Design and Construction of Six Coordination Polymers with Imidazole-4,5 Ligand

Abstract

Six new metal-organic frameworks based on a rigid multifunctional ligand imidazole 4,5-dicarboxylic acid (H<inf>3</inf>idc), namely, [Zn<inf>3</inf>(μ<inf>3</inf>-idc)(μ<inf>5</inf>-idc)]<inf>n</inf> (1), {[Zn<inf>3</inf>(μ<inf>3</inf>-idc)<inf>2</inf>(H<inf>2</inf>O)(dpeten)]<inf>n</inf>·2H<inf>2</inf>O}<inf>n</inf> (2), [Zn(μ-Hidc)(μ-obix)<inf>0.5</inf>]<inf>n</inf> (3), [Zn<inf>4</inf>(μ-Hidc)<inf>4</inf>(μ-mbix)<inf>2</inf>]<inf>n</inf> (4), {[Cd<inf>5</inf>(μ<inf>5</inf>-idc)<inf>2</inf>(μ<inf>4</inf>-Hidc)<inf>2</inf>(H<inf>2</inf>O)<inf>2</inf>]·2H<inf>2</inf>O}<inf>n</inf> (5) and [Cd<inf>2</inf>(μ<inf>3</inf>-Hidc)<inf>2</inf>(μ-obix)]<inf>n</inf> (6) (H<inf>3</inf>idc = imidazole-4,5-dicarboxylic acid, obix = 1,2-bis(imidazol-1-ylmethyl)-benzene, mbix = 1,3-bis(imidazol-1-ylmethyl)-benzene and dpeten = 1,2-di(pyridin-4-yl)ethene), have been constructed under hydro(solvo)thermal conditions and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD) and thermal analyses (TG, DTA, DSC) techniques. In these compounds, the ligand, H<inf>3</inf>idc, exhibits different coordination modes, constructing various architectures by bridging a variety of metal ions or polynuclear clusters. All of these coordination polymers exhibited intense fluorescent emissions in the solid state at room temperature. Furthermore, topological properties were studied. © 2015 Elsevier B.V. All rights reserved.