Tautomerism and spectral properties of δ-carboline (5H-pyrido[3,2-b]indole) and its N,N-dimethyl derivative in aqueous media
-
Add time:09/28/2019 Source:infona.pl
The influence of acidity on the absorption and fluorescence spectra of 5H-pyrido[3,2-b]indole or δ-carboline (δ-C) and its N,N-dimethyl derivative has been studied in aqueous media. The changes in the absorption spectra of δ-C are apparently simple and can be related with the formation of the cationic and anionic species resulting from the protonation of the pyridinic nitrogen atom and the deprotonation of the pyrrolic group, respectively. However, the wavelength dependence of the excitation and emission fluorescence spectra in acid media reveals the existence of tautomeric cations in the ground state. The influence of the acidity on the spectra of the N,N-dimethyl derivative, a model of fixed δ-C cation, allowed the identification of two tautomeric cations: the normal one, CN, where the positive charge is on the pyridinic nitrogen, and its tautomer, CT, with the positive charge mainly localised on the pyrrolic nitrogen. Upon excitation to the first singlet excited state, the pyridinic nitrogen of δ-C becomes more basic and the pyrrole group more acid by 7 and 7.6 pK a units, respectively.
We also recommend Trading Suppliers and Manufacturers of 5H-Pyrido[3,2-b]indole (cas 245-08-9). Pls Click Website Link as below: cas 245-08-9 suppliers
Prev:The chemistry of novel C 2 diazabiaryl ligands: Cycloocta[2,1-b:3,4-b']dipyridine, cycloocta[2,1-b:3,4-b']diquinoline and their related compounds
Next:A ruthenium(II) bipyridine complex containing a 4,5-Diazafluorene (cas 245-37-4) moiety: Synthesis, characterization and its applications in transfer hydrogenation of ketones and dye sensitized solar cells) - 【Back】【Close 】【Print】【Add to favorite 】