Experimental and theoretical investigation of hydrogen bonded complexes between glycolic acid and water.

Theoretical MP2 and B3LYPD3 calculations, as well as experimental matrix isolation infrared spectroscopy studies, were used to investigate the 1:1 complexes formed between glycolic acid and water. Out of five computationally predicted forms of GA⋯HO complex the most stable one was detected experimentally in solid argon. This structure is characterized by two intermolecular OH⋯O hydrogen bonds depicting a six-member ring in which water acts both as a proton acceptor and as a proton donor.

Weakly bound complexes of 1,2,3-triazole with nitrogen and carbon dioxide isolated in solid argon: A combined FT-IR matrix isolation and theoretical investigation.

Matrix isolation FT-IR spectroscopy was combined with quantum-chemical calculations in order to characterize complexes of 1,2,3-triazole (3TR) with nitrogen and carbon dioxide. Geometries of the possible 1:1 and 1:2 complexes, as well as 3TR dimers, were optimized at the DFT (B3LYP-D3) level of theory with the 6-311++G(3df,3pd) basis set. Six different 3TR⋯N structures of the 1:1 stoichiometry were optimized which are characterized by weak hydrogen bonds (N-H⋯N and C-H⋯N) and/or Van der Waals type interactions (N⋯C, N⋯N, N⋯π).

Experimental FTIR-MI and Theoretical Studies of Isocyanic Acid Aggregates.

Homoaggregates of isocyanic acid (HNCO) were studied using FTIR spectroscopy combined with a low-temperature matrix isolation technique and quantum chemical calculations. Computationally, the structures of the HNCO dimers and trimers were optimized at the MP2, B3LYPD3 and B2PLYPD3 levels of theory employing the 6-311++G(3df,3pd) basis set. Topological analysis of the electron density (AIM) was used to identify the type of non-covalent interactions in the studied aggregates.

UV Laser-Induced Phototransformations of Matrix-Isolated 5-Chloro-3-nitro-2-hydroxyacetophenone.

Conformational changes of 5-chloro-3-nitro-2-hydroxyacetophenone were studied by experimental and theoretical methods. Phototransformations of the compound were induced in low-temperature argon matrices by using UV radiation, which was followed by FT-IR measurements. Two types of changes within the molecule were detected: rotations of the hydroxyl and acetyl groups.

NIR and UV induced transformations of indazole-3-carboxylic acid isolated in low temperature matrices.

The molecular structure and NIR and UV induced phototransformations of indazole-3-carboxylic acid were studied in low temperature argon and nitrogen matrices by FTIR spectroscopy and B3LYP/6-311++G(2d,2p) calculations. Eleven minima of IC were located on the S potential energy surface. The three most stable structures were detected experimentally in both matrices after deposition.