부산대학교 도서관

To elucidate tentative assignments of metal–ligand modes of thiosemicarbazide complexes, a structural study and a assignment of the normal vibrations of 2-methylthiosemicarbazide copper(II) nitrate, [Cu(2MeTSC)2(NO3)2] have been done through the ab initio DFT: pBP86/DN** procedure, and through the normal coordinate analysis (NCA). In the vibrational calculations, the elongated Cu–ONO2 bonds of the nitrate groups were considered in the C=S and C=N tautomers of the complex. DFT calculations had revealed that the infrared spectra can be well interpreted through the C=N tautomer, failing in the prediction of the –NO2 group wavenumbers. A little difference stabilization energy for the tautomers were found: for the C=N tautomer was E =−3487,36376a.u., and for the C=S tautomer, E =−3473,93598a.u. The observed combination bands at 1763.0 and at 1754.0cm−1 are an indicative that the –NO3− groups acts as monodentate ligands. Calculations had confirmed the experimental assignment of the infrared spectrum. [Copyright &y& Elsevier]