摘要:
The nature of the lowest triplet state of enones is altered by the cations present within Y zeolites. Alkali metal ions, such as Li+, are predicted to interact with the carbonyl unit of enones in a collinear fashion and significantly lower both the p-type n and pi -2 orbitals. Excited state energies, estimated at the CIS(D)/6-31+G* level, show that the lowest triplet is n-pi* in character for the enones, but switch to pi-pi* on coordination with Li+. Observed product distribution within zeolite is consistent with this theoretical prediction. (C) 2001 Elsevier Science Ltd. All rights reserved.