Metallocycle and ring-opening polymerization of silver(I) complexes with 1,3-bis(4,5-dihydro-1H-imidazol-2-yl)benzene ligand

The reaction of 1,3-bis(4,5-dihydro-1H-imidazol-2-yl)benzene (bib) ligand with silver(I) nitrate in a 1:1 molar ratio generated a [2 + 2] metallocyclic complex [Ag₂(bib)₂](NO₃)₂ · 2H₂O, in which bib ligand displayed in cis configuration. When the additional competing ligands/counterions, such as oxlate salt, 1,2-diaminoethene (en), 1,3-diaminopropane (pn), and were introduced, respectively, to the above-mentioned reaction solution, ring-open polymerization of sliver(I) complexes {[Ag(bib)]NO₃ · H₂O}_n (1), {[Ag(bib)₂]X}_n ( (2), (3)), {[Ag₂(bib)₂(NO₂)](NO₂) · 19/8H₂O}_n (4) and {[Ag₂(bib)₂](V₄O₁₂)_0.5 · 3H₂O · 2MeCN}_n (5) were generated. In compounds 1, 4 and 5, bib ligand adopts trans configuration and twists around the Ag-Ag axis, giving rise to single-stranded helical structure with short adjacent Ag?Ag distances of 3.56, 3.56, 3.50 and 3.63 Å, respectively. Compounds 2 and 3 are 1D coordination polymers fusing the [2 + 2] metallocycle [Ag₂(bib)₂]²⁺, in which bib ligand exhibits in cis configuration and the metallocycles have longer Ag?Ag distances of 8.52 Å in 2 and 8.61 Å in 3 along with the strong intracyclicπ-π interactions between phenyl groups. Cis and trans configurations of bib coexist in solution and crystallize in complexes 1 and 2 in the solid state in the presence of en or pn. The solution of 1 and 2 can be converted into 3 via the addition of the bulky counter anion or into 4 through introduction of the competing ligand/conuterion .     

Manganese(II) complexes with V-shaped sulfonyldibenzoate: The 3D structures with interpenetrated threefold or tetra-nuclear manganese(II) units

Five Mn^II-sdba coordination polymers with mono-, di-, tri-, tetra-nuclear cores based on the V-shaped 4,4′-dicarboxybiphenyl sulfone (H₂sdba) ligands: [Mn(sdba)(phen)₂(H₂O)]_n·3nH₂O (1), [Mn₂(sdba)₂(μ-H₂O)(py)₄]_n (2), [Mn₃(sdba)₂(Hsdba)₂(2,2′-bipy)₂]_n (3), [Mn₄(sdba)₄(4-mepy)₂(H₂O)₄]_n·2nH₂O (4) and [Mn₄(sdba)₄(bpp)₄(μ-H₂O)₂]_n·0.5nH₂O (5) (phen = 1,10-phenanthroline, 2,2′-bipy = 2,2′-bipyridine, 4-mepy = 4-picoline, bpp = 1,3-bi(pyridine-4-yl)propane) were hydrothermally synthesized and structurally characterized. The M-O-C metal clusters in above complexes act as SBUs, and the V-shaped sdba ligands link the SBUs to generate the novel frameworks. In complexes 1 and 3 their 1D chains are linked into the 2D planes through various hydrogen bonding. Complex 2 displays the 3D structure with interpenetrated threefold, while complexes 4 and 5 both exhibit the 3D structures with the tetra-nuclear Mn₄ units. The magnetic susceptibility studies in the 2-300 K range for these complexes reveal the existence of anti-ferromagnetic exchange interactions between the Mn^II ions.     

