1H-3-(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (2,3′-Hbpt) as ligand in Cd(II) complexes: synthesis,crystal structures,and fluorescence

Hydrothermal reactions of 1H-3-(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (2,3′-Hbpt) with CdCl₂ and CdI₂ yielded three new coordination polymers, {[CdCl(2,3′-bpt)(H₂O)]·2H₂O}_n (1), {[Cd₂I₃(2,3′-H_0.5bpt)₂]}_n (2), and [CdI₃(2,3′-Hbpt)](2,3′-H₂bpt)·H₂O (3). Structural analysis reveals that 1 has a 1-D double chain structure; in 2, 2,3′-bpt bridges adjacent Cd(II) ions to form a 1-D twofold helical chain, which further connects via μ₂-I^-, giving a 2-D grid structure in the ab plane; 3 is mononuclear. These complexes are further connected through weak hydrogen bonding interactions, and/or weak π···π stacking interactions, to generate 3-D supramolecular structures. The fluorescence properties of 1 and 2 have been investigated in the solid state at room temperature.     

Synthesis and structural characterization of 2D Zn(II), Cd(II), and Co(II) coordination polymers containing 3-chloro-1,2-benzenedicarboxylate and positional isomers of triazole-bipyridine

Three compounds, [Zn₂L₂(4,4′-bpt)₂] _n (1), [Cd₂L₂(3,4′-bpt)(H₂O)₂] _n (2) and {[CoL(3,3′-bpt)(H₂O)]?H₂O} _n (3) (L?=?3-Cl-1,2-benzenedicarboxylate dianion, 4,4′-bpt?=?1H-3,5-bs(4-pyridyl)-1,2,4-itriazole, 3,4′-bpt?=?1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole and 3,3′-bpt?=?1H-3,5-bis(3-pyridyl)-1,2,4-triazole), based on three positionally isomeric triazole-bipyridine ligands, were synthesized. Structural analyses of 1–3 reveal diverse 2-D network structures, which are based on different [ML] _n (M?=?Zn, Cd, Co) chains. In the [ZnL] _n chains of 1, the carboxylic groups of L connect the adjacent Zn(II) centers with a monodentate bridging coordination mode (μ₂-η^{1 ?}/^? η¹ ). In 2, [CdL] _n is a double chain connected by the carboxylic groups of L with μ₃-η^{1 ?}/^? η²/η² and μ₃-η^{1 ?}/^? η^{1 ?}/^? η² bridges. The [CoL] _n chains of 3 are formed by the carboxylic groups of L with the μ₂-η^{1 ?}/^? η² coordination mode. The powder X-ray diffraction and the thermal stability of 1–3, the luminescent properties of 1 and 2, and the magnetic behavior of 3 have been briefly investigated.     

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.     

Synthesis,crystal structure,and magnetic properties of a linear trinuclear Cu(II) complex

A new linear trinuclear Cu(II) complex, [Cu₃(NTA)₂(4,4′-bpt)₄(H₂O)₂]?·?10H₂O (H₃NTA?=?nitrilotriacetic acid, 4,4′-bpt?=?4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole) (1), was obtained from evaporation of an aqueous solution containing Cu(NO₃)₂?·?6H₂O, 4,4′-bpt, nitrilotriacetic acid (H₃NTA), and NaOH. 1 was characterized using single-crystal X-ray diffraction, IR, and elemental analysis. In the trimer, the three linear copper ions are bridged by two NTA carboxylate groups in a syn–anti conformation and connected by 4,4′-bpt to produce a 1-D array. Temperature-dependent magnetic susceptibilities reveal the presence of weak antiferromagnetic exchange between metal centers.     

