Inclusion Complexes of γ-Cyclodextrin with Pendimethalin†

Abstract

Through the saturated water solution method,the guest body pendimethalin was tried to be included by the host body γ-cyclodextrin( γ-CD). Ultraviolet spectrum was used to determine the inclusion ratio in accordance with the Job's method,clarified that the inclusion molar ratio was 1∶ 1. Infrared spectrum proved that the benzene ring structure of the pendimethalin could be entered into the γ-CD's hydrophobicity cavity.The melting point of the pendimethalin was proved to be increased after the inclusion by thermal analysis. The emergence of the new diffraction peaks in powder X-ray diffraction atlas was attributed to the formation of new phase. The appearance of the inclusion was intuitively showed by the scanning electron microscopy( SEM).All of the results above indicated that the γ-CD-pendimethalin inclusion complex were obtained,and the equilibrium constant K was 1123. 99 L / mol. Both the melting point and the solubility of the pendimethalin were significantly improved by including,therefore,pendimethalin could be processed into water-based pesticide formulations in the form of the inclusion.