Two novel bimetallic transition metal-uranyl one-dimensional coordination polymers with manganese(II) and cobalt(II) incorporating bridging diglycolate (2,2'-oxydiacetate) ligands

Abstract

The crystal structures of two new bimetallic uranyl-transition metal compounds with diglycolic acid [or 2-(carboxymethoxy)acetic acid] have been hydrothermally synthesized and structurally characterized via single-crystal X-ray diffraction. The compounds, namely catena-poly[[[tetraaquamanganese(II)]-μ-2,2'-oxydiacetato-[dioxidouranium(VI)]-μ-2,2'-oxydiacetato] dihydrate], {[MnU(C₄H₄O₅)₂O₂(H₂O)₄]·2H₂O}_n, and catena-poly[[[tetraaquacobalt(II)]-μ-2,2'-oxydiacetato-[dioxidouranium(VI)]-μ-2,2'-oxydiacetato] dihydrate], {[CoU(C₄H₄O₅)₂O₂(H₂O)₄]·2H₂O}_n, both crystallize in the triclinic space group P-1. These compounds form one-dimensional chains via alternating uranyl and transition metal building units. The chains then assemble into three-dimensional supramolecular networks through several hydrogen bonds between water molecules and diglycolate ligands. Luminescence measurements were conducted and no uranyl emission was observed in either compound.

Keywords: bimetallic; cobalt(II); crystal structure; diglycolic acid; hydrogen interactions; luminescence; manganese(II); one-dimensional coordination polymers; uranyl.