000042308 001__ 42308 000042308 005__ 20200423203940.0 000042308 0247_ $$2DOI$$a10.1021/jp0489626 000042308 0247_ $$2WOS$$aWOS:000224538900018 000042308 0247_ $$2Handle$$a2128/2225 000042308 037__ $$aPreJuSER-42308 000042308 041__ $$aeng 000042308 082__ $$a530 000042308 084__ $$2WoS$$aChemistry, Physical 000042308 084__ $$2WoS$$aPhysics, Atomic, Molecular & Chemical 000042308 1001_ $$0P:(DE-HGF)0$$aKovacevic, B.$$b0 000042308 245__ $$aDominant Role of the pi Framework in Cyclobutadiene 000042308 260__ $$aWashington, DC$$bSoc.$$c2004 000042308 300__ $$a9126 - 9133 000042308 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article 000042308 3367_ $$2DataCite$$aOutput Types/Journal article 000042308 3367_ $$00$$2EndNote$$aJournal Article 000042308 3367_ $$2BibTeX$$aARTICLE 000042308 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000042308 3367_ $$2DRIVER$$aarticle 000042308 440_0 $$03693$$aJournal of Physical Chemistry A$$v108$$x1089-5639 000042308 500__ $$aRecord converted from VDB: 12.11.2012 000042308 520__ $$aThe extrinsic antiaromaticity of archetypal cyclobutadiene (CBD) is addressed with particular emphasis on the sigma-pi separability problem. The destabilization energy E(d)(CBD) of CBD is obtained by appropriate homodesmotic reactions involving the open chain zigzag, polyene(s). It is shown that E(d)(CBD) does not depend on the electron correlation and the zero-point vibrational energy contributions, since they are small and of the opposite sign. Consequently, they cancel in the first approximation. Further, it turns out that E(d)(CBD) can be estimated accurately enough with a very modest cc-pVDZ basis set at the Hartree-Fock (HF) level. The extrinsic antiaromatic destabilization E(ean)(CBD) of CBD is deduced after extracting the angular strain energy estimated to be 32 kcal/mol. The resulting E(ean)(CBD) value of 52 kcal/mol is in excellent agreement with the experimental thermodynamic data. If the E(ean)(CBD) is estimated relative to two isolated C=C double bonds, then it assumes 38 kcal/mol, which is roughly 10 kcal/mol per one pi electron. It is, therefore, safe to state that extrinsic antiaromaticity of CBD is larger than its angular strain. Although the sigma and pi electrons are coupled by a mutual Coulomb interaction V-ee(sigmapi), several attempts of their decoupling is made by using three partitioning schemes: stockholder, equipartition, and standard pi-electron theory recipe. The latter allocates the V-nn and V-ee(sigmapi) terms to the sigma- and pi-electron frameworks, respectively. The nuclear repulsion term V-nn is dissected into sigma and pi components in the former two partitioning schemes by using stockholder criterion. It appears that the extrinsic antiaromatic destabilization E(ean)(CBD) is determined by the pi-electron framework according to all three partitioning models. 000042308 536__ $$0G:(DE-Juel1)FUEK254$$2G:(DE-HGF)$$aBetrieb und Weiterentwicklung des Höchstleistungsrechners$$cI03$$x0 000042308 588__ $$aDataset connected to Web of Science 000042308 650_7 $$2WoSType$$aJ 000042308 7001_ $$0P:(DE-HGF)0$$aBaric, D.$$b1 000042308 7001_ $$0P:(DE-HGF)0$$aMaksic, Z.$$b2 000042308 7001_ $$0P:(DE-Juel1)132204$$aMüller, T.$$b3$$uFZJ 000042308 773__ $$0PERI:(DE-600)2006031-2$$a10.1021/jp0489626$$gVol. 108, p. 9126 - 9133$$p9126 - 9133$$q108<9126 - 9133$$tThe @journal of physical chemistry <Washington, DC> / A$$v108$$x1089-5639$$y2004 000042308 8567_ $$uhttp://hdl.handle.net/2128/2225$$uhttp://dx.doi.org/10.1021/jp0489626 000042308 8564_ $$uhttps://juser.fz-juelich.de/record/42308/files/58983.pdf$$yOpenAccess 000042308 8564_ $$uhttps://juser.fz-juelich.de/record/42308/files/58983.jpg?subformat=icon-1440$$xicon-1440$$yOpenAccess 000042308 8564_ $$uhttps://juser.fz-juelich.de/record/42308/files/58983.jpg?subformat=icon-180$$xicon-180$$yOpenAccess 000042308 8564_ $$uhttps://juser.fz-juelich.de/record/42308/files/58983.jpg?subformat=icon-640$$xicon-640$$yOpenAccess 000042308 909CO $$ooai:juser.fz-juelich.de:42308$$pdnbdelivery$$pVDB$$pdriver$$popen_access$$popenaire 000042308 9131_ $$0G:(DE-Juel1)FUEK254$$bInformation$$kI03$$lWissenschaftliches Rechnen$$vBetrieb und Weiterentwicklung des Höchstleistungsrechners$$x0 000042308 9141_ $$y2004 000042308 915__ $$0StatID:(DE-HGF)0010$$aJCR/ISI refereed 000042308 915__ $$0StatID:(DE-HGF)0510$$2StatID$$aOpenAccess 000042308 9201_ $$0I:(DE-Juel1)VDB62$$d31.12.2007$$gZAM$$kZAM$$lZentralinstitut für Angewandte Mathematik$$x0 000042308 970__ $$aVDB:(DE-Juel1)58983 000042308 980__ $$aVDB 000042308 980__ $$aJUWEL 000042308 980__ $$aConvertedRecord 000042308 980__ $$ajournal 000042308 980__ $$aI:(DE-Juel1)JSC-20090406 000042308 980__ $$aUNRESTRICTED 000042308 980__ $$aFullTexts 000042308 9801_ $$aFullTexts 000042308 981__ $$aI:(DE-Juel1)JSC-20090406