CARBONYL HALIDES OF GROUP 6 TRANSITION METALS .7. NITROSYL HALIDE DERIVATIVES OF MOLYBDENUM AND TUNGSTEN(2)

The previously reported dihalodinitrosylbis(triphenylphosphine)molybdenum and tungsten(II) 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. © 1968 CSIRO. All rights reserved.