Construction of a new 3D Zn(II) coordination polymer with (4,6)-connected topology: Synthesis,structure and luminescence

A new coordination polymer of {[Zn₂(odpa)(IP)]·4H₂O}_n (1) (H₄odpa = 3,3′,4,4′-oxydiphthalic acid and IP = 1-H-imidazo[4,5-f][1,10]-phenanthroline), is reported. The 3D (4,6)-connected {4⁴∙6²∙8⁸∙12}{4⁴∙6²} topology net is formed by IP and odpa ligands in 1. Interestingly, the IP ligand acts as a tridentate mode and extends the resulting 3D feature. The luminescence study indicates that the title compound emits bright red fluorescence.     

Two new luminescent Cd(II)/Zn(II) metal–organic frameworks for exceptionally selective detection of picric acid explosives

Two new coordination polymers, {[Cd(BIDPT)(oba)]·0.5H₂O}_n (1) and {[Zn(BIDPT)(4,4′-sdb)]·2.25H₂O}_n (2) (BIDPT = 4,4′-bis(imidazol-l-yl)diphenyl thioether, H₂oba = 4,4′-oxydibenzoic acid, 4,4′-H₂sdb = 4,4′-sulfonyldibenzoic acid), have been solvothermally synthesized and characterized. Both 1 and 2 show 2-fold interpenetrating 3D frameworks with {6⁵ ∙ 8} cds and {6⁶} dia topology, respectively. These two coordination polymers show strong luminescence and their luminescence could be quenched by a series of nitro explosives. Importantly, they exhibit very highly sensitive and selective detection of picric acid compared to other nitro explosives.     

Two new isomeric complexes containing a well-resolved 1D water morph and (6, 3)-connected framework through hydrogen bonding interactions

Two new isomeric complexes, namely {[Cu(fum)(tpy)] · 5H₂O}_n (1) and [Cu₂(fum)₂(tpy)₂] · 4H₂O (2), have been synthesized simultaneously from the reaction of Cu(fum) with tpy (where fum = fumarate, tpy = 2,2′:6′,2″-terpyridine) under mild condition. The crystal structures of complexes were determined by X-ray single-crystal diffraction. Complex 1 stabilizes in an unusual 1D water tape notated T4(2)10(2), which is directed by two chiral helical water chains; binuclear complex 2 represents a complicated (6, 3)-connected framework via supramolecular interactions. Additionally, complex 1 exhibits weak ferromagnetic behavior.     

Syntheses,crystal structures,and magnetic studies of two cobalt(II) coordination polymers based on concurrent ligand extension

An ether bridged tetracarboxylic acid ligand, 5-(3′,4′-Dicarboxylphenoxy)-isophthalic acid (H₄L) was used to construct two Co(II) coordination polymers in presence of different nitrogen donor ligands such as 4,4′-bipyridine (4,4′-bpy) and 4,4′-bis(pyrid-4-yl)biphenyl (bpbp). The products formed under hydrothermal conditions are formulated as [Co₂L(4,4′-bpy)₂(H₂O)₃]_n (1) and {[Co(bpbp)₂(H₂L)]·H₂O}_n (2). The compounds were characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, and powder X-ray diffraction (PXRD) measurement. Compound 1 shows an intriguing (3,4,5)-connected 3D framework with a point symbol of (4² · 6² · 8²)(4² · 6⁵ · 8³)(6² · 8). Compound 2 is an unusual 3D supramolecular framework generated by the one-dimensional [Co(bpbp)(H₂L)]_n polymer chain. The magnetic properties of compounds 1 and 2 were examined, indicating antiferromagnetic interactions between the cobalt(II) ions in the temperature range of 2–300 K.     

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.     

