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Uticaj rastvarača i strukture na reaktivnost 6-supstituisanih nikotinskih kiselina sa diazodifenilmetanom u aprotičnim rastvaračima

dc.creatorDrmanić, Saša
dc.creatorMarinković, Aleksandar
dc.creatorJovanović, Bratislav Ž.
dc.date.accessioned2021-03-10T11:02:43Z
dc.date.available2021-03-10T11:02:43Z
dc.date.issued2009
dc.identifier.issn0352-5139
dc.identifier.urihttp://TechnoRep.tmf.bg.ac.rs/handle/123456789/1391
dc.description.abstractThe rate constants for the reactions of diazodiphenylmethane (DDM) with 6-substituted nicotinic acids in aprotic solvents at 30°C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and nicotinic acids in protic solvents, were used for the calculation of solvent effects, employing the Kamlet-Taft solvatochromic equation (linear solvation energy relationship - LSER) in the form: log k = log k0 + + sΠ*+ aα + bβ. The correlations of the kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The sign of the equation coefficients (s, a and b) were in agreement with the postulated reaction mechanism, and the mode of the solvent influences on the reaction rate is discussed based on the correlation results. A similar contribution of the non-specific solvent effect and electrophilic solvation was observed for all acids, while the highest contribution of nucleophilic solvation was influenced by their high acidity. Correlation analysis of the rate data with substituent óp parameters in an appropriate solvent using the Hammett equation was also performed. The substituent effect on the acid reactivity was higher in aprotic solvents of higher dipolarity/polarizability. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute-solvent interaction on the acid reactivity.en
dc.description.abstractKonstante brzina 6-supstituisanih nikotinskih kiselina sa diazodifenilmetanom (DDM) su određene u različitim protičnim i aprotičnim rastvaračima na 30°C. Izračunate konstante brzina, kao i literaturni podaci, korišćeni su za izračunavanje efekata rastvarača korišćenjem Kamlet-Taft-ove solvatohromne jednačine. Konstante brzina su korelisane sa parametrima rastvarača korišćenjem Kamlet-Taft-ove jednačine oblika: log k = log k0 + + sΠ*+ aα + bβ. Korelacije dobijenih kinetičkih rezultata sa odgovarajućim parametrima rastvarača su izvedene primenom metode višestruke linearne regresione analize. Znak koeficijenata (s, a i b) u dobijenim korelacijama je u saglasnosti sa reakcionim mehanizmom. Sličan doprinos nespecifičnih efekata i elektrofilne solvatacije rastvarača je uočen za sve ispitivane kiseline, a najveći doprinos nukleofilne solvatacije polaznog stanja je posledica visoke kiselosti ispitivanih kiselina. Uticaj rastvarača na vrednosti reakcionih konstanti je diskutovan na osnovu dobijenih korelacionih rezultata. Korelaciona analiza konstanti brzina sa óp konstantama supstituenata, u ispitivanom rastvaraču, izvršena je primenom Hammett-ove jednačine. Efekti supstituenata na reaktivnost ispitivanih kiselina su značajniji u aprotičnim rastvaračima visoke dipolarnosti/polarizabilnosti. Način prenosa efekata supstituenata je diskutovan u svetlu doprinosa interakcija rastvorak-rastvarač na reaktivnost ispitivanih kiselina.sr
dc.publisherSerbian Chemical Society, Belgrade
dc.relationinfo:eu-repo/grantAgreement/MESTD/MPN2006-2010/142063/RS//
dc.rightsopenAccess
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/
dc.sourceJournal of the Serbian Chemical Society
dc.subjectpyridine carboxylic acidsen
dc.subjectdiazodiphenylmethaneen
dc.subjectrate constantsen
dc.subjectsolvatochromic parametersen
dc.subjectaprotic solventsen
dc.titleEffects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solventsen
dc.titleUticaj rastvarača i strukture na reaktivnost 6-supstituisanih nikotinskih kiselina sa diazodifenilmetanom u aprotičnim rastvaračimasr
dc.typearticle
dc.rights.licenseBY-NC-ND
dc.citation.epage1370
dc.citation.issue12
dc.citation.other74(12): 1359-1370
dc.citation.rankM23
dc.citation.spage1359
dc.citation.volume74
dc.identifier.rcubconv_668
dc.identifier.scopus2-s2.0-77349126339
dc.identifier.wos000275494600002
dc.type.versionpublishedVersion


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