DENSITY-FUNCTIONAL CALCULATION OF THE INNER-SHELL SPECTRA FOR 2 STABLE ENOL TAUTOMERS - ACETYLACETONE AND MALONALDEHYDE

In this paper we report results from our theoretical studies on two P- diketones which exist as stable enol tautomers: acetylacetone and malo naldehyde. We found that density functional theory (DFT) with Becke's exchange functional and Perdew's correlation functional can accurately predict the core-electron binding energies (CEBEs) of both molecules. The oxygen 1s --> pi inner-shell excitation spectra (ISES) of both t automers have also been studied using our DFT procedure. The CEBEs for the corresponding carbons and oxygens of the C=O and C-OH groups of m alonaldehyde are larger than those of acetylacetone, The first term va lues corresponding to a core-hole on the carbonyl oxygen were found to be larger than those with a core-hole on the enol oxygen. The observa tion indicates that the effect of a core-hole in the proximity of pi: orbital has a stronger effect on increasing the electron affinity of the core-ionized cation. (C) 1998 Elsevier Science B.V. All rights res erved.