Charge transfer interaction of 4-acetamidophenol (paracetamol) with 2,3-dichloro-1,4-naphthoquinone: a study in aqueous ethanol medium by UV-vis spectroscopic and DFT methods.
Spectrochim Acta A Mol Biomol Spectrosc
; 71(3): 835-40, 2008 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-18343717
ABSTRACT
4-Acetamidophenol (paracetamol) is shown to form charge transfer complex with 2,3-dichloro1,4-naphthoquinone in aqueous ethanol media exhibiting the unusual 21 (paracetamolquinone) stoichiometry. The complexation enthalpy and entropy have been estimated from the formation constant (K) determined spectrophotometrically at five different temperatures. In aqueous ethanol mixtures of varying composition K increases with increasing dielectric constant of the medium. This has been rationalized by calculating the electronic charge distribution in paracetamol molecule and its conjugate base at the DFT/B3LYP/6-31++G(d,p) level. The theoretically calculated vertical ionization potential of paracetamol also agrees with reported experimental value.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Naftoquinonas
/
Acetaminofen
Idioma:
En
Revista:
Spectrochim Acta A Mol Biomol Spectrosc
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Índia