ESR AND QUANTUM-CHEMICAL STUDIES OF THE STRUCTURES AND THERMAL TRANSFORMATIONS OF THE RADICAL CATIONS OF VINYLCYCLOPROPANE IN IRRADIATED FROZEN FREON MATRICES - SIMULATION OF RADICAL PROCESSES IN SOLIDS

Thermal transformations of vinylcyclopropane radical cations (VCP.+) in X-ray-irradiated frozen Freon matrices (CFCl2CF2Cl and CFCl3) were studied by ESR; radical processes involving VCP.+ in solid VCP were simulated. Gauche- and anti-VCP.+ were found to be the primary radical cations, however, the former, unlike the latter, is stable only under ''gas-phase'' conditions. The thermodynamic equilibrium between anti-VCP.+ and its less stable distonic form, dist(90,0)-C5H8.+, is established in frozen Freon matrices and the VCP host matrix; the structure of dist(90,0)-C5H8.+ is stabilized by a molecule of anti-VCP. In CFCl3, along with dist(90,0)-C5H8.+, pi-dimeric resonance rant[-VCP](.+)(2) complex was detected. A general scheme of the transformations of VCP.+ in the solid phase has been proposed.