2-mercapto-5-methyl-1,3,4-thiadiazole as a ligand in Ru(III), Rh(III), Os(III) and Ir(III) trichloride complexes

Some 2-mercapto-5-methyl-1,3,4-thiadiazole complexes of Rh(III), Ir(III), Ru(III) and Os(III) have been prepared and characterized by chemical-analysis, conductometric, room-temperature magnetic-moment, electronic, IR, EPR and thermogravimetric measurements. From the magnetic properties it was derived that the above ligand forms low-spin complexes with all the metal ions. The position and multiplicity of the metal-halogen stretching modes in the far-IR region have been investigated. The wavelengths of the principal electronic absorption peaks have been accounted for in terms of the crystal field theory and the various parameters have been calculated.