A One-dimensional Selenotungstate Based on Neodymium and {SeO3} Groups Connecting for Catalytic Synthesis of Imidazoles

Abstract

A novel neodymium-{SeO3}-bridged selenotungstate, [Na16Nd2.5(SeO3)2(mal)(W4O9)(SeW8O32)(SeW9O33)2(H2O)4]·ca.26H2O (NdSeW, mal = malic acid), has been synthesized. This compound is constructed from both {SeW9} and {SeW8} building units, which are linked through an organometallic {Nd2Se2(mal)W4} cluster, forming a distinctive triangular arrangement. Two triangular trimers are alternating connected by neodymium and {SeO3} groups to form a one-dimensional chain architecture, which is extremely rare in polyoxometalates chemistry. In addition, NdSeW exhibits excellent catalytic activity for the synthesis of 2,4,5-trisubstituted imidazoles through the condensation of aldehydes, benzils, and ammonium acetate under environmentally benign conditions.