Metal-regulated assemblies of CuII, NiII, and ZnII complexes with isoquinoline-3-carboxylate displaying diverse supramolecular networks

Three distinct coordination complexes, viz. {[Cu(μ-L)2] · (H2O)4}n (1), [Ni(L)2(CH3OH)2] (2), and [Zn(L)2(H2O)2] · (H2O)2 (3), have been prepared by the reactions of metal nitrates with isoquinoline-3-carboxylic acid (HL). X-ray single-crystal diffraction suggests that 1 is a 1D chain coordination polymer in which the CuII ions are connected by carboxylates, whereas complexes 2 and 3 represent discrete mononuclear species. In all the cases, the coordination entities are further organized via hydrogen-bonding interactions to generate multifarious supramolecular networks. Remarkably, a well-resolved 1D water morphology is observed for the first time in the crystalline lattice of 1 along [1 0 0], which consists of edge-sharing tetrameric subunits and stabilized by the metal-organic host surroundings.

Graphical abstractReactions of metal nitrates with the ligand isoquinoline-3-carboxylic acid (HL) afford a 1D chain coordination polymer {[Cu(μ-L)2] · (H2O)4}n (1) as well as two mononuclear species [Ni(L)2(CH3OH)2] (2) and [Zn(L)2(H2O)2] · (H2O)2 (3). The crystal structures of the three complexes display diverse hydrogen-bonding supramolecular networks, which are regulated by the metal centers. Notably, a well-resolved 1D water morphology consisting of edge-sharing tetrameric subunits is found in the crystalline lattice of 1.Figure optionsDownload full-size imageDownload as PowerPoint slide