Acetic acid dimers in a nitrogen matrix: Observation of structures containing the higher-energy conformer

Lopes S., Domanskaya A. V., Rasanen M., Khriachtchev L., Fausto R.

JOURNAL OF CHEMICAL PHYSICS, vol.143, no.10, 2015 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 143 Issue: 10
  • Publication Date: 2015
  • Doi Number: 10.1063/1.4929575
  • Journal Name: JOURNAL OF CHEMICAL PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Istanbul Kültür University Affiliated: Yes

Abstract

Acetic acid (AA) dimers are studied experimentally by infrared spectroscopy in a N-2 matrix and theoretically at the MP2/6-311++G(2d,2p) level of approximation. This work is focused on the first preparation and characterization of structures containing the higher-energy (cis) conformer of AA. Nine trans-trans, fourteen trans-cis, and six cis-cis dimers are theoretically predicted. Five trans-trans and a number of trans-cis dimers are identified in the experiments, but no indication of cis-cis dimers is found. Two trans-trans dimers and the trans-cis dimers are reported for the first time. One trans-cis dimer is prepared by selective vibrational excitation of the structurally related trans-trans dimer, which converts one of the trans subunits to the cis form. Several trans-cis dimers are obtained by annealing of a matrix containing both trans and cis monomers of AA. Tunneling-induced conversion of the trans-cis dimers into trans-trans forms (including two new trans-trans forms) is observed at low temperatures. (C) 2015 AIP Publishing LLC.