Potential tridentate salicylaldehyde hydrazone of arylalkanoic acid coordinate to copper(II) acting as dinegative tetradentate ligands

A chiral Schiff base N-(S)-2-(6-methoxylnaphthyl)-propanoyl-N′-(2-hydroxylbenzylidene)hydrazine (H₂L) has been synthesized. Reaction of H₂L with Cu(OAc)₂ · H₂O led to the formation of a metal complex {[CuL] · H₂O · 2DMF}_∞ (1). In complex 1, the potential dinegative tridentate L²⁻ ligand acting as tetradentate bridging ligand coordinate to two metal ions so as to form a novel infinite metal-organic coordination chain structure. The enantiomerically pure ligand H₂L presents two different sets of signals in the ¹H NMR spectrum either in chloroform solution or in dimethylsulfoxide solution, showing the presence of both (E) and (Z) isomers. The X-ray structural investigations of H₂L revealed that it is the fully extended E-configuration in the solid state.     

Four three-dimensional lanthanide coordination polymer constructed from benzene-1,4-dioxydiacetic acid

Four crystalline lanthanide(III) three-dimensional (3D) coordination polymers {[La(BDOA)_1.5(H₂O)] · H₂O}_n (1), {[Nd(BDOA)_1.5(H₂O)] · H₂O}_n (2), [Tm(BDOA)_1.5(H₂O)]_n (3), [Yb(BDOA)_1.5(H₂O)]_n (4) were obtained under hydrothermal conditions and characterized by elemental analysis, IR, as well as single-crystal X-ray diffraction. Compounds 1 and 2 crystallize in the monoclinic system, space group P2₁/c, they are isostructural and exhibit the same 3²¹.4⁵⁷.5¹³ topological network constructed from different coordination modes of two BDOA ligands, whereas isostructural 3 and 4 crystallizes in the triclinic system, space group , it holds 3⁹.4²⁰.5⁷ topological architecture based on another two different coordination modes BDOA ligands. Moreover, a computational method is applied to evaluate the potential porosity of complex 1.     

Squarato-bridged polymeric networks of iron(II) with N-donor coligands: Syntheses, crystal structures and magnetic properties

Two new squarato-bridged Fe(II) polymeric networks of molecular formula [Fe(squarate)(bpp)₂(H₂O)₂] (1) and [Fe(squarate)(bpee)(H₂O)₂] (2) [bpp = 1,3-bis(4-pyridyl)propane; bpee = 1,2-bis(4-pyridyl)ethylene; ] have been synthesized and characterized by single-crystal X-ray diffraction studies and low temperature (300-2 K) magnetic measurements. Complex 1 is a 1D coordination chain of Fe(H₂O)₂ units connected by μ-O,O″ squarate dianions with monocoordinated bpp ligands dangling from the polymer. These 1D chains ultimately transform to a thick 2D layer through π-π interaction of pyridyl rings as well as through hydrogen bonds. Whereas structural determination of complex 2 reveals an inclined interpenetrated 3D architecture. Magnetic data for both the complexes 1 and 2 have been fitted using the Fisher formula for S = 2 system and show antiferromagnetic coupling for both the complexes. The best fit parameters are J = −0.40 cm⁻¹, g = 2.30 and R = 0.01 for complex 1 and J = −0.49 cm⁻¹, g = 2.08 and R = 1.9 × 10⁻³ for complex 2.     

Luminescent cadmium and zinc diphenate coordination polymers containing pyridyl-piperazine type ligands: Grids, diamondoid lattices, and a rare 4-connected net

