A ferroferric oxide supported bidentate chelate platinum catalyst, a preparation method and application thereof

Abstract

The application belongs to the field of catalysis technology, and particularly relates to a ferroferric oxide supported bidentate chelate platinum catalyst, a preparation method and application thereof. The application first forms a silica layer on the surface of ferroferric oxide nanoparticles by hydrolysis of tetraethoxysilane; then the bidentate organic ligand compound, a platinum compound and an organic solvent are mixed for reaction to obtain a bidentate chelate platinum compound with a silane functional group; finally, a condensation reaction occurs between the triethoxysilane functional group and the silica on the surface of the ferroferric oxide, and the platinum compound is loaded on the surface of the ferroferric oxide. The ferroferric oxide supported bidentate chelate platinum catalyst prepared by the application has high product yield and high catalyst cycle stability in the addition reaction of unsaturated hydrocarbons and hydrogen-containing silane, and has a long service life.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalysts, and particularly relates to a ferroferric oxide supported bidentate chelate platinum catalyst and a preparation method and application thereof. BACKGROUND

[0002] The hydrosilylation reaction refers to an addition reaction of an organic compound containing a silicon-hydrogen bond and an unsaturated compound under certain conditions, is an important way for synthesizing organosilicon coupling agents and functional organosilicon compounds and polymers, and occupies an important position in the field of organosilicon chemistry. In the hydrosilylation reaction, the selection and preparation of a catalyst are particularly important, and directly affect the efficiency of the reaction and the selectivity of the product.

[0003] At present, platinum compounds are the main catalysts for catalyzing the hydrosilylation reaction. They have the highest activity and are most widely used. Speier catalyst: a chloroplatinic acid and isopropanol solution and Karstedt platinum catalyst: a complex of 1,3-divinyl-1,1,3,3,-tetramethyldisiloxane and platinum, since their discovery, have been widely used in the hydrosilylation reaction. They have high activity, but the selectivity of the addition product is low, and there are many by-products.

[0004] At present, researchers have designed and prepared a new generation of heterogeneous catalysts, and inorganic support and organic polymer supported metal catalysts have gradually become an important research field of organosilicon chemistry. The inorganic support loaded catalyst has good stability in the reaction medium, high mechanical strength, and greatly avoids the swelling of the support and the by-products derived therefrom, and therefore can be applied in a continuous reaction system. However, the current heterogeneous catalysts have poor cycle stability and cannot be repeatedly used. SUMMARY

[0005] The purpose of the present application is to provide a ferroferric oxide supported bidentate chelate platinum catalyst and a preparation method and application thereof. The ferroferric oxide supported bidentate chelate platinum catalyst provided by the present application has high product yield and high cycle stability of the catalyst when catalyzing the addition reaction of unsaturated hydrocarbons and hydrogen-containing silane, and has long service life.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] The present application provides a preparation method of a ferroferric oxide supported bidentate chelate platinum catalyst, comprising the following steps:

[0008] The ferroferric oxide, tetraethoxysilane and an organic solvent are mixed to perform a hydrolysis reaction, to obtain ferroferric oxide coated with silicon dioxide;

[0009] The silane-functionalized bidentate organic ligand compound, the platinum compound and the organic solvent are mixed to carry out a chelation reaction to obtain a silane-functionalized bidentate chelate platinum compound; the silane-functionalized bidentate organic ligand compound contains a diphenyl phosphine group, a diphenyl arsine group, a vinyl group or a bipyridine group.

[0010] The silane-functionalized bidentate chelate platinum compound, the silica-coated ferroferric oxide and the organic solvent are mixed to carry out a condensation reaction to obtain a ferroferric oxide-supported bidentate chelate platinum catalyst.

[0011] Preferably, the silane-functionalized bidentate organic ligand compound includes one or more of 4-[3-(triethoxysilyl)propylamino]-2-pentanone, vinyltriethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane, trimethoxysilylpropyldiphenylarsine vinyl ether and 4,4'-bis[3-(triethoxysilyl)propylamino methyl]-2,2'-bipyridine.

[0012] Preferably, the ferroferric oxide has a particle size of 50-100 nm, a saturation magnetic moment of 60-90 emu / g and a specific surface area of 40-50 m 2 / g.

[0013] Preferably, the silica-coated ferroferric oxide has a mass content of the tetraethoxysilane of ≥30%; and an acidity of the tetraethoxysilane of <0.001% as measured by HCl.

[0014] Preferably, the platinum compound includes one or more of PtCl4, chloroplatinic acid and K2PtCl4.

[0015] Preferably, the molar ratio of the ferroferric oxide to the tetraethoxysilane is (1-3):1.

[0016] Preferably, the method for preparing the silane-functionalized bidentate organic ligand compound includes the following steps:

[0017] The bidentate organic ligand compound, 3-aminopropyltriethoxysilane, triethylamine and an organic solvent are mixed to carry out a reaction to obtain a silane-functionalized bidentate organic ligand compound; the molar ratio of the bidentate organic ligand compound to the 3-aminopropyltriethoxysilane is 0.5-1:1.2.

[0018] Preferably, the molar ratio of the silane-functionalized bidentate organic ligand compound to the platinum compound is 1:1.

[0019] The application provides a four-iron oxide loaded bidentate chelate type platinum catalyst prepared by the preparation method.

