Unusual metal–organic network constructed from Zn(II), benzenetricarboxylate and bis(1,2,4-triazolyl)pyridine

Hydrothermal reaction of ZnSO₄ · 7H₂O with 1,3,5-benzenetricarboxylic acid (H₃btc) and 2,6-bis(1,2,4-triazolyl)pyridine (btp) afforded a novel metal–organic network {[Zn₃(btc)₂(btp)₂(H₂O)₂] · 4H₂O}_n (1) with a supramolecular cocrystal [H₃btc · btp · H₂O]_n (2). The complex 1 exhibits an unusual network containing two molecular squares and a rectangle. The networks interpenetrate to make a 3D metal–organic framework, which is quite thermal stable. Compound 2 shows a 2D supramolecular network assembled through strong hydrogen bonds.     

A new 3D pillared-layer porous framework with intersecting open channels in the Co/triazolate/carboxylate system: Synthesis,structure and magnetism

A new Co(II) coordination polymer, namely [Co₆(btc)₄(dtb)₂(H₂O)₃]_n (1) (H₃btc = 1,3,5-benzenetricarboxylic acid, dtb = 1,3-di-(1,2,4-triazole-4-yl)benzene), has been synthesized by combining the mixed ligands of H₃btc and dtb with Co(Ac)₂·4H₂O under solvothermal conditions. Single-crystal X-ray diffraction analysis reveals that 1 feature a 3D open framework with intersecting channels based on Co-btc^3 − layers and btc^3 − and dtb pillars. The magnetic property of the complex has also been investigated at room temperature.     

Synthesis,structure, and adsorption properties of a three-dimensional porous yttrium–organic coordination network

Deprotonation of 4,4′-biphenyldicarboxylic acid (H₂BPDC) with triethylamine followed by the copolymerization with Y(III) in N,N-dimethylformamide (DMF) at room temperature yields a new three-dimensional (3-D) porous metal–organic coordination network, [Y₂(BPDC)₃(DMF)₂(H₂O)₂]_n · (DMF)_n · (H₂O)_n (1). Compound 1 (C_24.50H₁₉N_1.50O₉Y) crystallizes in the triclinic P-1 space group (a = 8.220 (2), b = 13.998 (4), c = 14.212 (4) Å, α = 111.058 (5)°, β = 90.187 (5)°, γ = 94.318 (5)°, V = 1520.9 (7) ų, and Z = 2). X-ray crystallography reveals that 1 consists of a 3-D framework contained open 1-D channels with the dimension of 5 × 10 Å along the crystallographic a axis. The adsorption measurements show that compound 1 can adsorb N₂, Ar and CO₂ into its pores. The adsorption isotherms for MeOH and H₂O were also measured.     

Two highly connected frameworks and one polythreading architecture based on multidentate N-donor ligands: Syntheses,structures, characterizations and photoluminescent properties

Three coordination polymers based on multidentate N-donor ligands and polycarboxylate anions, namely, [Co₃(4,4′-tmbpt)₄(btc)₂]·9.5H₂O (1), [Ag₄(4,4′-tmbpt)(btec)(H₂O)₂]·H₂O (2) and [Zn(4,4′-tmbpt)(btec)_0.5(H₂O)]·0.5H₂O (3) (4,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(4-pyridyl)-1,2,4-triazole, H₃btc = 1,3,5-benzenetricarboxylic acid, and H₄btec = 1,2,4,5-benzenetetracarboxylic acid) have been prepared under hydrothermal condition. Compound 1 displays a 3D (3,6,8)-connected framework with (4·6²)(4⁴·6¹⁰·8)(4¹⁴·6¹²·8²) topology. Compound 2 is a 3D (4,5,8)-connected framework with (4³·6²·8)(4³·6⁵·8²)(4⁸·6²)(4¹⁰·6¹⁰·8⁸) topology. Compound 3 exhibits a 2D → 3D polythreading architecture. The photoluminescent spectra indicate that at room temperature, compounds 2 and 3 emit green and blue luminescence, respectively.     

