A THEORETICAL INVESTIGATION ON THE STRUCTURE AND VIBRATIONAL SPECTRA OF PHENINDIONE CARBANION

The structural and spectral changes, arising from the conversion of phenindione into corresponding carbanion, are studied on the basis of standard DFT method, employing the B3LYP functional and 6-311+G(2df,p) basis set. Its relative predictive capabilities are evaluated by comparing the theoretically predicted and experimental frequencies measured in DMSO. The calculations performed give good description of the strong decrease in carbonyl stretching frequencies and two-fold increase in nu CO splitting changes caused by the studied conversion. According to the calculation, the new carbanionic charge is delocalized over the whole anion.