![]()
AMBIENTUM BIOETHICA BIOLOGIA CHEMIA DIGITALIA DRAMATICA EDUCATIO ARTIS GYMNAST. ENGINEERING EPHEMERIDES EUROPAEA GEOGRAPHIA GEOLOGIA HISTORIA HISTORIA ARTIUM INFORMATICA IURISPRUDENTIA MATHEMATICA MUSICA NEGOTIA OECONOMICA PHILOLOGIA PHILOSOPHIA PHYSICA POLITICA PSYCHOLOGIA-PAEDAGOGIA SOCIOLOGIA THEOLOGIA CATHOLICA THEOLOGIA CATHOLICA LATIN THEOLOGIA GR.-CATH. VARAD THEOLOGIA ORTHODOXA THEOLOGIA REF. TRANSYLVAN
|
|||||||
Rezumat articol ediţie STUDIA UNIVERSITATIS BABEŞ-BOLYAI În partea de jos este prezentat rezumatul articolului selectat. Pentru revenire la cuprinsul ediţiei din care face parte acest articol, se accesează linkul din titlu. Pentru vizualizarea tuturor articolelor din arhivă la care este autor/coautor unul din autorii de mai jos, se accesează linkul din numele autorului. |
|||||||
STUDIA CHEMIA - Ediţia nr.2 din 2003 | |||||||
Articol: |
AZOCOUPLING PRODUCTS. PART IV. THE STRUCTURE OF DYES OBTAINED BY AZO-COUPLING REACTION OF 1-(4-HYDROXY-6-METHYLPYRIMIDIN-2-YL)-3-METHYLPYRAZOLIN-5-ONE WITH AROMATIC DIAZONIUM SALTS. Autori: IOAN PANEA, ADINA GHIRIȘAN, I. BALDEA, IOAN SILAGHI-DUMITRESCU, LILIANA CRĂCIUN, IOAN ALEXANDRU SILBERG. |
||||||
Rezumat: The number and positions of the absorption bands have been studied for the title dyes, in the range of 350-600 nm, as a function of solvent nature, acidity or basicity of the solutions as well as of the nature of the substituent X in para position on the benzene ring. The obtained results, including Hammett correlations, quantum calculation by using AM1- SM2 method and the mechanism of formation of the dyes 5 prove the existence of some tautomeric azo-hydrazono- and pyrazolin-5-one-5-hydroxy-pyrazole (5a 5b 5c 5d) equilibria, coupled with acid-base equilibria. The visible and (1H-, 13C-) NMR spectra support the hydrazonic structure 5d of the only species detectable in the used aprotic solvents. | |||||||
![]() |
|||||||