Lanthanum complex as well as preparation method and application thereof

The invention relates to the technical field of complexes, and provides a lanthanum complex as well as a preparation method and application thereof. Phthalic acid is used as a ligand, and lanthanum ions are used as central metal. The adsorbent provided by the invention finally realizes efficient adsorption of oxyacid radical ions under the combined action of a space orbit effect of central metal lanthanum ions, an isolated electron effect in ligand dicarboxylic acid and a space effect of an obtained complex. Experimental results show that the adsorption capacity of the complex for oxyacid radical ions containing phosphorus can reach 50 mg.g or above, the adsorption capacity of the complex for oxyacid radical ions containing heavy metal elements can reach 100 mg.g or above, and theadsorption capacity of the complex formed by isophthalic acid and lanthanum can reach 756.8 mg.g, and the selective adsorption property is very good compared with other oxyacid radical ions. 本发明涉及配合物技术领域，提供了一种镧配合物及其制备方法和应