Triplet photochemistry within zeolites through heavy atom effect, sensitization and light atom effect
作者:K Pitchumani、M Warrier、Lakshmi S Kaanumalle、V Ramamurthy
DOI:10.1016/s0040-4020(03)00865-2
日期:2003.7
rearrangement of barrelenes, oxa-di-π-methane rearrangement of β,γ-unsaturated ketones and photodimerization of acenaphthylene as probe reactions. The two methods, heavy cation effect and triplet sensitization, are well established solution techniques and these work well within zeolites. The Zimmerman rearrangement of dibenzobarrelene is enhanced even within Li+ and Na+ exchanged zeolites and these are
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.
Photochemistry of ketones in solution. 66. Experimental evidence for the intermediacy of singlet (S1) and triplet (T2) n,.pi.* states in the [1,3]-sigmatropic acyl shift of photoexcited 3-methyl-3-(1-cyclopentenyl)butan-2-one
作者:David I. Schuster、Lidia T. Calcaterra
DOI:10.1021/ja00387a041
日期:1982.11
Novel photochemical rearrangements of citral and related compounds at elevated temperatures