Title
Effect of inclusion of electron correlation in MM3 studies of cyclic conjugated compounds.
Abstract
Electron correlation at the Moller-Plesset second-order level was incorporated into the pi-system portion of MM3 calculations for several conformers of [10]annulene, [18]annulene, bicyclo[5.3.1]undecapentaene, and bicyclo[4.4.1]undecapentaene. The conformers with "localized" C-C pi bonds (strongly alternating bond lengths) were found to be of lower energy than their counterparts with "delocalized" C-C pi bonds (similar bond lengths) before correlation energy was included. Correlation always lowered the energies of the delocalized conformation more than it did that of the localized conformation, such that often the latter was found to be more stable after correlation energy was included in the calculation. When a delocalized structure was not at a stationary point on the MM3 energy surface, such comparison could not be made. An example is the porphin molecule. (C) 1998 John Wiley & Sons, Inc.
Year
DOI
Venue
1998
10.1002/(SICI)1096-987X(19980415)19:5<475::AID-JCC1>3.0.CO;2-J
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
Field
DocType
molecular mechanics,correlation energies,conjugated polyenes
Electronic correlation,Conformational isomerism,Molecule,Computational chemistry,Chemistry,Bond length,Annulene,Conjugated system,Porphin,Delocalized electron
Journal
Volume
Issue
ISSN
19
5
0192-8651
Citations 
PageRank 
References 
0
0.34
1
Authors
2
Name
Order
Citations
PageRank
Julia C. Tai100.34
Norman L. Allinger221236.95