GRAPH-THEORETIC STUDY OF CERTAIN INTERSTELLAR REACTIONS

Certain interstellar reactions have been studied through the graph-the oretic method using a Fortran-77 program. A plausible mechanism has be en proposed for the reactions. The criterion of the conversion of edge to loop and vice versa proposed by the Bratislava group [Theor. Chim. Acta 79, 65 (1991)] has been given a reasonable chemical insight. In the reaction scheme the nucleophilic/electrophilic/carbene (singlet, t riplet) or biradical loops have been generated by the fragmentation of reactant. Subsequently, Pearson's hard and soft acids bases (HSAB) th eory and frontier orbital (FO) theory have been applied to explain the reaction mechanism. Few possible reactions of the interstellar and ci rcumstellar molecules have been investigated with illustrations involv ing carbene intermediate and Woodward-Hoffmann rule. (C) 1997 John Wil ey & Sons, Inc.