N-donor co-ligand-driven zinc coordination polymers based upon a bithiophene dicarboxylate: syntheses,structures, and luminescent properties

Three zinc compounds assembled from a bithiophene dicarboxylic acid (H₂DMTDC) and different N-donor co-ligands, [Zn(DMTDC)(bpt)(H₂O)]_n (1), {[Zn(DMTDC)(5,5-dmbpy)]·0.5DMF·1.5H₂O}_n (2), and {[Zn(DMTDC)(1,3-bimb)]·2DMF·H₂O}_n (3) (H₂DMTDC?=?3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid, bpt?=?4-amino-3,5-bis(4-pyridyl)1,2,4-triazole, 5,5′-dmbpy?=?5,5′-dimethyl-2,2′-bipyridyl, 1,3-bimb?=?1,3-bis(imidazol-1ylmethyl)benzene), were solvothermally synthesized and characterized. Compounds 1 and 2 are 1-D linear and zigzag chains with different supramolecular structures. In 1, adjacent chains form zipper-like structures through N–H?N interactions. In 2, however, chains in adjacent layers are stacked in an unusual unparallel level through C–H?O interactions. Compound 3 features a highly corrugated 2-D (4,4) layer and the layers are penetrated by each other to give 3-D polycatenations. Right- and left-handed helical Zn-bimb chains are arranged alternately within and between the layers, leading to mesomeric property of the whole network. Thermal stability and the decomposed products of all compounds were investigated. Luminescent properties of the ligands and compounds in the solid state at room temperature have also been explored. Moreover, the luminescence intensities of the compounds in different solvents are largely dependent on the solvent.     

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 Mn(II) coordination polymers assembled from a dithiocarboxylic acid and N-donor ligands

Three new complexes, {[Mn(dtb)(bpe)·2H₂O]·H₂O} _n (1), {[Mn(dtb)(bpa)·2H₂O]·H₂O} _n (2), and {[Mn(dtb)(phen)]} _n (3) [H₂dtb?=?5,5′-dithiobis(2-nitrobenzoic acid), bpe?=?1,2-bis(4-pyridyl)ethene, bpa?=?1,2-bi(4-pyridyl)ethane, phen?=?1,10-phenanthroline], have been synthesized under hydrothermal conditions with Mn(OAc)₂·4H₂O, dtb, and different N-donor ligands. X-ray structure analyses of 1 and 2 reveal analogous structures with 1D helical chains and 2D 4⁴ chiral layers. The structure of 3 shows a 1D chain which is outwardly decorated with phen ligands. These neutral polymeric complexes exhibit structural diversity due to the different coordination modes of the flexible dtb ligand and the N-donor ligands. The thermogravimetric analyses and X-ray powder diffractions of 1–3 are also presented.     

Cobalt(II) coordination polymers built on isomeric dipyridyl triazole ligands with pyromellitic acid: Synthesis, characterization and their effects on the thermal decomposition of ammonium perchlorate

Three new cobalt(Ⅱ) coordination compounds,[Co(3,3’-Hbpt)2(H2pm)(H2O)2]·2H2O(1),[Co(4,4’-Hbpt)(pm)0.5(H2O)]·3H2O (2) and [Co(3,4’-Hbpt)(pm) 0.5 (H2O)3]·2H2O(3)(3,3’-Hbpt=3,5-bis(3-pyridyl)-1H-1,2,4-triazole;4,4’-bpt=3,5-bis(4-pyridyl)1H-1,2,4-triazole,3,4’-Hbpt=3-(3-pyridyl)-5-(4’-pyridyl)-1H-1,2,4-triazole and H4pm=pyromellitic acid) have been synthesized by hydrothermal reactions.Single-crystal X-ray diffraction reveals that compound 1 has a one-dimensional (1D) chain network,2 exhibits a four-connected three-dimensional (3D) structure with 1D open channels encapsulated by water molecules,while 3 displays a regular two-dimensional (2D) architecture connected through 1D metal helical chains.In addition,the efficacy of compounds 1-3 as additives to promote the thermal decomposition of ammonium perchlorate (AP) is explored by differential scanning calorimetry (DSC).     

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.     

