PROTONATED P-BENZOQUINONE

Citation
Kk. Irikura et al., PROTONATED P-BENZOQUINONE, Journal of organic chemistry, 61(9), 1996, pp. 3167-3171
Citations number
35
Categorie Soggetti
Chemistry Inorganic & Nuclear
ISSN journal
00223263
Volume
61
Issue
9
Year of publication
1996
Pages
3167 - 3171
Database
ISI
SICI code
0022-3263(1996)61:9<3167:PP>2.0.ZU;2-0
Abstract
The structure and energetics of protonated p-benzoquinone (pBQ) have b een investigated using high-pressure mass spectrometry and ab initio c alculations. The experimental proton affinity of pBQ is 801.4 +/- 8.9 kJ/mol (191.5 +/- 2.1 kcal/mol) (1 sigma) from bracketing measurements and hydration thermochemistry. This value is supported by theory and by analogies with related compounds. In its protonation chemistry, pBQ behaves as an aliphatic ketone, both structurally and energetically. The dissociation of the hydrate (pBQH(+)).(H2O) is characterized by De lta H degrees(D) = 90.0 +/- 2.3 kJ/mol and Delta S degrees D = 123.4 /- 4.9 J/mol . K (95% confidence).