SYNTHESIS AND SPECTRAL STUDIES OF PLATINUM-GROUP METAL-COMPLEXES OF 312-MEMBERED TETRADENTATE MACROCYCLIC LIGANDS

Platinum group metal complexes of the general compositions M(Ligand)Cl -3 [M = Ru(III), Ir(III)] and M(Ligand)Cl-2 [M = Pd(II), Pt(II) have b een synthesized [Ligand = enyl-1,4,7,10-tetraazacyclododeca-1,3,7,9-te traene (L-1), enyl-1,4,7,10-tetraazacyclododeca-1,3,7,9-tetraene (L-2) and thyl-1,4,7,10-tetraazacyclododeca-1,3,7,9-tetraene (L-3)]. The co mplexes have been characterized on the basis of elemental analyses, mo lar conductance, magnetic susceptibility measurements and electronic s pectral studies. Sharp bands were observed in the electronic spectra o f the complexes. The epsilon values could not be reported as the spect ra and been recorded in Nujol mulls. The Ru(III) and Ir(III) complexes have been found to stabilize an octahedral geometry while a square-pl anar geometry is assigned to the Pd(II) and Pt(II) complexes.