Metal(II) Coordination Polymers Derived from Mixed 4-Imidazole Ligands and Carboxylates: Syntheses, Topological Structures, and Properties

Four new metal⁻organic coordination polymers [Cu(L)(mpa)]·3H₂O (1), [Co(L)(mpa)]·H₂O (2), [Zn(L)(mpa)]·H₂O (3), and [Cd(L)(mpa)(H₂O)]·H₂O (4) were synthesized by reactions of the corresponding metal(II) salts based on mixed ligands of 1,4-di(1H-imidazol-4-yl)benzene (L) and 4-methylphthalic acid (H₂mpa), respectively. The structures of the complexes were characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction. Compound 1 exhibits a binodal 4-connected three dimensional (3D) architecture with (6⁵·8)-CdSO₄ topology, while complexes 2 and 3 are isostructural and have two-dimensional (2D) layer structure with (4, 4) sql topology based on the binuclear metal subunits. Complex 4 has the same 2D layer structure with (4, 4) sql topology as complexes 2 and 3, but the inclined interpenetration of parallel sets of layers result in the formation with 2D + 2D → 3D framework. The activated sample 1 shows selective CO₂ uptake over N₂. The photoluminiscent properties together with quantum yield (QY) and luminescence lifetime are also investigated for complexes 3 and 4 in the solid state at room temperature.

N-donor ligands enhancing luminescence properties of seven Zn/Cd(ii) MOFs based on a large rigid π-conjugated carboxylate ligand

Aggregation-induced emission (AIE) has been identified and studied based on a bulky π-conjugated ligand (H₂IDPA) with Zn/Cd^II metals.

Five Cd(ii) coordination polymers based on 2,3′,5,5′-biphenyltetracarboxylic acid and N-donor coligands: syntheses, structures and fluorescent properties

Five Cd(ii) coordination polymers based on 2,3′,5,5′-biphenyltetracarboxylic acid and different bis(imidazole) ligands have been synthesized.

Butane-1,2,3,4-tetra-carb-oxy-lic acid-1,10-phenanthroline-water (1/2/2)

The asymmetric unit of the title compound, 2C₁₂H₈N₂·C₈H₁₀O₈·2H₂O, contains one 1,10-phenanthroline mol­ecule, one half-mol­ecule of butane-1,2,3,4-tetra­carb­oxy­lic acid (H₄BTC) and a water mol­ecule, with the complete tetra-acid generated by crystallographic inversion symmetry. Inter­molecular O—H⋯O hydrogen bonds and π–π stacking inter­actions [centroid–centroid distances = 3.672 (2) and 3.708 (2) Å form an extensive three-dimensional network, which consolidates the crystal packing.

Synthesis, structures and properties of Cu(II) and Mn(II) complexes with 1,10-phenanthroline-2-carboxylic acid and 2,2'-bipyridine ligands

Four new 2,2’-bipyridine and 1,10-phenanthroline complexes, namely [Mn(phenca)₂]·(H₂O)₂ (1), [Cu₄(phen)₄(OH^-)₄(H₂O)₂](DMF)₄(ClO₄^-)₄(H₂O) (2), [Cu₂(2,2-bipy)₂(C₂O₄^2-)(H₂O)₂(NO₃)₂] (3) and [Cu(2,2-bipy)₂(ClO₄^-)](ClO₄^-) (4) (2,2’-bpy = 2,2’-bipyridine, Hphenca = 1,10-phenanthroline-2-carboxylic acid) have been synthesized by a hydrothermal reaction. The products were characterized by elemental analysis, infrared spectroscopy and X-ray crystal diffraction. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as π···π interactions is also evident in the structures. A preliminary investigation on the ion exchange properties of the complexes is presented.