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.     

An unusual 3D three-fold parallel interpenetrating network self-assembled from the grid-containing 2D layer motifs

The new complex {[Cu(dde)(bpe)] · H₂O}_n (1) (dde = 4,4′-dicarboxydiphenyl ether, bpe = 1,2-bis(4-pyridyl)ethene) has been synthesized and characterized. It exhibits a novel (2D → 3D) three-fold parallel interpenetrating architecture that is obtained for the first time from the self-assembly of grid-containing 2D (4, 4) layer motifs. The fluorescent property of 1 is discussed.     

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.     

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.     

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.     

Two stacked 2Dchiral/2Dchiral → 2Dachiral sheets based on V-shaped imidazolyl ligand and flexible aliphatic acids

Two new stacked 2D_chiral/2D_chiral → 2D_achiral coordination polymers {[Cd(BIDPE)(pim)]·(H₂O)}_n (1) and {[Cd(BIDPE)(glu)]·(H₂O)}_n (2) were prepared under hydrothermal conditions based on V-shaped ligand 4,4′-bis(imidazol-1-yl)diphenyl ether (BIDPE) and flexible polycarboxylic acids. In addition, the solid-state photoluminescent spectra were measured at room temperature.     

A pair of nonporous homochiral cobalt-based coordination polymers for enantioselective recognition and electrocatalysis

A pair of nonporous enantiomers [Co(H₂O)(bpy)(L-Mand)]•H₂O•Cl (L-1) and [Co(H₂O)(bpy)(L-Mand)]•H₂O•Cl (D-1) (L-Mand = L-Mandelic acid, D-Mand = D-Mandelic acid, bpy = 4,4′-bipyridine) with 3D supermolecule framework possess excellent enantioselective recognition and electrocatalysis ability towards L- and/or D-tart.     

1D lead(II) coordination chains with carboxylate containing ligands. A rare example of polyrotaxane 1D → 1D interpenetrated coordination polymer

The structural determination of two interesting lead(II) coordination polymers, namely [Pb(ind)₂(H₂O)]_n (1) and [Pb₂(dbsf)₂(bipy)]_n (2) (Hind = indane-2-carboxylic acid, H₂dbsf = 4,4′-sulfonyldibenzoic acid, and bipy 4,4′-bipyridine), reveals in the second an unexpected polyrotaxane 1D → 1D interpenetrated coordination polymer thanks to the hemidirected coordination geometry of the metal and the rings formed by the dicarboxybiphenyl sulfone ligands along the 1D chain.     

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).     

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.     

An unprecedented 3D honeycomb-shaped cobalt phosphonate containing sixfold helical chains: Synthesis,crystal structure and thermal stability

A new cobalt(II) phosphonate, [Co(aepa)(4,4′-bpy)(H₂O)₂]·2H₂O 1 (H₂aepa = 2-aminoethylphosphonic acid) has been hydrothermally synthesized and characterized by IR, elemental analysis, TGA and single crystal X-ray diffraction analysis. Compound 1 features a 3D alveolate network structure originating from the intertwist of the rare sixfold 1D helical chains, which are assembled from the coordination of the aepa^2? ligands to the cobalt atoms.     

An unusual 2-fold interpenetrated 3D PtS framework containing circular and rhombic tubular building blocks and hydrogen-bonded –O–metal–O–chain

Circular and rhombic tubular building blocks interweave mutually into a novel 2-fold interpenetrated 3D PtS framework [Zn(ADB)(H₂O)]_n (1) (H₂ADB = azobenzen-4,4′-dicarboxylic acid), with hydrogen-bonded–O–metal–O–chain. In additional, solid-state properties such as photoluminescence and thermal stability of the complex 1 have also been studied.     

An uncommon 3D Co5-cluster-based metal-organic framework: Synthesis,structure and magnetism

A highly connected metal–organic framework (MOF), namely, [Co₅(μ₃-OH)₂(iapt)₄(4,4′-bipy)_0.5(H₂O)·CH₃CN·3H₂O] (1) (H₂iapt = 5-aminoisophthalic acid and 4,4′-bipy = 4,4′-bipyridine), is reported. 1 shows a complicated pentanodal 4,4,4,4,13-c 3D net with (4³)(4³)(4³)(4³)(4²⁰·5¹⁴·6²³·7⁸·8¹³) topology based on an uncommon Co₅ cluster. The magnetic analysis reveals antiferromagnetic interactions in 1, and both the local spin–orbit coupling of octahedral Co(II) ions and the antiferromagnetic interactions are the primary factors in the magnetic behaviour.     

