A semiempirical study of radical anions CY3X- (Y = H, F, Cl and Br,Xx = Cl and Br)

Potential energy curves for a carbon-chlorine and carbon-bromine bond dissociation of CY3X- (Y = H, F, Cl and Pr, X = Cl and Br) radical anions are calculated by the semiempirical PM3 method, Enthalpies of the dissociative electron attachment reactions e + CY3X --> CY3 + X- in gas phase as well as vertical and adiabatic electron affinities of CY3X molecules are examined. The results of calculations are compared with the corresponding ab initio and experimental data. It was found that stable sigma*-radical anions are formed after attaching an electron to CY3X molecules, except when X = Cl and Y = H. Some of CY3X molecules can probably form also weakly bonded adducts ((.) CY3), (X-). (C) 1998 Elsevier Science B.V.