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 β-cyclodextrin polymer (β-CDP) was prepared by a facile strategy and characterized by FTIR, powder X-ray diffractometry, thermogravimetry, 1H NMR spectroscopy and UV–vis spectroscopy. The ratio of β-cyclodextrin (β-CD) unit in β-CDP to IDP is determined as 2:1. At 25 °C, the dissociated constant of IDP-β-CDP is measured as 1.79 ± 0.17 × 10−5 M2 by UV–vis spectroscopy. The well behaved electrochemical properties of IDP-β-CDP in water are observed. The diffusion coefficient of reduced state and the diffusion activation energy are calculated as 4.0 ± 0.5 × 10−7 cm2 s−1 and 9.8 ± 0.3 kJ mol−1, respectively. Compared with IDP, the solubility of IDP-β-cyclodextrin polymer (IDP-β-CDP) is greatly enhanced due to the water-soluble β-CDP host.