Abstract:
This thesis deals with the characterisation of a number of coordination compounds using various spectroscopic techniques. Cations of the type [LnHgX]+ (where L = AsMe3, PPh3, AsPh3, py,3,5Cl2py, l,10phen, 2,2'bipy; n=1,2; X=Cl,Br,I,SCN, OAc) have been prepared as the nitrate and terafluoroborate salts. Characterisation by infrared, Raman, 31p n.m.r. and n.q.r. spectroscopy and by conductivity suggest that two-(n=1) and three-(n=2) coordinate mercury atoms are involved in these cations.
Complexes of the type, [Cat] [Hg(SR)3] (R=Me,But; Cat=Net4+, NBun4+, [N(PPh3)2]+) have been prepared and characterized by infrared, Raman and 1H n.m.r. spectroscopy. In the complex, [NEt4][Hg(SMe)3], centrosymmetric dinuclear anions, Hg2(SMe)62-, exist in the solid state, while in ethanol solution the complex dissociates into mono-meric Hg(SMe)3- anions. The Buts- complexes appear to exist as mononuclear Hg(SBut)3- species in the solid state and in solution.
Metal-halogen vibrational frequencies have been assigned in the infrared and Raman spectra of the compounds, (PPh3)nMX (n=2, M=Au, X=Cl,Br, I; n=3, M=Au, X=Cl; M=Cu; X=Cl,Br). This work was carried out to resolve some apparent anomalies in the literature concerning assignments of these vibrations and shows that the frequencies have the expected dependence on metal coordination number.
A variety of species of the type [MmXn]n-m (where M=Cu,Ag; X=Cl,Br,I) have been prepared and characterised by infrared, Raman and n.q.r. spectroscopy as well as by conductivity. In particular, anions of the type, MX32-, have been isolated and shown to exist as D3h, trigonal planar entities in the solid state.
Mixed halide species of the type [MmXnYp] (n+p)-m (where M=Cu,Ag; X and Y = Cl,Br,I; m,n and p = 1,2 or 3) have been prepared and the metal-halogen stretches assigned.
Force constants for a series of species, M2X62- (M=Ga,In; X=Cl,Br,I) have been calculated using normal coordinate analysis procedures and compared with related compounds.