.g. silica and toluene) suspension is stirred, preferably for 5 to 60 minutes, more preferably from 10 to 30 minutes. Then aluminoxane cocatalyst, preferably MAO (e.g. as a 30 wt% solution in toluene), is added to the suspension of the porous inorganic support and the first hydrocarbon solvent, preferably with a stoichiometry of 3 to 12 mmol Al / g of support (e.g. silica). According to the present invention, all of the aluminoxane cocatalyst (ii) is added in step a). Thus, 100.0 wt% of the total amount of aluminoxane cocatalyst (ii) is added in step a). Step a) of reacting the porous inorganic support with aluminoxane cocatalyst in a first hydrocarbon solvent may include heating the porous inorganic support with aluminoxane cocatalyst in the first hydrocarbon solvent to a temperature of at least 50°C, preferably at least 60°C. It is preferred that, after addition of the aluminoxane cocatalyst, the mixture (e.g. of the porous inorganic support, the first hydrocarbon solvent and the aluminoxane cocatalyst) is optionally heated, e.g. up to a temperature in the range of from 60 °C to 120 °C, preferably from 70 °C to 120 °C, more preferably from 80 °C to 120 °C, and still more preferably from 80 °C to 100 °C. The porous inorganic support (iii) is preferably silica and first hydrocarbon solvent is preferably toluene. The mixture may be stirred up to 12 hours, preferably from 60 minutes up to 5 hours, more preferably from 90 minutes up to 3 hours, at a temperature of at least 50°C, preferably at least 60°C, or in the range defined above. Afterwards stirring is stopped, the resulting slurry is allowed to settle and the mother liquor is removed, e.g. by filtering off or decantation. Subsequently the remaining aluminoxane cocatalyst treated support is preferably washed one or more times, e.g. once or twice, more preferably twice with a first hydrocarbon washing solvent, preferably toluene, and optionally one more time with a second hydrocarbon washing solvent, preferably heptane, at an elevated temperature in a range of from 70 °C to 115 °C, preferably from 80 °C to 110 °C and more preferably from 90 °C to 100 °C, to obtain the aluminoxane cocatalyst treated support. Preferably, the aluminoxane cocatalyst treated support, preferably the aluminoxane cocatalyst treated silica support, is subsequently dried at a suitable temperature, such as at 40 to 100 °C, preferably at 50 to 90 °C, more preferably at 60 to 85 °C, under vacuum. Sensitivity: Internal Step b) In step b), the aluminoxane cocatalyst treated support is contacted with a solution comprising the metallocene complex as defined herein and a second hydrocarbon solvent. The solution does not include an aluminoxane cocatalyst. In one example, the solution may consist essentially of, or consists of, the metallocene complex and the second hydrocarbon solvent. Preferably, the second hydrocarbon solvent is the same as the first hydrocarbon solvent. The second hydrocarbon solvent is selected from toluene, xylene, hexane, isohexane and heptane. Preferably the second hydrocarbon solvent is toluene. In the solution in b), it is preferred that at least 1 wt%, preferably at least 5 wt%, of the metallocene complex is soluble in the second hydrocarbon solvent at a temperature of from 20 °C to 80 °C. Step b) may include mixing the metallocene complex with the second hydrocarbon solvent. The mixture may be stirred until the metallocene complex is fully dissolved. In other words, step b) includes mixing the metallocene complex with the second hydrocarbon solvent to produce a solution of the metallocene complex (e.g. in the second hydrocarbon solvent). Stirring may be carried out at a temperature of from 10 °C to 50 °C, preferably at 15 °C to 25 °C. The concentration of the metallocene complex in the second hydrocarbon solvent is preferably from 0.5 to 20 wt%. Step b) further includes adding the solution of the metallocene complex to the aluminoxane cocatalyst treated support (e.g. obtained in step a)). This is to obtain the supported catalyst system. In an optional final step, the supported catalyst system can be washed with an appropriate hydrocarbon solvent, such as toluene or heptane, and then dried, preferably at a suitable temperatures, e.g. at 0 to 100 °C, preferably at 20 to 90 °C, more preferably at 30 to 60 °C, preferably under vacuum to yield a free flowing powder. If desired, the 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%, such as up to 25 wt-%. The amounts of porous inorganic support (iii), aluminoxane cocatalyst (ii), preferably MAO, and metallocene complex (i) depend on the desired above defined