Group 6 transition metal carbonyl complexes with chalcogen-bridged diarsenic(II) ligands

摘要

The neutral complexes [Cr(CO)_4(Ph_2AsOAsPh_2)] 1, [Mo(CO)_4(Ph_2AsOAsPh_2)_2] 2, [Cr(CO)_4(Ph_2AsSAsPh_2)] 3, [Mo(CO)_4(Ph_2AsSAsPh_2)_2] 4, [Cr(CO)_5(Ph_2AsOAsPh_2)] 5 and [Cr(CO)_5(Ph_2AsSAsPh_2)] 6 have been prepared. The crystal structures of compounds 1-5 were determined. The diarsenic ligand in 2, 4, and 5 is monodentate and in 1 and 3 the ligand is bidentate. The crystal structure of the ligand Ph_2AsOAsPh_2 was redetermined and the As-O-As angle found to be 115.98(17) deg, significantly less than the value originally reported. Calculations, using density functional theory, assist discussion of the steric and electronic factors influencing the choice of binding mode.