Chemistry of the metal carbonyls. Part LXX. Trimethylsilyl, trimethylgermyl, and trimethylstannyl derivatives of cyclo-octatetraene and their complexes with the tricarbonyliron group
Abstract
Reactions of the compounds Me3MCl (M = Si or Sn) and Me3GeBr with diethyl ether solutions obtained by treating bromocyclo-octatetraene with n-butyl-lithium at –80 °C afford the monosubstituted cyclo-octatetraene compounds C8H7MMe3. The complex [Fe(CO)2(C8H7)(η-C5H5)] has been similarly prepared from [FeCl-(CO)2(η-C5H5)]. These cyclo-octatetraene derivatives react with enneacarbonyldi-iron to yield complexes of the tricarbonyliron group; the silicon and tin derivatives also form binuclear iron complexes [Fe2(CO)6(C8H7-MMe3)]. The complexes [Fe(CO)3(C8H7MMe3)](M = Si or Ge) react with Ph3CBF4 to yield tetrafluoroborate salts which on hydrolysis give complexes [Fe(CO)3{C8H6(MMe3)(CPh3)}] containing disubstituted cyclo-octatetraene ligands.