Two solvent directed zinc(II) coordination polymers with 1-D single-zigzag chain and 1-D double-zigzag chains

Two coordination polymers, {[Zn(NiL)(DMA)(H₂O)₂] (DMA)(H₂O)} _n (1) (DMA?=?N,N-dimethylacetamide) and {[Zn₂(NiL)₂(DMF)(H₂O)₄]?·?3DMF} _n (2) (DMF?=?N,N-dimethylformamide), have been prepared by reactions of Zn(NO₃)₂?·?6H₂O and NiL in CH₂Cl₂-DMA–H₂O and CH₂Cl₂-DMF–H₂O, respectively. H₂L denotes dimethyl 5,6,7,8,15,16-hexahydro-6,7-dioxodibenzo-9,10-benzo-[1,4,8,11]tetraazacyclotetradecine-13,18-dicarboxylate. Single-crystal X-ray diffraction analyses reveal that coordination geometries around Ni(II) are identical with slightly distorted square planar and all Ni–N bonds are very short. Complex 1 shows 1-D zigzag chain structure, while 2 has 1-D double-zigzag chains. The chains, which are packed parallel in 1 and 2, are interconnected by lattice solvent through O–H···O and C–H···O hydrogen bonds to form 3-D supramolecular networks. We discuss solvent effects on assembly of the two coordination polymers. The results reveal that coordinated solvent has influence on the assembly procedure.     

Crystal structures and luminescence of two cadmium(II) polymers constructed from aromatic polycarboxylate and bis(1,2,4-triazol-1-yl)methane ligands

Two new coordination compounds, {[Cd₂(btrm)(ip)₂(H₂O)₂]?·?2H₂O} _n (1) and {[Cd₂(btrm)(hip)₂(H₂O)₄]?·?3H₂O} _n (2) (btrm?=?bis(1,2,4-triazol-1-yl)methane, H₂ip?=?isophthalic acid, H₂hip?=?5-hydroxy isophthalic acid), have been synthesized and structurally characterized. Compound 1 is a 3-D network with CdSO₄ topology. Compound 2 contains 1-D ladder structures, which are interconnected by classical hydrogen-bonding interactions (O–H?···?O) to lead to 3-D supramolecular architectures. Luminescence was performed on 1 and 2, both of which showed strong fluorescent emissions in the solid state at room temperature.     

Synthesis,structures, and urease inhibition of nickel(II), zinc(II), and cobalt(II) complexes with similar hydroxy-rich Schiff bases

Four new nickel(II), zinc(II), and cobalt(II) complexes, [Zn(L¹)₂]?·?H₂O (1), [Ni(L¹)₂]?·?H₂O (2), [Ni(L²)₂] (3), and [Co(L³)₂]?·?H₂O (4), derived from hydroxy-rich Schiff bases 2-{[1-(5-chloro-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL¹), 2-{[1-(2-hydroxy-3-methoxyphenyl)methylidene]amino}-2-ethylpropane-1,3-diol (HL²), and 2-{[1-(5-bromo-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL³) have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray determination. Each metal in the complexes is six-coordinate in a distorted octahedral coordination. The Schiff bases coordinate to the metal atoms through the imino N, phenolate O, and one hydroxyl O. In the crystal structures of HL¹ and the complexes, molecules are linked through intermolecular O–H···O hydrogen bonds, forming 1-D chains. The urease inhibitory activities of the compounds were evaluated and molecular docking study of the compounds with the Helicobacter pylori urease was performed.     

Three double- or triple-stranded chains constructed from different cobalt(II) salts and a flexible bis-triazole ligand

Three coordination compounds, {[Co(btrp)₂(H₂O)₂]?·?NO₃?·?H₂O} _n (1), {[Co(btrp)₂(H₂O)₂]?·?H₂O?·?2H₂btc} _n (2), and {[Co(btrp)₃]?·?2ClO₄} _n (3) (btrp?=?1,3-bis(1,2,4-triazol-1-yl)propane; H₃btc?=?benzene-1,3,5-tricarboxylic acid), have been prepared via solvothermal method and characterized by single-crystal X-ray diffraction and elemental analyses. Compound 1 possesses a 1-D double-stranded chain composed of ribbons of 20-membered cycles. Binuclear water clusters link adjacent nitrate anions to form a 1-D supramolecular helix in the structure. Compound 2 has a 1-D double-stranded chain wherein free H₂btc ligands constitute 1-D negative chains through classical hydrogen-bonding interactions (O–H?···?O). Compound 3 exhibits a triple-stranded 1-D chain. For 1–3, 3-D supramolecular structures are consolidated by interchain weak hydrogen-bonding interactions as well as electrostatic interactions.     

