SYNTHESIS, CHARACTERIZATION, SOLID-STATE CONDUCTANCE AND THERMAL STUDIES OF SOME BIVALENT TRANSITION-METAL TETRATHIOCYANATO BISCUPRATE(I) COMPLEXES WITH HYDRAZIDES AND HYDRAZONES

MCu2(SCN)4.L complexes, where M = Ni(II), Co(II) and L = benzoic acid hydrazide (BH), salicylic acid hydrazide (SH), isonicotinic acid hydra zide (INH) and their isopropanone derivatives viz. isopropanone-benzoy lhydrazone (IBH), -salicyloylhydrazone (ISH), and -isonicotinoylhydraz one (IINH), were synthesised and characterized with the help of elemen tal analyses, electronic, and I.R. spectral, thermal, magnetic moment and solid state conductance data, The complexes are soluble in DMF and DMSO, dissociate in H2O and C2H5OH but are insoluble in other organic solvents and decompose above 190-degrees-C. Co(II) and Ni(II) in the complexes are spin-free and have distorted octahedral stereochemistry. The ligands bond through >C=O and -NH2 or -N=C< groups but in NiCu2(S CN)4.L (L = INH and IINH), the ligands are coordinated through -NH2/-N =C< and the pyridyl ring nitrogen. The SCN groups bridge the two metal centres. TG/DTG/DTA curves of the complexes CoCu2(SCN)4, CoCu2(SCN)4. SH, CoCu2(SCN)4.ISH, CoCu2(SCN)4.INH, NiCu2(SCN)4.BH, NiCu2(SCN)4.IBH and NiCu2(SCN)4.INH indicate a complicated multi-step decomposition wi th a number of exo- and endothermic peaks.