ratios (e.g. Al / Mt, AI / SiO2, Mt / SiO2). Sensitivity: Internal Polymerization The present disclosure provides process for preparation of a polypropylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers. For the polypropylene homopolymer, the process comprises polymerising propylene in the presence of a supported catalyst system of the invention. For polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers, the process comprises polymerising propylene and one or more C2 to 8 alpha olefin comonomers in the presence of the supported catalyst system. It is preferred that the process is for the preparation of a polypropylene homopolymer. The catalyst system as prepared according to the present invention is especially suited to the formation of propylene homopolymers or copolymers, especially with ethylene, with high activity levels, high molecular weight, and hence low MFR, and with ideal melting temperature polymer, preferably with increased melting temperature of propylene homopolymers. 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 a prepolymerization step. This prepolymerization step is a conventional step used routinely in polymer synthesis and is to be distinguished from the catalyst off-line prepolymerization step used for catalysts prepared with the emulsion / solidification technology, as discussed in the state of the art. 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 catalyst system prepared according to the invention especially possess excellent catalyst activity and / or productivity. The term “catalyst activity” as used herein refers to the amount of polymer produced / g catalyst / h. Catalyst metallocene activity is defined here to be the amount of polymer produced / g metallocene / or the amount of polymer produced / mmol metallocene. The term “catalyst productivity” is also sometimes used to indicate the catalyst activity although herein it designates the amount of polymer produced per unit weight of catalyst. Sensitivity: Internal The catalyst system prepared according to the invention is also able to provide polymers of high weight average molecular weight (Mw). For bulk and gas phase copolymerization reactions, the reaction temperature used will generally be in the range 60 to 115 °C (e.g.70 to 90 °C), the reactor pressure will generally be in the range 10 to 25 bar for gas phase reactions with bulk polymerization operating at higher pressures. The residence time will generally be 0.25 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. It is a particular feature of the invention that polymerization takes place at temperatures of at least 60 °C. The supported catalyst system prepared according to the invention enable the formation of polymers with high molecular weight. These features can be achieved at industrially relevant polymerization temperatures, e.g.60 °C or more. It is a preferred feature of the invention that the supported catalyst system of the invention is used to polymerize propylene at a temperature of at least 60 °C, preferably at least 70 °C, such as at least 80 °C. In one example, the propylene polymer obtained using the supported catalyst system of the invention has a polydispersity index (Mw / Mn) of 2.0 or greater, such as 2.2 to 4.5. It is preferred that the propylene polymer, such as a polypropylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers, does not contain a halogen and / or a fluorine derivative. The halogen is chlorine, bromine or fluorine, preferably chlorine or fluorine. The presence of a halogen and / or a fluorine derivative in the propylene polymer will depend on the supported catalyst system that is used to prepare the polymer, namely whether a halogen atom is bonded to the transition metal of the metallocene and / or whether a boron cocatalyst containing fluorine is used. Polypropylene homopolymers made by the catalyst system prepared according to the invention can be made with Mw (weight average molecular weight) values in the range of 50 to 2000 kg / mol, preferably in the range of 100 to 1500 kg / mol, more preferably in the range of 150 to 1000 kg / mol, even more preferably 200 to 800 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 Sensitivity: Internal has a melting point of more than 149.0°C, preferably more than 149.5°C, especially more than 150.0°C. The polymers made by the catalysts of the invention 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. Propylene copolymers Propylene copolymers with one or more C2 to 8 alpha olefin comonomers prepared according to the invention can be made with high productivity. 