Hydrothermal synthesis has afforded five d¹⁰ configuration divalent metal diphenate coordination polymers containing pyridyl-piperazine type ligands, which were structurally characterized by single-crystal X-ray diffraction. {[Cd(diphenate)(3-bpmp)(H₂O)]·0.5H₂O}_n (1, 3-bpmp = bis(3-pyridylmethyl)piperazine) has a double layer topology. Its perchlorate-containing analog {[Cd₃(diphenate)₄(H₂3-bpmp)(H3-bpmp)(H₂O)₂](ClO₄)·7H₂O}_n (2) possesses a very rare 4-connected 6⁵8 dmp topology based on anionic trinuclear nodes. {[Cd(diphenate)(4-bpfp)]·H₂O}_n (3, 4-bpfp = bis(4-pyridylformyl)piperazine) manifests a non-interpenetrated diamondoid lattice, while the related compound [Cd(diphenate)(4-bpmp)(H₂O)]_n (4, 4-bpmp = bis(4-pyridylmethyl)piperazine) has a simple (4,4) grid topology. {[Zn(diphenate)(4-bpmp)]·0.5H₂O}_n (5) displays a 2-fold interpenetrated diamondoid lattice. Luminescent properties of these materials are also reported.     

A comparative study of ferrocenyl carboxylate cadmium(II) complexes prepared by two different synthetic methods

Reaction of ferrocenyl carboxylate H₂bfcs with Cd(Ac)₂ · 2H₂O (H₂bfcs = 1,1′-bis(3-carboxy-1-oxopropyl)ferrocene) gives the mononuclear tetrahydrate precursor Cd(Hbfcs)₂(H₂O)₄ (1). Investigation on the substitution reactions of 1 with imidazole or 2,2′-bpy afforded two one-dimensional (1D) complexes {[Cd₂(bfcs)₂(C₃H₄N₂)₆] · 4H₂O}_n (2) and {[Cd(bfcs)(2,2′-bpy)(H₂O)] · 2H₂O}_n (4) (2,2′-bpy = 2,2′-bipyridine), respectively. However, the one-step reactions of H₂bfcs, Cd(Ac)₂ · 2H₂O with imidazole or 2,2′-bpy result in the formation of two different 1D complexes {[Cd(bfcs)(C₃H₄N₂)₂] · CH₃OH · 2H₂O}_n (3) and [Cd(bfcs)(CH₃OH)]_n (5). It can be seen from the results that applying different synthetic routes produce dissimilar complexes from however the same materials and under the same reaction conditions. In addition, investigations of differential pulse voltammetry of these four 1D complexes indicate that their half-wave potentials are slightly higher than that of H₂bfcs.     

Two-dimensional oxides constructed from octamolybdate clusters and M/tetrapyridylpyrazine subunits (M = Co, Ni: n = 2; M = Cu: n = 1)

The hydrothermal reactions of MoO₃, tetra-2-pyridylpyrazine (tpyprz) and M(CH₃CO₂)₂ · 2H₂O (M = Co, Ni) yielded the two-dimensional oxides [M₂(tpyprz)(H₂O)₂Mo₈O₂₆] · xH₂O [M = Co, x = 1.8 (1); M = Ni, x = 0.6 (2)]. However, the reaction of (NH₄)₆Mo₇O₂₄ · 4H₂O, tpyprz and Cu(CH₃CO₂)₂ · H₂O produced [{Cu₂(tpyprz)}₂Mo₈O₂₆] · 2H₂O (3 · 2H₂O). The isomorphous structures of 1 and 2 are constructed from clusters linked through {M₂(tpyprz)(H₂O)₂}⁴⁺ subunits into two-dimensional networks. While the structure of 3 is also two-dimensional, the molybdate building block is present as the δ-isomer and the secondary-metal/ligand component consists of a one-dimensional chain. The structure of 3 is compared to that of the previously reported three-dimensional material [{Cu₂(tpyprz)}₂Mo₈O₂₆] · 7H₂O which contains clusters and structurally distinct chains.     