[0020] The application provides an application of the four-iron oxide loaded bidentate chelate type platinum catalyst in an addition reaction of unsaturated hydrocarbon and hydrogen-containing silane.

[0021] The application provides a preparation method of a four-iron oxide loaded bidentate chelate type platinum catalyst, which comprises the following steps: mixing four-iron oxide, tetraethoxysilane and an organic solvent to perform a hydrolysis reaction, so as to obtain four-iron oxide coated with silicon dioxide; mixing a bidentate organic ligand compound functionalized with silane, a platinum compound and an organic solvent to perform a chelation reaction, so as to obtain a bidentate chelate type platinum compound functionalized with silane; the bidentate organic ligand compound functionalized with silane contains a diphenyl phosphine group, a diphenyl arsine group, a vinyl group or a bipyridine group; mixing the bidentate chelate type platinum compound functionalized with silane, the four-iron oxide coated with silicon dioxide and an organic solvent to perform a condensation reaction, so as to obtain the four-iron oxide loaded bidentate chelate type platinum catalyst. The preparation method provided by the application takes four-iron oxide magnetic material as a carrier of a supported catalyst, which is beneficial to separating the catalyst in a reaction system. In order to load the platinum compound on the four-iron oxide, the application first adopts tetraethoxysilane to form a silicon dioxide layer on the surface of the four-iron oxide through hydrolysis; then the bidentate organic ligand compound functionalized with silane, the platinum compound and the organic solvent are mixed to perform a chelation reaction, so as to obtain the bidentate chelate type platinum compound functionalized with silane by chelation reaction of the bidentate organic ligand compound and the platinum compound; finally, the condensation reaction of the silane functionalization and the silicon dioxide on the surface of the four-iron oxide is utilized to load the platinum compound on the surface of the four-iron oxide. The four-iron oxide loaded bidentate chelate type platinum catalyst prepared by the application has high product yield and high catalyst cycle stability in the addition reaction of unsaturated hydrocarbon and hydrogen-containing silane, and has a long service life. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A synthesis route diagram of the four-iron oxide loaded bidentate chelate type platinum catalyst Fe3O4@SiO2-(N,O)-Pt provided for the embodiment 2 of the application is provided.

[0023] Figure 2 A chemical reaction principle diagram of the four-iron oxide loaded bidentate chelate type platinum catalyst provided by the application in catalyzing an addition reaction of olefin is provided.

[0024] Figure 3A chemical reaction principle diagram of a conjugated olefin and a conjugated alkyne addition reaction catalyzed by the four-iron oxide loaded bidentate chelate platinum catalyst provided in the present application;

[0025] Figure 4 A chemical reaction principle diagram of a non-conjugated diene and a non-conjugated diyne addition reaction catalyzed by the four-iron oxide loaded bidentate chelate platinum catalyst provided in the present application;

[0026] Figure 5 Effect of reaction temperature on yield when the four-iron oxide loaded bidentate chelate platinum catalyst prepared in Example 1 is used for catalytic reaction;

[0027] Figure 6 Yield ratio comparison results of different reaction raw materials when the four-iron oxide loaded bidentate chelate platinum catalyst prepared in Example 1 is used for catalytic reaction. DETAILED DESCRIPTION

[0028] The present application provides a preparation method of a four-iron oxide loaded bidentate chelate platinum catalyst, comprising the following steps:

[0029] The four-iron oxide, tetraethoxysilane and an organic solvent are mixed to perform a hydrolysis reaction, to obtain four-iron oxide coated with silicon dioxide;

[0030] The silane functionalized bidentate organic ligand compound, a platinum compound and an organic solvent are mixed to perform a chelation reaction, to obtain a silane functionalized bidentate chelate platinum compound; the silane functionalized bidentate organic ligand compound contains a diphenyl phosphine group, a diphenyl arsine group, a vinyl group or a bipyridine group;

[0031] The silane functionalized bidentate chelate platinum compound, the four-iron oxide coated with silicon dioxide and an organic solvent are mixed to perform a condensation reaction, to obtain the four-iron oxide loaded bidentate chelate platinum catalyst.

[0032] In the present application, all the preparation raw materials / components are commercially available products well known to those skilled in the art, unless otherwise specified.

[0033] The four-iron oxide, tetraethoxysilane and an organic solvent are mixed to perform a hydrolysis reaction, to obtain four-iron oxide coated with silicon dioxide.

[0034] The four-iron oxide, tetraethoxysilane and an organic solvent (hereinafter referred to as the first organic solvent) are mixed (hereinafter referred to as the first mixing) to perform a hydrolysis reaction, to obtain four-iron oxide coated with silicon dioxide.

[0035] In the present application, the particle size of the ferroferric oxide is preferably 50-100 nm, more preferably 60-80 nm. The saturated magnetic moment of the ferroferric oxide is preferably 60-90 emu / g. The specific surface area of the ferroferric oxide is preferably 40-50 m 2 / g. In the present application, the preparation method of the ferroferric oxide preferably comprises the following steps: mixing ferric chloride, a complexing agent, a surfactant and a solvent to obtain a mixed solution, adjusting the pH value of the mixed solution to 7-9 by using a pH adjuster to obtain a sol, removing the solvent from the sol to obtain a dry gel, drying the dry gel and then performing a combustion reaction, and cooling to obtain ferroferric oxide. The ferric chloride is preferably ferric chloride hexahydrate. The complexing agent is preferably tartaric acid, and the surfactant is preferably polyvinyl alcohol. The solvent is preferably ethylene glycol. The molar ratio of the ferric chloride, the complexing agent and the surfactant is preferably 1:2:1. The present application does not have special requirements for the amount of solvent, as long as the ferric chloride, the complexing agent and the surfactant are completely dissolved. The pH adjuster is preferably ethylenediamine, and the temperature for removing the solvent is preferably room temperature. The drying temperature is preferably 70°C.