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. EXAMPLES The invention will now be illustrated by reference to the following non-limiting Examples. Measurement methods Al 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 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 in solutions of 5 % HNO3 distilled water. Each calibration solution contained 4 mg / L of Y and Rh standards. However, not every calibration point was used for each wavelength: Al Sensitivity: Internal 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. 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 standard which had 4 mg / L Y and Rh. A quality control sample was run to confirm the reslope. The content of aluminum 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 Al 394.401 nm and Y 224.306 nm {450} for Al 167.079 nm. Synthesis of rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7- tetrahydro-s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden- 1-yl]zirconium dichloride was carried out as described in WO2019 / 179959 in the section headed “Synthesis of MC-2”. MC-1M is rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7- tetrahydro-s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden- 1-yl]dimethylzirconium. MeMgBr in ether (2.0 M, 6.0 ml, 12.0 mmol) was added to a suspension of MC-1, namely rac-anti-dimethylsilanediyl[2-methyl-4,8-di(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride (3.9 g, 4.26 mmol) in a mixture of 20 ml of toluene and 30 ml of ether. The resulting mixture was stirred at room temperature overnight, refluxed for 30 min, and then evaporated to ca.15 ml. The obtained suspension was filtered through glass frit (G4), and the filtrate was evaporated almost to dryness. The residue was dissolved in 20 ml of n-hexane and filtered (G4). Yellow powder precipitated from this solution overnight at –30°C was collected and dried in vacuum. This procedure gave 3.3 g (ca.88%) of MC- 3M, which contains one equivalent of n-hexane molecule. Sensitivity: Internal Metallocene complex solubility The solubilities of MC-1 and MC-1M metallocene complexes have been measured in toluene (at room temperature). Table 1 presents the results of the solubility tests. Table 1: solubility test results Solubility Metallocene complex toluene (wt%) MC-1 24 MC-1M 9 To prepare a supported catalyst system, at least 1 wt% of the metallocene complex must be soluble in the second hydrocarbon solvent (e.g. toluene) at the temperature at which it is used in step b) of the process. Catalyst Preparations All catalysts were prepared using MAO in toluene from Lanxess. Synthesis of catalyst SiO2 / MAO / MC-1, comparative catalyst 1 (CE1) 5 kg of SiO2 carrier (Sunspera AGC DM-L-303-C1) was first added to a reactor, followed by addition of toluene (21.8 kg). SiO2 / toluene mixture was stirred during 15 min at 23 °C. 30 wt% MAO in toluene was added slowly (60-70 min) to the reactor, keeping the reactor temperature around 23 °C (Al-1=9.4 mol / kg SiO2). After MAO addition, the reactor temperature was quicky lifted up to 90 °C and the mixture was stirred at this temperature for a duration of 120 min. Hot toluene was then siphoned out and the carrier cake was washed two times with hot toluene (21.8 kg, 95 °C), followed by 6 h vacuum drying at 80 °C. A metallocene complex solution was prepared in another reactor starting with addition of 5.7 kg toluene (part of the toluene was left for metallocene cylinder flushing) to the reactor at 25 °C, followed by addition of 0.71 kg MAO (30 wt% solution in toluene, 0.7 mol / kg SiO2). Mixture was stirred for 20 min and then 0.1509 kg of the metallocene complex MC-1 (30 mmol / kg SiO2) and 1.7 kg of “flush toluene” were added to the reactor. The complex solution was stirred 60 min at 25 °C . The complex solution described above was added into the reactor with SiO2 / MAO carrier during 50 min following 30 min stirring at 25 °C. Then stirring was stopped and catalyst was let to stabilize 30 min at 25 °C. Catalyst was dried under vacuum 9 h at 60 °C. Sensitivity: Internal Synthesis of SiO2 / MAO (SM1) 10 kg of SiO2carrier (PQ silica, PD-19057, ES757) was first added to a reactor, followed by addition of toluene (43.5 kg). The SiO2 / toluene mixture was stirred for 25 min at 22 °C. 18kg of 30 wt% MAO in toluene was added slowly (130-140 min) to the reactor, keeping the reactor temperature around 22 °C (Al-1=9.3 mol / kg SiO2). After MAO addition, the reactor temperature was quicky lifted up to 90 °C and the mixture was stirred at this temperature for a duration of 120 min. Hot toluene was then siphoned out and the carrier cake was washed two times with hot toluene (43.5 kg, 90 °C), followed by 9h vacuum drying at 80 °C. SiO2 / MAO (SM1) (Al=14.5 wt%, toluene=0.27 wt%) was used for the synthesis of catalysts IE1 and IE2. Synthesis of SiO2 / MAO (SM2) Silica used was AGC Sunspera DM-L-303-C1. This is a silica that has been calcined, for example at 600 °C. For example, the commercially available silica AGC Sunspera DM-L- 303, that has been calcined at 600°C, such as for 24 hours, can be used. A steel reactor equipped with a mechanical stirrer and a filter net was flushed with nitrogen.10 kg of SiO2carrier 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. Composition of the SiO2 / MAO samples was analysed by MW-AD-ICP-OES (Microwave assisted acid digestion, inductively coupled plasma optical emission spectrometry) method. HS-GC-MS (headspace gas chromatograph with mass spectrometer) was used to check solvent (toluene) content of the prepared SiO2 / MAO and catalyst samples. Synthesis of catalyst SiO2 / MAO / MC-1, inventive catalyst 1 (IE1) In a nitrogen filled glovebox, dry toluene (2.1 mL) was added to an aliquot of metallocene complex MC-1 (purity 97.1 %, 43.1 mg, 45.7 µmol). The mixture was stirred for 30 minutes at room temperature. Next, 2.0 g of MAO treated silica SM1 (Al=14.5 wt%) was placed in Sensitivity: Internal a glass vial. The solution of the metallocene complex 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 in vacuum for 1 hour at 60 °C to yield the catalyst as red free flowing powder. Synthesis of catalyst SiO2 / MAO / MC-1M, inventive catalyst 2 (IE2) In a nitrogen filled glovebox, dry toluene (2.1 mL) was added to an aliquot of the metallocene complex MC-1M (1 mol equivalent toluene to Zr, 40.1 mg, 41.3 µmol). The mixture was stirred for 30 minutes at room temperature. Next, 2.0 g of MAO treated silica SM1 (Al=14.5 wt%) was placed in a glass vial. The solution of the metallocene complex 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 in vacuum for 1 hour at 60 °C to yield the catalyst as red free flowing powder. Synthesis of SiO2 / MAO-MC-1, inventive catalyst 3 (IE3) In a nitrogen filled glovebox, dry toluene (2.5 mL) was added to 32.3 mg of metallocene rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride (metallocene complex MC-1) placed in a septum bottle. The mixture was stirred for 30 minutes at room temperature. Next, 2.0 g of SiO2 / MAO SM2 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 and 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. The compositions of the catalysts are shown in Table 2. Table 2: catalysts tested and their metallocene (MC) content AlaAl / Zr MC in catalyst MAO in catalyst Catalyst (wt%) (molar) (mass, wt%) (wt%) CE1 13.9 329 1.98 29.9 IE1 13.5 289 2.1 29.0 IE2 14.1 353 1.8 30.3 IE3 13.2 314 1.56 28.4 a = measured by ICP method. Sensitivity: Internal MFR MFR were measured on the Schmelz-Index-Prüfgerät MI-4 (Göttfert Werkstoff- Prüfmaschinen GmbH) at 230°C with a loading of 2.16 kg (MFR2) according to DIN ISO 1133 and is indicated in g / 10 min. Range from 0,1g-11000g Graduated glass cylinder: Volume = max.250ml Plastic spoon: Volume=125ml Plastic funnel: D=105mm Execution: A glass cylinder is filled up to a volume of 250 ml by pouring in the unstabilized polymer powder, using a plastic spoon and a plastic funnel. Calculation: Mass of polymer (g) / measured volume (ml) 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, according to BTM00121. GPC The MWD and the corresponded molecular weight averages ^^^^^^, ^^^and^ ^^^^of the polymer sample were determined by using Gel Permeation Chromatography (GPC) at 160°C as described in BTM 00192. 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) instead of to the last point of the calibration curve as described in the BTM00192 method. Monomers and gases Ethylene was purified in columns filled with molecular sieves 3A EPG 1 / 16, PolyMax 301 T-4427B and Selexsorb COS. Hydrogen (quality 6.0) was supplied by Air Liquide and Sensitivity: Internal used as received. Propylene, quality 2.3, was purified via columns filled with PolyMax301 T-4427B (60°C; Cu / CuO), MS13X-APG 1 / 16 and Selexsorb COS. Propylene homopolymerisation procedure A stainless-steel reactor equipped with a ribbon stirrer, with a total volume of 20.9 dm³ containing 0.2 bar-g propylene, is filled with additional 4.45 kg propylene. Triethylaluminium (0.8 ml of 0.62 molar solution in n-heptane) is added using a stream of 250 g propylene, then 0.5 NL of H2is added via mass flow controller in one minute. The reactor temperature is stabilized at 25 °C (HB-Therm) and the solution is stirred and 250 rpm for at least 20 