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Thermochemical determination of the structure of negative ions on the basis of data from resonance electron capture mass spectrometry. Phenol, its chlorinated derivatives and a thioanalogue
Author(s) -
Muftakhov Mars V.,
Khatymov Rustem V.,
Mazunov Victor A.,
Ponomarev Dmitri A.,
Takhistov Vyatcheslav V.,
Vatlina Lidia P.
Publication year - 2000
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/1097-0231(20000830)14:16<1482::aid-rcm50>3.0.co;2-e
Subject(s) - chemistry , isodesmic reaction , pentachlorophenol , phenol , mass spectrometry , molecule , radical , ion , electron paramagnetic resonance , resonance (particle physics) , chlorophenol , analytical chemistry (journal) , medicinal chemistry , computational chemistry , organic chemistry , chromatography , nuclear magnetic resonance , physics , particle physics
Appearance energies for [M – H] − ions from phenol ( I ), 4‐chlorophenol ( II ), pentachlorophenol ( III ) and pentachlorothiophenol ( IV ) were measured. The following thermochemical data were deduced from experiment: ΔH acid values of 343.3, 335.7, 317.1 and 317.1 kcal mol −1 for RH molecules ( I, II, III , and IV , respectively) and electron affinities (EAs) of R · free radicals 2.55, 2.90, 3.79, and 3.65 eV, respectively. Our data for phenol ( I ) and 4‐chlorophenol ( II ) demonstrate a higher stabilization of ArO − anions than was previously accepted. Using the enthalpic shift procedure for molecules and a series of isodesmic reactions for free radicals, earlier elaborated by the authors, a new Δ ${\bf H}_{\bf f}^{\bf 0}$ values for the following gas‐phase species were obtained (kcal mol −1 ): C 6 Cl 5 Br (5.0), C 6 Cl 5 SH (8.5), p ‐ClC 6 H 4 C · (2.0), C 6 Cl 5 C · (−15), C 6 Cl 5 S · (44). Copyright © 2000 John Wiley & Sons, Ltd.