Probing the low-barrier hydrogen bond in hydrogen maleate in the gas phase : A photoelectron spectroscopy and ab initio study

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

36 Scopus Citations
View graph of relations

Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)10633-10637
Journal / PublicationJournal of Physical Chemistry A
Volume109
Issue number47
Publication statusPublished - 1 Dec 2005
Externally publishedYes

Abstract

The strength of the low-barrier hydrogen bond in hydrogen maleate in the gas phase was investigated by low-temperature photoelectron spectroscopy and ab initio calculations. Photoelectron spectra of maleic and fumaric acid monoanions (cis-/trans-HO 2CCH=CHCO 2 -) were obtained at low temperatures and at 193 nm photon energy. Vibrational structure was observed for trans-HO 2CCH=CHCO 2 - due to the OCO bending modes; however, cis-HO 2CCH=CHCO 2 - yielded a broad and featureless spectrum. The electron binding energy of cis-HO 2CCH=CHCO 2 - is about 1 eV blue-shifted relative to trans-HO 2CCH=CHCO 2 - due to the formation of intramolecular hydrogen bond in the cis-isomer. Theoretical calculations (CCSD(T)/aug-cc-pVTZ and B3LYP/aug-cc-pVTZ) were carried out to estimate the strength of the intramolecular hydrogen bond in cis-HO 2CCH=CHCO 2 -. Combining experimental and theoretical calculations yields an estimate of 21.5 ± 2.0 kcal/mol for the intramolecular hydrogen bond strength in hydrogen maleate. © 2005 American Chemical Society.

Citation Format(s)