A rare 2D coordination polymer of graphite-like structure extended by infinite silver–oxygen–silver bonds

The reaction of AgNO₃ and H₃btb (H₃btb = 1,2,3-benzenetricarboxylic acid) leads to the isolation of {[Ag(μ₂-H₂O)(μ₂-H₂btb)]}_n · 1.5nH₂O (1), which crystallizes in the orthorhombic space group Fddd with a = 11.436(2) Å, b = 6.876(1) Å, c = 58.837(1) Å, V = 4626.5(2) Å³, Z = 32. Silver ions are connected by both strong Ag?Ag interaction and μ₂-H₂O bridges to form hexagonal Ag₆ subunits, and are further assembled into a high ordered 2D grid, presenting an interesting graphite-like 6³ net. Both the fluorescence and the crystal transformation after dehydration are studied.     

A 3D Cu(II) coordination polymer constructed from BIBP (BIBP = 5,5′-bis(1H-imidazol-1-yl)-2,2′-bithiophene) ligand with semiconductive property

Hydrothermal reaction of Cu(NO₃)₂·3H₂O with BIBP and H₂hfipbb at 105 °C yielded a novel 3D Cu(II) coordination polymer, {[Cu₂(BIBP)_0.5(hfipbb)₂(CH₃CN)]·5H₂O}_n (1) [BIBP = 5,5′-bis(1H-imidazol-1-yl)-2,2′-bithiophene, H₂hfipbb = 4,4′-(hexafluoroisopropylidene)bis(benzoic acid)]. Compound 1 displays a 3D 2-fold interpenetrating framework with {4⁴.6⁶} sqp topology, containing interesting ⋯LRLR⋯ double helical chains. The compound 1 was characterized by IR spectra, elemental analysis, thermal analysis and single crystal X-ray diffraction. In addition, solid-state UV–vis spectra experiment shows that compound 1 exhibits semiconductive property with a band gap of 2.46 eV.     

Novel lanthanide coordination polymers with Eu-compound exhibits warm white light emission: Synthesis,structure, and magnetic properties

Five two-dimensional lanthanide coordination polymers: [Ln₂(TDA)₃(bipy)₂(H₂O)₂]·bipy·2H₂O (Ln = Nd (1), Sm (2), Eu (3), Tb (4), Yb (5), TDA = thiophene-2,5-dicarboxylic acid anion, bipy = 2,2′-bipyridine) were fabricated and structurally characterized. Compounds 1–5 are isostructural belonging to the triclinic system with space group P-1. Luminescence analyses were performed on coordination polymers containing Eu^3 + and Tb^3 +, and compound 3 shows a warm white light emission upon excitation.     

Two CdII-containing coordination polymers based on trinuclear and dodecanuclear clusters

Two new metal-organic coordination polymers, namely, [Cd₃(Tipa)₂(1,2,3-btc)₂]·2H₂O·0.5(C₂H₅OH) (1) and [Cd₆(Tipa)₂(1,2,3-btc)₄(H₂O)₃]·3H₂O (2), where 1,2,3-btc = benzene-1,2,3-tricarboxylic anion and Tipa = tris(4-(1H-imidazol-1-yl)phenyl)amine, have been synthesized under hydrothermal conditions with Cd(AcO)₂, CdCl₂ or CdSO₄. Single-crystal X-ray structure analysis reveals that compounds 1–2 show different three dimensional (3D) frameworks based on trinuclear and dodecanuclear cadmium clusters, respectively. For compound 1, the Tipa ligands bridge the trinuclear cadmium clusters in bi-dentate and tri-monodentate modes to give a 3D (3,6)-connected framework with the short Schläfli symbol of (6²·4)(6¹²·4³). For compound 2, all Tipa and 1,2,3-btc ligands connected dodecanuclear cadmium clusters to generate a rare 3D uninodal ten-connected topology with the short Schläfli symbol of 3¹²·4²⁸·5⁵. Moreover, the infrared spectra, elemental analyses, thermogravimetric analysis, and luminescent properties for the two compounds were also investigated.     