Solvothermal syntheses and structural characterization of a series of metal-hydroxycarboxylate coordination polymers

The combination of transition metal ions with mixed ligands resulted in the formation of three new coordination polymers, {[Co(C₄H₄O₅)(bpe)(H₂O)₂] · (0.5bpe)(H₂O)}_n (1), {[Cu(C₄H₄O₆)(bipy)] · 5H₂O}_n (2) and {[Cu(C₄H₄O₅)(bpa)] · 2.5H₂O}_n (3) (, , bpe = 1,2-bis(4-pyridyl)ethene, bipy = 2,2′-bipyridine, bpa = 1,2-bis(4-pyridyl)ethane), which were prepared under solvothermal conditions and characterized by single-crystal X-ray diffraction. 1 and 2 feature 1D chain structures. Interestingly, each pair of chains recognizes each other through aromatic π-π stacking interactions, generating a zipper-like double-stranded chain in 2. Compound 3 shows 2D 6³ topology framework with a rectangle-like grid.     

Crystal structure, thermal stability and theoretical investigation on four 1,3-bis(1,2,4-triazol-1-yl)propane-based copper(II) complexes

Self-assembly of flexible 1,3-bis(1,2,4-triazol-1-yl)propane (btp), inorganic Cu(II) salt and rigid benzene-based carboxylate coligand generates four complexes, {[Cu(btp)₂(CH₃OH)(H₂O)]·H₂O·2ClO₄}_n (1), {[Cu(btp)(Hbtc)₂]·0.5H₂O}_n (2), [Cu(btp)₂(H₃btea)₂]_n (3), and [Cu(btp)(nb)₂] (4) (H₃btc = 1,3,5-benzenetricarboxylic acid, H₄btea = 1,2,4,5-benzenetetracarboxylic acid, Hnb = p-nitrobenzoic acid), which are fully structural characterized by single-crystal X-ray crystallography, elemental analysis, IR, and TG-DTA techniques. Structural determinations reveal that the polymeric two-dimensional (2D) Cu-btp grid-like layer for 1, 1D linear single- and double-stranded chains for 2 and 3, as well as the discrete binuclear structure for 4, are jointly directed by the coordination polyhedrons of the Cu(II) ion and the exo-bidentate bridging btp core ligand with various conformations. The theoretical calculations suggest that the trans-trans btp is the most stable conformation, and the metal binding site is collectively determined by the electron density of N donors and the spatial orientation of the btp ligand. Unexpectedly, the polycarboxylate anions in 1-4 can only act as terminal coligands not popular bridging connectors. The thermal stability of the resulting complexes is also compared.     

Cd(II) coordination polymers constructed from flexible disulfide ligand: Solvothermal syntheses, structures and luminescent properties

Four novel coordination polymers, [Cd(Hdtbb)(dtbb)_0.5(DMF)]_n (1), {[Cd(dtbb)(2,2′-bpy)(H₂O)]·2DMA}_n (2), {[Cd₂(dtbb)₂(1,4-bix)₂]·3DMF}_n (3) and [Cd(dtbb)(1,4-btx)]_n (4) [H₂dtbb = 2,2-dithiobisbenzoic acid, 2,2′-bpy = 2,2′-bipyridine, 1,4-bix = 1,4-bis(imidazol-1-ylmethyl)benzene, 1,4-btx = 1,4-bis(triazol-1-ylmethyl)benzene] have been synthesized and structurally characterized. Complexes 1 and 2 possess one-dimensional (1D) infinite structures. The structures of complexes 3 and 4 exhibit two dimensional (2D) frameworks, which mainly due to the differences in the bridging modes of dtbb²⁻ ligand and the effect of the N-donor auxiliary ligands. The infrared spectra, thermogravimetric and luminescent properties were also investigated for these compounds.     

