Graph Theory and Molecular Orbitals. XII. Acyclic Polyenes

I. Gutman,a B. Ruščić,a N. Trinajstić,a,b and C. F. Wilcox, Jr.a,c

a Rugjer Bošković Institute, Zagreb, Croatia
b Department of Chemistry, Faculty of Natural Sciences and Mathematics, University of Zagreb, Zagreb, Croatia
c on leave from: Department of Chemistry, Cornell University, Ithaca, NY

J. Chem. Phys. 62(9), 3399-3405 (1975)


A graph-theoretical study of acyclic polyenes is carried out with an emphasis on the influence of branching on several molecular properties. A definition of branching is given and several branching indices are analyzed. The case of polyenes without a Kekulé structure is discussed briefly. The main conclusions are: (a) thermodynamic stability of conjugated polyenes decreases with branching, but (b) reactivity, in general, increases with branching.