OLIGOMERS WITH SILICON, GERMANIUM, AND TRANSITION-METAL GROUPS - SYNTHESIS AND CHARACTERIZATION OF METAL-CONTAINING POLY[(SILYLENE)DIACETYLENES] AND POLY[(GERMYLENE)DIACETYLENES]

In order to prepare polycarbosilanes containing organometallic moieties which could be precursors of transition metal-containing ceramics, poly[(silylene)diacetylenes] (silylene: SiMe2, SiMePh, SiPh2) and poly[(methylphenylgermylene)diacetylene] have been reacted with dicobalt octacarbonyl to give the corresponding polymers with approximately half of the acetylene groups complexed with CO2(CO)6 moieties. The introduction of a ferrocenyl group into the main chain of poly[(silylene)diacetylenes] has been achieved by the reaction of the di-Grignard reagent of diacetylene, C4(MgBr2), with various 1,1'-bis(chlorodiorganosilyl)ferrocene and led to the synthesis of [-R2Si-Fc-SiR2-C=C-C=C-]n (SiR2: SiMe2, SiMePh, SiPh2) (Fc: 1,1'-ferrocene). [-R2Si-Fc-SiR2-C=C-C=C-SiR2'-C=C-C=C-]n was obtained in the same way by polycondensation of 1,1'-(LiC=C-C=C-SiR2)2Fc with Cl2-SiR2' (R = Me, R' = Me, Ph; R = R' = Ph). The reaction of poly[(2,5-diphenyl-1-silacyclopentadiene-1,1-diyl)diacetylene] with Fe2(CO)9 and Mo(CO)4(COD) (COD:cyclooctadiene) gave only the complexation of some of the diene units.