Research Information System
MOLECULAR PHYSICS, no.13, pp.1708-1718, 2019 (SCI-Expanded)
Formic acid (HCOOH, FA) was studied experimentally, by infrared spectroscopy, in H-2 and D-2 matrices, with focus on the preparation and characterisation in these matrix media of structures containing the higher-energy (cis) conformer. The cis-FA monomer and the cis-FA(...)N(2) complex were successfully produced by selective vibrational excitation of corresponding trans-FA based species, and vibrationally characterised. The tunneling-induced conversion of the cis-FA(...)N(2) complex in the studied matrices into the corresponding trans-FA complex was also investigated, and the found tunnelling properties discussed, in particular in comparison with those observed for the spontaneous conversion of cis-FA monomer into trans-FA. This article constitutes the first report on the infrared spectrum of FA conformers and stability of cis-FA monomer in a D-2 matrix, and on the structure, spectroscopy and stability of the cis-FA(...)N(2) complex in both H-2 and D-2 matrices. Different attempts to prepare the cis-FA(...)H(2)O complex in the two investigated matrices are also described in detail, both from previously in situ generated cis-FA monomer followed by thermal mobilisation and by direct selective vibrational excitation of the trans-FA-H2O complex. [GRAPHICS] .