H. Muto, K. Nunome
Apr 1, 1991
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Influential Citations
13
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Journal
Journal of Chemical Physics
Abstract
An electron spin resonance (ESR) and optical study of carbon tetrachloride radical anion has been made to provide for a better understanding of the radiolysis of CCl4, following CCl⋅+4 cation previously studied. It was found that the anion was metastably trapped in tetramethylsilane (TMS) matrices γ irradiated at 4 or 77 K. The g tensor and the hyperfine coupling tensors of all atoms of the radical were determined from ESR spectral simulation by using 12 CCl4 and the 13C enriched compound: g∥=2.004–5, g1=2.015,(A∥,A⊥) =(24.3,18.3) mT for 13C , (0.9, 0.2) mT for one 35Cl atom, and (A1,A2=A3)=(1.98,0.45) mT for the other three equivalent 35Cl atoms. From these parameters and a consideration on the g anisotropy combined with the optical data, the anion was found to have a predissociating molecular structure (CCl3⋅⋅⋅Cl) − with C3v symmetry, where the unpaired electron occupies A*1γ antibonding orbital. The carbon atom has a large spin density and near sp3 hybridization: ρp=0.62, ρs=0.18, ρp/ρs=3.4, and three...