On the difference in bond orders between HMO and PPP methods

✍ Scribed by Milan Randić; Dejan Plavšića; Nenad Trinajstić

• Book ID: 104582799
• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 498 KB
• Volume: 37
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/qua.560370414

✦ Synopsis

Abstract

We have examined variations in bond orders in conjugated hydrocarbons that follow improvement in MO calculations on going from topological Hückel MO to self‐consistent Pariser‐Parr‐Pople–type calculations. Differences in individual bond orders can be interpreted as pointing to increased weights of selected Kekulé valence structures. Significantly, so indicated valence structures are those with the largest number of formal Kekulé benzene rings or the largest contribution to molecular resonance energy in terms of conjugated circuits.