Total Resonant Sextet Benzenoid Research Articles

A Formula Periodic Table for Benzenoid Hydrocarbons and the Aufbau and Excised Internal Structure Concepts in Benzenoid Enumerations

Abstract The genesis of two concepts of recent importance to isomeric polyhex enumeration is traced. As it will become evident from this review, the philosophy of our approach stresses the enumeration of select benzenoid groups of practical interest to chemists. These concepts were pivotal to the first published enumerations of the strictly peri-condensed, non-Kekulean, and essentially strain-free total resonant sextet benzenoid groups.

A theoretical study of C 60 benzenoids

The more stable C 60 benzenoids are enumerated. These benzenoids are at the upper limit of today's analytical capability for characterization and consist of total resonant sextet and strictly peri-condensed species. A graph theoretical decomposition of three-fold coronen-related molecules is presented for the first time and allows rapid computation of their characteristic polynomials and eigenvalues. Strictly peri-condensed and essentially strain-free total resonant sextet benzenoids are devoid of adjacent bay regions on their molecular perimeter. Total resonant sextet and three-fold symmetrical nonradical benzenoids both have formulae found only in the N c ≡ 0 (mod 6) column series of the formula periodic table for benzenoid hydrocarbons. On average, strictly peri-condensed, total resonant sextet, and three-fold benzenoids are generally among the more stable isomers.

Total resonant sextet benzenoid hydrocarbon isomers and their molecular orbital and thermodynamic characteristics

The more stable strain-free total resonant sextet isomers of benzenoid hydrocarbons are predicted to be probable combustion pollutants. These benzenoid hydrocarbons have been enumerated, and their topological characteristics examined. Total resonant sextet benzenoid isomers make up less than 1% of all the benzenoid hydrocarbons having formulas with N c divisible by 6. There is a thermodynamic preference for the larger and more highly condensed polycyclic aromatic hydrocarbon molecule. The Hückel molecular orbital (HMO) and thermodynamic parameters of these total resonant sextet benzenoid hydrocarbons have been computed and tabulated.