Publication:
A case study of antiaromaticity: carbomethoxy cyclopropenyl anion

dc.contributor.authorBLEDA, ERDİ ATA
dc.contributor.authorsAltun, Zikri; Bleda, Erdi Ata; Trindle, Carl
dc.date.accessioned2022-04-25T00:11:29Z
dc.date.available2022-04-25T00:11:29Z
dc.date.issued2019
dc.description.abstractThe simplest ideas of antiaromaticity refer to regular monocyclic systems and the eigenfunctions of the Huckel Hamiltonian for 4n pi electrons in such systems. The antiaromaticity is expressed in the energy penalty for such idealized systems relative to the Huckel energy for 2n noninteracting pi pairs. Observed systems seldom achieve the regular planar geometry assumed in this picture, owing to their ability to ease the antiaromaticity penalty by departures from the regular geometry and also by export of the 4n pi electrons' charge to substituents. In this report we estimate numerical values for the stabilization derived from such departures from the structure and the charge distribution of the idealized antiaromatic cyclopropenyl anion for a specific case, 3-dehydro-3-methyl carboxylate cyclopropenyl anion 1(-) using the thermochemical scheme CBSQB3 supplemented by CCSD(T) calculations. According to the isodesmic reaction, the anion 1(-) is destabilized by about 10-15 kcal/mol relative to the saturated 3-dehydro-3-methylcarboxylate cyclopropyl anion 2(-). We propose that the anion relieves a portion of the antiaromatic destabilization by (a) pyramidalization of one carbon of the ring, and (b) export of negative charge into the ester substituent. Both of these responses are expressed in the equilibrium structure of the anion. In the course of the study we estimate the acidity of several related anions and the enthalpy of formation of their neutral conjugate acids, and describe the interconversion of 1 to the dehydrotriafulvalene anion 3(-) by reaction with CO2. [GRAPHICS] .
dc.identifier.doi10.3906/kim-1808-58
dc.identifier.issn1300-0527
dc.identifier.urihttps://hdl.handle.net/11424/263915
dc.identifier.wosWOS:000466785800019
dc.languageeng
dc.publisherSCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK
dc.relation.ispartofTURKISH JOURNAL OF CHEMISTRY
dc.rightsinfo:eu-repo/semantics/openAccess
dc.subjectAntiaromaticity
dc.subjectmonocyclic system
dc.subjectcyclopropenyl anion
dc.subjectisodesmic reaction
dc.subjecthomoisodesmic reaction
dc.subjecttriafulvenone
dc.subjectcycloheptatrienyl anion
dc.subjectCBSQB3
dc.subjectCCSD(T)
dc.subjectLEVEL AB-INITIO
dc.subjectAROMATICITY
dc.subjectSINGLET
dc.subjectPI
dc.subjectDELOCALIZATION
dc.subjectDERIVATIVES
dc.subjectAFFINITIES
dc.subjectGAUSSIAN-2
dc.subjectSTABILITY
dc.subjectENERGIES
dc.titleA case study of antiaromaticity: carbomethoxy cyclopropenyl anion
dc.typearticle
dspace.entity.typePublication
local.avesis.id1cc6c397-3d99-4199-bb54-07fa041b502b
local.import.packageSS39
local.indexed.atWOS
local.journal.numberofpages20
local.journal.quartileQ4
oaire.citation.endPage+
oaire.citation.issue2
oaire.citation.startPage594
oaire.citation.titleTURKISH JOURNAL OF CHEMISTRY
oaire.citation.volume43
relation.isAuthorOfPublication643158c9-3c51-43ad-8cd2-709e24288c09
relation.isAuthorOfPublication.latestForDiscovery643158c9-3c51-43ad-8cd2-709e24288c09

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