STUDIES ON THE STEREOCHEMISTRY OF DIPHENYL DIKETONE MONOTHIOSEMICARBAZONE AND ITS TRANSITION-METAL COMPLEXES

The stereochemistry and complexation behaviour of diphenyl diketone mo nothiosemicarbazone (DKTS) with Cu-II, Co-II, Ni-II, Cd-II, Zn-II, Pd- II, Pt-II, Ru-III, Rh-III and Ir-III have been investigated by means o f chemical, magnetic and spectral (i.r., Raman, H-1- and C-13-n.m.r. a nd electronic) studies. The ligand forms complexes of the M(DKTS)(2) t ype with Ni-II, Cu-II and Co-II having a distorted octahedral geometry . The absence of a v(M-X) band in the i.r. spectra, coupled with their 1:1 electrolytic conductances, suggests that Ru-III, Rh-III and Ir-II I form octahedral complexes of the [M(DKTS)(2)]Cl type. A four-coordin ate structure involving bridging halides is proposed for the Zn-II, Cd -II, Pd-II and Pt-II complexes, which have relatively low v(M-X) vibra tion modes.