Jia-Ming Li

Four Co(II)/Zn(II) coordination polymers with a multidentate ligand: syntheses, structures, thermal, and photoluminescent properties

Abstract Two pairs of isostructural transition metal coordination polymers, {[Co(L)(H2O)]n} (1) and {[Zn(L)(H2O)]n} (3), {[Co(L)(4,4′-bipy)(H2O)]·H2O}n (2) and {[Zn(L)(4,4′-bipy)(H2O)]·H2O}n (4) (H2L = N-pyrazinesulfonyl-glycine acid and 4,4′-bipy = 4,4′-bipyridine), have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental and thermogravimetric analyses. The structures show that 1 and 3 display 2-D polymeric grid frameworks with a 3-connected (4, 82) topology. 2 and 4 also exhibit a 2-D polymeric grid structure, but are constructed by a 4-connected (4, 4) topology. The adjacent 2-D polymeric grid frameworks for 1–4 are further linked by hydrogen bonding O–H⋯O interactions to form 3-D supramolecular interweaved orderly networks. The fluorescent properties of 3 and 4 were investigated in the solid state.

A New Di-Copper(II) Complex of Schiff-Base and 1,3-Di(pyridin-4-yl)propane Ligands: Synthesis, Spectral, Thermal Properties, and Crystal Structure

A new binuclear copper(II) complex with the Schiff-base ligand N-(2-hydroxybenzyl)aminomethanesulfonic acid (H2Saes) has been synthesized, [Cu(Saes) (1,3-dpp)]2 (1,3-di(pyridin-4-yl)propane abbreviation as 1,3-dpp) (1), and characterized by single-crystal X-ray diffraction, elemental, IR spectra, and thermogravimetric analyses. Complex 1 shows phenoxo-bridged dinuclear Cu2O2 core with intermetallic distance of 3.19 (8) Å. In the crystal structure, 1D infinite chain structure is formed through weak π-π stacking interactions between the phenyl rings of adjacent dimmer units with ring-centroid distances of 3.787 (4) Å. In addition, 2-D layers structure are formed by intermolecular C-H···O hydrogen bonds with the separate C···O distances of 3.278 (8)-3.533 (9) Å. Molecules from neighboring stacks further interdigitate with each other in the c-direction, leading to an interwoven three-dimensional network held together by C-H···O interactions and π-stacking and stabilize the coordination complex.

Synthesis and crystal structure of a Zn(II) metal-organic framework based on 1,3,5-benzenetricarboxylate and 4,4′-bis(1-imidazolyl)biphenyl ligands: selective sensing of Mn2+ and Fe3+ ions in aqueous solution

Abstract A new metal-organic framework (MOF), {[Zn3(btc)2(bimb)2(H2O)2](H2O)3}n (1), where H3btc =1,3,5-benzenetricarboxylate and bimb = 4,4′-bis(1-imidazolyl)biphenyl, has been synthesized and characterized using single-crystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric, and photoluminescent analysis. X-ray diffraction crystallographic analyses indicate that 1 displays two types of Zn centers with a distorted pyramidal and a perfectly octahedral coordination sphere. The fully deprotonated btc3− ligand coordinates four Zn ions with two carboxylate groups having bidentate chelate modes and one binds µ2-η1:η1; bimb serves as a μ2-bridging ligand in 1, resulting in a new three-dimensional (3-D) metal-organic framework with an uncommon trinodal 4-connected network with a Schäfli symbol of (65 10)2(62 8 103)3(73 8 12) topology. In the crystal, a 3-D supramolecular architecture is further formed by O–H···O hydrogen bonds, C–H···O interactions, C–H···π as well as π···π stacking. 1 shows intense fluorescence in the solid state and exhibits high selectivity for Mn2+ and Fe3+ ions through fluorescence enhancement and the quenching effect in aqueous solutions at room temperature, respectively. Graphical Abstract

Synthesis, crystal structures, and thermal and spectroscopic properties of two Cd(II) metal-organic frameworks with a versatile ligand

Abstract Two new metal-organic frameworks, namely, [Cd(L)(H2O)]n (1) and {[Cd0.5(L)(4,4′-bipy)0.5][Cd0.5(H2O)(4,4′-bipy)0.5]·H2O}n (2), where H2L = N-pyrazinesulfonyl-glycine and 4,4′-bipy = 4,4′-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric, and photoluminescent analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a distorted octahedral metal coordination in a 3-connected (4, 82) topology, while the molecular structure of 2 has a 4-connected (4, 4) topology with two perfectly octahedrally coordinated Cd centers. The L2– ligand serves as a N,N,O-tridentate, μ2-pyrazine-bridging, and μ2-carboxylate-bridging ligand in 1, and as a N,O-bidentate and μ2-carboxylate-bridging ligand in 2. In the crystal, a 3D supramolecular architecture is formed by O–H···O hydrogen bond interactions in 1, but through O–H···O as well as π···π stacking in 2. The two compounds show intense fluorescence in the solid state at room temperature.

A New One-Dimensional Double Chains Cobalt Coordination Polymer With Taurine Schiff-Base and 4,4′-Bipyridine Ligands: Synthesis, Spectral, Thermal Properties, and Crystal Structure

A new 1D double chains cobalt(II) coordination polymer with the doubly deprotonated Schiff-base and 4,4′-bipyridine ligands, {[Co(Saes)(H2O)(Bipy)]·H2O}n, where H2Saes = 2-(2-hydroxy- benzylideneamino)ethanesulfonic acid, has been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental and thermogravimetric analysis. The asymmetric unit of 1 comprises two cobalt(II) dimmer with tridentate Schiff-base, 4,4′-bipyridine, and water molecule ligands with the N3O3 donor set, exhibiting a slightly distorted octahedral geometry. In the crystal, dimmers are interacted with O-H···O, C-H···O interactions and C-H···π stacking, leading to an interwoven three-dimensional network and stabilizing the coordination complex. The spectral and thermal properties are also discussed.

A New 2D Copper(II) Coordination Polymer with a Schiff Base Ligand with Weakly Coordinating Sulfonate Groups Affecting the Structure

A new 2D copper(II) coordination polymer with the doubly deprotonated Schiff base ligand 2- (2-hydroxybenzylideneamino)ethanesulfonic acid (H2Saes) has been synthesized, {[Cu(Saes)(4,4´- bpy)]2·H2O}n (1), and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental and thermogravimetric analysis. Dinuclear copper complexes serve as secondary building blocks (SBUs) to construct an unusual coordination network with an interpenetrating CdSO4 topology. In the crystal, the components form a stable 3D supramolecular architecture by O-H· · ·O, C-H· · ·O interactions and π stacking. Graphical Abstract A New 2D Copper(II) Coordination Polymer with a Schiff Base Ligand with Weakly Coordinating Sulfonate Groups Affecting the Structure