Revisiting a simple regularity for benzenoid hydrocarbons. Total π-electron energy versus the number of Kekulé structures

✍ Scribed by Ivan Gutman; Svetlana Marković; George G. Hall

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 251 KB
• Volume: 234
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00032-y

✦ Synopsis

The linear dependence, previously claimed, of the total -rr-electron energy (E~) of isomeric benzenoid hydrocarbons on the number of Kekul6 structures (K) is found to be a satisfactory approximation only for benzenoids having eight or fewer six-membered rings (h ~< 8), and is violated if h >1 9. For sets of isomeric unbranched catacondensed benzenoids (having fixed values of h, h/> 9), E~ is well reproduced by the expression a + bK-cK -1/2, where a, b and c are constant.