alpha-Substituent effects on C-13 NMR chemical shifts in some aliphatic compounds: Application of principal component analysis (PCA)

dc.creatorTasic, L
dc.creatorRittner, R
dc.date2009
dc.dateSEP 17
dc.date2014-11-14T23:04:09Z
dc.date2015-11-26T17:17:41Z
dc.date2014-11-14T23:04:09Z
dc.date2015-11-26T17:17:41Z
dc.date.accessioned2018-03-29T00:05:32Z
dc.date.available2018-03-29T00:05:32Z
dc.identifierJournal Of Molecular Structure. Elsevier Science Bv, v. 933, n. 41699, n. 15, n. 19, 2009.
dc.identifier0022-2860
dc.identifierWOS:000269472400003
dc.identifier10.1016/j.molstruc.2009.05.053
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/77175
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/77175
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/77175
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1282508
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionThe principal component analyses (PCA) were applied in investigations of alpha-substituent effects on C-13 NMR chemical shifts of the total of 169 aliphatic compounds represented by 13 organic classes: (a) carbonyl: acetones, acetophenones, camphors and cyclohexanones; (b) carboxyl: acetic acids, methyl-, ethyl- and phenyl-acetates, ethyl thioacetates, and N,N-diethylacetamides; and (c) unsaturated compounds: cyanides, oximes, and propenes. The effects of twelve alpha-substituents: F, Cl, Br, I, CMe, OEt, SMe, SEt, NMe2, NEt2, Me and Et were considered. In PCA matrix construction the experimentally C-13 NMR data for functional carbon and alpha-carbon atoms, and theoretically (ab initio) obtained data were used, and two type of PCA results were generated and discussed. In the first PCA score analysis, the division in three compound groups (a-c) was obtained principally because of variations in the lowest unoccupied molecular orbital (LUMO) energies and partial charges on functional carbon atoms. The second PCA results showed division of analyzed compounds in groups of substituents according to heteroatom present (O, N. S, C or H) principally due to the differences in partial charges on alpha-carbon atoms as detected in the first principal component (PC), as well as, in molecular orbital coefficient of alpha-carbon atoms according to the second PC loading values. The halogen derivatives were treated as outliers in this PCA. Thus, knowing the structure of the Y-CH2-X Compound and calculating few theoretical (ab initio) parameters, four in our case, one could be able to predict the functional and alpha-carbon NMR chemical shifts with high accuracy based on PCA scores considering two principal component models and PC1 versus PC2 plots. (C) 2009 Elsevier B.V. All rights reserved.
dc.description933
dc.description41699
dc.description15
dc.description19
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionFAPESP [05/59649-0, 04/14584-5, 98/01239-5]
dc.languageen
dc.publisherElsevier Science Bv
dc.publisherAmsterdam
dc.publisherHolanda
dc.relationJournal Of Molecular Structure
dc.relationJ. Mol. Struct.
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectNMR
dc.subjectC-13 NMR
dc.subjectalpha-Substituent effects
dc.subjectCarbonyl
dc.subjectCarboxyl
dc.subjectUnsaturated compounds
dc.subjectElectronic Interaction
dc.subjectCarbonyl-compounds
dc.subjectAcetates
dc.subjectN,n-diethylacetamides
dc.subjectH-1
dc.titlealpha-Substituent effects on C-13 NMR chemical shifts in some aliphatic compounds: Application of principal component analysis (PCA)
dc.typeArtículos de revistas


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