Perfluoroalkene Radical Anions Structural Distortion

The anisotropic /t/splittings can potentially provide more detailed experimental 

C-C4F6 before and after one electron reduction together with ground electronic state and point group (symmetry) 

Both the isotropic and anisotropic F hf splittings to the two fluorines at the C=C carbons of c-C3F4 are about two times larger than those to the four fluorines of C2p4 , see Table 5.1. This suggests that both anions have almost the same type of hybrid orbital for the unpaired electron, but that the degree of unpaired electron delocalization to the a -fluorine orbitals is inversely proportional to the number of F-atoms. 

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We do not intend to show full coverage of the ESR studies of radical anions reported so far, but to show some typical examples and to demonstrate general trends. Thus, here we present our recent ESR studies combined with quantum chemical computations on electron delocalization in perfluoroalkane radical anions [3, 31, 32] and on structure distortion in perfluoroalkene radical anions [33] and in the acetylene radical anion [34]. 

Acetylene is one of the simplest hydrocarbons and a fundamentally important chemical in organic chemistry. The electronic structure of acetylene and its related compounds have been extensively studied both experimentally and theoretically, and a number of interesting observations have been reported. For example, a trans-bent structure has been reported for acetylene in an excited state [42, 43] and also in a radical anion form [34, 44]. The interaction between acetylene and metal atoms such as A1 and Li has been studied by inert gas matrix isolation (MI) ESR and IR methods [45-48]. Here we present our ESR study on the structural distortion in acetylene radical anion in the glassy 2-MTHE matrix, which is another example showing a mixing of the k and higher-lying a orbitals at the C=C carbons similar to that at the C=C carbons for the perfluoroalkene radical anions. In addition photo-induced isomerization reaction of the acetylene radical anion in the matrix is briefly presented. 

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