Formation and decomposition of distonic o-, m-, and p-benzyne radical cations from photolysis of Mg(+)(o-, m-, p-C(6)H(4)F(2))

Hai-Chuan Liu; Chang-Sheng Wang; Wenyue Guo; Yun-Dong Wu; Shihe Yang

doi:10.1021/ja0122546

Formation and decomposition of distonic o-, m-, and p-benzyne radical cations from photolysis of Mg(+)(o-, m-, p-C(6)H(4)F(2))

J Am Chem Soc. 2002 Apr 10;124(14):3794-8. doi: 10.1021/ja0122546.

Authors

Hai-Chuan Liu¹, Chang-Sheng Wang, Wenyue Guo, Yun-Dong Wu, Shihe Yang

Affiliation

¹ Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.

PMID: 11929271
DOI: 10.1021/ja0122546

Abstract

Distonic o-, m-, and p-benzyne radical cations (1-3) have been generated by a novel photolysis reaction of mass-selected Mg(+)-difluorobenzene complexes. The energy required for the formation of these radical cations is within 2.2 eV. The formation of o-benzyne cation is most facile. The benzyne radical cations dissociate further to yield ethyne and 1,3-butadiyne radical cation as major products given a sufficient amount of energy. The whole process involves only a single photon, and is very efficient. The calculated threshold for the formation of 1,3-butadiyne radical cation from Mg(+)(o-C(6)H(4)F(2)) is about 4.6 eV, quite comparable with the experimental estimate.