Coordination of ambidentate Te,N-donor ligands, the structure of tungsten pentacarbonyl(2-phenylbenzo-1,3-tellurazole)

Reactions of 2-phenyl- (L) and 2-methylbenzotellurazoles (L') with M(CO)(6) in tetrahydrofuran (UV irradiation, room temperature) yielded hitherto unk nown LW(CO)(5) and L'Cr(CO)(5) complexes. X-ray crystallography suggested t he formation of a Te --> W coordination bond in LW(CO)(5). The value of 2.8 09 Angstrom found for the W-Te distance is equal to the average of two stat istical positions (2.836 and 2.781 Angstrom). The complex is the first repr esentative of azole complex compounds, in which metal coordinates with the chalcogenide endocyclic donor center.