[0036] In the present application, the mass content of the silicon dioxide of the tetraethoxysilane is preferably ≥30%, and the acidity of the tetraethoxysilane, calculated as HCl, is preferably <0.001%. The molar ratio of the ferroferric oxide and the tetraethoxysilane is preferably (1-3):1, more preferably (1.3-2.6):1. The first organic solvent is preferably toluene and trichloromethane. The toluene is preferably anhydrous toluene. The trichloromethane is preferably anhydrous trichloromethane. The first mixing preferably comprises the following steps: dispersing the ferroferric oxide in part of the first organic solvent to obtain a ferroferric oxide dispersion; dissolving the tetraethoxysilane in the remaining first organic solvent to obtain a tetraethoxysilane solution; and adding the tetraethoxysilane solution to the ferroferric oxide dispersion. The part of the first organic solvent is preferably toluene, and the remaining first organic solvent is preferably trichloromethane. The temperature of the hydrolysis reaction is preferably 100°C, and the holding time is preferably 24 h. The hydrolysis reaction is performed under stirring. After the hydrolysis reaction, a hydrolysis reaction liquid is obtained, which is preferably subjected to solid-liquid separation to obtain a solid phase product. The solid phase product is washed with trichloromethane and then dried to obtain ferroferric oxide coated with silicon dioxide. In the present application, the solid-liquid separation is preferably filtration. The washing is preferably performed twice. The drying is preferably vacuum drying, and the temperature of the vacuum drying is preferably 160°C, and the time is preferably 5 hours.

[0037] The present application is a chelation reaction of mixing (hereinafter referred to as second mixing) a silane-functionalized bidentate organic ligand compound, a platinum compound, and an organic solvent (hereinafter referred to as second organic solvent) to obtain a silane-functionalized bidentate chelate platinum compound; the silane-functionalized bidentate organic ligand compound contains a diphenylphosphino group, a diphenyl arsine group, a vinyl group, or a bipyridine group.

[0038] In the present application, the silane-functionalized bidentate organic ligand compound preferably includes one or more of 4-[3-(triethoxysilyl)propylamino]-2-pentanone, vinyltriethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane, trimethoxysilylpropyldiphenylarsine vinyl ether, and 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine.

[0039] In the present application, the vinyltriethoxysilane is a commercially available product. In specific embodiments of the present application, 4-[3-(triethoxysilyl)propylamino]-2-pentanone, 3-(2-aminoethylamino)propyltriethoxysilane, bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane, trimethoxysilylpropyldiphenylarsine vinyl ether, and 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine are preferably obtained by self-preparation. Among them, the raw material for preparing the bidentate organic ligand compound of 4-[3-(triethoxysilyl)propylamino]-2-pentanone is 4-bromo-2-pentanone. The raw material for preparing the bidentate organic ligand compound of 3-(2-aminoethylamino)propyltriethoxysilane is ethylenediamine. The raw material for preparing the bidentate organic ligand compound of bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane is chloromethyl diphenylphosphine. The raw material for preparing the bidentate organic ligand compound of trimethoxysilylpropyldiphenylarsine vinyl ether is 1,2-bis(diphenylarsino)ethanol. The raw material for preparing the bidentate organic ligand compound of 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine is 4,4'-bis(bromomethyl)-2,2'-bipyridine.

[0040] In the present application, the organic silane used for preparing 4-[3-(triethoxysilyl)propylamino]-2-pentanone, 3-(2-aminoethylamino)propyltriethoxysilane, bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane, and 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine is 3-aminopropyltriethoxysilane. The organic silane used for preparing trimethoxysilylpropyldiphenylarsine vinyl ether is 3-chloropropyltrimethoxysilane.

[0041] In the present invention, the method for preparing 4-[3-(triethoxysilyl)propylamino]-2-pentanone, 3-(2-aminoethylamino)propyltriethoxysilane, bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane and 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine comprises the following steps: mixing (hereinafter referred to as third mixing) a bidentate organic ligand compound, 3-aminopropyltriethoxysilane, triethylamine (Et3N) and an organic solvent (hereinafter referred to as third organic solvent) to react, thereby obtaining a bidentate organic ligand compound functionalized with silane. In the present invention, the bidentate organic ligand compound preferably includes 4,4'-bis(bromomethyl)-2,2'-bipyridine, 4-bromo-2-pentanone, ethylenediamine or chloromethyl diphenylphosphine. The third organic solvent is preferably tetrahydrofuran (THF), more preferably anhydrous THF. The molar ratio of the bidentate organic ligand compound to 3-aminopropyltriethoxysilane is 0.5-1:1.2. The ratio of the amount of substance of the bidentate organic ligand compound to the volume of triethylamine is preferably (0.5-1) mol:2.04 mL. The present invention does not have a special requirement for the amount of the third organic solvent. The third mixing is preferably: adding Et3N and 3-aminopropyltriethoxysilane to a solution of the bidentate organic ligand compound in the third organic solvent. The temperature of the reaction is preferably 20-60°C, and the time is preferably 4 hours. The present invention preferably performs post-treatment on the reaction solution obtained from the reaction, and the post-treatment preferably includes: mixing the reaction solution with anhydrous n-hexane to obtain a mixed solution; passing the mixed solution through a short MgSO4 column to remove ammonium salt by filtration; and finally concentrating the obtained clear solution and vacuum drying at 100°C for 24 hours to obtain a bidentate organic ligand compound functionalized with silane.

