Publicação

Electrochemical Studies and Thermodynamic Parameters of Citrazinic Acid Azo Dye and its Nitro Derivatives in DMF-Aqueous Solutions

Ver documento

Detalhes bibliográficos
Resumo:The electrochemical behavior of citrazinic acid azo dye derivatives (I-V) was recorded in aqueous buffer solutions containing 10% (v/v) DMF using DC-polarography and cyclic voltammetry. The DC-polarograms displayed one or two reduction waves depending on the nature of substituent and the pH of the electrolyte solution. The reduction process takes place irreversibly and diffusion controlled at the electrode surface through the uptake of four electron/molecules for compound I and eight electron/molecules for each of compounds II-V. The recorded cyclic voltammograms displayed two irreversible cathodic peaks at different pH values. The kinetic parameters of the electrode process such as, an, heterogeneous rate constant (k s) and activation energy (ΔG#) were evaluated and discussed from cyclic voltammetry. Also, the electrode reaction mechanism is proposed and discussed. The effect of introducing substituents on the half-wave potential of the reduction process is illustrated. The different thermodynamic parameters such as activation energy (ΔG#), enthalpy change (ΔH#) and entropy change (ΔS#) revealed the endergonic nature of the electrode reaction.
Autores principais:Yasin,Shalaby A.
Assunto:citrazinic azo dyes polarography cyclic voltammetry thermodynamic parameters
Ano:2006
País:Portugal
Tipo de documento:artigo
Tipo de acesso:acesso aberto
Instituição associada:Fundação para a Ciência e Tecnologia
Idioma:inglês
Origem:SciELO Portugal

Registos relacionados

Registos relacionados