A novel heterometallic BaGa coordination polymer based on the bifunctional ligand 2,5-pyridine dicarboxylic acid

• Compound 1 is the first heterometallic CP based on Ba(II) and Ga(III) ions.
• The different affinity to N and O between Ba(II) and Ga(III) ions can provide useful guidance in the design of new BaGa-CPs.
• Luminescence of 1 is mainly ascribed to the emission of ligand-to-ligand charge transfer.

The first heterometallic BaGa coordination polymer (CP), namely [Ba2Ga2(pydc)4(OH)2(H2O)2]·3H2O (1) (H2pydc = 2.5-pyridine dicarboxylic acid), has been successfully synthesized by the reaction of the bifunctional ligand H2pydc, BaCl2·2H2O and Ga2O3 under hydrothermal conditions. Single-crystal X-ray diffraction analysis reveals that compound 1 features a three-dimensional (3D) network structure constructed from Ga2(OH)2 dimers incorporated Ba-pydc skeletons. Luminescence measurements showed that 1 exhibited strong emission band centered at 412 nm ascribed to the emission of ligand-to-ligand charge transfer, which was confirmed by theoretical studies.

Presented is the first fluorescent heterometallic coordination polymer constructed from Ba(II), Ga(III) and the bifunctional ligand 2.5-pyridine dicarboxylic acid.Figure optionsDownload as PowerPoint slide