The chemistry of molybdenum and tungsten. Part XIII. Molybdenum(V) complexes of dithiocarbamates and dithioethers

Abstract

Oxotrichloromolybdenum(V) reacts with dithiocarbamates. R 2dtc − (R 2  Me 2, Et 2, [CH 2] 4) in acetonitrile at room temperature with cleavage of the terminal molybdenum-oxygen bond to yield [Mo(R 2dtc) 4] +, isolated as the chloride or tetraphenylborate salts; infrared spectra indicate bidentate coordination by the ligands, and these complexes appear to have dodecahedral geometry. From this same reaction can be isolated the dimeric [Mo 2O 4(R 2dtc) 2] species which contain a double MoOMo bridges as well as terminal MoO bonds, and also the [Mo 2O 3(Et 2dtc)] complex containing a single MoOMo bridge and two terminal MoO linkages. With a series of dithioethers oxotrichloromolybdenum(V) yields [MoO(ligand)Cl 3], but the ability to complex depends critically on the structure of the dithioether. The structures of these complexes have been assigned with the aid of vibrational, electronic and electron paramagnetic resonance spectroscopy.