[0042] In the present invention, when preparing trimethoxysilylpropyldiphenylarsino vinyl ether, the molar ratio of 3-chloropropyltrimethoxysilane to 1,2-bis(diphenylarsino)ethanol is preferably 1:1.1.

[0043] In a specific embodiment of the present invention, the method for preparing 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine preferably comprises the following steps: adding Et3N and 3-aminopropyltriethoxysilane to a solution of 4,4'-bis(bromomethyl)-2,2'-bipyridine in anhydrous THF, and stirring the mixture at 50°C for 6 hours. After cooling the solution to room temperature, adding anhydrous n-hexane (20 mL), passing the mixture through a short MgSO4 column, and removing ammonium salt by filtration. Finally, concentrating the clear solution and vacuum drying at 100°C for 24 hours to obtain a light yellow viscous oil with a yield of 96%.

[0044] In the present invention, the chemical structural formula of 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine is:

[0045]

[0046] In the present application, the platinum compound preferably comprises one or more of PtCl4, chloroplatinic acid and K2PtCl4, more preferably PtCl4or K2PtCl4. The second organic solvent is preferably ethanol, which is preferably anhydrous ethanol. The molar ratio of the silyl-functionalized bidentate organic ligand compound and the platinum compound is preferably 1:1. The second mixing is preferably: dissolving the platinum compound in part of the second solvent to obtain a platinum compound solution; dissolving the silyl-functionalized bidentate organic ligand compound in the remaining second organic solvent, and then mixing with the platinum compound solution. The chelation reaction is carried out at room temperature, and the time is preferably 2 hours. In the present application, after the reaction is completed, the present application preferably filters the obtained chelation reaction solution, washes the obtained crude product with cold anhydrous ethanol, to obtain the silyl-functionalized bidentate chelated platinum compound.

[0047] In the present application, when the silyl-functionalized bidentate organic ligand compound is preferably 4-[3-(triethoxysilyl)propylamino]-2-pentanone, the silyl-functionalized bidentate chelated platinum compound is preferably:

[0048] In the present application, when the silyl-functionalized bidentate organic ligand compound is preferably vinyltriethoxysilane, the silyl-functionalized bidentate chelated platinum compound is preferably:

[0049] In the present application, when the silyl-functionalized bidentate organic ligand compound is preferably 3-(2-aminoethylamino)propyltriethoxysilane, the silyl-functionalized bidentate chelated platinum compound is preferably:

[0050] In the present application, when the silyl-functionalized bidentate organic ligand compound is preferably bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane, the silyl-functionalized bidentate chelated platinum compound is preferably:

[0051] In the present application, when the silyl-functionalized bidentate organic ligand compound is preferably trimethoxysilylpropyl diphenylarsine vinyl ether, the silyl-functionalized bidentate chelated platinum compound is preferably:

[0052] In the present application, when the silyl-functionalized bidentate organic ligand compound is preferably 4,4'-bis[3-(triethoxysilyl)propylamino methyl]-2,2'-bipyridine, the silyl-functionalized bidentate chelated platinum compound is preferably:

[0053] After obtaining the silane-functionalized bidentate chelate platinum compound and the silica-coated ferroferric oxide, the present application mixes (hereinafter referred to as fourth mixing) the silane-functionalized bidentate chelate platinum compound, the silica-coated ferroferric oxide and an organic solvent (hereinafter referred to as fourth organic solvent) to perform a condensation reaction, thereby obtaining the ferroferric oxide-supported bidentate chelate platinum catalyst. In the present application, the fourth organic solvent is preferably methanol. The mass ratio of the silane-functionalized bidentate chelate platinum compound and the silica-coated ferroferric oxide is preferably 0.5-1.2:1, and more preferably 0.77:1. The present application does not have a special requirement for the amount of the fourth organic solvent. The fourth mixing is preferably performed by dispersing the silica-coated ferroferric oxide in the fourth organic solvent to obtain a dispersion liquid, and then adding the silane-functionalized bidentate chelate platinum compound into the dispersion liquid. The condensation reaction is preferably performed under heating reflux, and the heating reflux time is preferably 24 h. After the condensation reaction, a condensation reaction liquid is obtained, and the present application preferably performs solid-liquid separation on the condensation reaction liquid to obtain a solid-phase product, which is then dried to obtain the ferroferric oxide-supported bidentate chelate platinum catalyst. In the present application, the solid-liquid separation is preferably filtration. The drying is preferably vacuum drying, and the vacuum drying temperature is preferably 160°C, and the time is preferably 5 h.

