ESR and Optical Evidence on Formation of the Cl(1-)...CCl3(1+) Ion Pair in 3-Methylpentane Matrices ψ-Irradiated at 77 K

Article abstract of DOI:10.1021/j100348a026

The well-known absorption band at 470 nm in CCl4-alkane systems is investigated.The results obtained are as follows: (1) the absorption band due to the radical cation of 5-methyldecane (5MD(1+)) in 5MD-CCl4-3MP systems converts into the 470-nm band. (2) In the conversation, the positive charge of the 5MD(1+) reacts with the unpaired electron of CCl3^. radical. (3) CBrCl3 and CCl3F in 3MP glasses produce the absorption bands at 480 nm and 438 nm, respectively, and the nature of these bands is the same with that of the 470-nm band in the all points examined.Results 1 and 2 lead to the formation of CCl(3+) cations.We also obtain evidence on the formation of CCl3(1+) cations from CBrCl3 and CCl2F(1+) cations from CCl3F.It is evident that the band shift observed in the case of CBrCl3 is not attributable to the free ions CCl3(1+) nor to the solvent-separated ion pairs Br(1-)/solvent/CCl3(1+) but the formation of the charge-transfer contact ion pairs Br(1-)...CCl3(1+).Therefore, it is concluded that CCl4 and CCl3F in 3MP produce Cl(1-)...CCl3(1+) and Cl(1-)...CCl2F(1+), respectively.We also obtained the results that CBrF3, CClF3, and CCl2F2 in 3MP glasses yield the corresponding radical anions with absorption bands at 314, 300, and 314 nm, respectively, and that these radical anions are neutralized with the migrating positive charges of the 5MD(1+) formed.