CONTRIBUTION OF THE REPULSIVE INTERACTION BETWEEN FRAGMENTS TO ROTATIONAL DISTRIBUTION OF THE FRAGMENTS IN PHOTOLYSIS

Abstract

Many studies on rotational distribution of photofragments have been done both in experimental and in theoretical aspects during the past decade, but comparisions of the theoretical results with the experimental ones remain few and far between. An attempt has been made to emphasize the effects of the repulsive interaction between photofragments on their rotational distribution. A simple classical model was postulated and the interpretation with this model is qualitatively in good ag reement with a series of experimental observations listed in Table 1. Based on this model, the angular momentum of the photofragments could be divided into two parts, one from the rotation of the parent molecule, the other produced during the sepa ration, i. e, by the repulsive interaction. The cooling of the parent molecules in a supersonic jet could only affect the first part. The second part depends mainly upon the nature of the dissociative potential surface. Using this simple model, one can also obtain some dynamic informations including some characteristics of the potential surface. A number of examples are given in the discussion, which show that the interpretation with this model is fairly consistent with the results observed in the photolysis of CICN, BrCN, C2N2 C4N2 etc. in effusive or super sonic molecular beams. This qualitative agreement means that the classical model is helpful if the quantum theory on the rotational distribution of photofragraents is not available in practice