On <img src='/image/spc_char/pi.gif' border=0>-electron excess of rings of benzenoid molecules

Abstract

In a previous paper [Gutman I, <i>Indian J Chem </i>43A (2004) 1615], the concept of <img src='/image/spc_char/pi.gif' border=0>-electron excess of rings of benzenoid hydrocarbons has been introduced, aimed at amending the <img src='/image/spc_char/pi.gif' border=0> electron contents of rings computed on the basis of Pauling bond orders. We now show how a <img src='/image/spc_char/pi.gif' border=0>-electron-content-like quantity can be computed from the Hosoya bond orders and establish its close relation with the π-electron excess.