Syntheses, structures and luminescence of a series of Cd(II)-containing coordination polymers constructed from a long flexible bis-triazole ligand

Six novel Cd(II) coordination polymers based on 4,4′-bis(1,2,4-triazol-1-ylmethyl)biphenyl (btmb), namely, [Cd(btmb)₂I₂]_n (1), [Cd(btmb)I₂]_n (2), {[Cd(btmb)₂(NO₃)₂]·H₂O}_n (3), {[Cd(btmb)₂(SCN)₂]·3H₂O}_n (4), {[Cd(btmb)(CH₃COO)₂(H₂O)]·CH₃CN}_n (5) and [Cd(btmb)Cl₂(H₂O)]_n (6) have been synthesized by the reactions of btmb with Cd(II) salts in the presence of different anions (I⁻, , NCS⁻, CH₃COO⁻ or Cl⁻) under appropriate reaction conditions. The assemblies of btmb with CdI₂ afford two different structures: two-dimensional (2D) rhombohedral grid layer network structure 1 and 2D layer structure 2 involved with one-dimensional (1D) linear cadmium chains. Treatment of btmb with Cd(NO₃)₂·4H₂O gives rise to a 2D grid network structure 3 which is similar to 1. When the I⁻ or NO₃⁻ anions were replaced by NCS⁻, CH₃COO⁻ or Cl⁻, different 1D coordination polymers 4-6 were obtained, respectively. Polymer 4 displays a 1D double-chain structure, while both polymers 5 and 6 show 1D zigzag chain structures. In addition, the luminescence measurements reveal that polymers 1-6 exhibit different fluorescent emissions in the solid-state at room temperature, which can be attributed to the various coordination environments of Cd(II), solvent molecules and different packing interactions in these polymers.     

In situ 5-sulfosalicylate decarboxylation or dimethylformamide hydrolysis generating supramolecular assembly architectures

Six transition-metal complexes, {[Co(4,4′-bipy)(H₂O)₄](Hbs)₂ · 3H₂O}_n (1), [Mn(4,4′-bipy)₂(H₂O)₄](Hbs)₂ · 2H₂O (2), {[Mn(HCOO)(H₂O)₂(4,4′-bipy)]₂[Mn(4,4′-bipy)(Hssal)₂(H₂O)₂]}_n (3), [Cd(4,4′-bipy)₂(H₂O)₄](Hbs)₂ · 2H₂O (4), {[Cd₃(CH₃COO)₄(4,4′-bipy)₄](Hbs)₂ · 10H₂O}_n (5), and {[Cd(HCOO)(H₂O)₂(4,4′-bipy)]₂[Cd(4,4′-bipy)(Hssal)₂(H₂O)₂]}_n (6), have been synthesized by hydrothermal or reflux synthetic method and characterized by single-crystal X-ray diffraction, IR, elemental analysis, thermogravimetric analysis and fluorescence analysis, where Hssal²⁻ is doubly deprotonated 5-sulfosalicylate, Hbs⁻ is 4-hydroxybenzenesulfonate and 4,4′-bipy is 4,4′-bipyridine. The structural analyses showed that all of the six complexes are cation-anion species containing in situ synthesized ligands, Hbs⁻ or HCOO⁻, and the former arises from the decarboxylation of 5-sulfosalicylic acid under the hydrothermal conditions. The formate anions derived from the hydrolysis of DMF. A series of supramolecular compounds show that the structural diversity is strongly associated with their properties.     

Mononuclear manganese(III) catechol compounds as substrate adduct complexes for manganese-substituted intradiol cleaving catechol dioxygenases