min. Then the catalyst is injected as described below. The desired amount of solid catalyst was loaded into a 5 ml stainless steel vial and a second 5 ml vial containing 4 ml n-heptane was added on top inside a glovebox. Then the vial on top was pressurized with 5 bars of nitrogen. This dual feeder system is mounted on a port on the lid of the autoclave. The valve between the two vials is opened and the solid catalyst is contacted with n-heptane under N2pressure for 2 s, and then flushed into the reactor with 250 g propylene. Stirring speed is kept at 250 rpm and pre-polymerisation is run for 10 minutes at 25 °C. Then the polymerisation temperature is increased to 85 °C. The second aliquot of H2is added at 62 °C over 2 min. The reactor temperature is kept constant throughout the polymerization. The polymerization time is measured starting when the temperature is 2 °C below the set polymerization temperature. When the polymerization time of 40 min has lapsed, the reaction is 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 is opened, the polymer powder is taken out and dried overnight in a fume hood.100 g of the polymer is 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. Bulk propylene polymerization experiments have been performed at 85 °C, using two different H2 concentrations, with the above three catalysts. The results are shown in Figures 1 to 3. The following can be seen from the results. 1. the inventive catalyst 2 (IE2) with the metallocene complex MC-1M has a higher activity than inventive catalyst 1 (IE1) with the metallocene complex MC-1 at both H2 levels. Both IE1 and IE2 showed higher catalyst productivity compared to comparative catalyst 1 (CE1). 2. The two catalysts (IE1 and IE2) without the 2ndaddition of MAO showed faster initiation compared to the comparative catalyst (CE1). This suggests that the 2ndSensitivity: Internal MAO has no positive influence on activation of MC-1 and MC-1M, and therefore can be eliminated from the method for synthesizing the catalysts. 3. The catalytic behavior of the two catalysts (IE1 and IE2) without the 2ndaddition of MAO was nearly identical. In addition, the polypropylene melting points were virtually identical, confirming the equality of MC-1 and MC-1M in catalysis. The catalysts without the 2ndaddition of MAO showed both a faster activation and a better productivity compared to the comparative catalyst. The productivities of the catalysts after 40 minutes are shown in Figure 4. Two-step (bulk+gas phase) propylene homopolymerisation experiments were also performed. 2-step propylene homopolymerisation in bulk and gas phase Step 1 was performed as described above. Step 2 was performed as follows. After the bulk step was completed, the stirrer speed was reduced to 50 rpm and the pressure was reduced to 20 bar-g by venting propylene. The stirrer speed was set to 180 rpm and the reactor temperature was set to 80 °C. Then 1 NL of hydrogen was fed via mass flow controller to the reactor and the reactor pressure was increased to 21 bar-g by feeding propylene. The temperature was held constant by thermostat and the pressure was kept constant by feeding propylene via mass flow controller, until the set time for this step had expired. Then the reactor was cooled down (to about 30 °C) and the volatile components flashed out. After purging the reactor 3 times with N2 and one vacuum / N2 cycle, the product was taken out and dried overnight in a fume hood.100 g of the polymer was additivated with 0.5 wt% Irganox B225 (solution in acetone) and dried overnight in a hood followed by 2 hours in a vacuum drying oven at 60°C. Shelf life The shelf-life of the catalysts has been evaluated by storing the catalysts, as both dry powder and oil slurry, under inert atmosphere in the absence of light and at room temperature, and by testing them in the 2-step propylene homopolymerisation experiments after increasing storage times. Catalysts prepared using two additions of MAO, such as the catalyst CE1 above, have shelf-life issues, and often there is a strong loss of activity after only a few months of storage time at room temperature. For example, a dry catalyst batch of CE1 has been Sensitivity: Internal tested after more than 1 year from its preparation. In this period, its productivity has decreased by ca.50%. Tests were performed on the catalyst IE3. This catalyst was tested over a period of 25 months as both dry and an oil slurry. It was found to be remarkably stable, as demonstrated by its productivity, gas phase split, melting point and bulk density are shown in Figures 5 to 7, respectively. Sensitivity: Internal

