Haiyan He

A metal-organic nanotube exhibiting reversible adsorption of (H2O)12 cluster.

A novel 1D metal-organic nanotube, exhibiting reversible and fast adsorption of the (H2O)12 cluster, has been synthesized and characterized.

Control over Interpenetration in Lanthanide−Organic Frameworks: Synthetic Strategy and Gas-Adsorption Properties

Two isostructural lanthanide-organic frameworks (1 and 2) with 2-fold interpenetrating nets have been synthesized based on 1,4-benzenedicarboxylic acid (H(2)BDC). By application of an organic ligand with hindrance groups and a terminal chelating ligand to replace BDC and coordinated solvates, interpenetration has been effectively controlled. The gas-sorption properties of the noninterpenetrating net have been studied.

A 3D porous metal–organic framework constructed of 1D zigzag and helical chains exhibiting selective anion exchange

Slow diffusion of AgClO44 with Me2Si [(4-(Im-1-yl)Ph]2 (BIPS) yields the crystalline complex 1 with a 3D-braided porous metal–organic framework via self-assembly of two series of 1D polymer chains through both braiding and interpenetrating. Complex 1 consists of two distinct kinds of channels with different sizes and shapes along a and b directions occupied by perchlorate anions and water molecules.

Construction of copper metal–organic systems based on paddlewheel SBU through altering the substituent positions of new flexible carboxylate ligands

Three flexible dicarboxylate ligands 2,2′-(1,2-phenylenebis(methylene))bis(sulfanediyl)dibenzoic acid (H2L6), 2,2′-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)bis(oxy)dibenzoic acid (H2L7) and 2,2′-(1,4-phenylenebis(methylene))bis-(sulfanediyl)dinicotinic acid (H2L8), have been designed and synthesized. All ligands can adopt syn or anti conformations and the positions of the functional substituents in the central benzene ring change gradually from 1,2-, 1,3- to 1,4-position. By applying these flexible ligands to assemble with copper ions, four metal–organic complexes based on paddlewheel SBU have been isolated. Complexes 1 and 2 are discrete molecular chairs. Complex 3 is a 1D molecular-chair-based coordination polymer. The molecular chairs, similar to that found in 1 and 2, are infinitely connected by the bridging 4,4′-bipy ligands to result in the formation of the 1D chain structure. Complex 4 is a two-dimensional wavelike layer structure containing a 68-member ring. Both L6 and L7 in 1 and 2 adopt syn conformation, while L8 adopts anti conformation, which results in the formation of the 2D layer structure of complex 4.

1D zigzag chain vs. 1D helical chain: the role of the supramolecular interactions on the formation of chiral architecture

Two 1D coordination polymers with a 1D zigzag and a helical chain, respectively, have been solvothermally synthesized. The different coordinated small molecules on the cadmium ion have significant influences on the formation of different architectures. Due to the existence of supramolecular interactions between the helices in complex 2, the same chirality is preserved, resulting in a chiral architecture. By introducing a chiral molecule as cosolute, the bulk homochiral crystallization from achiral precursors for 2 can be achieved.

Three novel 3D metal–organic frameworks with a 1D ladder, tube or chain as assembly units

Three novel metal–organic frameworks, Cu4(OH)2(SO4)(HBTC)2(bpy)·bpy (1), Cu1.5(H2O)(TMBTC)(bpy)·1/2H2O (2) and Cd2(H2O)5(TMBTC)(bpy)2·NO3·3H2O (3), constructed from mixed organic ligands, have been synthesized and characterized. Complex 1 crystallizes in monoclinic space groupC2/c and possesses a 3D three-fold interpenetrating framework. The copper ions were first connected by HBTC and SO42− to generate a 1D ladder, which was further linked by a 4,4′-bipyridine ligand to give rise to a 3D interpenetrating framework. Complex 2 crystallizes in monoclinic space groupP2/c and possesses a 3D two-fold interpenetrating framework. Similar to 1, the copper ions were first connected by TMBTC to generate a 1D tubular unit, which can be considered as the assembly block. The 1D tubular unit was further linked by 4,4′-bipyridine ligands to result in the formation of the 3D framework. Complex 3 crystallizes in monoclinic space groupCc and has a three-dimensional structure. Different from 1 and 2, the cadmium ions were first connected by a 4,4′-bipyridine ligand to form a 1D chain as the assembly unit, which was further linked by TMBTC ligand to generate the final 3D framework. The photoluminescence measurement of 3 in the solid state at room temperature showed that complex 3 exhibits luminescence, which can be assigned to an intraligand π → π* transition.

