Ability of 2,4D and 2,4DP Herbicides to Combin with Metal Ions of Biological Interest(Part 2):Zinc(II)Complexes

摘要

Zinc(II)complexes with the commercial auxin herbicides 2,4-dichlorophenoxyacetic acid(2,4D;C_8H_6O_3Cl_2)and 2-(2,4-dichlorophenoxy)-propionic acid(2,4DP;C_9H_8O_3Cl_2)were prepared and characterized.The formulae of the solid complexes Zn_2(C_8H_5O_3Cl_2)_3 centre dot 5H_2O(Zn-2,4D)and Zn(C_9H_7O_3Cl_2)_2 centre dot 1.5H_2O(Zn-2,4DP)were established on the basis of the results of elemental analysis and Zn(II)determination.Water solubility of synthesized complexes at room temperature was examined.X-ray powder analysis was carried out.The discussion of IR spectra and conductivity data is presented.Thermal decomposition of these complexes in air was studied by TG,DTG,DTA and TG/MS methods with simultaneous analysis of the solid and gaseous products.The formation of complexes Zn-herbicide in the water solution by potentiometric pH titration was also investigated.The dissociation constants(pK)of 2,4D and 2.4DP were determined at 25 deg C and I=0.1(KNO_3).