Lanzhi Wu

Coordination polymers based on 3,3′,4,4′-benzophenone-tetracarboxylate and N-containing pillars: syntheses, structure, characterization and properties

Three novel coordination polymers including {[Mn2(bptc)2(phen)4]·2H2O}∞ (I), [Zn2(bptc)4·(bpy)2·H2O]∞ (II), and {[Zn2(bptc)4·(bpy)2·H2O] ⊃ bpy}∞ (III) (bptc = 3,3′,4,4′-benzophenone-tetracarboxylate, bpy = 4,4′-bipyridine, phen = 1,10-phenanthroline) were prepared under hydrothermal conditions and characterized by elemental analysis, infrared spectrometry, and single crystal X-ray diffraction. Moreover, the thermal stability of as-synthesized coordination polymers was evaluated by thermogravimetric analysis; and their magnetic and luminescent properties were also investigated. Findings indicate that coordination polymer I displays a three-dimensional (3D) network constructed via π–π interactions of the building block {[Mn2(bptc)2(phen)4]·2H2O}. Besides, Zn(1) and Zn(2) centers in coordination polymer II are four-coordinated and six-coordinated, respectively, thereby affording two-dimensional (2D) planar sheet and 3D porous frameworks that are interlinked through identical linkers of four-coordinated motif (COO–Zn–COO). As-synthesized coordination polymer III contains a 3D framework similar to that of II, but the cavities in III are occupied by uncoordinated bpy guest molecules. Moreover, as-synthesized coordination polymer I presents antiferromagnetic coupling through the (O2C–C–C–CO2)2 bridges, and II displays selectivity towards Hg+ ion in terms of the luminescent emission.

Construction of 0D to 3D Copper(II) MOFs based on heterocyclic carboxylic acid: Synthesis, structures, cyclic voltammograms, and luminescent properties

The crystal structures of MOFs [Cu(PDA)(Phen)(H2O)]2 · 5H2O (I) and [Cu(PZCA)2(H2O)2] · 2H2O (II) (H2PDA = pyridine-2,6-dicarboxylic acid, Phen = 1,10-phenanthroline, HPZCA = pyrazine-2-carboxylic acid, H2PZDA = pyrazine-2,3-carboxylic acid) have been prepared under hydrothermal conditions. These MOFs have been characterized by element analysis, single-crystal X-ray diffraction, thermogravimetric analyses and IR spectroscopy. 3D frameworks of MOFs I and II are fabricated from zero-dimensional (0D) motifs through hydrogen bonds and π-π interactions. In MOF II, the PZCA ligand comes from in situ decarboxylation of the part of pyrazine-2,3-dicarboxylic acid (H2PZDA). Luminescent emissions bands of MOF I in methanol have been measured at room temperature and it displays selectivity to Zn2+, Cu2+, Pb2+, and Cd2+ ions. Cyclic voltammetry of MOFs I and II showed that the Cu(II/I) couple is irreversible.

Synthesis, structure, and luminescent properties of a novel binuclear Gd(III) compound

The compound [Gd2(PZDA)3(H2O)]n (I), where H2PZDA = 2,3-pyrazinedicarboxylic acid, was synthesized under hydrothermal conditions and characterized by elemental analysis, infrared spectrometry, thermogravimetric analysis and single crystal X-ray diffraction (CIF file CCDC no. 848802). In I, Gd(III) centers adopt eight-coordinated and nine-coordinated modes to construct distorted triangular dodecahedral and tricapped trigonal prism configurations, respectively. Three-dimensional (3D) structure of the compound is formed through C-H⋯π interactions and π-π stacking. Measurement of the luminescent property at room temperature shows that the as-synthesized compound presents good selectivity towards Pb2+ ion, suggesting that it may be promising potential as selective luminescent probes of Pb2+ ion.