Carbonyl halides of the Group VI transition metals. VII. Nitrosyl halide derivatives of molybdenum and tungsten(II)

Abstract

The previously reported dihalodinitrosylbis(triphenylphosphine)molybdenum and tungsten(11) type complexes, M(NO)₂L₂X₂ (M = Mo, W; L = PPh₃, AsPh₃, SbPh₃; X = Cl, Br), have been prepared by a new method involving the action of nitric oxide on the corresponding tricarbonyl derivatives. The new feature of this method is that, unlike the previous methods, it is not stereospecific, and in some cases all three possible cis isomers are formed. The identification of the various isomers has given a natural explanation of the apparently anomalous order of π-bonding effects in these complexes previously reported by Cotton and Johnson.