Claims

CLAIMS 1. A process for preparation of a supported catalyst system, wherein the supported catalyst system comprises: (i) a metallocene complex of formula (I); (ii) a cocatalyst system comprising an aluminoxane cocatalyst; and (iii) a porous inorganic support; wherein the process comprises: a) reacting the porous inorganic support with the aluminoxane cocatalyst in a first hydrocarbon solvent to obtain an aluminoxane cocatalyst treated support; b) contacting the aluminoxane cocatalyst treated support with a solution to obtain the supported catalyst system, wherein the solution comprises the metallocene complex of formula (I) and a second hydrocarbon solvent, and the solution does not include an aluminoxane cocatalyst; wherein the metallocene complex of formula (I) iswherein: Mt is Zr or Hf; X is a monoanionic ligand; R1are the same or different, with each R1independently selected from H and a C1-C8-hydrocarbyl group, wherein the C1-C8hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms; R2and R2’ are each independently CH2-R21, with R21being H or a linear or branched C1-C6alkyl group, C3-C8cycloalkyl group or C6-C10aryl group; R3are the same or different and R4are the same or different, wherein each R3and each R4is independently selected from H, a linear or branched C1-C6-alkyl group, a C7-C20-arylalkyl, a C7-C20-alkylaryl group, C6-C20-aryl group, an OY and a NY2group, Sensitivity: Internalwherein each Y is independently a C1-C10-hydrocarbyl group, and / or two adjacent R3 or two adjacent R4form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded; each R5, R6and R7is independently selected from hydrogen and a C1-C20- hydrocarbyl group, wherein the C1-C20-hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10- hydrocarbyl group, and / or the C1-C20-hydrocarbyl group of R6and the C1-C20- hydrocarbyl group of one of R5and R7form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded, with the provisos that (i) when R7is H, then both R5and R6are not H, and (ii) R5and R6can be hydrogen only when R7is not H; R5’ and R6’ is each independently a C1-C20-hydrocarbyl group, wherein the C1- C20-hydrocarbyl group optionally contains up to two silicon, oxygen, sulphur or nitrogen atoms, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1-C20-hydrocarbyl group of R5’ and the C1-C20-hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded.

2. A process according to claim 1, wherein the porous inorganic support is a silica support.

3. A process according to claim 1 or claim 2, wherein the aluminoxane cocatalyst in a) is methylaluminoxane (MAO) cocatalyst.

4. A process according to any one of claims 1 to 3, wherein the first hydrocarbon solvent is toluene.

5. A process according to any one of claims 1 to 4, wherein the second hydrocarbon solvent is selected from toluene, xylene, pentane, hexane, isohexane and heptane, preferably the second hydrocarbon solvent is toluene.