The complexes [Mn(L₁)(tcc)] (1), [Mn(L₂)(tcc)] · H₂O · 0.5CH₃OH (2), [Mn(L₃)(tcc)] · CH₂Cl₂ (3), [Mn(L₄)(tcc)] · 1.5CH₂Cl₂ (4), [Mn(L₅)(tcc)] (5), and (HN(C₂H₅)₃)[Mn(L₆)(tcc)] · CH₂Cl₂ (6) have been synthesized using the ligands HL₁ (2-[(bis(pyridin-2-ylmethyl)amino)methyl]phenol), HL₂ (2-[[((6-methylpyridin-2-yl)methyl)(pyridin-2-ylmethyl)amino]methyl] phenol), HL₃ (2-[[((6-methylpyridin-2-yl)methyl)(pyridin-2-ylmethyl)amino]methyl]-4-nitrophenol), HL₄ (2-[(bis(pyridin-2-ylmethyl)amino)methyl]-4-bromophenol), HL₅ (2-[(bis(pyridin-2-ylmethyl)amino)methyl]-6-methoxyphenol) and H₂L₆ ([(bis(2-hydroxy-5-nitrobenzyl))(pyridin-2-ylmethyl)]amine) and characterized by X-ray crystallography, mass spectrometry, IR, UV-Vis spectroscopy, cyclic voltammetry, and elemental analysis. Compounds 1 and 6 crystallize in the monoclinic space groups P2₁/n and P2₁/c, respectively, whereas the crystal structures of complexes 2, 3, and 4 were solved in the triclinic space group . Complex 5 crystallizes in the orthorhombic space group P2₁2₁2₁. Complexes 1-6 are structural related to the proposed active site of intradiol cleaving catechol dioxygenase exhibiting a distorted octahedral N₃O₃ (1-5) and N₂O₄ (6) donor set, respectively. Complexes 1-6 can be regarded as structural manganese analogous for substituted forms of iron-containing intradiol cleaving catechol dioxygenases, where the substrate tetrachlorocatechol (tcc) is asymmetrically bound to the metal center.     

Triaminoguanidine derivatives as supports to construct magnetic assemblies: Synthesis and characterization of trinuclear nickel(II) complexes

The synthesis of two nickel(II) complexes based on a central bridging triaminoguanidine scaffold and a capping ligand per metal ion is reported. When 2,2′-bipyridine (bipy) is utilized as co-ligand the complex [Ni₃L^Br(bipy)₃(H₂O)₃]NO₃ · 9H₂O · 1.5DMF (1) is obtained which crystallizes in the hexagonal space group P6₃/m. Complex 1 shows an interesting supramolecular structure pattern with alternating hydrophilic and hydrophobic layers characterized by extensive hydrogen-bonding and π-π-stacking, respectively. With 2,4,6-(2-pyridyl)-1,3,5-triazine (tptz) as capping ligand, complex [Ni₃L^Br(tptz)₃]ClO₄ · 7H₂O · 1.5DMF (2) is obtained. The magnetic susceptibility data can be fitted using an equilateral triangle model () with an isotropic coupling constant of J=-31.0±0.6 for 1 and for 2.     

Structural and magnetic characterization of one-dimensional oxalato-bridged metal(II) complexes with 4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole ligand: A supramolecular open-framework

A new family of one-dimensional oxalato-bridged metal(II) complexes with formula {[M(ox)(abpt)]·4H₂O}_n [M^II = Mn (1), Fe (2), Co (3), Zn (4); ox = oxalate dianion; abpt = 4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole] has been synthesized and chemically, structurally and magnetically characterized. The crystal structures of compounds 2-4 have been solved by single crystal X-ray diffraction, whereas complex 1 has been studied by means of X-ray powder diffraction methods. All of them are isomorphous and crystallize in the triclinic space group P. The metal atoms are bridged by bis-bidentate oxalate anions forming zig-zag chains in which bidentate chelating abpt ligands complete the octahedral O₄N₂ donor set. The crystal structures show an open-framework that contains rectangular channels in which easily removable hydrogen bonded ribbons of water molecules are located. The occurrence of antiferromagnetic intrachain interactions for compounds 1-3 was determined by cryomagnetic susceptibility measurements.     

