Two 3D Coordination Polymers with New Topology Based on Mixed Ligands: Synthesis,Structure, and Photoluminescence Properties

Employing tetracarboxylate and imidazole mixed ligands to react with different transition meat salts afford two new 3D coordination polymers, {[Zn₂(BPTC)(BBI)₂]·(H₂O)₃·DMSO}_n (1) and {[Cd₂(BPTC)(BBI)₂]·H₂O}_n (2) (H₄BPTC?=?biphenyl-3,3′,4,4′-tetracarboxylic acid, BBI?=?1,1′-(1,4-butanediyl)bis(imidazole)). Both these two coordination polymers are 4-connected network topologies. Compound 1 features a unprecedented 3-nodal (4,4,4)-connected network topology with the point symbol {6⁴·8²}, and 2 displays a (4,4)-connected binodal network bearing new topology with the point symbol of {7²·8⁴}2{7³·8³}. Additionally, thermal stability and photoluminescence properties of 1 and 2 were investigated.     

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.     

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.     

Two New Dy(III) and Cu(II) Coordination Polymers: Crystal Structures and Anti-liver Cancer Activity

Two new three-dimensional coordination polymers (H₂NMe₂)[Dy₄(µ₃?OH)₄(NMF)₃(H₂O)(L₁)₃](H₂O)₂ (1, NMF?=?N-methylformamide, H₃L₁?=?3,5-bis(4-(1H-tetrazol-5-yl)phenoxy)benzoic acid) and [Cu(L₂)₂(H₂O)](H₂O)₂ (2, H₂L₂?=?4-(4-pyridyl)-isophthalic acid) have been successfully prepared using two N,O-mixed donor organic ligands. The structures of these complexes have been successfully determined by single crystal X-ray diffraction. In addition, in vitro antitumor activity of compounds 1 and 2 on four human liver cancer cells (SMMC7721, Bel-7402, MHCC97 and HCCLM3) was further determined and the results show that the two compounds showed promising activity.     

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.     

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 & 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.     

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.     

Supramolecular Architectures in Three Metal(II) Coordination Polymers with 2,5-Dichloroterephthalate and Flexible Bis(Benzimidazole) Ligands

Three supramolecular coordination polymers, namely [Ni(L1)(DCTP)(H₂O)] _n (1), [Cu(L2)(DCTP)] _n (2), [Co(L3)(DCTP)] _n (3) (L1?=?1,5-bis(5,6-dimethylbenzimidazole)pentane, L2?=?1,4-bis(5,6-dimethylbenzimidazole)butane, L3?=?1,4-bis(benzimidazole)-2-butylene) have been hydrothermally synthesized and characterized by single crystal X-ray structure determination, FT-IR, elemental analysis, X-ray powder diffraction (XPD), and thermogravimetric analysis (TGA). CP 1 exhibits 2D 6³ honeycombed network structure, which is further extended into a 3D Moganite (mog) supramolecular framework by classical O–H?O hydrogen-bonding interaction. CPs 2 –3 present 2D (4,4) layers, and 3D supramolecular frameworks that are formed by π–π stacking interactions. Furthermore, the catalytic activities of CPs 1–3 for the degradation of methyl orange in a Fenton-like process has been investigated, and CPs 1–3 show strong photoluminescence properties at room temperature in solid state.     

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.     

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.     

Two 3D Supramolecular Coordination Polymers Constructed from Aromatic Carboxylic Acids and Flexible Bis(thiabendazole) Ligands

Two coordination polymers (CPs), [Zn(L1)(H₂bta)] (1) and [Co(L2)(ndc)]·0.75H₂O (2), (L1?=?1,6-(thiabendazole)hexane), L2?=?1,3-(thiabendazole)propane, H₄bta?=?1,2,4,5-benzenetetracarboxylic acid, H₂ndc?=?2,6-naphthalenedicarboxylic acid) have been hydrothermally synthesized and characterized. Single crystal X-ray diffraction analyses reveal that CP 1 and CP 2 feature 1D infinite zigzag and “Ω”-like chains, and further extend into 3D supramolecular framework by O–H?O and C–H?O hydrogen bonding interactions, respectively. Furthermore, the luminescence properties, thermal stability, and catalytic degradation of methyl orange in a Fenton-like process are also investigated in detail.     

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.     

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.     

