Minima on the (C6H6)•+ radical cation potential energy surface: A DFT exploration

The B3LYP and M06-2X functionals, with the CBS-QB3 method, are used to explore minima on the (C6H6)(center dot+) energy surface. Electron ionization of neutral C6H6 isomers to generate (C6H6)(center dot+) species is studied. Relative energies for 37 (C6H6)(center dot+) radical cation isomers, derived from the three computational strategies, correlate well with one another and with other experimental and computational data. Relative energies of isomers are related to delocalization, small ring and angle strain, and positively charged sp carbons. Spin density usually resides on the most positively charged carbon atom. For the few distonic cases, spin density is located separately from the charged center.