Cumulated double bond systems as ligands : III. 1H NMR studies of the intra- and inter-molecular exchange processes of dialkylsulfurdiimine compounds of palladium(II)

The preparation, properties and kinetic behaviour of trans-PdCl₂(RNSNR)L] (L  PhMe₂As and Et₃As; R  Me, Et, i-Pr and t-Bu) are reported.In the case of R  t-Bu only one isomer, which participates in various intermolecular exchange reactions, is found. For R  Me, Et and i-Pr two isomers occur in solution. The most abundant isomer, which has a structure analogous to the t-butyl compound, is similarly involved in intermolecular exchange reactions of the sulfurdiimine. However, the second isomer, in which non-bonded Pd···HC interactions between the metal atom and the uncoordinated end of the sulfurdiimine group are probably present, does not participate in intermolecular exchange reactions if free sulfurdiimine is present. For this isomer fluxional behaviour is observed.