CS240639B1 - Transition metal cyclopentadienyl complexes bound to the surface of an inorganic support - Google Patents

Abstract

Cyclopentadienyl complexes of transition metals bound to the surface of an inorganic support formed by the interaction of a transition metal complex of the general formula MrLs, where M represents an atom of a transition metal IV., VI or VIII. groups of the periodic table, L is a carbonyl, cyclopentadienyl, alkene of two to four carbon atoms or a phosphine group or a bromine or chlorine atom, r is an integer from 1 to 6 and s is an integer from 4 to 16, with a cyclopentadienyl anion chemically bound to the surface of a porous or non-porous inorganic support A, where A represents silica, alumina, titanium dioxide, ceramics, glass or aluminosilicates, via a spacer « of the general formula -O-Si-(CH2)n~, where n represents an integer from 1 to 12. These heterogenized complexes of transition metals on inorganic supports are used as catalysts for hydrogenation, hydrosilylation, hydroformylation, isomerization, and possibly other reactions.

Description

The invention relates to cyclopentadienyl complexes of transition metals bound to the surface of an inorganic support.

It is known that so-called heterogeneous transition metal complexes on both organic and inorganic supports are used in a number of technical fields.

The invention is based on cyclopentadienyl complexes of transition metals, bound to the surface of a porous or non-porous inorganic support via a silylalkylcyclopentadienyl group, formed by the interaction of a transition metal complex of the general formula where M represents an atom of a transition metal of groups IV, VI or VIII of the periodic table,

L is a carbonyl, cyclopentadienyl, alkene of two to four carbon atoms or a phosphine group, a bromine or chlorine atom, r is an integer of 1 to 6 and s is an integer of 4 to 16, with a cyclopentadienyl anion chemically bound to the surface of a porous or non-porous inorganic support A (wherein A represents silica, alumina, titanium dioxide, ceramics, glass or aluminosilicates) via a spacer of the general formula, \

-O-Si-(CH _o ) / ^{2 n} where n represents an integer from 1 to 12.

These materials can be prepared in two steps, creating a relatively strong h ³ -bond between the support and the metal complex, which prevents the complex from leaching into the solution.

Materials modified with a cyclopentadienyl ligand can be easily prepared according to Czech Patent No. AO 240 634 by interacting surface hydroxyls of an inorganic material with cyclopentadienylalkylsilicon reagents. Transition metal complexes are commonly available.

The actual preparation of heterogenized cyclopentadienyl complexes consists first of converting the cyclopentadienyl ring, which is the modified surface of the support, into the cyclopentadienyl anion using a reducing agent. The reducing agent can be alkali metals or organometallic compounds, for example alkyllithium or Grignard reagents.

reductive reagent \ A-O-Si-(CH,)C,-H, - j of n □ b -ř AO-Si-<CH ₂ ) _n C ₅ H ₄ The cyclopentadienyl alcohol thus prepared anion interacts with metal complex \ χ Z x(AO-Si-(CH ₂ ) _n C ₅ H ₄ ) ⁺ “A-»(AO-Si- (CH ₂ ) _n C ₅ H ₄ )

where A, M, L, s, r have the above validity, χ = 1 or 2.

Both reactions can be carried out in a solvent that does not react with organometallic reagents such as toluene, benzene, tetrahydrofuran, 1,4-dioxane at laboratory, reduced or elevated temperatures. Before adding the reducing agent solution, it is advisable to treat the surface of the support with a mixture of trimethylchlorosilane and hexamethyldisilazane (1 : 1) to minimize free OH groups on the surface of the support, but this is not absolutely necessary. If an excess of the transition metal complex M _r L _g was used, it is expedient to remove the unreacted complex by washing the inorganic material with a solvent, which can then be removed from the inorganic material advantageously under reduced pressure.

The heterogenized complexes prepared in this way are used as catalysts for hydrogenation, hydrosilylation, isomerization, hydroformylation, and other reactions.

The following examples characterize the substances according to the invention without defining or limiting it. The weights are given in parts by weight. The yields are based on the weight of the carrier.