Two new three-dimensional (3,4)-connected lanthanide (III) coordination polymers based on 2-(3-Pyridyl)-1H-imidazole-4, 5-dicarboxylate: Structures and luminescent properties

Two new lanthanide (III) coordination polymers, namely, {[Eu₃(μ₃-HPyIDC)₄]·Cl}_n, (1) and {[Tb₂(μ₃-HPyIDC)₂(μ₂-Ox) (H₂O)₂]·4H₂O}_n (2) (H₃PyIDC = 2-(3-Pyridyl)-1H-4, 5-imidazoledicarboxylic acid; Ox = oxalate), were successfully synthesized under hydro(solvo)thermal conditions and structurally characterized. Compound 1 displays a 3D framework with new (3,4)-connected {4.8.10}₄{4.8⁴.12}₂{4².8⁴} topology built by 3-connected μ₃-HPyIDC⁻ nodes and 4-connected metal ions. Compound 2 exhibits a rare (3,4)-connected dmc topology, in which μ₃-HPyIDC⁻ anions are 3-connected nodes and metal ions are 4-connected nodes. Moreover, the thermal stabilities and luminescence of compounds 1–2 were also investigated.     

A new 3D cobalt(II) complex with left- and right-handed helical channels

A new 3D complex, {[Co(btec)_0.5(imb)(H₂O)]∙1.5H₂O}_n (1) (imb = 2-(1H-imidazol-1-methyl)-1H-benzimidazole, H₄btec = 1,2,4,5-benzenetetracarboxylic acid) has been synthesized by solvothermal technique. X-Ray diffraction analysis indicates that complex 1 displays a 3D framework with left- and right-handed helical channels and very high porous, which can be simplified as a 4,4,4-connected 3D topology with a Schläfli symbol of (3² · 10³ · 11)(3² · 10⁴)(3² · 10³ · 11). Moreover, its IR spectra, PXRD patterns, thermogravimetric curves, and luminescent emissions were studied at room temperature.     

Amine-directed structural studies of four zinc metal-organic frameworks based on a novel phosphonocarboxylate ligand

A novel phosphonocarboxylic ligand, 4′-phosphonobiphenyl-3,5-dicarboxylic acid (H₄pbpdc), was synthesized to construct 4 zinc compounds, namely, {[Zn₃(pbpdc)₂·2R}_n (R = C₅H₁₂N for 1, C₄H₁₀N for 2 and C₆H₁₆N for 3) and {[Zn₂pbpdc]·C₆H₁₈N₃}_n(4), which were characterized by X-ray crystallography, elemental analysis, FTIR and TG. Structures 1 ~ 3 have the same 3-dimensional (3-D) frameworks with point symbol of {4.6.7³.8}₂{4².6.7².8}₂{4².6².7.8}₂{4².6².7²}. Structure 4 is constructed from a 6-connected metallic cluster and 3-connected phosphonocarboxylic building units resulting in a topology of flu-3,6-C2/c. The luminescent properties of compounds 1 ~ 4 and organic ligand were studied.     

Two novel cadmium(II) coordination polymers based on bis-functionalized ligand 4′-(4-carboxyphenyl)-2, 2′:6′, 2″-terpyridine

Two novel cadmium(II) coordination polymers [Cd(cptpy)₂]_n·nH₂O (1) with a 1D double chain structure and [Cd₂(cptpy)₂(ox)]_n·2.5nH₂O (2) with an interesting 3-connected uninodal six-fold interpenetrating ths network (Hcptpy = 4′-(4-carboxyphenyl)-2,2′:6′,2″-terpyridine, H₂ox = oxalic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, single crystal X-ray diffraction and fluorescence spectra.     

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.     

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.     

