PREPARATION, CRYSTAL-STRUCTURE AND FLUXIONAL BEHAVIOR OF SIGMA-S-BONDED PALLADIUM AND PLATINUM COMPLEXES OF THE PH4P2N4S2R- (R = ME OR BUT) ANIONS

The reaction of the Ph4P2N4S2R anions (R = Me or Bu(t)), generated from 1,5-Ph4P2N4S, and the appropriate alkyllithium reagent, with cis- or trans-[MCl2(PEt3)2] (M = Pd or Pt) produces the complexes [MCI(PEt3)2(Ph4P2N4S2R)] (R = Me, M = Pd or Pt; R = Bu(t), M = Pt) shown by X-ray crystallography (M = Pd, R = Me) to involve cy-S bonding of the P2N4S, ring to the metal; variable-temperature P-31 NMR spectra of these complexes indicate a significant energy barrier to rotation about the M-S bond of 41-46 kJ mol-1