Reversible adsorption and desorption of water in nanoporous copper(II) metal–organic nanocapsules

Nanocapsule of [Cu₂(bda)₂(bpy)₂]·4H₂O (1) with nanoparticle morphology (bda^2? = 2,2?-biphenyl dicarboxylate and bpy?=?2,2?-bipyridine), was synthesized by sonochemical process. Guest water molecules can be removed from the nanopores of 1 by thermal treatment at 200?°C. The color of this compound changed from blue to deep green during this process. This process is reversible and compound [Cu₂(bda)₂(bpy)₂] (2) with the pore size of 4.3?×?5.5 Å can absorb water again. Thus nanoparticles of compound 2 with 1.53% weight absorption of water/compound 2 at room temperature could be used as water adsorption material like silica gel. Adsorption and desorption of water in these copper(II) metal–organic nanocapsules were studied by IR spectroscopy, thermo gravimetric analyses (TGA), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM).     

Fluorescence Properties Change of Lanthanide Coordination Polymers Dispersed in Mesoporous SBA-15 by Energy Transition Process

Four lanthanide coordination polymers, {[Ln(HPDA)(PDA)(H₂O)₂]·4H₂O} _n (Ln?=?Sm (1), Eu (2), Tb (3)) and {[Sm₃(H₂PDA)₂(HPDA)₂(PDA) (OH)₅(H₂O)₃]·2dta·4H₂O} _n (4) (H₂PDA?=?pyridine-2,6-dicarboxylic acid, dta?=?diethyl amine), have been synthesized under hydrothermal conditions and were characterized by elemental analysis, IR spectrometer, and single-crystal X-ray crystallography. In the complexes 1–3, the 1D chains are assembled into 2D layer by hydrogen bonds formed between the carboxyl groups, and were further assembled into 3D framework by hydrogen bonds and π–π stacking interactions. In complex 4, each Sm³⁺ ion connected to the neighboring Sm³⁺ ion through bridging carboxyl oxygen atoms, and then give rise to a new 2D layered open-framework structure. The 3D supramolecular structure of 4 is constructed through hydrogen-bonding and π–π stacking interactions between adjacent metal–organic polymeric coordination chains. Complexes 1–3 were dispersed in mesoporous materials SBA-15 in DMF solution (denoted as ML-SBA-15, ML?=?1, 2, 3), which were characterized by XRD, IR, and fluorescence spectra. Compared to the complexes 1–3, the photoluminescence efficiency of hybrid material was improved by the energy transition between mesoporous materials and the complexes. The complexes encapsulated in mesoporous materials SBA-15 exhibited stronger luminescence intensity and longer fluorescence lifetime.     

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.     

Syntheses, Structures and Properties of Two 2D Transition Metal Coordination Polymers Based on Oxalate and Two Types of N-donor Auxiliary Ligands

Two new two-dimensional (2D) metal–organic coordination polymers [Co(ox)(bbbm)]·H₂O (1) and [Cu(ox)(bppdca)]·2H₂O (2) (H₂ox = oxalic acid, bbbm = 1,1-(1,4-butanediyl)bis-1H-benzimidazole and bppdca = N,N′-bis(pyridin-3-yl)-2,6-pyridinedicarboxamide) were synthesized under hydrothermal conditions and structurally characterized. Both 1 and 2 exhibit a 2D four-connected network formed by the Co^II/Cu^II ions as four-connected nodes; and, the ox anions and bbbm/bppdca ligands as linkers with a (4⁴.6²) topology as determined by single crystal X-ray diffraction. In addition, the thermal stability, electrochemical and luminescent properties for 1 and 2 were investigated.     

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.     

New Zn/Cd Coordination Polymers Constructed from Mixed Ligands: Crystal Structures and Photocatalytic Performances Toward Organic Dyes Degradation

Two coordination polymers (CPs), Cd(bpp)(H₂O)L (BUC-18) and Zn(bpp)L (BUC-19), (H₂L?=?cis-1,3-dibenzyl-2-imidazolidone-4,5-dicarboxylic acid, bpp?=?1,3-bis(4-pyridyl)propane), have been synthesized under hydrothermal conditions, and characterized by single crystal X-ray analysis, Fourier transform infrared spectra (FTIR), thermogravimetric analyses (TGA), CNH element analysis and UV–Vis diffuse reflectance spectra (UV–Vis DRS). Upon the UV light irradiation, BUC-19 exhibited excellent photocatalytic performances toward methylene blue (initial concentration 10 mg L^?1), methyl orange (initial concentration 10 mg L^?1) and reactive red X-3B (initial concentration 50 mg L^?1) with degradation efficiency of 93, 80 and 92%, respectively. The possible mechanism was proposed, which was further confirmed by trapping experiments.