Synthesis, Fluorescence Spectra, Redox Property and the DNA Binding Studies of 7-phenylacenaphtho[1,2-b]quinoxalin-7-ium chloride: Evidences of the Formation of Neutral Radical Analogue.
J Fluoresc
; 25(6): 1645-54, 2015 Nov.
Article
em En
| MEDLINE
| ID: mdl-26399541
ABSTRACT
Reaction of acenaphthoquinone with N-phenyl-o-phenylenediamine in methanol in presence of HCl yielded 7-phenylacenaphtho[1,2-b]quinoxalin-7-ium chloride, [1][Cl]. [1][Cl] is brightly fluorescencent in dichloromethane (λex = 403 nm and λem = 442, 464, 488 nm) and water (λex = 408 nm and λem = 545 nm). Density functional theory (DFT) and time dependent (TD) DFT calculations on [1](+) at the B3LYP level of the theory elucidated that the origin of the lower energy excitation at around 400 nm is due to π â π(*) transition. [1](+) is redox active and exhibits a reversible cathodic wave at -0.66 V referenced to Fc(+)/Fc couple due to [1](+)/[1](â¢) redox couple. Electrogenerated neutral radical analogue [1](â¢) was characterized by electron paramagnetic resonance (EPR), UV-vis spectra and DFT calculations. DNA binding studies using the techniques of UV-vis absorption, fluorescence, circular dichroism (CD) spectra, viscosity, gel electrophoresis, hydrodynamic, isothermal titration calorimetry (ITC) and UV optical melting studies of [1][Cl] revealed that [1](+) is a strong DNA intercalator obeying neighbor exclusion principle. ITC experiment authenticated that the binding of [1](+) to DNA is entropy driven.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Quinoxalinas
/
DNA
/
Acenaftenos
Limite:
Animals
Idioma:
En
Revista:
J Fluoresc
Assunto da revista:
BIOFISICA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Índia