Preparation and characterization water-soluble inclusion complexes of imidacloprid-β-cyclodextrin polymer and their electrochemical behavior

A new water-solution inclusion complex of imidacloprid (IDP) with beta-cyclodextrin polymer (beta-CDP) was prepared by a facile strategy and characterized by FTIR, powder X-ray diffractometry, thermogravimetry, H-1 NMR spectroscopy and UV-vis spectroscopy. The ratio of beta-cyclodextrin (beta-CD) unit in beta-CDP to IDP is determined as 2:1. At 25 degrees C, the dissociated constant of IDP-beta-CDP is measured as 1.79 +/- 0.17 x 10(-5) M-2 by UV-vis spectroscopy. The well behaved electrochemical properties of IDP-beta-CDP in water are observed. The diffusion coefficient of reduced state and the diffusion activation energy are calculated as 4.0 +/- 0.5 x 10(-7) cm(2) s(-1) and 9.8 +/- 0.3 kJ mol(-1), respectively. Compared with IDP, the solubility of IDP-beta-cyclodextrin polymer (IDP-beta-CDP) is greatly enhanced due to the water-soluble beta-CDP host. (C) 2013 Elsevier B.V. All rights reserved.