In situ Synthesis,Crystal Structure and Photoluminescence of a Novel Coordination Polymer with (4,6,6)-Connected sqc111 Topology

Employing the mixed ligands to react with Cd(NO₃)₂·4H₂O afforded a new 3D coordination polymer [Cd₃(BPTC)(bmp)₂(ox)(H₂O)₄] (1) (H₄BPTC?=?biphenyl-3,3′,4,4′-tetracarboxylic acid, bmp?=?3,6-bis(imidazol-1-yl)pyridazine, H₂ox?=?oxalic acid), in which ox^2? was from the in situ oxidation of ethanol. Compound 1 bears a novel trinodal (4,6,6)-connected net structure, and it is the first replica of the theoretically predicted sqc111 topology net. Moreover, the thermal and photoluminescent properties for 1 were also investigated.     

Hydrothermal Syntheses and Photoluminescent Properties of Two Zinc(II) Coordination Polymers Based on 4,6-di(1<Emphasis Type="Italic">H</Emphasis>-imidazol-1-yl)-1,3,5-triazin-2-ol

Two new Zn(II) coordination polymers based on the tridentate ligand 4,6-di(1H-imidazol-1-yl)-1,3,5-triazin-2-ol (Hdit), namely, {[Zn(dit)₂(H₂O)₂]·4H₂O}_n (1) and [Zn(dit)(CH₃COO)]_n (2), have been successfully constructed by varying the metal salts. Compound 1 shows 1D zigzag chain structure, and compound 2 is a 3D binodal (3,5)-connected architecture with {4²·6⁶·8²}{4²·6} topology. The photoluminescent spectra indicate that at room temperature, compounds 1 and 2 emit violet and blue luminescence, respectively.     

Assembly,Fluorescent and Adsorption Properties of Two Cadmium(II)/Cobalt(II) Coordination Complexes Functionalized by the Flexible Bis(Pyridyl)-bis(Amide) Ligand

A new cadmium(II) and a new cobalt(II) coordination complexes [Cd₅(BTB)₄(HL)₂]·2H₂O (1) and [Co(HBTB)(L)]·2H₂O (2) [H₃BTB?=?1,3,5-tri(4-carboxylphenyl)benzene, L?=?N,N′-bis(3-pyridyl)octandiamide] were prepared under the solvothermal conditions by the assembly of cadmium(II)/cobalt(II) chloride, the flexible bis(pyridyl)-bis(amide) ligand L and the aromatic tricarboxylic acid H₃BTB. The structures of complexes 1–2 have been characterized by X-ray single crystal diffraction analyses, infrared spectroscopy (IR), powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complex 1 is a 3D metal–organic network with the penta-nodal (2,4,4,5,6)-connected {4·6³·8·10}₂{4²·6⁵·8³}₂{4³·6³}₂{4⁶·8⁹}{6}₂ topology constructed from the 3D [Cd₅(BTB)₄]_n^2n? coordiantion framework and the protonated HL ligands. Complex 2 displays a binodal (4,4)-connected {6⁴·8·10}{6} topological 2D layered architecture based on the 1D [Co(HBTB)]_n chains and the 1D [CoL]_n chains, which are further linked by hydrogen bonding interactions to form a 3D supramolecular network. Moreover, the fluorescent properties of the cadmium(II) complex and the dyes adsorption performances of complexes 1–2 have been studied.     

Four New Metal–Organic Supramolecular Networks Based on Aromatic Acid and Flexible Bis(imidazole) Ligand: Synthesis,Structures and Luminescent Properties