Influence of symmetric benzene–polycarboxylate acids on the structures of silver-aminopyrimidyl derivative system

Two novel coordination polymers, [Ag(BTC)_1/3(ADMP)]_n (1), [Ag(BDC)_1/2(ADMP)]_n (2) (2-amino-4,6-dimethylpyrimidine = ADMP; H₃BTC = 1,3,5-benzenetricarboxylic acid; H₂BDC = 1,4-benzenedicarboxylic acid), have been synthesized under the ammoniacal conditions and structurally characterized. In complex 1, H₃BTC ligand showing a new coordination mode links silver atoms to generate a two-dimensional (2-D) honeycomb-like structure, which is further linked through ADMP ligands to produce a complicated three-dimensional (3-D) framework. Complex 2 features a 2-D infinite layer framework consisting of binuclear silver clusters, which is further stacked via intermolecular C_methyl–H?π short contacts and Van der Waals interactions to form a 3-D supramolecular architecture.     

Six-, seven- and eight-coordinated Cd(II) ions with N-heterocyclic multicarboxylic acids

Two novel cadmium complexes [Cd₃(pta)₂(H₂O)₄]_n (1) (H₃pta = 2,4,6-pyridinetricarboxylic acid) and {[Cd(H₂pza)(H₂O)₂] · 2H₂O}_n (2) (H₄pza = 2,3,5,6-pyrazinetetracarboxylic acid) were synthesized. In both complexes, Cd(II) ions show three different coordination numbers of six and seven in 1 and eight in 2, respectively. Complex 1 displays a three-dimensional network structure and 2 shows a one-dimensional chain structure. The one-dimensional chains in 2 are vertical or parallel to each other and form a three-dimensional network structure by hydrogen bonds. In addition, 1 emits intense fluorescence on excitation of 342 nm.     

Two different Zn(II) interpenetrating networks derived from different dicarboxylate ligands mixed with a flexible imidazole-based ligand

Two interpenetrating networks based on 1,4-bis(2-methylimidazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene (bmimx), namely, {[Zn₂(bmimx)₂(cba)₂]·2.5H₂O}_n (1) and {[Zn(bmimx)(suc)]·2H₂O}_n (2) (H₂cba = 4,4′-carbonyldibenzoic acid, H₂suc = succinic acid) have been prepared at hydrothermal condition by varying the dicarboxylate ligands. Single-crystal X-ray diffraction indicates that complex 1 shows a 4-connected dmp net with 3-fold interpenetration which contains 1D (Zn − cba)_n right- and left-handed helical chains; complex 2 shows a dia topology with 4-fold interpenetration. The results indicate that the spacers of dicarboxylate coligands have an important effect on the interpenetrating characters and ultimate frameworks. Moreover, the photoluminescence properties of the two complexes were studied in the solid state at room temperature.     

Structures and photoluminescence of coordination polymers assembled from bifunctional ligand containing both tetrazole and imidazole groups

Three new coordination polymers, namely, {[Cu₂(IPT)(SO₄)(OH)(H₂O)]·H₂O}_n (HIPT = 5-(4-(1H-imidazol-1-yl)phenyl)- 1H-tetrazolate, 1), {[Cd₂(IPT)(NPA)(OH)]·H₂O}_n (H₂NPA = 5-nitroisophthalic acid, 2), and {[Zn₂(IPT)(IDC)(H₂O)]·3H₂O}_n (H₃IDC = 1H-imidazole-4,5-dicarboxylic acid, 3), were assembled from a bifunctional organic ligand containing both tetrazole and imidazole groups with/without the aid of carboxylate coligands. Compound 1 possesses 2D structure built by 1D [Cu₂(IPT)(SO₄)(OH)]_n secondary building blocks and IPT⁻ linkers. The 2D networks are linked into 3D supramolecular framework via water chains in helical conformation. Compound 2 displays 3D pillar-layer framework with 2D layers based on tetranuclear Cd(II) SBUs and NPA^2 − pillars. Compound 3 exhibits a 3D framework constructed from the interconnection of 1D [Zn-IDC]_n chains and binuclear Zn₂(IPT)₂ rings. The thermal stabilities of porous compound 3 and luminescent properties of compounds 2 and 3 have also been studied in detail. They exhibit intense solid-state fluorescent emissions at room temperature.     