[0054] The present application provides the ferroferric oxide-supported bidentate chelate platinum catalyst prepared by the preparation method described in the above technical solution, which comprises the silica-coated ferroferric oxide and the bidentate chelate platinum compound coupled to the silica surface of the silica-coated ferroferric oxide.

[0055] In the present application, the molar amount of platinum in the ferroferric oxide-supported bidentate chelate platinum catalyst preferably accounts for 0.2-0.4 mmol / g of the mass percentage of the ferroferric oxide-supported bidentate chelate platinum catalyst (loading amount).

[0056] In the ferroferric oxide-supported bidentate chelate platinum catalyst provided by the present application, the bidentate chelate platinum compound and the ferroferric oxide carrier are connected through an intermediate silica layer, and the bidentate chelate platinum compound is chemically connected to the surface of the silica layer. Therefore, the connection strength between the bidentate chelate platinum compound and the ferroferric oxide is high, and the cycle stability of the obtained ferroferric oxide-supported bidentate chelate platinum catalyst is high, and the service life is long in the catalytic addition reaction of olefins and hydrogen-containing silane.

[0057] The present application provides the application of the ferroferric oxide-supported bidentate chelate platinum catalyst described in the above technical solution in the addition reaction of unsaturated hydrocarbons and hydrogen-containing silane, wherein the unsaturated hydrocarbons include olefins and / or acetylenes.

[0058] In the present application, the application is preferably: catalytic addition reaction of mixing unsaturated hydrocarbon, ferroferric oxide loaded bidentate chelate type platinum catalyst and hydrogen-containing silane (hereinafter referred to as the fifth mixing). The unsaturated hydrocarbon includes olefin and / or alkyne, more preferably olefin or alkyne. The olefin preferably includes olefin having the structure shown in formula 1, olefin having the structure shown in formula 2, olefin having the structure shown in formula 3, or olefin having the structure shown in formula 4;

[0059] R in formula 1 1 is alkyl or aryl;

[0060] In formula 2: when R 2 = R 3 , R 2 and R 3 are alkyl or aryl; when R 2 ≠ R 3 , R 2 is alkyl or aryl, and R 3 is SiMe3;

[0061] In formula 3: when R 1 = R 2 , R 1 and R 2 are alkyl or aryl; when R 1 ≠ R 2 , R 1 is alkyl or aryl, and R 2 is SiMe3;

[0062] In formula 4: X is O, S, NH, CH2, CHCH3 or CH2CH2CH.

[0063] The alkyne preferably includes alkyne having the structure shown in formula 5, alkyne having the structure shown in formula 6, alkyne having the structure shown in formula 7, or alkyne having the structure shown in formula 8;

[0064] R in formula 5 1 is alkyl or aryl;

[0065] In formula 6: when R 2 = R 3 , R 2 and R 3 are alkyl or aryl; when R 2 ≠ R 3 , R 2 is alkyl or aryl, and R 3 is SiMe3;

[0066] In formula 7: when R 1 ≠ R 2 , R 1 and R 2 are alkyl or aryl; when R 1 = R 2 , R 1 is alkyl or aryl, and R 2 is SiMe3;

[0067] In formula 8: X is O, S, NH, CH2, CHCH3 or CH2CH2CH2;

[0068] In the present application, the chemical formula of the hydrogen-containing silane is shown in formula 9: HSiR3 formula 9; SiR3 in formula 9 is SiMe2Ph, SiMe2(OSiMe3), SiMe(OSiMe3)2, SiEt3 or SiPh3, and is particularly preferably triethoxysilane. The molar ratio of the olefin to the hydrogen-containing silane is preferably 5:5.5. The molar ratio of the ferroferric oxide-supported bidentate chelate platinum catalyst to the olefin, calculated in terms of the molar amount of platinum element, is preferably (1.0 x 10 -3 ~ 2.0 x 10 -2 ): 5.0, and is particularly preferably 1.0 x 10 -3 : 5.0, 5.0 x 10 -3 : 5.0 or 2.0 x 10 -2 : 5.0. In the present application, the fifth mixing is preferably: the unsaturated hydrocarbon and the ferroferric oxide-supported bidentate chelate platinum catalyst are premixed, and then the temperature is raised to the temperature of the catalytic addition reaction, and then the hydrogen-containing silane is added dropwise. The temperature of the premixing is preferably room temperature, the time of the premixing is preferably 30 min, and the premixing is performed under stirring. The temperature of the catalytic addition reaction is preferably 100~120°C, and the time is preferably 1~2 hours. The catalytic addition reaction is performed under stirring. In the present application, after the catalytic addition reaction, the product in the catalytic addition reaction liquid is separated by the method of reduced pressure distillation.

[0069] In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.

[0070] Example 1

[0071] The method for preparing 4,4'-bis(bromomethyl)-2,2'-bipyridine is as follows: 2.67 g of 4,4'-bis(hydroxymethyl)-2,2'-bipyridine is added to a 200 mL single-neck flask, and 58 mL of 48% HBr and 24 mL of concentrated sulfuric acid (98%) are added. The resulting solution is stirred at 100°C for 6 hours, and then cooled to room temperature and diluted with 80 mL of water. The pH is adjusted to neutral with a NaOH solution, and the solid product is filtered, washed with water, and dried to obtain a crude product. The crude product is recrystallized with dichloromethane and dried to obtain 4,4'-bis(bromomethyl)-2,2'-bipyridine as a white solid with a yield of 65.2%.