Four new metal–organic supramolecular networks, namely, [Zn(H₂pdc)₂(H₂O)₂]·2H₂O·bbi (1), {[Cd(Hpdc)₂]·2H₂O₂·H₂bbi}_n (2), [Zn(BA)₂(bbi)]_n (3), and {[Cd(BA)₂(bbi)]·H₂O}_n (4) (H₃pdc = 3,5-pyrazoledicarboxylic acid, HBA = 3-hydroxybenzoic acid and bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) have been synthesized under hydrothermal conditions and characterized by IR spectra, elemental analyses, and single-crystal X-ray diffraction analyses. Compound 1 possesses zero-dimensional (0D) structure, which is finally extended into a two-dimensional (2D) supramolecular network via O–H···O and C–H···O hydrogen bonds. Complex 2 displays a 2D network structure built from Cd²⁺ atoms interconnected by Hpdc^2? ligands. The adjacent networks are further assembled into three-dimensional (3D) supramolecular structure through O–H···O hydrogen bonds. Compounds 3 and 4 show similar one-dimensional (1D) chains, in which four-coordinated Zn(II) atoms and six-coordinated Cd(II) atoms are bridged by bbi ligands. Through O–H···O and C-H···O hydrogen bonding interactions, the 1D chains are further packed into 2D and 3D supramolecular frameworks for 3 and 4, respectively. Obviously, the structural differences among compelxes 1–4 are attributed to the different central metal atoms and organic ligands. In addition, compounds 1–4 exhibit blue fluorescent emission in the solid state at room temperature.     

Synthesis,Structures, and Catalytic Properties of Two Zinc(II) Coordination Polymers Constructed from Polycarboxylate and Bis(Benzimidazole) Ligands

Two Zn(II) coordination polymers, formulated as {[Zn(L1)_0.5(btc)_0.5(H₂O)]·H₂O} _n (1) and {[Zn(L2)(1,4-ndc)]·2H₂O} _n (2) [L1 = 1,4-bis(2-methylbenzimidazole-1-ylmethyl)benzene, L2 = 1,4-bis(2-methylbenzimidazole)butane, H₄btc = butane-1,2,3,4-tetracarboxylic acid, 1,4-H₂ndc = 1,4-naphthalenedicarboxylic acid] have been synthesized and structurally characterized by single crystal X-ray diffraction. Complex 1 features a 3D (3,4)-connected network with the topology of fsh-3,4-P2₁/c. Complex 2 is a 2D (4,4) grid with sql topology and further extends into a 3D supramolecular framework by π–π stacking interactions. In addition, the thermal stability, fluorescence, and catalytic properties of two complexes for degrading methyl orange dye in a Fenton-like process were investigated.     

Synthesis,Characterization, and Magnetic Properties of Two Transition Metal Coordination Polymers Based on 2,5-Furandicarboxylic Acid and N-Donor Ligands

Two new transition metal-based coordination polymers, [Cu(fdc)(dmbpy)(H₂O)]_n (1) {[Ni₂(fdc)₂(bipy)₂(H₂O)₄]·(H₂O)₂}_n (2) (fdca = 2,5-furandicarboxylic acid, dmbpy = 3,3′-dimethyl-4,4′-bipyridine, bipy = 4,4′-bipyridine) have been synthesized under the same reaction conditions (H₂O, pH 7–8, and 130 °C) and were structurally characterized. 1 is a ladder chain, whereas 2 shows a 2D (4,4) network. Both 1 and 2 are further connected into 3D structures through hydrogen bonds. Furthermore, the magnetic properties of 1 and 2 are also investigated.     

Syntheses,Structures, and Catalytic Properties of Five Isomorphous 3D Transition Metal Complexes Derived from Formate

Five isomorphous 3D complexes of formates, namely, {Cu(HCOO)₂·4H₂O} _n (1), {Co(HCOO)₂·2H₂O} _n (2), {Mn(HCOO)₂·2H₂O} _n (3), {Co(HCOO)₂·DMF·H₂O} _n (4), and {Mn₂(HCOO)₆·0.5[HN(CH₃)₂]} _n (5), were synthesized and characterized by microanalysis. The catalytic activities of these complexes for the oxidation of phenol by H₂O₂ to catechol (CAT) and hydroquinone (HQ) were investigated. Complex 1 showed the best performance by exhibiting a high conversion rate of 68.02% and a high selectivity for CAT with a maximum CAT/HQ ratio of 2.74.     

