engleski

Acidity of the Lowest Excited States of Benzocyclopropene

Lately we have been engaged in studying acidity of small ring hydrocarbons fused to the aromatic ring. Typical example is provided by benzocyclopropene (1) for which Delta H_a = 386 +/- 3 kcal mol^-1 was determined by bracketing technique and high level ab initio calculations. In this contribution we report on the effect of electronic excitation on acidity of 1 based on results of CASPT2 calculations employing ANO-L basis set. Results show that acidity of 1 increases by 44.6 and 39.5 kcal mol^-1 on excitation to the first excited singlet and triplet valence states, respectively. Molecular and electronic structure of the lowest excited states will be discussed in some detail.

acidity; benzocyclopropene; excited states

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