QSPR for physical properties of cata-condensed benzenoids using two simple dualist-based descriptors.

Dualists of benzenoids are a special type of graphs that have as vertices the centers of hexagons and as edges the pairs of condensed rings. Catafusenes (cata-condensed benzenoids) have acyclic dualists. Codes of catafusenes with h benzenoid rings start from one end of a dualist and consist of digits 0 (indicating linear annelation, angle of 180° between two adjacent edges) and 1 or 2 for kinks (120° or 240° angles) with the convention of choosing the lowest number formed from these h−2 digits. A shape parameter (n) for the dualist consists of the number of adjacent zeros in the code plus 1. It is shown in the present communication that many molecular properties of catafusenes depend mainly on n, whereas most bulk properties depend mainly on h. Monoparametric or biparametric correlations in terms of the simple integer parameters n and/or h are presented for molecular properties (energy of the p-band in electronic absorption spectra, ionization potentials, electron affinities, hardness and softness) and bu...