Imidazole-Containing Ligands Assisted Self Assembly of Two New Cd(II) Coordination Polymers: Syntheses, Crystal Structures and Photoluminescent Properties

Two new coordination polymers, {[Cd₂(PDC)₂(H₂O)₂(L₁)]·2H₂O}_n (1) and {[Cd (2,5-PDC)(H₂O)(L₂)]·H₂O}_n (2), have been obtained from hydrothermal reactions of Cd²⁺ ion with the 2,5-pyridinedicarboxylic acid (H₂PDC) and two imidazole-containing ligands [L₁ = 1,4-bis(imidazol-1-yl)benzene and L₂ = 1,4-bis(1-imidazol-yl)-2,5-dimethylbenzene]. Complex 1 features a three-dimensional 6-connected rob topological net. Complex 2 shows a two-dimensional 6-connected hxl topological net. The structural differences between 1 and 2 demonstrate that the different imidazole-containing ligands play critical roles in the formation of the resulting frameworks. The photoluminescent properties of 1 and 2 have also been investigated.     

Syntheses and Characterization of Three Coordination Polymers of Zinc(II) and Cadmium(II) with Dicarboxylates and Bis(thiabendazole) Ligands

Three d ¹⁰ coordination polymers formulated as [Zn(L1)₂(mip)] _n (1), [Zn(L1)(2,6-ndc)] _n (2) and [Cd(L2)_0.5(bpdc)] _n (3) (L1 = 1,1′-(1,3-propanediyl)bis(thiabendazole), L2 = 1,1′-(1,6-hexanediyl)bis(thiabendazole), H₂mip = 5-methylisophthalic acid, 2,6-H₂ndc = 2,6-naphthalenedicarboxylic acid, H₂bpdc = 4,4′-biphenyldicarboxylic acid) were hydrothermally synthesized. Complexes 1–3 were characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction analysis, and single crystal X-ray diffraction. Complexes 1 and 2 present different chain structures, both of them are extended into 2D supramolecular architectures via C–H···O hydrogen bonds, while 3 is a three-fold interpenetrating three-dimensional framework with binodal 4,4-connected mog topology. The thermal stability, UV–visible spectroscopy and luminescence properties of complexes 1–3 were also examined. Furthermore, complex 3 exhibits relatively positive catalytic activity towards the degradation of methyl orange in a Fenton-like process.     

Metal-Controlled Assembly of Two Coordination Polymers Built from 4,4′-Methylenedibenzoic Acid with or Without Methyl-Functionalized N-Donor Ligand

By changing the metal salts, two new transition metal-based coordination polymers (CPs), {[Co₃(DBA)₃(dmbpy)]·(DMF)·(H₂O)₄}_n (1), and {[(Me₂NH₂)₂Cd(DBA)₂]·(DMF)₃}_n (2) ((H₂DBA = 4,4′-methylenedibenzoic acid, dmbpy = 3,3′-dimethyl-4,4′-bipyridine) has been synthesized under the same reaction conditions (DMF and 130 °C) and were structurally characterized. Both compounds are synthesized using dual linkers (H₂DBA and dmbpy). 1 performs a 2-fold interpenetration 3D framework with pcu topology and is stable in aqueous solutions at pH range from 5 to 9, whereas 2 shows a 2D (4,4) network and is unstable in air. Furthermore, the magnetic and 3D luminescent properties of 1 and 2 are also investigated, respectively. The results suggest that metal salts influence on the final resulting CPs and the introduction of water repellent functional groups within the structure can largely enhance the hydrophobic properties of CPs.     

Three New Metal(II) Complexes with Unusual 2D Hydrogen Bond Network Based on <Emphasis Type="Italic">N</Emphasis>-methylimidazole

Three new metal(II) complexes based on N-methylimidazole, [ML₆]·(SH)₂·(H₂O)_2, (M = Ni(II) (1), Co(II) (2), Cu(II) (3), L=N-methylimidazole), have been synthesized and characterized. The single crystal X-ray structural analyses show that complexes 1, 2, and 3 have isomorphous structures and crystallize in monoclinic system with space group P2₁/c. The complexes containing isolated SH^? anions, which may come from the thermochemical sulfate reduction, are located in the gap with lattice water molecules and provide multiple intermolecular hydrogen bonds to form 2D layers. Topology analyses show a 2D hydrogen bond network, which can be regarded as an unprecedented trinodal (3,4,6)-connected topology with Schläfli symbol (3.4.5³.6)₂(3.4.5)₂(3²;5⁴;6⁴;8²;9³). Cyclic voltammetry and UV–vis spectra were studied.     