Synthesis, crystal structures and properties of three metal–organic supramolecular architectures based on mixed organic ligands

Three metal–organic supramolecular architectures, Co(H2O)2(H2THFTCA)(4,4′-bpy)·1/2H2O (1), Zn(H2THFTCA)(phen)·H2O (2) and Cd3(H2O)2(HTHFTCA)2(4,4′-bpy)2·4H2O (3), constructed from mixed organic ligands of tetrahydrofuran-2,3,4,5-tetracarboxylic acid (H4THFTCA) and 4,4′-bipyridine or 1,10-phenanthroline, have been synthesized and characterized. Complex 1 crystallizes in triclinic space group P-1 and has a discrete mononuclear structure. The multiple hydrogen bonding interactions connect 1 into a three-dimensional NaCl-like supramolecular architecture. Complex 2 crystallizes in monoclinic space groupP21/n and possesses a one-dimensional helical chain structure. The π⋯π stacking between the chains further connects 2 into a two-dimensional layer architecture. Complex 3 crystallizes in monoclinic space groupC2/c and has a rare three-dimensional 4,6-connected net. The THFTCA ligand connects the cadmium ions to form a two-dimensional layer, which is further connected by pillared 4,4′-bpy ligands to form the three-dimensional porous framework. The thermal stabilities of 1, 2, 3 and the photoluminescence properties of 2 and 3 have been studied.

Synthesis, crystal structures and properties of four topological structures based on 2,3,5,6-tetramethyl-1,4-benzenedicarboxylate acid and bipyridine ligands

Five coordination polymers with four different typological structures have been obtained based on 2,3,5,6-tetramethyl-1,4-benzenedicarboxylate acid (H2TBDC) and bipyridine ligands: 1D zigzag chain Cd(2,2′-bpy)(TBDC)(H2O)·H2O (1), 2D grid with (4,4)-net Co(H2O)2(4,4′-bpy)(TBDC)·2H2O (2), 3D interpenetrating frameworks with diamond topology Ni(4,4′-bpy)(TBDC) (3) and Cu(4,4′-bpy)(TBDC) (4), 3D porous framework with pcu network Co2(4,4′-bpy)(TBDC)2·2H2O·5DMF (5). Especially, complexes 2 and 5 with different topologies were obtained by use of the same reactant but change of the solvents. The gas sorption of complex 5 has also been studied.

A new Cu(I) coordination polymer with the CdSO4 structure type prepared via biphasic solvothermal reaction

Biphasic solvothermal reaction of Cu(NO3)2·6H2O and 2,3,5,6-tetramethyl-1,4-benzenedicarboxylic acid (H2TBDC) resulted in the formation of a novel coordination polymer, [Cu(TBDC)1/2]·H2O (BPS-1). BPS-1 possesses a 3D framework containing 1D Cu(I)–COO helical chains. The use of an organic solvent with a high boiling point and an extension of the reaction time play important roles in the reduction of Cu(II) ions to Cu(I) ions and the formation of BPS-1.

Self-assembly of a novel metal–organic coordination cage (MOCC) based on a new flexible dicarboxylate ligand: synthesis, crystal structure and magnetic property

The self-assembly of flexible bended dicarboxylate ligand, 2,2′-(2,4,6-trimethyl-1,3-phenylene)bis(methylene)-bis(sulfanediyl)-dibenzoic acid (H2L), with Mn(OAc)2·4H2O resulted in the formation of a novel metal–organic coordination cage with binuclear manganese SBU as the vertex, which represents the first metal–organic coordination cage constructed from a flexible dicarboxylate ligand and a binuclear SBU.