Abstract
The interaction of bis(O,O′-diethyldithiophosphato)oxovanadium(IV), VOdtp2, with pyridine has been studied in toluene by means of the optical absorptions. It has been found that the visible absorption band characteristic of VOdtp2 was shifted toward longer wavelengths upon the formation of the complex species identified as VOdtp2·Py and VOdtp2·Py2. The equilibrium constants and enthalpy and entropy changes for the formation of VOdtp2·Py were determined from the spectral characteristics, measured as a function of the solvent composition and the temperature. The results obtained were then discussed in comparison with those for the base addition of other oxovanadium complexes.