The synthesis,characterization, and theoretical hydrogen gas adsorption properties of copper(II)-3,3′-thiodipropionate complexes with imidazole derivatives

Three new coordination polymers, [Cu(μ₃-tdp)(im)₂]_n (1), {[Cu(μ₃-tdp)(1-mim)₂]·0.5H₂O}_n (2) and {[Cu₂(μ₃-tdp)₂(4-mim)₄]·H₂O}_n (3) [tdpH₂ = 3,3′-thiodipropionic acid, im = imidazole, 1-mim = 1-methylimidazole and 4-mim = 4-methylimidazole], have been prepared and characterized by spectroscopic techniques (IR and UV–Vis), elemental analyzes, magnetic measurements, thermal analyzes, and single-crystal X-ray diffraction. Complexes 1–3 crystallize in the monoclinic system with space groups of C2/c and P2₁/c, respectively. In 1–3, tdp is a bridging ligand to form 1-D chains, which are extended into a 2-D layer by hydrogen bonding and π···π interactions. The 3,3′-thiodipropionate exhibits an unexpected coordination mode in 1–3. Simulations were used to assess the potential of the complexes in H₂ storage applications.     

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.     

Preparation,characterization, and properties of a Ag(I) coordination polymer {[Ag(H3bptc)(bpe)] · 2H2O} n

A new coordination polymer, {[Ag(H₃bptc)(bpe)]?·?2H₂O} _n (1) (H₄bptc?=?3,3′,4,4′-benzophenonetetracarboxylic acid, bpe?=?1,2-bis(4-pyridyl)ethene), has been synthesized through a hydrothermal technique and structurally characterized. The crystal structure of 1 exhibits a 2-D hydrogen-bonding sheet between H₃bptc^? and two free water molecules. Fluorescent property, TG analysis, and X-ray powder diffraction for 1 were also measured and discussed.     

Synthesis,crystal structure,and properties of cobalt,zinc, and manganese coordination polymers based on fluconazole

Three complexes based on fluconazole, namely, {[Co₂(HFlu)(dpa)₂(H₂O)₂]·H₂O}_n (1), {[Zn(HFlu)(IPA)]·H₂O}_n (2), and {[Mn(HFlu)₂(IPA)(H₂O)]·H₂O}_n (3) (HFlu?=?fluconazole, 2-(2,4-difluoro-phenyl)-1,3-bis(1,2,4-triazol-1-yl)-propan-2-ol; H₂dpa?=?diphenic acid; H₂IPA?=?isophthalic acid) have been synthesized. Single-crystal X-ray analysis revealed that 1 is a 2-D-network framework containing a trinuclear Co(II) unit, 2 is a 3-D framework, and 3 is 1-D double chain structure with a Mn₂ metallocyclic core. The complexes have also been characterized by elemental analyses, IR, UV/vis and fluorescence spectroscopy, and thermal gravimetry. The phase purity of these polymers has been confirmed via powder X-ray diffraction.     

Hydrothermal Synthesis,Solid State Structure,and Thermal Properties of a Family of Isomorphous 1‐D Coordination Polymers Aggregated by Extensive Hydrogen Bonding: {[M(3,3′‐bpy)(H2O)4](SO4)·2H2O} (M = Co,Ni, Zn)

Hydrothermal synthesis has afforded a family of new coordination polymers incorporating 3,3′‐bipyridine (3,3′‐bpy), {[M(3,3′‐bpy)(H₂O)₄](SO₄)·2H₂O} (M = Co, Ni, Zn). The crystal structures revealed 1‐D undulating cationic ribbons of formulation {[M(3,3′‐bpy)(H₂O)₄]}_n²ⁿ⁺ with both unligated charge‐balancing sulfate anions and water molecules of crystallization entrapped by hydrogen bonding. The 1‐D ribbons run along the (101) crystal direction and further aggregate via extensive hydrogen bonding patterns. Thermal decomposition data were consistent with stepwise loss of water molecules of crystallization and aquo ligands followed by decomposition due to ligand removal.     