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

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.     

Syntheses,crystal structures,and catalytic activities of three new Cu(II) coordination polymers based on 2-(1H-1,2,4-triazole)-1-acetic acid

Three new coordination polymers, {[Cu(trza)(2,2′-bipy)(H₂O)]?·?(ClO₄)} _n (1), {[Cu(trza)(2,2′-bipy)(H₂O)]?·?(BF₄)} _n (2), and {[Cu(trza)(4,4′-bipy)]?·?(H₂O)?·?(ClO₄)} _n (3) (Htrza?=?2-(1H-1,2,4-triazole)-1-acetic acid), have been synthesized and characterized by single-crystal X-ray diffraction analysis. Both 1 and 2 exhibit 1-D chain structure while 3 displays 2-D layer structure. The catalytic activities of 1 and 3 in the green oxidative coupling of 2,6-dimethylphenol have been investigated.     

Syntheses,structures, and fluorescent properties of two new d10-metal coordination polymers containing 1-((benzotriazol-1-yl)methyl)-1-H-1,2,4-triazole ligand

Two new coordination polymers formulated as {[Zn(bdic)(bmt)H₂O]?·?0.5H₂O} _n (1) and {[Cd(bdic)(bmt)(H₂O)₂]?·?2H₂O} _n (2) (H₂bdic?=?1,3-benzenedicarboxylic acid, bmt?=?1-((benzotriazol-1-yl)methyl)-1-H-1,2,4-triazole) have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Both coordination polymers exhibit 1-D chain structure where bmt is unidentate and bdic^2? bridging. In 1, bmt hangs at two sides of the main chain, whereas bmt hangs at one side of the main chain in 2. Fluorescent properties have also been determined.     

Syntheses,structures, and luminescence of three 4-connected zinc coordination polymers with bis(1,2,4-triazol-1-yl)propane and benzenebiscarboxylate

Three zinc(II) coordination polymers {[Zn(btp)(1,2-bdc)(H₂O)]?·?H₂O} _n (1), {[Zn(btp)(1,3-bdc)(H₂O)]?·?1.5H₂O} _n (2), and {[Zn(btp)(NO₂-1,3-bdc)(H₂O)]?·?2H₂O} _n (3) were synthesized by 1,3-bis(1,2,4-triazol-1-yl)propane (btp) and bis-carboxylate. Compound 1 is a thick 2-D network; 2 and 3 are undulated 2-D (4,4) networks. In 2 and 3, two adjacent networks interpenetrate to form a new 2-D double-layer network, which is sustained by hydrogen-bonding interactions. Compounds 1 and 2 reveal blue emission maximum at 351 and 403, respectively, in the solid state at room temperature.     

Syntheses,structures, and properties of CdII and CoII complexes with 5-(pyridin-4-yl)isophthalate

A N-donor containing carboxylic ligand, 5-(pyridin-4-yl)isophthalic acid (H₂L), was applied to construct two new coordination polymers [Cd(L)(DMF)] _n (1, DMF?=?N,N-dimethylformamide) and {[Co(L)(H₂O)₂]?·?0.5CH₃OH?·?1.5H₂O} _n (2) under different conditions. The complexes were characterized by IR, elemental, and thermogravimetric analyses, powder and single crystal X-ray diffraction. In 1 each L^2? links four Cd^II to form a 3-D framework, while in 2 each L^2? connects three metals to form a 2-D layer structure, which is further connected together by hydrogen bonds to form a 3-D architecture. The thermal stability of the complexes and the photoluminescence of 1 were investigated.     

