@prefix prodottidellaricerca: . @prefix istituto: . @prefix prodotto: . istituto:CDS087 prodottidellaricerca:prodotto prodotto:ID51947 . @prefix rdf: . prodotto:ID51947 rdf:type prodotto:TIPO1101 . @prefix retescientifica: . prodotto:ID51947 rdf:type retescientifica:ProdottoDellaRicerca . @prefix rdfs: . prodotto:ID51947 rdfs:label "Stopped-Flow and DFT Studies of ProtonTransfer and Isomerisation Rate Constants in Water for 5-Amino-3-imino-1,2,6,7-tetracyano-3H-pyrrolizine and Its Related Base 2-(5-Amino-3,4-dicyano-2H-pyrrol-2-ylidene)-1,1,2-tricyanoethanide:a Complete Square Scheme (Articolo in rivista)"@en . @prefix xsd: . @prefix pubblicazioni: . prodotto:ID51947 pubblicazioni:anno "2002-01-01T00:00:00+01:00"^^xsd:gYear . @prefix skos: . prodotto:ID51947 skos:altLabel "
Collange E., Flamini A., Poli R. (2002)
Stopped-Flow and DFT Studies of ProtonTransfer and Isomerisation Rate Constants in Water for 5-Amino-3-imino-1,2,6,7-tetracyano-3H-pyrrolizine and Its Related Base 2-(5-Amino-3,4-dicyano-2H-pyrrol-2-ylidene)-1,1,2-tricyanoethanide:a Complete Square Scheme
"^^rdf:HTML ; pubblicazioni:autori "Collange E., Flamini A., Poli R."^^xsd:string ; pubblicazioni:paginaInizio "200"^^xsd:string ; pubblicazioni:paginaFine "208"^^xsd:string ; pubblicazioni:numeroVolume "106"^^xsd:string ; skos:note "ISI Web of Science (WOS)"^^xsd:string ; pubblicazioni:titolo "Stopped-Flow and DFT Studies of ProtonTransfer and Isomerisation Rate Constants in Water for 5-Amino-3-imino-1,2,6,7-tetracyano-3H-pyrrolizine and Its Related Base 2-(5-Amino-3,4-dicyano-2H-pyrrol-2-ylidene)-1,1,2-tricyanoethanide:a Complete Square Scheme"^^xsd:string ; prodottidellaricerca:abstract "A complete kinetic study of pH-dependent isomerization \nof species 5-amino-3-imino-1,2,6,7-tetracyano-3H-\npyrrolizine (HL) and 2-(5-amino-3,4-dicyano-2H-pyrrol-2-\nylidene)-1,1,2-tricyanoethanide (L'-) in the pH range \nfrom 0.5 to 13 in aqueous solution, which spans over 7 \norder of magnitude for the pseudo-first order rates \n(log k from 4.8 to 2.5) has revealed for the first \ntime the existence of the corresponding conjugate \nspecies L- and HL'. The study has allowed the \ndetermination of the pKa values of HL and HL', as well \nas all the individual forward and reverse isomerization \nrates of the acidic (HL/HL') and basic (L-/L'-) forms. \nWhile L'- is the sole species present at pH > ca. 7, \nspecies HL and HL' establish an equilibrium favoring \nthe former compound at low pH, the distribution being \nca. 79:21 at pH < ca. 2. At pH < 2, a slow \ndecomposition of HL occurs via the initial formation of \nan unobserved and unstable protonated form H2L+. \nGeometry optimizations of all species at the \nB3LYP/LANL2DZ level, including water solvation energy, \nafford results in qualitative agreement with experiment \nand indicate the structural nature of the new species L-\n and HL'." ; prodottidellaricerca:prodottoDi istituto:CDS087 .