Two new 3-D coordination polymers with 5-tert-butyl isophthalic acid and flexible N-donor co-ligands bearing linear trinuclear secondary building blocks

Two new 3-D coordination polymers bearing linear trinuclear secondary building blocks with mixed bridging ligands, {[Ni₃(tbip)₂(Htbip)₂(bib)₂]·4H₂O}_n (1) and {[Co₃(tbip)₂(Htbip)₂(btb)₂]·4H₂O}_n (2) (H₂tbip = 5-tert-butyl isophthalic acid, bib = 1,4-bis(imidazol-1-yl)butane, btb = 1,4-bis(1,2,4-triazol-1-yl)butane), were obtained and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single-crystal X-ray crystallography and powder X-ray diffraction. Both complexes 1 and 2 display similar 3D 6-connected pcu networks containing the linear trinuclear [M₃(COO)₆] (M = Ni and Co) clusters as nodes.     

Co-existence of heterometallic Zn2Er and ZnEr arrayed chromophores for the sensitization of near-infrared (NIR) luminescence

With the Zn-Schiff-base [ZnL(Py)] from the simple Salen-type Schiff-base ligand H₂L (H₂L = N,N′-bis(salicylidene)ethylene-1,2-diamine) as the precursor, two co-crystallized heterometallic (Zn₂Ln and ZnLn array) complexes [Zn₂Ln(L)₂(Py)₂(NO₃)₂]·[ZnLn(L)(Py)(NO₃)₃(H₂O)]·NO₃·mMeOH·nS (Ln = Er(1), S = CH₃CN, m = 2, n = 1 or Gd(2), S = H₂O, m = 1, n = 3) were obtained by the further reaction with Ln(NO₃)₃·6H₂O, respectively. The result of their photophysical properties shows the intramolecular effective energy transfer has been demonstrated in the Zn₂Er and ZnEr arrayed complex 1, and the co-existence of different chromophores should be a potentially new way to the fine-tuning properties of NIR luminescence from Er³⁺ ions.     

Template-assisted assembly of porous lanthanide coordination polymers with 2-aminoterephthalic acid

Porous lanthanide coordination polymers, {[Ln₂(atpt)₃(H₂O)₂] · 0.5(4,4′-bpy)(H₂O)}_n [Ln = Eu(1), Gd(2), Yb(3), H₂atpt = 2-aminoterephthalic acid, 4,4′-bpy = 4,4′-bipyridine] were obtained by hydro-solvothermal reaction, in which 4,4′-bpy acts as template. For the first time the nitrogen atom of an atpt ligand coordinates to metal ions in 1–3. The photophysical properties and thermal stability of 1 were investigated.     

Three-dimensional 3d–4f heterometallic coordination polymer containing Sm2Mn4 clusters: Synthesis,crystal structure and properties

Heterometallic coordination polymers of the form {[SmMn₂(imdc)₂(OAc)(H₂O)]·2H₂O}_n (1) (H₃imdc = 4,5-imidazoledicarboxylic acid, HOAc = acetic acid) were hydrothermally synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The results reveal that 1 has a three-dimensional framework containing Sm₂Mn₄ clusters. The luminescence and magnetic properties of 1 were also investigated.     