Structures and Properties of New Cadmium(II) and Copper(II) Metal–Organic Frameworks Based on Flexible Bridged 1,4-bi(1H-imidazol-1-yl)butane Ligand

Two new metal–organic frameworks (MOFs) based on cadmium(II) ions, 1,2-benzenedicarboxylic acid (BDC), flexible ligand 1,4-bi(1H-imidazol-1-yl)butane (BIIM), coordinated water molecules, [(BIIM)(BDC)(H₂O)Cd]_3n (1) and copper(II) ions, BIIM, coordinated water, free thiophene-2,5-dicarboxylate (TDC), free water, {[(BIIM)₄(H₂O)₄Cu₂]·(TDC)₂·(H₂O)₁₂}_n (2) are prepared and characterized by X-ray diffraction, thermal gravimetric analysis (TGA), infrared (IR) spectrum and the photoluminescence property for complex (1). The X-ray diffraction analysis reveals that the structures of complexes 1 and 2 are 2D structures through the C–H···π stacking interactions (for 1) and the BIIM bridging connections (for 2). The IR spectrum for 1 and 2 are presented in the paper, for 1, the strong peaks at 1399 and 1573 cm^?1 are owing to the carboxylic CO₂ ^? symmetry and asymmetry stretching vibrations of BDC. The features of the IR spectrum are consistent with the single crystal structures. The TGA reveal the water is the first lost material from complex, then the ligands removed, and finally the residues of these two complexes are the metal oxide.     

Four Flexible Bis(Thiabendazole)-Based Cd(II) Coordination Polymers with Various Aromatic Carboxylates: Syntheses,Structures and Properties

Four Cd(II) coordination polymers (CPs) including [Cd(btbb)_0.5(L1)] _n (1), [Cd(btbb)(L2)·(H₂O)_1.5] _n (2), [Cd(btbb)(L3)] _n (3), and [Cd(btbb)(HL4)] _n (4) (btbb?=?1,4-bis(thiabendazole)butane, H₂L1?=?5-hydroxyisophthalic acid, H₂L2?=?4,4′-biphenyldicarboxylic acid, H₂L3?=?tetrabromoterephthalic acid, H₃L4?=?5-nitro-1,2,3-benzenetricarboxylic acid) were prepared under hydrothermal conditions based on flexible bis(thiabendazole) ligand and different co-carboxylates. Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, X-ray powder diffraction, and thermogravimetric analyses. CP 1 exhibits a 3D 2-nodal (3,4)-connected framework with the 3,4T10 topology. CP 2 and 3 feature typical hcb layer structure, and 3 is further combined into a 3D supramolecular architecture through C–H?O hydrogen bonds. CP 4 possesses an infinite chain and further extended into 2D supramolecular network by O–H?O hydrogen-bonding interactions. The effects of the aromatic polycarboxylate co-ligands on the CPs framework have been discussed and the catalytic activities of CPs 1–4 for degradation of methyl orange in Fenton-like process are also investigated.     

Syntheses and Structural Characterization of Co(II) Coordination Polymers Supported by Bis(<Emphasis Type="Italic">N</Emphasis>-benzimidazolyl)methane and Bis(<Emphasis Type="Italic">N</Emphasis>-imidazolyl)methane

[Co₂(L¹)₂(NCS)₄]·4MeOH 1, [Co(L²)₂(H₂O)₂](Sal)₂·4H₂O (Sal = salicylate) 2 were obtained from self-assembly of the cobalt salts with bis(N-benzimidazolyl)methane (L¹), and bis(N-benzimidazolyl)methane (L²), and their structures were characterized by IR and X-ray diffraction analysis. Complex 1 exhibits a two-dimensional grid structure, whereas complex 2 is a coordination polymer having a one-dimensional linear chain structure. The grid in 1 lies parallel to the crystallographic ab plane and exhibits intra-grid M–M separations of 10.508 × 10.508 Å. Hydrogen bonds hold the cationic chains in 2 together leading to a three-dimensional network structure.     

