AN ESR STUDY OF RADICAL REACTIONS IN IRRADIATED LIQUID CYCLOPROPANE

Radicals resulting from X-ray irradiation of concentrated (2-30 mol %) solutions of cyclopropane in Freon-113 (CFCl2CF2Cl) were characterize d by ESR technique. A distonic radical cation dist(90,0)-C3H6.+ was fo und to be stable in the temperature range 113-116 K (i.e., under the c onditions corresponding to a quasiliquid state of the matrix). However , two H-beta in dist(similar to 90,similar to 0)-C3H6.+ become nonequi valent presumably due to solvation of its cationic site by a cycloprop ane molecule. An ESR study of cyclopropane solutions containing 2,4,6- tri-tert-butylnitrosobenzene (BNB) irradiated with X-rays at 293 K rev ealed formation of the BNB adducts with dist(90, 0)-C3H6.+, cyclo-C3H5 . and CH2=CHCH2. radicals. Only adducts with cyclo-C3H5. radicals were observed after irradiation of these solutions at 77 K. It was found t hat cyclo-C3H5. radicals resulted from ion-molecule reaction between c yclo-C3H6.+ and cyclo-C3H6. Ring opening in the cyclo-C3H5. radical re sults in formation of the CH2=CHCH2.; radical. Dist(90,0)-C3H6.+ radic al cation is chemically nonreactive in liquid cyclopropane.