SINGLET AND TRIPLET EXCITED-STATE FORMATION IN HIGH-ENERGY ELECTRON TRACKS IN LIQUID CIS-DECALIN AND TRANS-DECALIN AS STUDIED BY PRODUCT FORMATION IN RADIOLYSIS AND PHOTOLYSIS

The yields of products formed as a result of irridation of liquid cis- and trans-decalin with gamma-rays and 3 MeV electrons as well as with 7.6 eV photons have been determined by means of gas-liquid chromatogr aphy (GLC). The major products for both cis- and trans-decalin are hyd rogen, unsaturated C10 products and dimers; in the case of cis-decalin , cis-trans isomerization takes place via a chain reaction. Singlet an d triplet excited states are formed by direct excitation and by charge recombination in the tracks of high-energy electrons. The product for mation resulting from the singlets is determined by the photolysis. Fr om a knowledge of the total yield of singlets from the radiolysis, the contribution of the singlet excited states to product formation durin g radiolysis is calculated and the remaining products are assigned to the triplets. For the sum of the yields of singlets and triplets a val ue of 6.4 (100 eV)-1 (= 6.6 x 10(-7) mol J-1) is found for cis-decalin and 6.0 (100 eV)-1 (= 6.2 x 10(-7) mol J-1) for trans-decalin and for the singlet fractions 0.53 and 0.47 in cis- and trans-decalin, respec tively. The probability of C-H bond breakage in the singlet and triple t states is 0.42 and 0.82, respectively, for cis-decalin and 0.50 and 0.94, respectively, for trans-decalin.