Pagacz-Kostrzewa M, Sałdyka M, Bil A, Gul W, Wierzejewska M, Khomenko D M, Doroschuk R O
Faculty of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland.
Department of Chemistry , Taras Shevchenko National University of Kyiv , Volodymyrska Street, 64/13 , Kyiv 01601 , Ukraine.
J Phys Chem A. 2019 Jan 31;123(4):841-850. doi: 10.1021/acs.jpca.8b10762. Epub 2019 Jan 22.
Phototransformations of 2-(1,2,4-triazol-3-yl)benzoic acid induced by tunable UV laser were studied in low temperature matrices by FTIR spectroscopy. Out of 36 possible isomers of this molecule the most stable one, comprising the intramolecular N-H···O hydrogen bond, was detected experimentally in argon and xenon matrices after deposition. Upon irradiation with λ = 325 nm, two new conformers of the precursor were formed. The corresponding reverse photorotamerizations were also detected at 250 nm partly reproducing the initial molecules. In addition to the conformational changes, an interesting photoisomerization took place in the studied matrices leading to a proton transfer from N atom of the triazole ring to the carbonyl oxygen of the carboxylic group. As a result of this reaction, a new product with two OH groups was identified for the first time. The experimental studies were supported by DFT calculations in both ground and excited electronic states.
利用傅里叶变换红外光谱（FTIR），在低温基质中研究了可调谐紫外激光诱导的2-(1,2,4-三唑-3-基)苯甲酸的光转化。在该分子的36种可能异构体中，最稳定的异构体包含分子内N-H···O氢键，在沉积后的氩气和氙气基质中通过实验检测到。用λ = 325 nm照射后，形成了前体的两种新构象异构体。在250 nm处也检测到了相应的反向光旋转异构化，部分重现了初始分子。除了构象变化外，在所研究的基质中还发生了有趣的光异构化，导致质子从三唑环的N原子转移到羧基的羰基氧上。作为该反应的结果，首次鉴定出一种具有两个OH基团的新产物。实验研究得到了基态和激发态电子态的密度泛函理论（DFT）计算的支持。
