001     54979
005     20180211163255.0
024 7 _ |2 pmid
|a pmid:16913689
024 7 _ |2 DOI
|a 10.1021/jp062917b
024 7 _ |2 WOS
|a WOS:000239817900021
037 _ _ |a PreJuSER-54979
041 _ _ |a eng
082 _ _ |a 530
084 _ _ |2 WoS
|a Chemistry, Physical
084 _ _ |2 WoS
|a Physics, Atomic, Molecular & Chemical
100 1 _ |a Maksic, Z. B.
|b 0
|0 P:(DE-HGF)0
245 _ _ |a Clar's sextet rule is a consequence of the sigma-electron framework
260 _ _ |a Washington, DC
|b Soc.
|c 2006
300 _ _ |a 10135 - 10147
336 7 _ |a Journal Article
|0 PUB:(DE-HGF)16
|2 PUB:(DE-HGF)
336 7 _ |a Output Types/Journal article
|2 DataCite
336 7 _ |a Journal Article
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|2 EndNote
336 7 _ |a ARTICLE
|2 BibTeX
336 7 _ |a JOURNAL_ARTICLE
|2 ORCID
336 7 _ |a article
|2 DRIVER
440 _ 0 |a Journal of Physical Chemistry A
|x 1089-5639
|0 3693
|y 33
|v 110
500 _ _ |a Record converted from VDB: 12.11.2012
520 _ _ |a A number of condensed PAHs are examined to identify the underlying reasons governing empirical Clar's rule taking benzene as a limiting case. It is found that the so-called Clar's structures are the only minima on the MP2(fc) potential energy hypersurfaces, meaning that other conceivable valence isomers are nonexistent. The influence of the electron correlation energies to the stability of Clar's structures is substantial with predominating influence of the sigma-electrons. However, the contributions arising from the sigma- and pi-electron correlation energies are approximately the same, if Clar's structures are compared with some artificial pi-electron localized or graphite-like delocalized planar systems. Analysis of the Hartree-Fock (HF) energies provides a compelling evidence that the origin of stability of Clar's structures lies in a decrease of the positive T, V(ee) and V(nn) energy terms relative to some characteristic virtual "delocalized" or "localized" model geometries. Partitioning of the mixed and terms in the sigma- and pi-type contributions, by using the stockholder (SHR), equipartitioning (EQP) and standard pi (SPI) schemes, unequivocally shows that the driving force leading to Clar's structures are more favorable sigma-type interactions. All these conclusions hold for the archetypal benzene too, which could be considered as a limiting Clar system. Finally, the boundaries of Clar's hypothesis and some common misconceptions are briefly discussed. Perusal of the geometric parameters and pi-bond orders reveals that there are no benzene rings completely "vacant" or "fully occupied" by the pi-electrons, envisaged by Clar in his picture of condensed benzenoid compounds. Instead, there are six-membered rings with higher and lower total pi-electron density. The bond length anisotropy of the former rings is smaller. It is concluded that Clar's proposition is a useful rule of thumb providing qualitative information on the stability of the PAH systems, which in turn should not be overinterpreted.
536 _ _ |a Scientific Computing
|c P41
|2 G:(DE-HGF)
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588 _ _ |a Dataset connected to Web of Science, Pubmed
650 _ 7 |a J
|2 WoSType
700 1 _ |a Baric, D.
|b 1
|0 P:(DE-HGF)0
700 1 _ |a Müller, T.
|b 2
|u FZJ
|0 P:(DE-Juel1)132204
773 _ _ |a 10.1021/jp062917b
|g Vol. 110, p. 10135 - 10147
|p 10135 - 10147
|q 110<10135 - 10147
|0 PERI:(DE-600)2006031-2
|t The @journal of physical chemistry / A
|v 110
|y 2006
|x 1089-5639
856 7 _ |u http://dx.doi.org/10.1021/jp062917b
909 C O |o oai:juser.fz-juelich.de:54979
|p VDB
913 1 _ |k P41
|v Scientific Computing
|l Supercomputing
|b Schlüsseltechnologien
|0 G:(DE-Juel1)FUEK411
|x 0
914 1 _ |y 2006
915 _ _ |0 StatID:(DE-HGF)0010
|a JCR/ISI refereed
920 1 _ |k ZAM
|l Zentralinstitut für Angewandte Mathematik
|d 31.12.2007
|g ZAM
|0 I:(DE-Juel1)VDB62
|x 0
970 _ _ |a VDB:(DE-Juel1)85821
980 _ _ |a VDB
980 _ _ |a ConvertedRecord
980 _ _ |a journal
980 _ _ |a I:(DE-Juel1)JSC-20090406
980 _ _ |a UNRESTRICTED
981 _ _ |a I:(DE-Juel1)JSC-20090406


LibraryCollectionCLSMajorCLSMinorLanguageAuthor
Marc 21