Synthesis,Characterization and Properties of Four 3-D Supramolecular Architectures Assembled by Ni(II), Co(II), Zn(II), Cu(II) and 4-Nitro-1,3-benzenedicarboxylic Acid

Four new complexes M(NO₂–HBDC)₂(H₂O)₄·2H₂O [M = Ni (1), Co (2) and Zn (3)] and [Cu(NO₂–BDC)(H₂O)₃]₂ (4) (NO₂–H₂BDC = 4-nitro-1,3-benzenedicarboxylic acid) were prepared under hydrothermal conditions and were determined by single-crystal X-ray diffraction. X-ray structural analysis reveals that hydrogen bonds among the coordination water molecules and carboxyl oxygen atoms in complexes 1–3 bridge molecules forming an infinite chain, which is further interconnected to form a 3-D framework by a novel infinite 1-D metal–water chain containing the cyclic uudd water tetramer. In complex 4, Two five-coordinated Cu atoms are interlinked by NO₂–BDC ligands and coordinated water molecules to form a 3-D framework via hydrogen bonds and π···π stacking interactions. The elemental analysis, IR spectra, UV–vis and thermogravimetric analysis of complexes 1–4 were examined. The photoluminescence properties of complex 3 and temperature-dependent magnetic susceptibility for complex 4 were also studied.     

Homo and Dinuclear Heteroleptic Zn,Cd &amp; Pb Complexes Derived from FcCOOH and DTBbpy Ligands: Structural,Luminescence and Electrochemical Studies

Mononuclear [Zn(FcCOO)(DTBbpy)₂]ClO4.(H₂O)₃ (1) and dinuclear [Cd₂(FcCOO)₂(DTBbpy)₄]ClO₄·(H₂O) (2), [Pb₂(FcCOO)₂(DTBbpy)₂(H₂O)₂]·ClO₄ (3) (FcCOO = ferrocenecarboxylate, DTBbpy = 4,4′-di-tert-butyl-bipyridyl) metal complexes have been synthesized and characterized by single crystal X-ray diffraction. It reveals that the Zn(II), Cd(II) and Pb(II) metal complexes have different coordination geometries [Zn and Pb = distorted octahedral, Cd = distorted pentagonal bipyramidal]. The compound 3 shows the hemidirected mode of coordination in the geometrical system due to the inert pair effect of the lone pair of an electron on Pb(II) metal atom. The molecules are further forms 2D & 3D framework structure via intermolecular hydrogen bonding. All the three compounds exhibit strong fluorescence emission bands in the liquid state at ambient temperature, of which the emission maxima show red-shifted and the solution-state electrochemistry of compounds 1–3 in CH₃CN has been investigated.     

A Novel Co(II) Coordination Polymer Assembled from V-shaped 2,3,2’,3’-Thiodiphthalic Acid and N-donor Ancillary Ligand: Syntheses,Structure and Properties

A novel coordination polymer {[Co₂(tdpa)(bpe)_1.5(H₂O)]·(bpe)_0.5·(H₂O)} _n (1) has been hydrothermally synthesized through the reaction of 2,3,2’,3’-thiodiphthalic acid (H₄tdpa) with divalent cobalt salt in the presence of ancillary nitrogen ligand (bpe = trans-1,2-bis(4-pyridyl)ethene) and characterized by IR spectra, elemental analysis and single crystal X-ray diffraction. Due to various coordination modes and conformations of the versatile 2,3,2’,3’-thiodiphthalic acid ligand, the complex exhibits structural and dimensional novelty. In complex 1, metal–organic ribbons (Co-tdpa) are connected together through bpe ligands to generate a three-dimensional (3D) metal–organic framework. The structure of 1 can be described as a (3,6)-connected network with a Schläfli symbol of (4²·6)(4⁴·6¹⁰·8) topology. The thermal stability of the complex 1 was studied by thermal gravimetric analyses (TGA), and the UV?vis absorption property of complex 1 was also investigated.     

