Cobalt complexes of silicon and germanium heterocyclotriynes with one or two cyclyne rings

The synthesis and structural characterization of Ge(OBET)(2), SiPh2(OBET)(C o-2(CO)(6))(2), and Ge(OBET)(2)(Co-2(CO)(6))(2) are reported. Reaction of L i-2(OBET), generated in situ from the reaction of nBuLi and o-(bisethynyl)t olane (OBET)H-2, with GeCl4 in a 2:1 molar ratio gave Ge(OBET)(2) in 64% yi eld. Ge(OBET)(2) was characterized by H-1 NMR, C-13 NMR, elemental analysis , FDMS, and X-ray crystallography. Co-2(CO)(8) selectively complexes to the bent alkynes adjacent to Ge or Si of Ge(OBET)(2) and SiPh2(OBET) and sever ely distorts the ligands. Comparisons are made to related complexes.