Acetic acid-water complex: The first observation of structures containing the higher-energy acetic acid conformer

Lopes S., Fausto R., Khriachtchev L.

JOURNAL OF CHEMICAL PHYSICS, vol.144, no.8, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 144 Issue: 8
  • Publication Date: 2016
  • Doi Number: 10.1063/1.4942027
  • Journal Name: JOURNAL OF CHEMICAL PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Istanbul Kültür University Affiliated: Yes

Abstract

Non-covalent interaction of acetic acid (AA) and water is studied experimentally by IR spectroscopy in a nitrogen matrix and theoretically at the MP2 and coupled-cluster with single and double and perturbative triple excitations [CCSD(T)]/6-311++ G(2d,2p) levels of theory. This work is focused on the first preparation and characterization of complexes of higher-energy (cis) conformer of AA with water. The calculations show three 1:1 structures for the trans-AA center dot center dot center dot H2O complexes and three 1:1 structures for the cis-AA center dot center dot center dot H2O complexes. Two trans-AA center dot center dot center dot H2O and two cis-AA center dot center dot center dot H2O complexes are found and structurally assigned in the experiments. The two cis-AA center dot center dot center dot H2O complexes are obtained by annealing of a matrix containing water and cis-AA molecules prepared by selective vibrational excitation of the ground-state trans form. The less stable trans-AA center dot center dot center dot H2O complex is obtained by vibrational excitation of the less stable cis-AA center dot center dot center dot H2O complex. In addition, the 1:2 complexes of trans-AA and cis-AA with water molecules are studied computationally and the most stable forms of the 1:2 complexes are experimentally identified. (C) 2016 AIP Publishing LLC.