FTIR matrix isolation studies of thermal decomposition of 1,2,4-triazolyl-3-carboxylic acid

摘要

The title compound 1,2,4-triazolyl-3-carboxylic acid (TC) belongs to the rarely studied N-H azoles bearing a carboxylic group attached directly to the ring. Thermal decomposition of TC was studied in detail both experimentally using FTIR matrix isolation technique and theoretically at the B3LYPD3 and B3LYP levels with 6-311++G(2d,2p) basis set. Both concerted and stepwise pathways were considered theoretically for unimolecular decarboxylation of TC. Experimentally, in addition to the 1,2,4-triazole (TR) and carbon dioxide, two weak molecular complexes formed between TR and CO2 were detected in the studied matrices. Based on a comparison of the predicted and observed wavenumber shifts, the structures of the complexes have been confirmed. (C) 2020 Elsevier B.V. All rights reserved.