[0072] To a solution of 1.0 mmol of 4,4'-bis(bromomethyl)-2,2'-bipyridine in 20 mL of anhydrous THF, 2.04 mL of Et3N and 1.2 mmol of 3-aminopropyltriethoxysilane are added, and the mixture is stirred at 60°C for 6 hours. After the solution is cooled to room temperature, 30 mL of anhydrous n-hexane is added, and the mixture is passed through a short MgSO4 column and filtered to remove the ammonium salt. Finally, the clear solution is concentrated and dried under vacuum at 100°C for 24 hours to obtain 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine as a light yellow solid with a yield of 96%.

[0073] In a 50 mL single-neck flask, 1.0 mmol of PtCl4 and 10 mL of anhydrous ethanol are added, stirred and dissolved, and then a mixed solution of 1.0 mmol of 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine and 5 mL of ethanol is added dropwise, and the reaction is performed at room temperature for 2 hours. The crude product is filtered, and then washed with cold anhydrous ethanol (3 x 2 mL) to obtain a yellow platinum complex (BrCH2)2bipy-PtCl2 with a yield of 99.2%.

[0074]

[0075] A mixed solution is formed by adding 1 mol of iron trichloride hexahydrate, 1 mol of salicylic acid, and 0.01 mol of polyvinyl alcohol into 500 mL of ethylene glycol, adjusting the pH of the mixed solution to 7, removing the ethylene glycol at room temperature, performing low-temperature drying, and then performing combustion in an inert atmosphere in a reactor to obtain magnetite nanoparticles, which have a particle size of 50 to 100 nm, a saturation magnetic moment of 60 to 90 emu / g, and a specific surface area of 40 to 50 m 2 / g.

[0076] Magnetic nanoparticles of Fe3O4(2.20 g) and dry toluene (120 mL) were added to a reactor and stirred to form a suspension. A solution of tetraethoxysilane (1.70 g, 7.1 mmol) dissolved in dry CHCl3(12 mL) was then added to the reactor and heated to 100 °C and stirred for 24 h. The solid was filtered and washed with CHCl3(20 mL) twice and finally dried under vacuum at 160 °C for 5 h to obtain silica coated Fe3O4nanoparticles.

[0077] The silica coated Fe3O4nanoparticles (0.75 g) were dispersed in 40 mL of toluene and then 0.58 g of silane functionalized platinum complex was added. The mixture was heated to reflux for 24 h and filtered and dried to obtain the magnetic Fe3O4nanoparticle supported platinum complex catalyst.

[0078] Example 2

[0079] 4-[3-(triethoxysilyl)propylamino]-2-pentanone: To a solution of 1.0 mmol of 4-bromo-2-pentanone in 10 mL of dry THF, 2.04 mL of Et3N and 1.2 mmol of 3-aminopropyltriethoxysilane were added. The mixture was stirred at 40 °C for 4 h. After cooling the solution to room temperature, 20 mL of dry n-hexane was added and the mixture was passed through a short column of MgSO4and filtered to remove the ammonium salts. The clear solution was finally concentrated and dried under vacuum at 100 °C for 24 h to obtain a light yellow viscous oil in 94% yield.

[0080] To a solution of 1.0 mmol of PtCl4in 10 mL of dry ethanol, 1.0 mmol of 4-[3-(triethoxysilyl)propylamino]-2-pentanone in 5 mL of ethanol was added dropwise and the reaction was allowed to proceed at room temperature for 2 h. The crude product was filtered and washed with cold dry ethanol (3 x 2 mL) to obtain the yellow platinum complex in 98.6% yield.

[0081]

[0082] The Fe3O4magnetic nanoparticles were prepared according to the procedure of Example 1. The Fe3O4magnetic nanoparticles had a particle size of 50-100 nm, a saturation magnetization of 60-90 emu / g, and a specific surface area of 40-50 m2 / g. 2 / g.

[0083] Magnetic nanoparticles of Fe304(2.20 g) and dry toluene (120 mL) were added to a reactor and stirred to form a suspension liquid. Then a solution of tetraethoxysilane (1.70 g, 7.1 mmol) dissolved in dry CHCl3(12 mL) was added to the reactor and stirred at 100 °C for 24 h. The solid was filtered and washed with CHCl3(20 mL) twice and finally dried under vacuum at 160 °C for 5 h to obtain silica-coated Fe304nanoparticles.

[0084] The silica-coated Fe304nanoparticles (0.75 g) were dispersed in 40 mL of toluene and then 0.58 g of silane-functionalized platinum complex was added. The mixture was heated to reflux for 24 h and then filtered and dried to obtain the magnetic Fe304nanoparticle-supported platinum complex catalyst, denoted as Fe304@Si02-(N,O)-Pt.

[0085] Example 3

[0086] Method for preparing 3-(2-aminoethylamino)propyltriethoxysilane: 2.04 mL of Et3N and 1.2 mmol of 3-aminopropyltriethoxysilane were added to a solution of 1.0 mmol of ethylenediamine in 10 mL of dry THF and the mixture was stirred at 60 °C for 5 h. After cooling the solution to room temperature, 20 mL of dry n-hexane were added and the mixture was passed through a short MgS04column and filtered to remove the ammonium salts. Finally, the clear solution was concentrated and dried under vacuum at 100 °C for 24 h to obtain a light yellow viscous oil with a yield of 95%.

