Spectroscopy, structure, thermal and photochemical decomposition of 5-chloro-3-trifluoromethyl-1,2,4-thiadiazole: Generation of trifluoroacetonitrile N-sulfide
Abstract
The structure and thermal and photochemical decomposition of the synthetic precursor 5-chloro-3-trifluoromethyl-1,2,4-thiadiazole (1) have been investigated for the first time by mid-infrared, Raman, ultraviolet and He I photoelectron spectroscopy. Spectroscopies, supported by quantum-chemical calculations using the B3LYP and SAC-CI methods, provided a detailed investigation into the vibrational and electronic character of the molecule. Thermal stability and photochemical decomposition of 1 have been studied in the gas phase and solid matrix, respectively. Flash vacuum thermolysis of the molecule produced fast quantitatively CF3CN, ClCN, and sulfur. However, UV irradiation of 1 in solid argon matrix at selected wavelengths of 213, 228, 240, and 250 nm resulted in a retro-cycloaddition reaction leading to the formation of a novel nitrile sulfide, CF3CNS (2), and ClCN. The structure of 2 was computed at the B3LYP and CCSD(T)/aug-cc-pVTZ levels, and its IR identification was supported by quantum chemical calculations.
- Publication:
-
Journal of Molecular Structure
- Pub Date:
- March 2019
- DOI:
- 10.1016/j.molstruc.2018.11.003
- Bibcode:
- 2019JMoSt1179..118P
- Keywords:
-
- 1;
- 2;
- 4-Tiadiazole;
- Nitrile sulfide;
- Thermolysis;
- Photolysis;
- Spectroscopy;
- Structure