Inclusion Complexation of Benzyl Viologen by β-Cyclodextrin in DMF-H2O Mixed Solution

Shazia Perveen; Iftikhar Imam Naqvi

doi:10.21743/pjaec/2016.06.009

Authors

Shazia Perveen Department of Chemistry, University of Karachi- 75270, Karachi, Pakistan Author
Iftikhar Imam Naqvi Department of Chemistry, University of Karachi- 75270, Karachi, Pakistan Author

DOI:

https://doi.org/10.21743/pjaec/2016.06.009

Keywords:

Benzyl viologen, β-Cyclodextrin, EC mechanism, DMF- H2O mixed solvent, cyclic voltammetry.

Abstract

Complex formation between benzyl viologen and β-Cyclodextrin (βCD) in 9:1(v/v) DMF-H₂O mixed solution was studied by cyclic voltammetry. In order to examine the probable mechanism of the reaction of benzyl viologen dication (BzV²⁺) and its reduced forms with βCD, cyclic voltammograms were digitally simulated. Detailed analysis of the mechanism by digital simulation revealed that in 9:1(v/v) DMF-H2O mixed solution, benzyl viologen mono-cation (BzV⁺∙) formed inclusion complex with βCD according to EC mechanism, while its fully reduced form (BzV°), could not form inclusion complex with βCD. Bonding equilibrium constant, Keq, pertaining to the bonding of BzV+∙ with βCD was estimated as 10.6 M-n. The second order rate constant for the reaction of BzV⁺∙ with βCD was determined as 4.93 M-nS-. By the use of this solvent system (9:1(v/v) DMF- H₂O mixed solution) the comprehensive study of non-alkyl group substituted viologens and long alkyl chain viologens with βCD is possible.