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.     

Fluorescent selectivity for small molecules of two coordination polymers based on a tetracarboxylate ligand

Two coordination polymers [Cd(tptc)_0.5(4,4′–bibp)]_n (1) and {[Zn₃(Htptc)₂(phen)₂]·1.5H₂O}_n (2) (H₄tptc = terphenyl-3,3″,5,5″-tetracarboxylic acid, 4,4′-bibp = 4,4′-bis(imidazolyl)biphenyl, and phen = 1,10-phenanthroline) were synthesized under solvothermal conditions. Complex 1 displays a 3D structure with a Schläfli symbol of {4⁴.6²}{4⁸.6²⁰}. Complex 2 possesses a 2D layer network, incorporating [Zn₃(COO)₆] second building units (SBUs), which is packed into a 3D supramolecular architecture by π ⋯ π interactions. Both of them exhibit strong luminescence characteristics. It is worth to note that complexes 1 and 2 show potential application to detect small organic molecules.     

Syntheses,structures and magnetic property of two copper complexes with cyclic dimer and 2D herringbone-like network built from helical motif

Two copper(II) complexes, Cu₂{3,5-(NO₂)₂sal}₂(2,2′-bipy)₂ · 0.5H₂O (1) and [Cu₂{3,5-(NO₂)₂sal}₂(4,4′-bipy)(H₂O)₂]_n (2) (3,5-(NO₂)₂sal = 3,5-dinitrosalicylate, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), were synthesized by hydrothermal reactions and characterized by single crystal X-ray analysis. There are discrete cyclic binuclear structure in 1 and 2D herringbone-like network structure in 2, although bridging ligand 3,5-(NO₂)₂sal in 1 and 2 has same coordination model. Variable temperature magnetic measurement reveals small ferromagnetic interactions in complex 1.     

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 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.     

A 2D brickwall architecture from a double-T-shaped ligand and hybrid coordinatively unsaturated copper: Synthesis,structure, and framework dynamic

A double-T-shaped ligand (H₄BPTC) as the spacer has been first used to direct the assembly of a 2D coordination polymer with brickwall network topology, [Cu₂(BPTC)(Im)₄(H₂O)(DMF)]_n (1) (DMF = N,N-dimethylformamide, H₄BPTC = Biphenyl-3,3′,4,4′-tetracarboxylic acid, Im = imidazole), which exhibits an interesting framework dynamic upon de-/resolvation.     

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.     

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.     

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.     

Synthesis and characterization of nickel phosphonopropionate hybrid materials

Hydrothermal reaction of nickel acetate with 3-phosphonopropionic acid and 4,4′-bipyridine resulted in two novel phosphonate compounds Ni(HO₃PC₂H₄COO)(4,4′-bpy)(H₂O) · 0.5(4,4′-bpy) (bpy = bipyridine) (I) and Ni(O₃PC₂H₄COOH)(4,4′-bpy)(H₂O)₃ · H₂O (II). Single-crystal X-ray studies reveal that self-assemblies between the ligands and metal ion result in layer (I) and chain (II) structures. Magnetic measurement of I indicate there are ferromagnetic couplings between adjacent Ni²⁺ ions (C = 1.29 cm³ mol⁻¹ K and θ = 2.25 K).     

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.     

Synthesis,characterization and crystal structure of one Mn(II) complex with 4,4′-bisimidazolylbiphenyl and 4,4′-sulfonyldibenzoic acid

One new title compound [Mn₃(BIBP)(sdb)(NO₂⁻)₂(H₂O)₂]_n·2DMF (1) (BIBP = 4,4′-bisimidazolylbiphenyl, sdb = 4,4′-sulfonyldibenzoic acid) has been synthesized under hydrothermal condition. The title compound was characterized by IR spectra, thermal analysis, single crystal and powder X-ray diffraction. Magnetic susceptibility measurements indicate that compound 1 exhibits antiferromagnetic coupling interaction.     

Assembly of an eight connected porous Cd(II) framework with octahedral and cubo-octahedral cages: Sorption and luminescent properties

An eight connected 3D porous coordination polymer, {[Cd(BTC)_0.66(BPz)₂] · 6H₂O}_n (1) (BTC = benzene-1,3,5-tricarboxylic acid, BPz = 3,3′,5,5′-tetramethyl-4,4′-bipyrazole) has been synthesized from hydrothermal reaction of Cd(NO₃)₂ · 4H₂O with BPz and BTC. Complex 1 is a thermally stable microporous MOF having cubo-octahedral and octahedral cages as the Supermolecular Building Block (SBB) with an eight connected reo topology. It shows moderate N₂ sorption (101 cm³ g^− 1) at 77 K with a BET surface area of 330 m² g^− 1. Complex 1 also exhibits photoluminescent property in solid state with λ_max at 397 nm.     

Hydrothermal synthesis and structure of di-copperII-complex substituted monovacant polyoxotungstate with a 1D chain structure

A novel di-copper^II-complex substituted monovacant Keggin polyoxotungstate [Cu(2,2′-bpy)(H₂O)][H₂PW₁₁O₃₉Cu₂(2,2′-bpy)₂(H₂O)(OH)] · 1.5H₂O (1) (2,2′-bpy = 2,2′-bipyridine) with a 1D polymeric chain has been hydrothermally synthesized and structurally characterized. To our knowledge, 1 is the rare magnetic di-transition metal-complex substituted monovacant Keggin polyoxotungstate with a unique 1D dual-bridging chain structure. Its magnetic behavior has been quantitatively analyzed by the Bleaney–Bowers equation, indicating the presence of weak antiferromagnetic interactions within dinuclear Cu^II centers.     