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.     

Diverse architectures of hybrid materials induced by different mixed-ligands and applications in luminescence

For investigating the effects of different azacyclo-assisting ligands and O-donor bridging ligands on the structural construction, three different structural complexes, namely, {Zn(DBTA)(phen)(H₂O)}_n (1) (DBTA = 2, 5-Dibromo-terephthalic acid, phen = 1,10-Phenanthroline), [Zn(DBTA)(bimb)]_n (2) (bimb (1,4-bis(imidazole-1-ylmethyl)benzene) and {[Zn₂(bmimb)(PO₄)₂]·(H₂O)₂}_n (3) (bmimb = 1,2-bis(methylimidazole-1-ylmethyl) benzene) have been constructed by different mixed-ligands and Zn atoms. Their structures have been characterized by single-crystal X-ray diffraction analysis, elemental analysis, and Infrared spectroscopy. Complex 1 exhibits a common 2D layer with 4,4-connected topology. Complex 2 features an interesting 2-fold interpenetrating net with the aid of long-chain flexible azacyclo-assisting ligands. Complex 3 shows 3D supramolecular architecture with tetranuclear water cluster filling in the pores. Their fluorescence properties were also measured.     

Absolute helicity of 1D chains influenced by enantiopure ligands

Two novel coordination polymers, [Cd(D-1-Hcam)(nta)(H₂O)₂]₂[Cd(D-3-Hcam)(nta)(H₂O)₂]₂·4H₂O (1) and [Cd(DL-Hcam)(nta)(H₂O)₂]·H₂O (2) (D-1-Hcam/D-3-Hcam = monodehydrated d-camphoric acid, Hnta = nicotinic acid and DL-Hcam = monodehydrated dl-camphoric acid), have been synthesized under hydrothermal conditions. Complex 1 is a three-dimensional hydrogen bonding framework composed of two kinds of 1D helical chains which exhibit the same right-handed helix, whereas complex 2 is constructed with one kind of 1D racemic chains. Interestingly, both two chiral molecules in the structures play important roles in the absolute helicity although they are not in the backbones of the helix which are made of rigid achiral ligands. Furthermore, different coordination modes of chiral ligands regulated the fluorescent emission.     

Three 3D Cu(II) coordination polymers constructed from 1,2,4,5-benzenetetracarboxylate acid and three positional isomeric ligands

Based on 1,2,4,5-benzenetetracarboxylate acid (H₄btc), and mixed with three isomeric dipyridyl ligands, three novel 3D Cu(II) coordination polymers [Cu₂(btc)(4,4′-bpt)]·2H₂O (1) [4,4′-bpt = 1H-3,5-bis(4-pyridyl)-1,2,4-triazole], [Cu(btc)_0.5(3,4′-bpt)]·0.5H₂O (2) [3,4′-bpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4- triazole] and [Cu(btc)_0.5(3,3′-bpt)]·2H₂O (3) [3,3′-bpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole] have been synthesized and characterized, respectively. 1 is a 3D pillared double-layer complex containing a novel bilayer unit; 2 is a 3D pillared-layer architecture with (4,4)-sql layer; 3 exhibits a 3D structure containing 3D [Cu(btc)]_∞ motif and 1D [Cu(bpt)]_∞ chain. The topological analysis shows that 1 can be simplified to a (4,6)-connected network with the Schläfli symbol of (4²·6⁴)₂(4⁸·6⁷), 2 a (4,6)-connected network with the symbol of (4⁴·6²)(4⁴·6¹⁰·8), and 3 a four-connected topology with the symbol of (3²·10³·11)₂(3²·10⁴).     

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.     

Hydrothermal synthesis of a novel microporous framework sustained by polycatenated [CuI2(ip)(4,4′-bipyridine)]n (ip = isophthalate) ladders

A novel ladder coordination polymer [Cu^I₂(ip)(4,4^′-bipyridine)] · 3.5H₂O (1) (ip=isophthalate) was prepared via redox reaction under hydrothermal conditions and characterized by single-crystal X-ray diffraction analysis. In the crystal structure of 1, each ring of the ladder is interlocked by two different, symmetry-related ladders, and the polycatenation of ladders forms a 3D network with rhombic channels clathrating water molecules.     

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.