An organic–inorganic hybrid nickel-substituted arsenotungstate consisting of three types of polyoxotungstate units

A new organic–inorganic hybrid nickel-substituted arsenotungstate [Na(H₂O)₃]₂[Ni(H₂O)₆]₂[Ni(H₂O)₅]{[Ni₃(dap)(H₂O)₂]₂(H₂W₄O₁₆)}{(α-H₂AsW₆O₂₆)[Ni₆(OH)₂(H₂O)(dap)₂](B-α-HAsW₉O₃₄)}₂·7H₂O (1) (dap = 1,2-diaminopropane) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Crystal data for 1: C₁₈H₁₄₄As₄N₁₂Na₂Ni₂₁O₁₇₆W₃₄, Mr = 11174.92, triclinic, space group P-1, a = 15.004(4) Å, b = 16.357(5) Å, c = 22.070(6) Å, α = 80.458(5)°, β = 79.291(5)°, γ = 72.074(5)°, V = 5030(3) Å³, Z = 1, GOOF = 1.007, R₁ = 0.0703, wR₂ = 0.1670. The skeleton of 1 is a centric nanoscale cluster and is composed of two asymmetric sandwich-type clusters {(α-H₂AsW₆O₂₆)[Ni₆(OH)₂(H₂O)(dap)₂](B-α-AsW₉O₃₄)}^7? linked by a symmetric cluster {[Ni₃(dap)(H₂O)₂]₂(H₂W₄O₁₆)}⁶⁺. Notably, 1 is an interesting polyoxometalate containing the trivacant Keggin [B-α-AsW₉O₃₄]^9?, hexavacant Keggin [α-AsW₆O₂₆]^11? and tetrameric [W₄O₁₆]^8? units. Magnetic measurements indicate that 1 shows the ferromagnetic interactions within Ni^II centers.     

Hydrothermal synthesis and characterization of ternary lanthanide-2,2′-bipyridine-3,3′-dicarboxylate coordination polymers

Two lanthanide coordination polymers, [{Ln₂(bpdc)₃(phen)₂(H₂O)₂} · (H₂O)₆]_n (Ln = Dy (1); Ho (2)) were obtained from 2,2′-bipyridine-3,3′-dicarboxylic acid (H₂bpdc), 1,10-phenanthroline (phen) and corresponding lanthanide oxides by hydrothermal synthesis. Polymers 1–2 are found to be isostructural. Single-crystal X-ray diffraction shows that 1–2 are all one-dimensional zigzag chain structures and extend to two-dimensional networks through π–π interactions and hydrogen bonds. Thermogravimetric analysis of 1–2 displays a considerable thermal stability. The variable-temperature magnetic susceptibility of both compounds was measured. Photoluminescence measurement indicates that 1 is a strong yellow emitter.     

1D chain lanthanide coordination polymers with 6-hydroxynicotinic acid: Crystal structures and luminescent properties

Four new lanthanide coordination polymers {[Ln(HL)₂(H₂O)₅] · HL ·  H₂O}_n (Ln = Sm for 1, Eu for 2, Tb for 3 and Dy for 4) (H₂L = 6-hydroxynicotinic acid) have been synthesized and characterized by elemental analysis, FT-IR spectra and X-ray single-crystal diffraction. They all exhibit 1D chain structure, which are further linked via hydrogen bonds to form 3D supramolecular architecture. Luminescent properties of these lanthanide coordination polymers are studied.     

A rare twofold interpenetrating NbO mixed-ligand mesomeric network from two individual heterochiral 3D frameworks

A novel 3D NbO metal-organic framework, [Cd₂(pam)₂(bpt)₂(H₂O)]_n·0.68nH₂O (1) (H₂pam = pamoic acid and bpt = 2,5-bis(4-pyridyl)-1,3,4-thiadiazole), has been synthesized by the structural cooperation of well-chosen flexible aromatic acid and rigid bipyridyl ligand. The rare severely distorted mixed-ligand mesomeric networks accommodate two individual heterochiral frameworks interpenetrating with each other. The bulk materials of 1 display excellent fluorescent properties.