Synthesis, spectral and thermal investigations of some mixed ligand complexes of thorium(IV) derived from semicarbazones and diphenyl sulfoxide

In the present work, the authors describe the synthesis of some mixed ligand complexes of thorium(IV) derived from 4[N-(2'-hydroxy-1'-naphthalidene)amino]antipyrine semicarbazone (HNAAPS) or 4[N-(cinnamalidene)amino]antipyrinesemicarbazone (CAAPS) as primary ligand and diphenyl sulfoxide (DPSO) as secondary ligand with the general composition ThX(4 center dot)n(L). DPSO (n = 1, X = Cl, Br, NCS or NO3; n = 2, X = I or ClO4, L = HNAAPS or CAAPS). All the compounds were characterized through elemental analysis, molar conductance, molecular weight, infrared data and thermogravimetric analysis. The infrared studies reveal that the semicarbazones behave as neutral tridentate (N, N, O) while DPSO coordinates through its oxygen atom. The nitrates are bicovalently bonded, while thiocyanates are N- coordinated in these compounds. In conclusion, the coordination number of the central metal ion displays coordination number 7, 8, 9 or 12 depending on the nature of the anionic ligands.