Diverse Zn(II) MOFs assembled from V-shaped asymmetric multicarboxylate and N-donor ligands

• Four compounds based on a new semirigid tricarboxylate ligand, which has been rarely reported before.
• These compounds display four different structures varying from OD to 2D.
• Compounds 1–4 exhibit strong blue luminescence at room temperature.

By reacting an asymmetry semi-rigid V-shaped linker H3L (H3L = 3-(3-carboxyphenoxy) phthalic acid) and Zn(NO3)2·6H2O under different N-donor ligands in different solvents, four new Zn-based coordination polymers, [Zn(HL)(2,2′-bpy)(H2O)]n(1), [Zn(HL)(4,4′-bpy)]n·n(DMA) (2), [Zn3(L)2(phen)3(H2O)]n·n(H2O) (3) and [Zn(HL)(phen)(H2O)]2(4) (2,2′-bpy = 2,2′-bipyridine; 4,4′-bpy = 4,4′-bipyridine; phen = 1,10-phenanthroline; DMA = N,N-dimethylacetamide) have been obtained. All of these compounds have been clearly identified by single crystal X-ray diffraction analysis. Compound 1 exhibits one-dimensional (1D) chain structure constructed from uninuclear Zn(II) motif, which further extends into 2D supramolecular architecture via intermolecular π–π interactions and hydrogen bonds. Structural analysis reveals that the structure of 2 and 3 can be described as a 2D hcb topology network with the point symbol of {63}. Compound 4 shows a 0D binuclear motif while its 3D packing network has a large potential solvent voids. The results of this research demonstrate that the solvent and the secondary ligands could co-regulate different structural coordination polymers with interesting properties. In addition, the thermal stabilities and solid-state luminescence properties of compounds 1–4 have also been investigated.

Presented here are four MOFs based on a new semirigid tricarboxylate ligand. Of particular interest is that the four compounds are co-regulated by different auxiliary N-donor ligands and solvents.Figure optionsDownload as PowerPoint slide