Polarograms of Uranium() and Rare Earth() Metal Complexes with Macrocyclic Ligands in Dimethylsulfoxide Solvent

摘要

The uranium(￥μ) complexes with new unsaturated macrocyclic ligands of cryptand types and the neodymium(￥2) complexes with cryptand 222 and DBC ligands have been investigated polarographically in dimethylsulfoxide solvent. The reduction states, electron numbers involved in the reduction process, effects of the added acid on the polarograms of complexes, and the mechanisms of the reduction electrode reactions have been examined. The stability constants and mole-ratio of new complexes were also obtained by polarographic method. The reaction of ligands was controlled by the diffusion in the reduction with four electrons at a step, whereas the redox reaction with six electrons at three steps in UO22+ complexes with macrocyclic ligands and the redox reaction with one electron at a step in Nd3+ complexes with cryptand 222 and DBC have been observed. The imine ligands formed stable complexes with uranium(￥μ) above pH 7.0, and the neodymium(￥2) complexes with cryptand 222 and DBC ligands were stable above pH 4.0.