Cd(II) and Cu(II) coordination polymers based on a multidentate N-donor ligand: syntheses,crystal structures,optical band gaps,and photoluminescence

Four Cd(II)- and Cu(II)-containing coordination polymers (CPs) based on a multidentate N-donor ligand and varied dicarboxylate anions, [Cd(3,3′-tmbpt)(p-bdc)]·2.5H₂O (1), [Cd(3,3′-tmbpt)(m-bdc)]·2H₂O (2), [Cu(3,3′-tmbpt)(m-bdc)]·H₂O (3), and [Cu(3,3′-tmbpt)(p-bdc)]·2H₂O (4), where 3,3′-tmbpt = 1 ? ((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(3-pyridyl)-1,2,4-triazole, p-H₂bdc = 1,4-benzenedicarboxylic acid, and m-H₂bdc = 1,3-benzenedicarboxylic acid, have been prepared hydrothermally. The structures of the compounds were determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra and elemental analyses. Compound 1 exhibits a 3-D twofold interpenetrating framework with a 6⁵·8 CdSO₄ topology. Compound 2 is a 2-D layer containing meso-helical chains with a 4⁴·6² sql topology. Compound 3 shows a 1-D → 3-D interdigitated architecture while 4 displays a 2-D → 3-D interdigitated architecture. The structural differences of the compounds indicate that the dicarboxylate anions and the central metal ions play important roles in the resulting structures of CPs. Optical band gaps and solid-state photoluminescent properties have also been studied.     

Syntheses and structures of three coordination polymers based on 4-methylbenzenethiolates of Zn(II) and Cd(II) and bipyridine

Using 4-methylbenzenethiolates of Zn or Cd as precursors and 4,4′-bipyridine (4,4′-bpy) as bridges, we have synthesized three new Zn(II)/Cd(II) coordination polymers, {[Cd(4,4′-bpy)₂(NCS)₂] · 2(SC₆H₄CH₃-4)₂} _n (1), {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · DMF} _n (2) and {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · H₂O · 0.5CH₃OH} _n (3). Compound 1 is a 2-D sheet-like square polymer in which four 4,4′-bpy ligands and two isothiocyanate ligands complete the octahedral Cd(II) coordination sphere. Compounds 2 and 3 have similar coordination around Zn(II), but have different polymer structures. In 2, Zn(II) centers are linked via a bidentate 4,4′-bipyridine to form 1-D twisted arched chains, which is a new structural type for Zn(II). Compound 3 has 1-D zigzag chains. The 2-D sheets in 1 and 1-D chains in 2 and 3 are assembled via intermolecular C–H ··· π and C–H ··· S interactions into 3-D supramolecular networks. C–H ··· S interactions are a vital factor in constructing the sulfur-containing coordination polymers. Different coordination modes and packing schemes in 1–3 show that the guest molecule has a critical influence on formation of polymers.     

From discrete dinuclear to 1-D and 2-D structures: nickel dipicolinate complexes with flexible bis(imidazole) ligands

Three new complexes, [Ni₂(dpc)₂(L₁)₂(H₂O)₂]?·?4H₂O (1), [Ni(dpc)(L₂)_1.5] _n (2), and {[Ni(dpc)(L₃)_1.5]?·?2H₂O} _n (3), where H₂dpc?=?dipicolinic acid, L₁?=?1,4-bis(2-methylimidazol-1-yl)butane, L₂?=?4,4′-bis(2-methylimidazol-1-ylmethyl)biphenyl, and L₃?=?1,4-bis(benzimidazol-1-yl)-2-butylene, have been synthesized by hydrothermal methods and characterized by elemental analyses, infrared spectra, thermogravimetric analysis, and X-ray crystallography. The common structural characteristic of the three complexes is that the Ni²⁺ is coordinated by tridentate dipicolinate through nitrogen of pyridine and oxygen of carboxylate, serving as a terminal ligand. In 1, two L₁ link two [Ni(dpc)(H₂O)] units to a discrete binuclear metallomacrocycle with a 22-membered ring, which is assembled through multiple O–H?···?O hydrogen bonds to form a 3-D supramolecular framework. Complex 2 exhibits a 1-D ladder-like chain structure constructed by cis/trans-conformation L₂ linking metal centers; 3 displays a 2-D (6,3) topology, being constructed from the linking of [Ni(pdc)] by L₃. These results indicate the merits of flexible bis(imidazole) ligands as building blocks with dipicolinate for the construction of complexes with diverse structural motifs.     