Influence of coanions on construction of copper(II)/4,4′-dipyridyl sulfide(dps) coordination polymers

The influence of coanion on self-assembly of CuSO₄ and 4,4′-dipyridyl sulfide (dps) was studied in this paper. During the formation of Cu(II)/dps coordination polymers, coanions Cl⁻, SCN⁻ and were added in the solution respectively. Three novel coordination polymers were obtained, {[Cu(dps)₂ · (SO₄)₂][Cu(dps) · Cl · (H₂O)₂]₂ · 12H₂O}_n (1 · 12H₂O, a 3D network), {[Cu(SCN)₂(dps)(CH₃OH)₂][Cu(dps)₂ · SO₄][Cu(dps)(CH₃CH₂OH)₂ · SO₄] · 5H₂O}_n (2 · 5H₂O, a 3D network), and {[Cu(dps)₂(H₂O)₂] · (PF₆)₂ · 3H₂O}_n (3 · 3H₂O, a 2D lattice network). Different coanion shows different influence on framework construction. In 1 and 2, Cl⁻ and SCN⁻ act as terminal ligands and similar 3D frameworks were composed of [Cu(dps)] layer with larger cavity (ca. 400 Å) and sulfate bridge; in 3, replaces entirely and the 3D framework was broken due to the removal of bridging anions. However, a 2D [Cu(dps)]₄ undulating grid was preserved in 3.     

Synthesis, crystal structures and properties of novel zinc(II) and cadmium(II) polymeric and cyclic bimetallic complexes with fluconazole and dicarboxylate co-ligands

Four new fluconazole-bridged zinc(II) and cadmium(II) complexes with dicarboxylate co-ligands, namely [Zn(HFlu)(TPA)]_n (1), {[Cd(HFlu)₂(TPA)]·2CH₃OH}_n (2), [Zn(HFlu)₂(Suc)(H₂O)₂]·H₂O (3), and [Cd(HFlu)₂(Suc)(H₂O)₂]·H₂O (4), have been synthesized and characterized by elemental analysis, IR, TG, and single-crystal X-ray diffraction (HFlu = 2-(2,4-difluorophenyl)-1,3-bis(1,2,4-triazol-1-yl)-propan-2-ol, H₂TPA = terephthalic acid, and H₂Suc = succinic acid). Complex 1 displays a 2-D corrugated network with common (4,4) topology, in which two types of grids constructed by two bridging TPA dianions and two HFlu ligands are found. Complex 2 shows an unusual (3,6) coordination layer consisting of alternative PMPM Cd-HFlu helical chains in which the Cd(II) nodes are also fixed by terephthalate dianions in a cis fashion. The isostructural complexes 3 and 4 have 20-membered dimeric macrocyclic motifs with the Zn···Zn and Cd···Cd distances of 11.258(2) and 11.528(2) Å, respectively. The fluorescence and thermal stability of complexes 1-4 have also been investigated.     

Construction of several d metal coordination polymers based on aromatic polycarboxylate and flexible triazole-based ligand

To investigate the effect of organic anions on the coordination frameworks, we synthesized five new complexes, namely, {[Zn₃(μ-OH₂)₂(btc)₂(btx)₃]·4H₂O}_n (1), [Zn(bdc)(btx)]_n (2), {[Ag₈(3,5-pydc)₄(btx)₄]·8H₂O}_n (3), [Ag(2,6-Hpydc)(btx)]_n (4) and [Cd₂(μ₂-OH₂)(2,6-pydc)₂(btx)]_n (5) (H₂bdc = 1,4-benzenedicarboxylic acid; H₃btc = 1,3,5-benzenetricarboxylate; 3,5-H₂pydc = pyridine-3,5-dicarboxylic acid; 2,6-H₂pydc = pyridine-2,6-dicarboxylic acid), which were obtained by the reactions of 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (btx) as main ligand, and several aromatic polycarboxylate as organic anions with different d¹⁰ metal salts. Single crystal structure analysis shows that complexes 1, 3 and 5 possess 3D structures, 2 takes a 2D layer motif, and 4 displays a 1D chain structure. The distinct structures indicate that polycarboxylate anions with the diverse coordination modes and coordination groups can affect the topologies of metal-organic frameworks. In addition, the luminescence measurements reveal that the complexes 1, 2 and 5 exhibit strong fluorescent emissions in the solid state at room temperature.