Novel silver(I) compounds assembled from hybrid ligands based on linear or T-shaped coordination environment

Two novel 1D compounds {[Ag₃(Hbptc)(bpa)₂]·H₂O}_n (1) and [Ag₂(H₂bptc)(bpp)₂]_n (2) (H₄bptc = 3,3′,4,4′-benzophenonetetracarboxylic acid, bpa = 1,2-bis(4-pyridyl)ethane and bpp = 1,3-bis(4-pyridyl)propane) were synthesized and structurally characterized. The crystal structures of compounds exhibit two kinds of ladder-like chains based on linear or T-shaped coordination environment of Ag(I). Fluorescence spectra of compounds 1 and 2 indicate the unusual intensity of fluorescent emission upon photoexcitation which may be attributed to ligand-to-metal charge transfer and Ag–Ag interactions.     

Conformational isomerism of a flexible fluorinated bis-pyridinecarboxamide ligand in the structural direction of two distinct layered CuII coordination polymers

Reaction of a flexible pyridinecarboxamide ligand N,N′-[(2,3,5,6-tetrafluoro-1,4-phenylene) bis(methylene)]bis(pyridine-4-carboxamide) (H₂tfpbbp) with Cu^II chloride or perchlorate affords two coordination polymers {[Cu(H₂tfpbbp)(tfpbbp)(H₂O)] · 2DMF · 4H₂O}_n (1) and {[Cu(H₂tfpbbp)₂(ClO₄)₂] · 3H₂O}_n (2). Both complexes have 2-D (4,4) layered networks extended by the exo-bidentate bridging ligands, which however consist of distinct [Cu–ligand]₄ meshes owing to the conformational difference of ligands. Their spectroscopic, thermal, and fluorescence properties have also been investigated.     

A 3D heterometallic Pb(II)-Na(I) coordination polymer as a sensitive and selective fluorescent sensor for detecting Fe3 +

A Pb(II)-Na(I) coordination polymer, {[Pb₃NaL₃](Me₂NH₂)₂(C₂H₅OH)_1.5(H₂O)_10.5}_n (1) (H₃L = 4,4′,4″-s-triazine-2,4,6-triyl-tribenzoic acid), was synthesized under solvothermal condition. This structure crystallizes in the orthorhombic system and shows a 3D pillar-layer network. Topologically, it shows complicate (3,4,5,6,7)-connected net with Schläfli symbol of (4²·6⁸·8⁹·10²)(4³·6²·8)₂(4³·6⁶·8)₂(4⁸·6⁶·8)(6³). Luminescent investigations reveal that 1 can detect Fe^3 + with relative high sensitivity and selectivity, and show broad linear range of 0–1000 μM, as well as low detection limits of 8.65 nM for Fe^3 +.     

Assembly of a pcu topological porous Cd-trimesate framework with free carboxylic acid group: Sorption and luminescent property

A six connected 3D porous coordination polymer {[Cd(HBTC)(BPz)]·3EtOH}_n (1) (H₃BTC = benzene-1,3,5-tricarboxylic acid, BPz = 3,3′,5,5′-tetramethyl-4,4′-bipyrazole) has been synthesized from mild solvothermal reaction of Cd(NO₃)₂·4H₂O with BPz and H₃BTC in ethanol. Complex 1 is a thermally stable microporous MOF having (Cd₂(COO)₂) as the secondary building unit (SBU) with a six connected pcu topology. The pores of the polymer are decorated with free COOH groups which show moderate N₂ sorption (38 cc g^− 1) at 77 K with a BET surface area of 129 m² g^− 1. Complex 1 also exhibited photoluminescent property in solid state with λ_max at 396 nm.     

Synthesis,structure and magnetic properties of a copper molybdate hybrid inorganic/organic solid with a novel 10-connected three-dimensional network topology