Three-pillared layer metal–organic frameworks assembled by imidazole-4,5-dicarboxylate and rigid bisimidazole ligands: synthesis,crystal structure,and sensing nitroaromatics

Three-pillared layer metal–organic frameworks based on 1H-imidazole-4,5-dicarboxylate and linear bis(imidazole) ligands generally formulated as {[Co₃(idc)₂(bib)₃]·8H₂O}_n (1), {[Cd(Hidc)(bib)_0.5]}_n (2) and {[Cd(Hidc)(bibp)]}_n (3), where H₃idc = 1H-imidazole-4,5-dicarboxylate, bib = 1,4-bis(1-imidazolyl)benzene and bibp = 4,4′-bis(1-imidazolyl)biphenyl, have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Compound 1 features a 3-D-pillared layer structure with 1-D channels, generated by honeycomb-like 2-D layer linked by bib ligands. Compound 2 consists of 2-D lumpy layers of [Cd₄(Hidc)₄], which are further connected by bridging ligands of bib to generate a pillared layer 3-D framework with 1-D channels. In 3, the 2-D corrugated honeycomb networks, structurally analogous to CFx, are pillared by bibp ligands to form a 3-D architecture with 1-D channels. Through selecting different metal ions and the length of pillared ligands, the pore sizes are adjusted in the three complexes. The potential of 2 and 3 for nitro explosive sensing is investigated through luminescence quenching experiments, which show that 3 can be applied as a fluorescent sensor for nitro compounds.     

Syntheses, crystal structures, and magnetic and fluorescence properties of three complexes of mixed flexible N,N′-bis(3-pyridylmethyl)amine and rigid pyromellitate ligands

Three new complexes, {[Mn(Hbpma)₂(pm)(H₂O)₂]·8H₂O}_n, {[Co(Hbpma)₂(pm)(H₂O)₂]·8H₂O}_n and {[Zn(Hbpma)₂(pm)(H₂O)₂]·8H₂O}_n (bpma = N,N′-bis(3-pyridylmethyl)amine and H₄pm = pyromellitic acid) were synthesized and structurally characterized by single-crystal X-ray diffraction. All three complexes are isomorphous consisting of one-dimensional coordination polymers bridged by rigid pm ligands, while the flexible dipyridyl bpma only acts as a terminal ligand. The bpma ligand adopts the trans–trans conformation in all three complexes. The magnetic properties of the Mn(II) and Co(II) complexes show the occurrence of antiferromagnetic interactions between adjacent metal atoms. The Zn(II) complex exhibits fluorescent emission in the solid state at room temperature.     

Crystal structures and magnetic properties of three cobalt(II)–organic frameworks with nanoscale channels

Three cobalt(II) coordination polymers, {[Co(nip)(4,4′-bpy)] · 3H₂O} _n (1), [Co(nip)(bpe)] _n (2), and [Co(nip)(bpp)(H₂O)] _n (3), were hydrothermally synthesized by the reaction of cobalt nitrate hexahydrate and nip with 4,4′-bpy, bpe, and bpp [nip = 5-nitro-1,3-benzenedicarboxylato, 4,4′-bpy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane], respectively. Co(II) displays different coordination in the three complexes, resulting in different structures with nanoscale channels. Compounds 1 and 2 form 2-D layer structures, but 3 has a two-fold interpenetrated 3-D framework. The magnetic properties associated with their crystal structures were investigated.     

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.     

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.     

Effect of bis-triazole based secondary ligands on the structure of coordination polymers generated from terephthalic acid

Reactions of Zn/Cd(ClO₄)₂·6H₂O and terephthalic acid (H₂BDC) with three bis-triazole ligands afforded three coordination polymers under solvothermal conditions, {[Zn(BDC)(L1)]·H₂BDC}_n (1), {[Zn(BDC)(L2)_0.5]·H₂O}_n (2), and {[Cd₂(BDC)₂(L3)(DMF)(H₂O)₂]·2H₂O]}_n (3) (L1 = bis(4-(4H-1,2,4-triazol-4-yl)phenyl)methane, L2 = bis(4-(4H-1,2,4-triazol-4-yl)phenyl)ethane, and L3 = 1,4-bis(4H-1,2,4-triazol-4-yl)benzene). Solid 1 displayed a 2-D structure which contained two kinds of rings. Both 2 and 3 were 3-D threefold interpenetrating frameworks. Solid 2 showed a α–Po-related net, while 3 exhibited an acs-related network with a binuclear node. Furthermore, the photoluminescent properties of 1–3 were investigated.