Synthesis and Structural Characterization of Metallogermylenes, Cp-Substituted Germylene, and a Germanium(II)-Borane Adduct from Pyridyl-1-azaallyl Germanium(II) Chloride

The reaction of [{N(SiMe 3 )C(Ph)C(SiMe 3 )(C 5 H 4 N-2)}GeCl] ( 1 ) with Na[M(η 5 -C 5 H 5 )(CO) 3 ]·2DME (M = Mo, W) afforded the metallogermylenes [{N(SiMe 3 )C(Ph)C(SiMe 3 )(C 5 H 4 N-2)}Ge-M(η 5 -C 5 H 5 )(CO) 3 ] (M = Mo ( 2 ), W ( 3 )). Compounds 2 and 3 have been characterized by X-ray crystallography and NMR and IR spectroscopy. Structural analyses of compounds 2 and 3 are consistent with the presence of lone-pair electrons at the germanium(II) center. The Ge–Mo and Ge–W bond distances of 2.875(1) and 2.852(1) Å are consistent with Ge–metal single bonds. The chlorogermylene 1 was also used in the synthesis of a substituted germylene, [{N(SiMe 3 )C(Ph)C(SiMe 3 )(C 5 H 4 N-2)}Ge(η 1 -C 5 H 5 )] ( 4 ), by reaction with sodium cyclopentadienylide. The reaction of compound 1 with tris(pentafluorophenyl)borane led to the formation of a Lewis acid–base adduct, [{N(SiMe 3 )C(Ph)C(SiMe 3 )(C 5 H 4 N-2)}Ge(Cl)→B(C 6 F 5 ) 3 ] ( 5 ).