[0087] A 50 mL single-necked flask was charged with 1.0 mmol of PtCl4and 10 mL of dry ethanol and, after stirring to dissolve, a solution of 1.0 mmol of 3-(2-aminoethylamino)propyltriethoxysilane in 10 mL of ethanol was added dropwise and the reaction was allowed to proceed at room temperature for 3 h. The crude product was filtered and washed with cold dry ethanol (3 x 2 mL) to obtain a yellow platinum complex with a yield of 97.6%.

[0088]

[0089] The Fe304magnetic nanoparticles were prepared according to the method of Example 1 and had a particle size of 50-100 nm, a saturation magnetization of 60-90 emu / g and a specific surface area of 40-50 m2 / g. 2 / g.

[0090] Magnetic nanoparticles of iron oxide (2.20 g) and dry toluene (120 mL) were added to a reactor and stirred to form a suspension liquid. Then a solution of tetraethoxysilane (1.70 g, 7.1 mmol) dissolved in dry CHCl3(12 mL) was added to the reactor and stirred at 100 °C for 24 h. The solid was filtered and washed with CHCl3(20 mL) twice and finally dried under vacuum at 160 °C for 5 h to obtain silica-coated iron oxide nanoparticles.

[0091] The silica-coated iron oxide nanoparticles (0.75 g) were dispersed in 40 mL of toluene and then 0.58 g of the silane-functionalized platinum complex was added. The mixture was heated to reflux for 24 h and then filtered and dried to obtain the magnetic Fe3O4nanoparticle-supported platinum complex catalyst, denoted as Fe3O4@SiO2-(N,N)-Pt.

[0092] Preparation of bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane ligand: 2.04 mL of Et3N and 1.2 mmol of 3-aminopropyltriethoxysilane were added to a solution of 0.5 mmol of chloromethyl diphenylphosphine in 20 mL of dry THF and the mixture was stirred at 20 °C for 4 h. After cooling the solution to room temperature, 20 mL of dry n-hexane was added and the mixture was passed through a short MgSO4column to remove the ammonium salts by filtration. Finally, the clear solution was concentrated and dried under vacuum at 100 °C for 24 h to obtain a light yellow viscous oil with a yield of 93.7%.

[0093] In a 50 mL single-necked flask, 1.0 mmol of PtCl4and 10 mL of dry ethanol were added and stirred to dissolve. Then a mixture of 1.0 mmol of bis-(diphenylphosphinomethylene)aminopropyltriethoxysilane and 10 mL of ethanol was added dropwise and the reaction was allowed to proceed at room temperature for 2 h. The crude product was obtained by filtration and then washed with cold dry ethanol (3 x 2 mL) to obtain a yellow platinum complex with a yield of 96.6%.

[0094]

[0095] The iron oxide magnetic nanoparticles were prepared according to the method of Example 1. The size of the iron oxide magnetic nanoparticles was 50-100 nm, the saturation magnetization was 60-90 emu / g, and the specific surface area was 40-50 m2 / g. 2 / g.

[0096] Magnetic nanoparticles of Fe3O4(2.20 g) and dry toluene (120 mL) were added to a reactor and stirred to form a suspension. A solution of tetraethoxysilane (1.70 g, 7.1 mmol) dissolved in dry CHCl3(12 mL) was then added to the reactor and heated to 100°C and stirred for 24 hours. The solid was filtered and washed with CHCl3(20 mL) twice and finally dried under vacuum at 160°C for 5 hours to obtain silica-coated Fe3O4nanoparticles.

[0097] The silica-coated Fe3O4nanoparticles (0.75 g) were dispersed in 40 mL of toluene and then 0.58 g of the silane-functionalized platinum complex was added. The mixture was heated to reflux for 24 hours. The magnetic Fe3O4nanoparticle-supported diphenyl platinum complex catalyst was obtained by filtration and drying.

[0098] Application Example

[0099] The unsaturated olefins (styrene, 1-heptene, 1-dodecene, phenoxy ethylene, benzyl ethylene, chloromethyl ethylene, epoxy ethylene) and the magnetic Fe3O4nanoparticle-supported bipyridyl platinum complex catalyst prepared in Example 1 were added to a three-necked reactor equipped with a magnetic stirrer and a reflux condenser, which was connected to a drying system at the top. The mixture was stirred at room temperature for 30 minutes and then heated slowly to 90-120°C. Triethoxysilane was then added dropwise. After the addition was completed, the reaction was continued for 1-2 hours. The product was separated by distillation under reduced pressure. The amounts of the olefins, triethoxysilane and the magnetic Fe3O4nanoparticle-supported bipyridyl platinum complex catalyst were 5.0 x 10 -3 / 5.0 x 10 -3 / 2.0 x 10 - 2 mmol Pt, respectively.

