Synthesis, Structures, and Properties of a Series of Isostructural Lanthanide‐Thiopheneacrylate Complexes

Abstract

We report the synthesis, crystal structures, and properties of three lanthanide(III) coordination complexes based on 2‐thiopheneacrylic acid (Htpa) of the formula [Ln(tpa)3(H2O)3] ⋅ 3(Htpa) (Ln=Tb (1), Dy (2), Er (3)). The complexes were characterized by single crystal X‐ray diffraction, powder X‐ray diffraction, elemental analysis, IR, TGA, and photoluminescence spectroscopy. Structural analysis indicates that all three complexes are isostructural and crystallize in the trigonal space group R3. The structures of these complexes consist of a discrete neutral mononuclear species [Ln(tpa)3(H2O)3] and the Htpa molecule. In the crystal, the complex species are self‐assembled into a one‐dimensional (1D) supramolecular chain through classical O−H⋅⋅⋅O hydrogen bonds existing between water molecules and carboxylate oxygen atoms. The adjacent chains are further joined together by C−H⋅⋅⋅π hydrogen bonds involving the thiophene moieties, resulting in the formation of a 3D supramolecular framework. The frameworks feature 1D channels with a dimeter of ca. 1.5 nm that can accommodate Htpa molecules to allow the formation of cocrystals via strong hydrogen bonds. In addition, the solid‐state luminescence and thermal properties of these complexes were also investigated.