Patent GB-1041237-A (GB)
Title: Organic rhodium compounds and complexes and their use in the production of dryanosilicon compounds
IPC: C08G77/38
Filed: 1963-06-19
Abstract: In the preparation of organo-silicon monomers or polymers by the addition reaction between a Si-H compound and a compound containing aliphatic unsaturation, the catalyst is an organic rhodium compound or complex soluble in at least one of the reactants.  The Si-H compound may be inorganic or organic, monomeric or polymeric, and may be substituted with, e.g., halogen atoms, hydrocarbon radicals, halogenated hydrocarbon radicals, cyanoalkyl radicals, -OR or OOCR radicals, wherein R is an organic radical.  Silicon atoms may be separated as in polysiloxanes, polysilalkylenes, polysilarylenes and organosilazanes.  The compound containing ethylenic or acetylenic unsaturation may also contain silicon.  The catalyst may be a rhodium carboxylate prepared by reacting rhodium chloride with 3-6 mols./mol. of the alkali metal salt of a carboxylic acid.  In aqueous solution a precipitate, which may be of the basic salt, is produced.  In alcoholic solution the tri-carboxylate is formed. The preparation of rhodium heptanoate is described. Alternatively, the catalyst may be an organorhodium complex prepared by reacting an alcoholic solution of rhodium chloride, containing optionally a basic compound free of complexing groups, e.g. NaOH, with at least one mol./atom of rhodium of an olefin at 50-125 DEG  C.  Such complexes include Rh2(C2H4)Cl2, HRh(C8H16)2-Cl2, H2Rh2(C6H12)2Cl4 and H2Rh(C4H8)Cl3.  The reaction product is evaporated to dryness, extracted with chloroform, evaporated to an oily liquid, and extracted with hexane to yield a powder.  Another suitable organorhodium complex is that prepared by adding an alcoholic solution of rhodium chloride to at least 2 mols./mol. alcohol of a silane R3SiH, where R is a monovalent hydrocarbon radical.  The silicon containing complex is of unspecified composition. In the addition reaction, as low as 1 mol. of rhodium compound or complex may be used per 109 moles. compound containing aliphatic unsaturation, and the reaction mixture contains 0.005-20 Si-H links per pair of C atoms linked by double bonds, or 0.06-16 per pair linked by triple bonds.  Reaction may take place at 0-200 DEG  C., in an inert solvent and the rhodium complex may be added in solution.  In Example 3 one part of a complex formed by reacting rhodium chloride with triethylsilane is added to 100 parts of an equimolar mixture of tetramethyl tetravinyl cyclo-tetrasiloxane and tetramethylcyclotetrasiloxane and the mixture heated to yield a glass-like polymer.  In Example 6, using the same catalyst and 200 parts of an equimolar mixture of trichlorosilane and hexene-1, hexyltrichlorosilane is obtained.ALSO:In the preparation of organo-silicon monomers or polymers by the addition reaction between a Si-H compound and a compound containing aliphatic unsaturation, the catalyst is an organic rhodium compound or complex soluble in at least one of the reactants.  The Si-H compound may be inorganic or organic, monomeric or polymeric, and may be substituted with e.g. halogen atoms, hydrocarbon radicals, halogenated hydrocarbon radicals, cyanoalkyl radicals, -OR or OOCR radicals, wherein R is an organic radical.  Silicon atoms may be separated as in polysiloxanes, polysilalkylenes, polysilarylenes and organosilazanes. The compound contains ethylenic or acetylenic unsaturation may also contain silicon.  The catalyst may be a rhodium carboxylate prepared by reacting rhodium chloride with 3-6 mols./mol. of the alkali metal salt of a carboxylic acid.  In aqueous solution a precipitate, which may be of the basic salt, is produced. In alcoholic solution the tri-carboxylate is formed. The preparation of rhodium heptanoate is described. Alternatively, the catalyst may be an organorhodium complex prepared by reacting an alcoholic solution of rhodium chloride, containing optionally a basic compound free of complexing groups, e.g. NaOH, with at least one mol./atom of rhodium of an olefin at 50-125 DEG  C.  Such complexes include Rh2(C2H4) Cl2, HRh(C8H16)2Cl2, H2Rh2(C6H12)2Cl4 and H2Rh(C4H8)Cl3.  The reaction product is evaporated to dryness, extracted with chloroform, evaporated to an oily liquid, and extracted with hexane to yield a powder. Another suitable organorhodium complex is that prepared by adding an alcoholic solution of rhodium chloride to at least 2 mols./mol. alcohol of a silane R3SiH, where R is a monovalent hydrocarbon radical.  The silicon containing complex is of unspecified composition.  In the addition reaction, as low as 1 mol. of rhodium compound or complex may be used per 109 moles compound containing aliphatic unsaturation and the reaction mixture contains 0.005-20 Si-H links per pair of C atoms linked by double bonds, or 0.06-16 per pair linked by triple bonds. Reaction may take place at 0-200 DEG  C., in an inert solvent and the rhodium complex may be added in solution.  In Example (3), one part of a complex formed by reacting rhodium chloride with triethylsilane is added to 100 parts of an equimolar mixture of tetramethyl tetravinyl cyclo-retrasiloxane and tetramethylcyclotetrasiloxane and the mixture heated to yield a glass-like polymer.  In Example (6), using the same catalyst and 200 parts of an equimolar mixture of trichlorosilane and hexene-1, hexyltrichlorosilane is obtained.