Ligand-protected strain-free diarylgermylenes

Reaction of 2 molar equiv of 2,6-di(1'-naphthyl)phenyllithium with bis[bis(trimethylsilyl)-amino]germylene afforded the red, crystalline, stable bis[2,6-bis(1-naphthyl)phenyl]germylene [(bisap)(2)Ge, 6] in good yield. The structure of the solvate 6.C6H6 was determined by single-crystal X-ray methods. The molecule features a largely strain-free conformation with a C-Ge-C angle of 102.72(9)degrees and Ge-C distances of 2.036(2) and 2.030(2) Angstrom. These parameters are very close to those calculated for the diphenylgermylene prototype by ab initio methods [101.6; 2.006 Angstrom]. The two new wing-like 2,6-di(1-naphthyl)phenyl substituents appear to protect the germylene center of 6 in a very efficient way without inducing destabilizing distortions. Bis[2,4,6-triphenylphenyl] germylene [(triph)(2)Ge, 1] was also prepared. Germylenes 1 and 6 were oxidized to yellow products of the composition (triph)(2)GeO (2) and (bisap)(2)GeO (7), respectively. The compounds have been characterized by their mass spectra, which show the parent ions in full accordance with the proposed formulas.