Three New Coordination Polymers Constructed from Mixed Ligands: Syntheses,Luminescence and Magnetism

Three new coordination polymers, namely, {[Cd(H₂bptc)(IP)(H₂O)]·2H₂O} _n (1), {[Mn₂(IP)₂(dstc)]·6H₂O} _n (2) and {[Zn₂(IP)₂(dstc)]·3H₂O} _n (3) (IP = 1H-imidazo[4,5-f][1,10]-phenanthroline, H₄bptc = 3,3′,4,4′-benzophenonetetracarboxylic acid, and H₄dstc = 3,3′,4,4′-diphenylsulfonetetracarboxylic acid) have rationally designed and characterized by single crystal X-ray diffraction. Polymer 1 shows a 1D ribbon-like structure. Although compounds 2 and 3 feature 2D grid networks, the coordinative modes of dstc ligand and the arrangements of IP ligand are very different. Furthermore, the luminescence properties for 1 and 3, as well as the magnetism of 2 are explored in detail.     

Targeted Highly-Thermostable Metal–Organic Frameworks Directed by Imidazole: Syntheses, Structures, Thermal Behaviors and Luminescent Properties

Three new isostructural 3D lanthanide MOFs (Ln(HBPTC)(H₂O)) (Ln = Tb (1), Pr (2), Nd (3); H₄BPTC = 3,3′,4,4′-biphenyltetracarboxylic acid) have been synthesized under hydrothermal conditions using imidazole as a structure-directing agent, and characterized by elemental analyses, IR, thermogravimetric analyses (TGA) and powder X-ray diffraction (PXRD) analyses. Topologically, compounds 1–3 demonstrate an intriguing 3D (6, 6)-connected network with the Schläfli symbol of (4¹⁰·6⁵)(4⁹·6⁶); and if the dinuclear (Ln₂) clusters are considered as the single 8-connected nodes, they can be described as a scarcely reported (4, 8)-connected alb net constructed from two intertwining sqp-4 nets. TGA and PXRD analyses reveal that compounds 1–3 exhibit high thermal stability, at least being stable up to 410 °C. Furthermore, the luminescence studies were performed on compound 1 and its dehydrated phase in the solid state at room temperature. The results demonstrate that compound 1 displays intense green emission, implying its potential application as fluorescence material. And the luminescence of 1 is quenched when removing the coordinated water molecules.     

Synthesis,Characterization, Crystal Structures and Thermal and Fluorescence Studies of Dinuclear and Polymeric Silver(I) Complexes of 5,5-Diethylbarbiturate with 2,5-Dimethylpyrazine and Piperazine Involving Ag–Ag Interactions

Two silver(I) complexes, [Ag(dmpyz)₂][Ag(barb)₂] (1) and {[Ag(ppz)][Ag(barb)₂]·H₂O} _n (2) (barb = 5,5-diethylbarbiturate, dmpyz = 2,5-dimethylpyrazine and ppz = piperazine), have been synthesized and characterized by elemental analyses, IR, thermal analysis (TG-DTA) and single-crystal X-ray diffraction. Complex 1 consists of [Ag(dmpyz)₂]⁺ and [Ag(barb)₂]^? ions in which the silver(I) ions are linearly coordinated by two dmpyz or two barb ligands. These two ions are connected by strong Ag–Ag interactions (Ag–Ag = 2.896 (1) Å). Complex 2 is a 1D coordination polymer in which the silver(I) ions are bridged by the ppz ligands in a linear fashion, leading to a zigzag chain of [Ag(ppz)] _n ⁺ , which interacts with the [Ag(barb)₂]^? units by Ag–Ag interactions of 3.183 (1) Å. The 1D chains are further assembled to form 3D networks by strong N–H···O and OW–H···O hydrogen bonds. IR spectra and TG-DTA data are in agreement with the crystal structures. The fluorescent properties of 1 were also evaluated.