[0100] (1) The temperature of the catalytic addition reaction was 110°C and the amounts of the magnetic Fe3O4nanoparticle-supported bipyridyl platinum complex catalyst were 1.0 x 10 -3 / 5.0 x 10 -3 / 2.0 x 10 -2 mmol Pt, respectively. The relationship between the yield of the reaction product and the reaction time is shown in Figure 1. Figure 5 As can be seen from Figure 1, the yield of the product reached 90% when the amounts of the catalysts of the above three groups were used and the reaction time was more than 70 minutes. Figure 5

[0101] (2) The amount of the magnetic Fe3O4nanoparticle-supported bipyridyl platinum complex catalyst was 5.0 x 10 -3 ​mmol Pt, the reaction temperature is set to 90℃, 100℃, 110℃ and 120℃ respectively, and the yield of the reaction product changes with the reaction time as shown in the following table. Figure 6 Figure 6 It can be seen that when the reaction temperature is 90℃, the reaction basically occurs in the first 20min, and the reaction time lasts to 80min, the yield of the reaction at 100-120℃ is the same.

[0102] (3) The dosage of the magnetic Fe3O4 nanoparticle loaded bipyridyl platinum complex catalyst is 5.0×10 -3 mmol Pt, the reaction temperature is set to 110℃, the types of the olefins are shown in Table 1, and the yield and selectivity of the obtained product are shown in Table 1.

[0103] Table 1: The results of the addition reaction of different types of olefins

[0104] Serial number Unsaturated olefin Time / min Yield / % Selectivity (β / α) 1 1-heptene 80 95 95:5 2 1-dodecene 90 92 90:10 3 Phenoxy ethylene 70 87 90:10 4 Benzyl ethylene 110 78 85:15 5 Chloromethyl ethylene 80 93 95:5 6 Styrene 130 67 80:20 7 Epoxy ethylene 100 86 90:10

[0105] (4) The dosage of the magnetic Fe3O4 nanoparticle loaded bipyridyl platinum complex catalyst is 5.0×10 -3 mmol Pt, the reaction temperature is set to 110℃, the olefin is 1-heptene, the magnetic Fe3O4 nanoparticle loaded bipyridyl platinum complex catalyst is recycled, and the yield and selectivity of the obtained product under different recycling times are shown in Table 2.

[0106] Table 2: The yield and selectivity of the obtained product under different recycling times

[0107]

[0108]

[0109] It can be seen from Table 1 and Table 2 that the ferric oxide nanoparticle loaded bidentate chelate type platinum catalyst prepared in Example 1 of the present application is easy to separate from the reaction system, has high yield of the addition reaction product and high stability of the catalyst, can be recycled, and has long service life.

[0110] Although the above examples have made a detailed description of the present application, it is only a part of the examples of the present application, but not all the examples, and other examples can be obtained according to the present examples without creativity, which all belong to the protection scope of the present application.​

Claims

1. A method for preparing a bidentate chelate platinum catalyst supported on iron oxide, characterized in that, Includes the following steps: Ferric oxide, tetraethoxysilane, and an organic solvent were mixed and hydrolyzed to obtain silica-coated ferric oxide. A silane-functionalized bidentate organic ligand compound, a platinum compound, and an organic solvent are mixed and chelated to obtain a silane-functionalized bidentate chelated platinum compound; the silane-functionalized bidentate organic ligand compound is 4-[3-(triethoxysilyl)propylamino]-2-pentanone, 3-(2-aminoethylamino)propyltriethoxysilane, or 4,4'-bis[3-(triethoxysilyl)propylaminomethyl]-2,2'-bipyridine; The silane-functionalized bidentate chelate platinum compound, silica-coated iron oxide, and an organic solvent were mixed and subjected to a condensation reaction to obtain an iron oxide-supported bidentate chelate platinum catalyst.

2. The preparation method according to claim 1, characterized in that, The iron(III) oxide has a particle size of 50–100 nm, a saturation magnetic moment of 60–90 emu / g, and a specific surface area of ​​40–50 m². 2 / g.

3. The preparation method according to claim 1, characterized in that, The tetraethoxysilane has a silica content of ≥30% by mass; the acidity of the tetraethoxysilane, calculated as HCl, is <0.001%.

4. The preparation method according to claim 1, characterized in that, The platinum compound includes one or more of PtCl4, chloroplatinic acid, and K2PtCl4.

5. The preparation method according to claim 1, 2 or 3, characterized in that, The molar ratio of iron(III) oxide to tetraethoxysilane is (1~3):

1.

6. The preparation method according to claim 1, characterized in that, The preparation method of the silane-functionalized bidentate organic ligand compound includes the following steps: A bidentate organic ligand compound, 3-aminopropyltriethoxysilane, triethylamine, and an organic solvent are mixed and reacted to obtain a silane-functionalized bidentate organic ligand compound; the molar ratio of the bidentate organic ligand compound to 3-aminopropyltriethoxysilane is 0.5~1:1.

2.

7. The preparation method according to claim 1, characterized in that, The molar ratio of the silane-functionalized bidentate organic ligand compound to the platinum compound is 1:

1.

8. The iron oxide-supported bidentate chelate platinum catalyst prepared by the preparation method according to any one of claims 1 to 7, characterized in that, It includes silicon dioxide-coated iron(III) oxide and a bidentate chelate platinum compound coupled with the silicon dioxide.

9. The application of the iron oxide-supported bidentate chelate platinum catalyst of claim 8 in the addition reaction of unsaturated hydrocarbons with hydrogen-containing silanes, wherein the unsaturated hydrocarbons include alkenes and / or alkynes.

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