کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1231744 1495276 2012 27 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Chemical speciation and equilibria of some nucleic acid compounds and their iron(III) complexes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Chemical speciation and equilibria of some nucleic acid compounds and their iron(III) complexes
چکیده انگلیسی

The pH effect on electronic absorption spectra of some biologically active nucleic acid constituents have been studied at room temperature and the mechanism of ionization was explained. These compounds are of two categories (pyrimidines: [barbital; 5,5′-diethyl-barbituric acid], [SBA; 4,6-dihydroxy-2-mercapto-pyrimidin], [NBA; 5-nitro-2,4,6(1H,3H,5H)-pyrimidine trione] and [TU; 2,3-dihydro-2-thioxo-pyrimidin-4(1H)-one]) and (purines: [adenine; 6-amino purine], its [Schiff bases derived from adenine-acetylacetone; (Z)-4-(7H-purin-6-ylimino)pentan-2-one) and adenine-salicylaldehyde; 2-((7H-purin-6-ylimino) methyl) phenol] and its [Azo derived from adenine-resorcinol; 4-((7H-purin-6-yl)-diazenyl) benzene-1,3-diol]. The phenomena of tautomerization assigned different tautomers. Different spectrophotometric methods are applied to evaluate the pK's values that explained with their molecular structures. The interaction of Fe3+ with some selected pyrimidines (barbital, NBA and SBA) was explained using familiar six spectrophotometric methods. The data typified the existence of different absorbing species with the different stoichiometries 1:1, 1:2, 1:3 and 2:3. The stability constant of the complexes was computed. More approach was deduced to assign the existence of different species applying the distribution diagrams.

The molecular structures of the investigated compounds and its predicted tautomers.Figure optionsDownload as PowerPoint slideHighlights
► The pH effect on electronic absorption spectra of some nucleic acid and mechanism of ionization.
► Different spectrophotometric methods are applied to evaluate pK's values of different tautomers.
► Chemical speciation and equilibria of iron complexes applying distribution diagrams.
► The phenomena of tautomerization is assigned were different tautomers are detected.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 92, 15 June 2012, Pages 256–282
نویسندگان
, , , ,