Three d10 coordination polymers based on rigid ligands with flexible functional groups: Syntheses,structures and luminescence

Three coordination polymers, namely, {[Zn(L)(BPY)]·DMF·H₂O}_n (1), {[Zn(L)(TPY)]·0.5H₂BDC·H₂O}_n (2), {[Cd(L)(H₂O)₂]·DMF}_n (3), have been synthesized based on a rigid linear carboxylate ligand (H₂L = 2′,5′-dimethoxy-[1,1′:4′,1″-terphenyl]-4,4″-dicarboxylic acid) and different lengths of pyridine ligands (TPY = 4,3′:5′,4″-terpyridine; BPY = 4,4′-bipyridine). These complexes have been characterized by single crystal X-ray diffraction, infrared spectroscopy, thermogravimetry, elemental analysis, and powder X-ray diffraction measurements. Complex 1 is a 6-connected 3-fold interpenetrating pcu net with point symbol {4¹² ∙ 6³}, 2 and 3 can be simplified as 4-connected sql nets with point symbol {4⁴ ∙ 6²}. In addition, their photoluminescent properties are also investigated in detail.     

Polycatenation and photoluminescence of two zinc coordination polymers based on arched and linear mixed ligands

Two polycatenated coordination polymers, {[Zn₃(adc)₃(bpp)₄]₂ · 3H₂O}_n (1) and [Zn(adc)(bphy)]_n (2) (adc = azobenzene-4,4′- dicarboxylate, bpp = 1,3-bis(4-pyridyl)propane, bphy = 1,2-bis(4-pyridyl)hydrazine), have been obtained from Zn(NO₃)₂∙ 6H₂O, linear H₂adc ligand and arched bpp/azpy (azpy = 4,4′-azobispyridine) ligands by hydro(solvo)thermal reactions. Compound 1 presents a 2-D structure catenated from 1-D double ladders (1-D → 2-D polycatenation), while compound 2 displays a 3-D structure catenated from 2-D (4,4) stair-stepping layers (2-D → 3-D polycatenation). Luminescence properties of 1 and 2 have been explored, together with study of photoluminescent mechanism by density of states (DOS) calculation.     

Two Mn(II)–Au(I) supramolecular assemblies bonded by coordination,aurophilicity and hydrogen-bonding, π–π interactions and their magnetic properties

Two Mn(II)–Au(I) supramolecular assemblies {{Mn[Au(CN)₂]₂(H₂O)₄} [Au(CN)₂]₂(H₂bpy) · H₂O}(bpy = 4,4′-bipyridine) 1 and {Mn(4,4′-dmbpy) [Au(CN)₂]₂(CH₃OH)} (4,4′-dmbpy = 4,4′-dimethyl-bipyridine) 2 have been synthesized and magnetic properties have been investigated The interplay of aurophilicity, coordination, hydrogen-bonding and π–π interactions in two complexes result in three-dimensional network.     

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.     

Two d10 coordination polymers based on 4,4′-(hexafluoroisopropylidene)diphthalic acid: Syntheses,structures and physical properties

Two novel coordination polymers, [Zn₂(FA)(4,4′-bipy)₂]·2H₂O (1) and Cd₂(FA)(2,2′-bipy) (2), (H₄FA = 4,4′-(hexafluoroisopropylidene)diphthalic acid, 4,4′-bipy = 4,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine), have been synthesized under hydrothermal conditions, and their structures were determined by single-crystal X-ray diffraction. Polymer 1 features an unusual three-dimensional (3D) network with (4 · 6² · 8³)(4² · 6² · 8²) topology. Polymer 2 has a complicated 3D framework and crystallizes in non-centrosymmetric space group (Fdd2) belonging to polar point group (C_2v), which displays a strong SHG response and ferroelectric properties. Moreover, the luminescent properties of 1 and 2 have also been investigated.     

Gas sorption studies on a highly-thermostable microporous Zn(II) coordination polymer constructed from 2D honeycomb layers

By combining experiment with molecular simulation, the CO₂ sorption performance of a 2D honeycomb layered coordination polymer, {[Zn₂(bpydb)₂(H₂O)₂](DMA)₃(H₂O)}_n (1) (bpydb = 4,4′-(4,4′-bipyridine-2,6-diyl) dibenzoate) was systematically investigated. The desolvated 1 not only shows high CO₂ capacity (72.5 cm³/g at 273 K and 42.9 cm³/g at 298 K) with a moderate high zero-coverage adsorption enthalpy (29.7 kJ/mol), but also exhibits excellent CO₂/N₂ selectivity around room temperature. To better understand the adsorption behaviors and adsorption sites for CO₂ in 1, GCMC simulations were carried out, which indicate that the open metal sites between two adjacent layers account for the high CO₂ sorption capacity and strong CO₂ binding ability. Moreover, the thermal stability of 1 was further confirmed by the TGA and VT-PXRD, which indicate that 1 could be thermally stable up to 400 °C.