SPECTROSCOPIC STUDY OF NEW SCHIFF-BASES DERIVED FROM DIBENZOYLMETHANE AND BENZOYLACETONE

UV, H-1-NMR, IR and Mass spectra of new Schiff bases derived from dibenzoylmethane and benzoylacetone are described. The strong absorption bands in the UV region between 350-380 nm have been attributed to the electronic transitions which arise from hydrogen bonded conjugate chelate rings. The other bands in the region 250-200 nm were attributed to aromatic and conjugated aromatic rings. The appearance of the signals due to the methylene protons adjacent to the nitrogen atom as a doublet centered at delta = 4.5 ppm in the NMR spectra and the ion C6II5CO+ at m/z 105 in the mass spectra were taken as evidence that these compounds exist primarily in the keto-enamine form in solution.