Hydrothermal reaction of CuCl₂, MoO₃, and 4,4′-dipyridylketone (4,4′-dpk) afforded green crystals of the mixed metal oxide phase {[Cu₂(MoO₄)₂(4,4′-dpk)(H₂O)]·H₂O}_n (1). According to single-crystal X-ray diffraction, {Cu₂O₂} dimers link into 1-D {Cu₂O₂(μ-H₂O)}_n chains via bridging aqua ligands. These chains form [Cu₂(MoO₄)₂(H₂O)]_n slabs via linkage through tetrahedral molybdate anions. In turn, the copper molybdate slabs are pillared through tethering 4,4′-dpk ligands into a 10-connected three-dimensional lattice with an unprecedented 3¹²4³⁰5²6 topology. Variable temperature magnetic data above 140 K were fit to the Curie–Weiss law, with C = 0.17 cm³ K/mol Cu and Θ = 70 K, indicating likely ferromagnetic coupling within the dinuclear kernels of 1; low temperature data points towards the possibility of interdimer antiferromagnetic interactions.     

Blue-green photoluminescent 5- and 10-connected metal 5-(4′-carboxy-phenyl)tetrazolate coordination polymers

Hydrothermal reaction of Zn/Cd salts, NaN₃ and 4-cyanobenzoic acid via in situ [2 + 3] cycloaddition generated two blue-green photoluminescent coordination polymers [Zn(cptta)(H₂O)] (1) and [Cd(cptta)(H₂O)] (2) (H₂cptta = 5-(4′-carboxy-phenyl)tetrazole). When only metal ions are considered as nodes, 1 shows rare 5-connected Shubnikov plane topological type and 2 has unprecedented 10-connected {3¹².4²⁴.5⁹} topological type.     

Binuclear, 2D grid and 3D interlocking coordination polymers based on 1,2,4,5-benzenetetracarboxylic acid and 4,4′-azobispyridine

Three new nickel(II) complexes [Ni₂(btec)(azopy)₂(H₂O)₈]·2H₂O (1), {[Ni(H₂btec)(azopy)(H₂O)₂]·(azopy)}_n (2) and {[Ni₄(btec)₂(azopy)₃(H₂O)₁₀]·8H₂O}_n (3) (H₄btec = 1,2,4,5-benzenetetracarboxylic acid; azopy = 4,4′-azobispyridine) have been synthesized by tuning the reaction temperature and the metal–ligand ratio. They were characterized by single-crystal X-ray diffraction and elemental analysis. 1 shows a binuclear structure, 2 exhibits a 2D grid, and 3 features an interesting 3D framework with (6³)(4.6²)(4².6².8²) topology formed by two types of interlocked 2D layers.     

Tunable photoluminescence of a dual-emissive zinc(II) coordination polymer with an in-situ generated tetrazole derivative and benzenetetracarboxyli

Hydrothermal reaction of the cyano-substituted derivative, NaN₃, ZnCl₂ and H₄PMA (H₄PMA = 1,2,4,5-benzenetetracarboxylic acid) yielded a dual-emissive coordination polymer: {[Zn₂(PMA)(tzmb)₂]∙6H₂O}_n (1) (tzmb = N-(tetrazolmethyl)-4,4′-bipyridinium). In 1, the μ₂-κN2,κN6 tzmb and μ₄-bridging PMA^4 − connect four-coordinated Zn(II) atoms to form a 2D (4,4)-connected topologic structure. The solid-state sample of 1 exhibits tunable blue-to-white-to-yellow photoluminescence (PL) upon variation of excitation wavelengths, and the PL appearance has been studied by the theoretical calculation.     

A new cadmium-organic framework fluorescent sensor for Al3 + and Ca2 + ions in aqueous medium

A new metal-organic framework (MOF), [Cd₂(bptc)(HCOO)]·NH₂(CH₃)₂·3H₂O (1), where H₄bptc = 3,3′,5,5′-biphenyltetracarboxylic acid, was obtained by solvothermal reaction. The topology of MOF 1 is a (5,8)-connected net with {4¹⁶ · 5⁸ · 6⁴}{4⁴ · 5⁶}₂ point symbol. MOF 1 shows high stability in aqueous solution. Luminescence study indicates that MOF 1 possesses selective turn-on luminescent sensing functions towards Al^3 + and Ca^2 + ions in aqueous solutions.