Organometallic ferrocene-based polymers and poly(carbosilane)s prepared via transition-metal catalysis.

摘要

New ferrocene-based polymers and their corresponding model compounds were prepared via hydrosilylation polymerization and characterized using spectroscopic and electrochemical techniques. The syntheses of poly(carbosilane)s and new Pt-based precatalysts that promote ring-opening polymerization of silacyclobutanes is described.; Model compounds were prepared from one equivalent of 1,1′ -bis(dimethylsilyl)ferrocene and two equivalents of RC≡CR 1 (where R=H, R1=C6H5; R=Si(CH₃)₃, R1=C₆H₅; R=H, R1=Si(CH₃)₃) or from two equivalents of dimethylsilylferrocene and one equivalent of a dialkyne, {lcub}R-C≡C-X-C≡C-R (R=H, X=C₆H₄ (p- and m-); R=Si(CH₃)₃, X=C₆H₄ (p- and m-); R=H, X=Si(CH₃)₂; R=C₆H₅, X=nothing){rcub}, via hydrosilylation using Karstedt's catalyst and Rh(P(C₆H₅)₃)₃I. X-ray studies of the major adduct obtained from 1,1′-bis(dimethylsilyl)ferrocene, C₆H₅C≡CSi(CH₃)₃ (Pt ( ca.)) and dimethylsilylferrocene, (CH₃)₃Si-C≡C-C ₆H₄-C≡C-Si(CH₃)₃ (p- ) are also described.; Hydrosilylation polymerization was successfully employed in the syntheses of ferrocene-based polymers via addition of one equivalent of 1,1′ -bis(dimethylsilyl) ferrocene with one equivalent of various dialkynes, R-C≡C-X-C≡C-R (R=H, X=C₆H₄ (p- and m-); R=Si(CH₃)₃, X=C₆H ₄ (p- and m-); R=H, X=Si(CH₃ )₂; R=C₆H₅, X=nothing) using Karstedt's catalyst and Rh(P(C₆H₅)₃)₃I. Regiochemistry of addition was compared with the model systems described earlier. The preparation of ferrocene-based polymers with two ferrocene units per repeat unit are also presented.; Electrochemical studies were performed on selected model compounds and polymers showing a single reversible wave in all cases.; The syntheses of the silacyclobutanes, 1-methyl-1,2-diphenyl-1-silacyclobutane and (rac.)1,1′-bi-2-napthoxy-1-silacyclobutane are presented. X-ray studies of the latter revealed a planar silacarbocyclic ring. New (R+)- and (rac.)-BINOL substituted sila-ferrocenophanes were reacted with bis(1,5-cyclooctadiene)platinum(0) to afford the corresponding [2]-platina-silaferrocenophanes. Similarly, precatalysts, prepared via insertion of the Pt(1,5-cyclooctadiene) fragment into 1,1-dimethyl-2-phenyl-1-silacyclobutane and 1,1-dimethyl-2,3-benzo-1-sila-2-cyclobutene, are presented.; Transition metal-catalyzed ring-opening polymerization of 1-methyl-1-phenyl-1-silacyclobutane using these precatalysts gave an atactic polymer. The ring-opening polymerization of 1-methyl-1,2-diphenyl-1-silacyclobutane and 1,1-dimethyl-2-phenyl-1-silacyclobutane using bis(1,5-cyclooctadiene)platinum(0), and Karstedt's catalyst, were studied. Anionic ring-opening polymerization of (rac.)1,1′ -bi-2-napthoxy-1-silacyclobutane is reported.