Thermally and vibrationally induced conformational isomerizations, infrared spectra, and photochemistry of gallic acid in low-temperature matrices

Justino L. L. G., Reva I., Fausto R.

JOURNAL OF CHEMICAL PHYSICS, vol.145, no.1, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 145 Issue: 1
  • Publication Date: 2016
  • Doi Number: 10.1063/1.4954894
  • Journal Name: JOURNAL OF CHEMICAL PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Istanbul Kültür University Affiliated: Yes

Abstract

Near-infrared (near-IR) narrowband selective vibrational excitation and annealing of gallic acid (3,4,5-trihydroxybenzoic acid) isolated in cryogenic matrices were used to induce interconversions between its most stable conformers. The isomerizations were probed by infrared spectroscopy. An extensive set of quantum chemical calculations, carried out at the DFT(B3LYP)/6-311++G(d,p) level of approximation, was used to undertake a detailed analysis of the ground state potential energy surface of the molecule. This investigation of the molecule conformational space allowed extracting mechanistic insights into the observed annealing-or near-IR-induced isomerization processes. The infrared spectra of the two most stable conformers of gallic acid in N-2, Xe, and Ar matrices were fully assigned. Finally, the UV-induced photochemistry of the matrix isolated compound was investigated. Published by AIP Publishing.