Synthesis, Bioactivities And Soil Leaching From Contaminated Soil Of Hexaconazole And Benzothiazole Derivatives And Their Metal Complexes

The small molecules that bind to metal ions is an exciting field of research in bio inorganic chemistry, while chelation of the pesticide and metal ions is a concern of study. After coordinating with metals, it will increase the activity, extende the duration of the efficacy, and reduce the toxicity to mammals, or some multiple biological functions. Since each nitrogen atom of a triazole ring has lone-pair electrons,1,2,4-triazole and its derivatives prefer coordination with transition-metal ions. The benzothiazole derivatives have strong coordination ability and the diversity of ligand conformation, which has been a focus for researchers.In this paper, the complexes of hexaconazole and benzothiazole derivatives with transition metal ions have been prepared and characterized by elemental analysis, infrared spectra, UV, and mass spectra. The molecular formulas of the complexes were proposed. Meanwhile, the fungicidal activities of the complexes have been tested on different microorganisms. The dissertation includes the three results:1. The complexes of hexaconazole with Cu2+, Zn2+and Cd2+have been prepared and characterized by elemental analysis, infrared spectra, UV, and mass spectra. Meanwhile, bactericidal activity was studied, and the results indicated that the complex show excellent inhibition activity against wheat powdery mildew, pear scab pathogen, sclerotinia sclerotiorum, botrytis cinerea and fusarium graminearum. At concentrations of2.50and1.25mg L-1, copper-complex give an inhibition rate up to95and90%while hexaconazole was only80and70%against blumeria graminis.2. Three benzothiazole derivatives and their complexes with Cd2+and Co2+were synthesized by polyphosphoric acid. All the compounds were characterized by elementary analysis, IR spectra, UV spectra, NMR spectra and mass spectra. The relationship between structure and fluorescent properties was also discussed in this paper. Meanwhile, bactericidal activity was studied, and the results indicated that the complex has good bactericidal activity. At the concentration of50mg L-1,2-(2-hydroxy-5-chlorophenyl)benzothiazole and the inhibition rate of cobalt complexes is0.4%higher than2-(2-hydroxy-5-chlorophenyl)benzothiazole against rhizoctonia solani, while cadmium complex is4%higher than the ligand.3. With soil leaching experiment, the results show that hexaconazole and2-(2-hydroxy-5-chlorophenyl)benzothiazole is observed high adsorptive capability on copper at low pH value through soil experiments. The removal rates of copper reached80and83%at pH3by hexaconazole and2-(2-hydroxy-5-chlorophenyl)benzothiazole, while65and72%at pH4, respectively.Therefore, our studies presented herein demonstrate that hexaconazole and benzothiazole derivatives have both notable competitive capability to chelate transition metal ions from soil and excellent antifungal activities as metal chelator.