Spectroscopic studies of sulphide, selenide and telluride complexes of palladium (II), rhodium (III) and mercury (II)

The work described in this thesis is concerned with the preparation of dialkyl sulphide (selenide and telluride) and the alkyl phenyl sulphide (selenide) complexes of palladium(II), rhodium(III) and mercury(II) and a study of their spectroscopic properties. Trans-square-planar complexes PdX₂L₂ (where X=halogen, nitrite and nitrate; L=R₂S, Et₂Se, Et₂Te, Ph.S.R, Ph.S.Et) have been prepared and studied using n.m.r., low frequency infra-red and electronic spectroscopic techniques. The influence of the ligand X, cis to the sulphide (selenide and telluride) ligands, on the protons of the α and β carbon atoms of L has been investigated by means of proton magnetic resonance spectroscopy. The results can be interpreted in terms of a significant dπ -dπ bonding between the ligand X and palladium. Metal-halogen, metal-nitrogen, metal-sulphide (selenide and telluride) stretching frequencies have been assigned in the low frequency infra-red region. Both ligand field and ligand to metal charge transfer transitions have been observed in the visible and ultra-violet region of the spectra and assignments have been made. Octahedral complexes mer-RhX₃L₃ (where X=halogen, L=Ph.S.R) and dimeric complexes (Hgx₂.L)₂ containing mercury in a tetrahedral environment (X=halogen, L=R₂S, Et₂Se and Et₂Te) have also been prepared and investigated in a similar manner. Some exploratory work on reactions of dialkyl sulphide complexes of palladium(II) and preparation of new complexes of rhodium(I) was carried out