
%0 Journal Article
%A Young, CG 
%A Enemark, JH 
%T An Investigation of Adduct Complexes of M(S<sub>2</sub>CNEt<sub>2</sub>)<sub>2</sub>(Co)<sub>2</sub> (M=Mo,W) by <sub>95</sub>Mo and <sub>183</sub>W N.M.R-Spectroscopy
%J Australian Journal of Chemistry
%D 1986/07/01
%V 39
%N 7
%P 997-1006
%K 
%R https://doi.org/10.1071/CH9860997
%U https://www.publish.csiro.au/paper/CH9860997 
%X The seven-coordinate adducts M(S2CNEt2)2(CO)2L and [M(S2CNEt2)2(CO)2]2-&#956;-L (M = Mo, W;L below), derived from the 16-electron complexes M(S2CNEt2)2(CO)2, have been investigated by 95Mo and 183W n.m.r. spectroscopy. The molybdenum and tungsten adducts exhibit resonances in the regions from 310 to -430 and from -465.5 to -1500 ppm , respectively. All the resonances are shielded relative to those of the M(S2CNEt2)2(CO)2 precursors. The dependence of the nuclear shielding on L is as follows. For M = Mo: NH2NHSO2C6H4Me < Cl - < OPPh3 < &#956;- pyrazine < pyridine < NH2NHCOPh < NH2NMe2 < &#956;-NH2NHMe < &#956;-NH2NH2 < &#956;-NH2CH2CH2NH2 < NH3 < N3- < F- < AsPh3 < PPh3 < SbPh3 < PPh2Et < PPh2Me < PMe3 < P( OPh )3 < P( OEt )3 < P( OMe )3 < CO. For M = W: NH2NHCOPh < AsPh3 < Ph2PCH2PPh2 < PPh3 < PPh2Et < Ph2PCH2CH2PPh2 < PPh2Me < PMe3 < P( OPh )3 < P( OEt )3 < P( OMe )3 < CO. The OPPh3, halide and nitrogen-donor ligand adducts participate in a dynamic equilibrium with Mo(S2CNEt2)2(CO)2 on the n.m.r . time scale. The remaining adducts do not exhibit such behaviour. The chemical shifts of both the molybdenum and tungsten adducts are correlated with the &#960;- acceptor ability of the ligand , L, and the stereochemistry of the adducts. A linear relationship between the chemical shifts of analogous molybdenum and tungsten complexes is observed; the equation of the line is &#948;(183W) = 1.46&#948;(95Mo)-857.5. 
