Collect. Czech. Chem. Commun. 1988, 53, 2023-2054

Aromaticity in heterocyclic molecules containing divalent sulfur

Milan Randića, Sonja Nikolićb and Nenad Trinajstićb

a Department of Mathematics and Computer Science, Drake University, Des Moines, Iowa 50311
b The Rugjer Bošković Institute, P.O.B. 1016, 41001 Zagreb, Croatia, Yugoslavia


The conjugated circuits model is applied to heterocycles containing divalent sulfur. A novel parametrization is introduced for 4n + 2 and 4n conjugated circuits containing a single sulfur atom. The relative aromatic stabilities of a number of heterocyclic systems containing divalent sulfur are studied. Comparison is made whenever possible with earlier reported resonance energies of these compounds, obtained by using Huckel MO and SCF π-MO models, and appropriate reference structures. Special attention is given to positional isomers. An explanation of the differences amongst such isomers is given.