6. A process according to any one of claims 1 to 5, wherein the step of reacting the porous inorganic support with aluminoxane cocatalyst in a first hydrocarbon solvent includes heating the porous inorganic support with aluminoxane cocatalyst in the first hydrocarbon solvent to a temperature of at least 50°C, preferably at least 60°C. Sensitivity: Internal7. A process according to any one of claims 1 to 6, wherein the metallocene complex is of formula (II):wherein: R5” and R6’ is each independently a C1-C10-hydrocarbyl group, wherein the C1- C10-hydrocarbyl group optionally contains up to one silicon, oxygen, sulphur or nitrogen atom, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1-C10-hydrocarbyl group of R5”, the oxygen atom to which R5” is bonded and the C1-C10-hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded.

8. A process according to any one of claims 1 to 7, wherein the metallocene complex is of formula (III):wherein: R5” and R6’ is each independently a C1-C10-hydrocarbyl group, wherein the C1- C10-hydrocarbyl group optionally contains up to one silicon, oxygen, sulphur or Sensitivity: Internalnitrogen atom, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1-C10-hydrocarbyl group of R5”, the oxygen atom to which R5” is bonded and the C1-C10-hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded; each Y is independently H or a C1-C10-hydrocarbyl group; and n is 2, 3 or 4.

9. A process according to any one of claims 1 to 8, wherein the metallocene complex is of formula (IV):wherein: R5” and R6’ is each independently a C1-C10-hydrocarbyl group, wherein the C1- C10-hydrocarbyl group optionally contains up to one silicon, oxygen, sulphur or nitrogen atom, or an OY group, wherein Y is a C1-C10-hydrocarbyl group, and optionally wherein the C1-C10-hydrocarbyl group of R5”, the oxygen atom to which R5” is bonded and the C1-C10-hydrocarbyl group of R6’ form a 4 to 7 atom ring together with the two C atoms of the phenyl ring to which they are bonded; each Y is independently H or a C1-C10-hydrocarbyl group; and n is 2, 3 or 4.

10. A process according to any one of claims 1 to 9, wherein the metallocene complex is of formula (V): Sensitivity: Internal(V).

11. A process according to any one of claims 1 to 10, wherein the metallocene complex is selected from: rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; Sensitivity: Internalrac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]zirconium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; Sensitivity: Internalrac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylzirconium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]hafnium dichloride; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; Sensitivity: Internalrac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethylhafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(4’-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethyl hafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(4’-tert-butylphenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-methyl-4-(3’,5’-di-tert-butylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethyl hafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethyl hafnium; rac-anti-dimethylsilanediyl[2-methyl-4,8-bis(3’,5’-dimethylphenyl)-1,5,6,7-tetrahydro- s-indacen-1-yl][2-propyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethyl hafnium; and rac-anti-dimethylsilanediyl[2-ethyl-4,8-bis(3’,5’-dimethyl phenyl)-1,5,6,7-tetrahydro-s- indacen-1-yl][2-ethyl-4-(3’,5’-dimethylphenyl)-5-methoxy-6-tert-butylinden-1- yl]dimethyl hafnium.

12. A process according to any one of claims 1 to 11, wherein each X is independently C1-C10 hydrocarbyl group, preferably each X is independently C1-C6-alkyl, more preferably both X are methyl.

13. A supported catalyst system obtained or obtainable from a process according to any one of claims 1 to 12, preferably the supported catalyst system according to claim 13, which does not include a halogen, preferably fluorine and / or chlorine. Sensitivity: Internal14. A process for preparation of a polypropylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers, wherein the process comprises polymerising propylene and optionally one or more C2 to 8 alpha olefin comonomers in the presence of a supported catalyst system according to claim 13.

15. A polypropylene homopolymer or a polypropylene copolymer of one or more C2 to 8 alpha olefin comonomers obtained from a process according to claim 14, which does not contain a halogen. Sensitivity: Internal

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