Example 1

100 parts of silica modified with 3-(cyclopentadienyl)propylsilyl ligand were coated with 500 parts of toluene and 15 parts of butyllithium in 50 parts of n-hexane were added to the mixture. The reaction mixture was shaken for 3 hours, then the silica was washed three times with a solvent and dried under vacuum. A solution of 7 parts of C^H^TiCl^ in 50 parts of toluene was added to the silica thus treated. After adding the complex, the mixture was shaken intensively for 4 hours, then washed with toluene until the washing solution became colorless and dried under high vacuum. A heterogenized cyclopentadienyl titanium complex containing 1.1% titanium was obtained. Yield 97%, based on the support.

Example 2

To 100 parts of alumina with an anchored 5-(cyclopentadienyl)pentylsilyl group were added 500 parts of methylene dichloride, 25 parts of trimethylchlorosilane and 25 parts of hexamethyldisilazane in sequence. The mixture was shaken for 3 hours, then washed three times with solvent and dried under vacuum.

To the alumina thus treated was added 10 parts of isopropylmagnesium bromide, the reaction mixture was shaken for 1 hour, washed three times with solvent and dried under vacuum. A solution of 5 parts of Co ₂ (CO) _g in 30 parts of the same solvent was added to the reaction vessel to the alumina thus treated and coated with 300 parts of solvent. The mixture was treated in the same manner as in Example 1.

The obtained material contained 0.8% cobalt. Yield 98%, based on the support.

Example 3

Example 1 was repeated with the difference that instead of silica modified with 3-(cyclopentadienyl)propylsilyl group, titanium dioxide modified with 12-(cyclopentadienyl)dodecylsilyl ligand was used and instead of CeHeTiCl- complex solution in toluene, _ 3 3 solution of (h -C^H,.) ^Ni^ (CO) in benzene was used. A heterogenized cyclopentadienyl nickel complex with a nickel content of 0.6% was obtained. Yield 96%, based on the support.

Example 4

Example 2 was repeated except that ceramic substrate was used instead of alumina. The product contained 0.03% cobalt. Yield 97%, based on the support.

Example 5

Example 1 was repeated except that instead of silica, A4 molecular sieve was used and the obtained material contained 0.7% titanium. Yield 96%, based on the support.

Example 6

Example 3 was repeated except that porous glass was used instead of titanium dioxide. A heterogeneous nickel complex containing 0.1% nickel was obtained. Yield 98%, based on the support.

Example 7

Example 1 was repeated with the difference that instead of the complex C^H^TiCl·^ the complex Pe ₂ (CO)g was used and the obtained product contained 0.2% iron. Yield 97%, based on the support.

Example 8

Example 1 was repeated with the difference that tetrahydrofuran was used instead of toluene and instead of the CgHgTiClg complex, the chromium complex CgHgCr(CO) ₂ N0 was used and the obtained material contained 0.2 i of chromium. Yield 95 i, based on the support.

Example 9

Example 1 was repeated except that instead of the CgHgTiClg complex, the Rhg(CO)|g complex was used and the obtained material contained 0.2% rhodium. Yield 96%, based on the support.

Example 10

Example 2 was repeated with the difference that instead of the Co ₀ (CO) complex, the CgHgNiC ₃ H ₄ complex was used and the material obtained contained 0.38% nickel. Yield 97%, based on the support.

Example 11

Example 1 was repeated with the difference that instead of the CgHgTiCl ₃ complex, the complex /Rh(Cg(CHj)g)P(CgHg) ₃ / was used and the product contained 0.2% rhodium. Yield 96%, based on the support.

example 12

Example 1 was repeated with the difference that /Rh(Cg(CHg)g)Br ₂ /2 was used instead of the CgHgTiClg complex and the obtained material contained 0.3% rhodium. Yield 98%, based on the support.

Claims (1)

Cyclopentadienyl transition metal complexes bound to the surface of an inorganic carrier formed by the interaction of a transition metal complex of the formula wherein M represents a transition metal atom IV, VI. or VIII. Periodic table groups L a carbonyl, cyclopentadienyl, alkene of two to four carbon atoms or a phosphine group or a bromine or chlorine atom, r an integer of 1 to 6 and an integer of 4 to 16, with a cyclopentadienyl anion chemically bonded to the surface of porous or non-porous inorganic carrier A represents silica, alumina, titanium dioxide, ceramics, glass or alumosilicates, by means of a spacer coupling of the general formula \ -O-Si- (CH-) wherein n represents an integer from 1 to 12.