The dimer yields in the radiolysis of the neo-C5H12-cyclo-C5H10 (1 mol%) mixtures at 77 and 4 K have been measured by capillary gas chromatography. Analysis of the results indicates that cyclopentyl radicals are produced selectively at 77 K, while their selective formation is suppressed at 4 K. This result coincides well with the data obtained by ESR spectroscopy.

Disproportionation/combination ratios of self-reactinq t-alkyl radicals are estimated in solid phase at low temperature. The low temperature solid state limit was estimated to be 7-25, this value is considerably lower than ratios of the literature (100 to 500) and is compatible with the FISCHER limit in liquid state. In the present work, the ratios are determined by product analysis from the gamma radiolysis of isobutane.