Journal article

Publication year: 2021

Pages: 16307-16315

Journal: Physical Chemistry Chemical Physics

Volume number: 23

Issue number: 30

ISSN: 1463-9076

DOI Link: https://doi.org/10.1039/d1cp02584h

Publisher: Royal Society of Chemistry

Abstract: 
The simplest alpha,beta-unsaturated sulfinyl radical CH2 = C(H)SO has been generated in the gas phase by high-vacuum flash pyrolysis (HVFP) of sulfoxide CH2 = C(H)S(O)CF3 at ca. 800 degrees C. Two planar cis and trans conformers of CH2 = C(H)SO were isolated in cryogenic matrixes (N-2, Ne, and Ar) and characterized with IR and UV/Vis spectroscopy. In addition to the photo-induced cis reversible arrow trans conformational interconversion, CH2 = C(H)SO displays complex photochemistry. Upon irradiation with a purple light LED (400 nm), CH2 = C(H)SO isomerizes to novel radicals CH3SCO, CH2SC(O)H, and CH2C(O)SH with concomitant dissociation to a caged molecular complex CH3SMIDLINE HORIZONTAL ELLIPSISCO. Subsequent UV-laser (266 nm) irradiation causes fragmentation to CH3/OCS and additional formation of an elusive carbonyl radical CH3C(O)S, which rearranges to CH2C(O)SH upon further UV-light irradiation (365 nm). The vibrational data and bonding analysis of the two conformers of CH2 = C(H)SO suggest that both are floppy radicals in which the unpaired electron conjugates with the vicinal pi(C = C) bond, leading to significant contribution of the canonical resonance form of CH2-C(H)SO. The mechanism for the isomerization of CH2 = C(H)SO is discussed based on the observed intermediates along with a computed potential energy profile at the CCSD(T)-F12a/aug-cc-pVTZ//B3LYP/6-311++G(3df,3pd) level of theory.

Harvard Citation style: Wu, Z., Wang, L., Lu, B., Eckhardt, A., Schreiner, P. and Zeng, X. (2021) Spectroscopic characterization and photochemistry of the vinylsulfinyl radical, Physical Chemistry Chemical Physics, 23(30), pp. 16307-16315. https://doi.org/10.1039/d1cp02584h

APA Citation style: Wu, Z., Wang, L., Lu, B., Eckhardt, A., Schreiner, P., & Zeng, X. (2021). Spectroscopic characterization and photochemistry of the vinylsulfinyl radical. Physical Chemistry Chemical Physics. 23(30), 16307-16315. https://doi.org/10.1039/d1cp02584h