A new class of compounds of the family M(H₂O)₆(OPTA)₂ (where M = Co(II), Ni(II), and Zn(II); OPTA = 1-oxopyridinium-2-thioacetato) was prepared from the appropriate metal acetates, 1-oxo-pyridinium-2-thioacetic acid (OPTAH), and potassium hydroxide in hydrothermal media and structurally characterized. The structure is constructed from M(H₂O)₆²⁺ and two anions of OPTAH (C₇H₆NO₃S) linked through hydrogen bonding into an extended network.

The FTIR and FT Raman spectra of dacarbazine were recorded in the regions 4000-400 and 3500-100 cm^-1, respectively. The optimized geometry, wavenumber, polarizability and several thermodynamic properties of dacarbazine were studied using ab initio Hartree-Fock, MP2 and DFT methods. A complete vibrational assignment aided by the theoretical harmonic wavenumber analysis was proposed. The calculated harmonic vibrational frequencies were compared with experimental FTIR and FT Raman spectra. Based on the comparison between calculated and experimental results and the comparison with related molecules, assignments of fundamental vibrational modes were made. The X-ray geometry and experimental frequencies were compared with the results of theoretical calculations.