Synthesis and crystal structures of nickel(II) supramolecules containing hexaazamacrocycles and aromatic carboxylate ligands

Two new nickel(II) complexes, {[Ni(L)(4,4′-bpdc)] · 3H₂O} _n (1) and {[Ni(L)(2,6-ndc)] · 2CH₃CN} _n (2) (L = 1,8-dihydroxylethyl-1,3,6,8,10,13-hexaazacyclotetradecane, 4,4′-bpdc = 4,4′-biphenyldicarboxylate, 2,6-ndc = 2,6-naphthalenedicarboxylate), have been synthesized and structurally characterized by spectroscopic and X-ray diffraction methods. Compound 1 shows a 3-D supramolecule which is composed of two different series of 1-D coordination polymers, where each 1-D chain runs in different directions and interacts by π–π stacking at the intersection. Compound 2 contains 1-D coordination polymers in which 1-D chains run in the same direction. The 1-D chains are interconnected by hydrogen bonds in an undulated fashion to form a 3-D supramolecule.     

Synthesis,structures, and characterization of cadmium(II), cobalt(II), and copper(II) metal polymers with tetrazole-1-acetate

Three new coordination polymers {[Cd(tza)(2,2′-bpy)(H₂O)](ClO₄)} _n 1, {[Co(tza)(2,2′-bpy)(H₂O)](ClO₄)} _n 2, and {[Cu(tza)(phen)](ClO₄)} _n 3 (Htza = tetrazole-1-acetic acid, 2,2′-bpy = 2,2′-bipyridyl, phen = 1,10-phenanthroline) were synthesized and characterized by X-ray single-crystal diffraction, elemental analysis, and IR spectra. Complexes 1 and 2 exhibit 3-D architectures formed by π–π interaction of 2,2′-bpy ligands interlinking to the adjacent 2-D layers. Complex 3 is a 1-D zigzag double chain and the 3-D structure is formed by π–π stacking interaction of phen and nonclassical hydrogen bonding.     

Two cobalt(II) complexes based on 2-propyl-4,5-imidazoledicarboxylic acid: syntheses,crystal structures,and properties

Two complexes, [Co(H₂pimdc)₂(H₂O)₂]?·?2DMF (1) and [Co(H₂pimca)₂(H₂O)₂]?·?4H₂O (2), have been designed, synthesized, and characterized (X-ray single crystal analysis, thermal analysis, electrochemical analysis, and infrared spectrum) based on the imidazole ligand [H₃pimdc?=?2-propyl-4,5-imidazoledicarboxylic acid]. Both compounds have 3-D hydrogen-bonding networks. Because of different coordination of water, 1 forms a layer-like geometry via hydrogen bonds, but 2 forms a fishingnet-like latticed geometry via hydrogen bonds.     

Two Supramolecular Nickel(II) Complexes: Syntheses,Crystal Structures and Solvent Effects

Two nickel(II) complexes, namely {[NiL(MeOH)(μ‐OAc)]₂Ni} · 2CH₂Cl₂ · 2MeOH ( 1 ) and {[NiL(EtOH)(μ‐OAc)]₂Ni} · 2EtOH ( 2 ) {H₂L = 5, 5′‐dimethoxy‐2, 2′‐[(ethylene)dioxybis(nitrilomethylidyne)]diphenol}, were synthesized and structurally characterized. Two trinuclear Ni^II complexes are both hexacoordinate around the central Ni^II atoms, showing octahedral coordination arrangements, and each complex comprises three divalent Ni^II atoms, two deprotonated L^2– ligands, in which four μ‐phenoxo oxygen atoms forming two [NiL(X)] (X = MeOH or EtOH) units, and coordinated and non‐coordinated solvent molecules. Complex 1 exhibits a 2D supramolecular network through intermolecular O–H ··· O, C–H ··· O and C–H ··· π interactions, whereas complex 2 forms an infinite 1D chain by intermolecular C–H ··· O hydrogen bonding interactions.     

