Voltammetric, Spectroscopic and Thermal Studies on the Binding of Some Heterocyclic Azo Compounds with alpha- and beta-Cyclodextrins: pH Effect and Association Affinity

Ozdemir N., Bicer E.

RUSSIAN JOURNAL OF ELECTROCHEMISTRY, vol.53, no.5, pp.486-499, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 53 Issue: 5
  • Publication Date: 2017
  • Doi Number: 10.1134/s102319351705007x
  • Journal Name: RUSSIAN JOURNAL OF ELECTROCHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.486-499
  • Keywords: heterocyclicazo dyes, alpha- and beta-cyclodextrins, inclusion and non-inclusion complexes, association constant, pH effect, stoichiometry, INCLUSION COMPLEXES, GAMMA-CYCLODEXTRIN, GUEST, RECOGNITION, HOST, ION, THERMODYNAMICS, SENSORS, WATER, DYES
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

The binding abilities of alpha- and beta-cyclodextrins (alpha-CD and beta-CD) with some heterocyclic azo compounds (1,1'-(azodicarbonyl)dipiperidine (ADP) and azodicarboxylic dimorpholide (ADM)) were studied at different pHs (4, 7.4 and 10) by UV-Vis spectroscopy and square-wave voltammetry techniques. The association constants (K-i) and stoichiometries of the binding of these azo compounds with alpha-CD and beta-CD were determined by using square-wave voltammetry technique. These bindings were formed with a stoichiometry of 1 : 1 in solution. The solid samples, obtained from the mixtures (molar ratio of 1 : 1) of these azo dyes and CDs in aqueous phase were analyzed by FT-IR spectroscopy and thermal analysis methods. Thermal analysis results showed that ADP and ADM formed the inclusion complexes with alpha-CD; however, the binding of the azo dyes with beta-CD gave non-inclusion complexes.