Understanding the g-tensors of perchlorotriphenylmethyl and Finland-type trityl radicals. Issue 36 (10th September 2020)

• Record Type: Journal Article
• Authors: Demay-Drouhard, Paul; Ching, H. Y. Vincent; Decroos, Christophe; Guillot, Régis; Li, Yun; Tabares, Leandro C.; Policar, Clotilde; Bertrand, Helene C.; Un, Sun
• Is Part Of: Physical chemistry chemical physics. Volume 22:Issue 36(2020)
• Page Start: 20792
• Page End: 20800
• Publication Date: 2020-09-10
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d0cp03626a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : HFEPR measurements and DFT calculations reveal the critical role of heteroatoms in the g -anisotropy of trityl radicals. Abstract : The 285 GHz EPR spectra of perchlorotriphenylmethyl and tetrathiatriarylmethyl radicals in frozen solution have been accurately measured. The relationship between their molecular structures and their g -tensors has been investigated with the aid of DFT calculations, revealing that the degree of spin density delocalization away from the central methylene carbon is an important determining factor of the g -anisotropy. In particular, the small amount of spin densities on the Cl or S heteroatoms at the 2 and 6 positions with respect to the central carbon have the strongest influence. Furthermore, the amount of spin densities on these heteroatoms and thus the anisotropy can be modulated by the protonation (esterification) state of the carboxylate groups at the 4 position. These results provide unique insights into the g -anisotropy of persistent trityl radicals and how it can be tuned.