A series of lanthanide-organic frameworks constructed by 2-methyl imidazole dicarboxylate and oxalate: synthesis,structures, and properties

Five lanthanide(III) coordination polymers with 2-methyl-1H-imidazole-4,5-dicarboxylic acid (H₃MIDC) and ammonium oxalate, {[(Ln1)₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?3H₂O} _n (Ln1?=?Nd (1), Sm (2)), {[Eu₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?0.5EtOH?·?3H₂O} _n (3), {[Ce₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?EtOH?·?3H₂O} _n (4), and {[Gd₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?MeOH?·?3H₂O} _n (5), have been prepared and structurally characterized. Single-crystal X-ray diffraction analyses reveal that 1 and 2 are isostructural, as are 3, 4, and 5. Each exhibits a 3-D open framework, which is built by a regular 2-D grid connected by HMIDC^2? and Ln(III). The luminescence and thermal properties of these complexes have been investigated as well.     

Three lanthanide coordination polymers with nitrilotriacetic acid: hydrothermal syntheses,crystal structures and fluorescent property

Hydrothermal reactions of Sm₂O₃, Gd(ClO₄)₃?·?6H₂O and Tb(ClO₄)₃?·?6H₂O with nitrilotriacetic acid, give rise to three lanthanide coordination polymers, {[Sm(NTA)(H₂O)₂]?·?H₂O} _n (1), {[Gd(NTA)(H₂O)]?·?H₂O} _n (2) and {[Tb(NTA)(H₂O)]?·?H₂O} _n (3). Their solid-state structures have been characterized by elemental analysis, and IR spectroscopy. X-ray single-crystal diffraction analyses indicated that 2 and 3 are isomorphous three-dimensional coordination polymers with eight-coordinate Gd(III) (or Tb(III)), while 1 forms a two-dimensional coordination polymer containing nine-coordinate Sm(III). The photophysical properties of 3 have been studied with excitation and emission spectra, which exhibit strong green emission.     

A holodirected Pb(II) architecture based on bifunctional tetrazole-carboxylate and photoluminescence

A new 1-D Pb(II) complex {[Pb₂(H₂O)₄(tppbc)₂]?·?(CH₃)₂NCHO} _n (1) based on tetrazole-carboxylate bifunctional ligand has been prepared and characterized (tppbc?=?3-(4-(2-(1H-tetrazol-5-yl)phenyl-4-yl)phenyl)-2-ethoxy-3H-benzimidazole-4-carboxylic acid). Photo-luminescence measurements indicate that although the fluorescence of tppbc is quenched after coordination, the Pb(II) complex shows strong intense phosphorescence emission. Lifetimes at 298?K and low temperatures agree with the large Stokes shift of 1.     

Syntheses,crystal structures and antibacterial activities of M(II) benzene-1,2,3-triyltris(oxy)triacetic acid complexes

Four metal(II) complexes with benzene-1,2,3-triyltris(oxy)triacetic acid (H₃L), {[Co_1.5(L)(H₂O)₆]·6H₂O}_n (1), {[Co_1.5(L)(4,4′-bipy)_1.5(H₂O)₄]·4H₂O}_n (2), {[Co(HL)(2,2′-bipy)(H₂O)₂]·1.5H₂O}_n (3), and {[Cu(HL)(phen)(H₂O)₂]·H₂O}_n (4) (4,4′-bipy = 4,4′-bipyridine; 2,2′-bipy = 2,2′-bipyridine; phen = phenanthroline), were prepared and structurally characterized. Complex 2 displays a 1-D structure, while 1, 3, and 4 reveal 0-D structures, which further extend to 3-D supramolecular networks by hydrogen bonding interactions, of which 1 and 4 contain double-helical chains, 2 includes meso-helices, and 3 comprises single-helices. Furthermore, the thermal stabilities and antibacterial activities of the complexes were studied.