Two novel supramolecular isomers based on 2,2′-biimidazole derivative and zinc ions: Syntheses,structures and luminescent properties

Two Zn(II)-2,2′-biimidazole derivative supramolecular isomers 1 and 2 formulated as [Zn(L)] · 2H₂O (H₂L = 4,4′-(1H,1′H-2,2′-biimidazole-1,1′-diylbis(methylene))dibenzoic acid) have been synthesized, and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography. Complex 1 exhibits a 2D four-connected network with (4³.6³) topology when the zinc center and the L^2? ligand act as four-connected nodes (or a distorted (4,4) grid if the [Zn₂(imidazole)₄] units are considered as four-connected nodes). Complex 2 shows a novel four-connected twofold interpenetrated net with (4².6².8²) topology when the zinc center and the L^2? ligand act as four-connected nodes (or a twofold interpenetrated α-Po topology when [Zn₂(imidazole)₄] units are identified as six-connected nodes). Moreover, complexes 1 and 2 both exhibit strong luminescent properties at room temperature.     

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.     

PMMA-supported near-infrared (NIR) luminescent hybrid materials doped with Zn2Ln2-arrayed Schiff-base complexes

For a series of 4,4′-bpe-linked Zn₂Ln₂-arrayed Schiff-base complexes [Zn₂(L)₂Ln₂(4,4′-bpe)(NO₃)₆] (Ln = La, 1; Ln = Nd, 2; Ln = Yb, 3; Ln = Er, 4 or Ln = Gd, 5), degradative chain transfer of the central CC double bond from 4,4′-bpe within restrains their effective copolymerization with MMA, while PMMA-supported doped hybrid materials PMMA@[Zn₂(L)₂Ln₂(4,4′-bpe)(NO₃)₆] are obtained, respectively. Their physical properties show that thermal-stability and film-forming properties are distinctively improved while NIR luminescent properties can be retained.     

A three-dimensional open framework constructed by rod SBUs and T-shaped linkers

A metal-coordination polymer [Co₄(BPTC)₂(H₂0)₈]^.13H₂O (1, BPTC = 3,3′4,4′-benzophenone-tetracarboxylate) containing nano-sized channels was hydrothermally synthesized. It has remarkable 3D architecture generated by unique rod-shaped SBUs(SBUs = Secondary Building Units) linked up by T-shaped ligands and present a novel constructional strategy of 3D porous metal-organic framework. One-dimensional water pipes are formed in the channels, which further stabilize the 3D framework.     

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 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.     

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.     

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).     

Solvothermal synthesis,crystal structure and photoluminescent property of a novel 3D cadmium(II) coordination polymer containing [Cd5(μ3-OH)2(μ3-OAc)2]6+ cores

A novel 3D coordination polymer, {[Cd₅(μ₃-OAc)₂(μ₂-OAc)₂(μ₃- OH)₂(pam)₂(4,4′-bpy)₂] · CH₃CH₂OH}_n (1) (H₂pam = pamoic acid, HOAc = acetic acid, 4,4′-bpy = 4,4′-bipyridyl), was solvothermally synthesized and characterized by the single crystal X-ray diffraction. The title compound contains unprecedented [Cd₅(μ₃-OH)₂(μ₃-OAc)₂]⁶⁺ pentanuclear building units which are linked through pam and 4,4′-bpy ligands to afford a three-dimensional structure. The infrared spectroscopy, thermal stability and photoluminescence of the complex were studied.     

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.     

Assembly of one 2D layer and two 3D pillared-layer structures derived from metal ions and 5-(pyridin-4-yl)isophthalic acid with or without pillars

Three new coordination polymers, [Mn(L)(H₂O)₂]₂·5H₂O (1), [Cu(L)(4,4′-bipy)]₂·H₂O (2) and [Pb(L)(4,4′-bipy)_0.5] (3) (H₂L = 5-(pyridin-4-yl)isophthalic acid; 4,4′-bipy = 4,4′-bipyridine) have been synthesized and characterized by IR, thermogravimetric analysis, X-ray powder diffraction and X-ray single crystal diffraction. Complex 1 shows a 2D layer structure which stacks with the other ones to form 1D channels to hold 1D water chains. Complex 2 displays a 3D + 3D → 3D polycatenation network. 3 shows a unique 2D + 2D → 3D polycatenation net in which each Pb center has a hemidirected coordination geometry due to the existence of “inert pair effect”. The thermal and luminescent properties of 1–3 were also examined.     

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.     

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.     

A novel three-dimensional cadmium(II) coordination polymer constructed from dinuclear molecular building block,syntheses, structure and photoluminescence property

A novel cadmium(II) coordination polymer, [Cd₂(pzdc)₂(4,4′-bpy)₂]·4H₂O (1) (H₂pzdc = pyrazine-2,3-dicarboxylic acid; 4,4′-bpy = 4,4′-bipyridine), has been synthesized by hydrothermal reaction of Cd(OAC)₂, H₂pzdc and 4,4′-bpy. Single-crystal X-ray diffraction analysis reveals that 1 constructed from dinuclear building blocks has a three-dimensional (3-D) structure with rob topology. Fluorescent measurement of 1 exhibits strong blue-green emission in the solid state at room temperature, and its framework possess remarkable thermal stability.     

Tuning structural topologies of two coordination polymers via alter N-donor auxiliary ligand

Based on the N-donor auxiliary ligand effect, two new Ni(II) coordination polymers [Ni₂(HL)₂(bpe)₂] (1) and [Ni(HL)(bipy)(H₂O)₂] (2) [H₃L = 2-(4′-carboxyphenyl)terephthalic acid; bpe = 1,2-bis(4-pyridyl)ethane; bipy = 4,4′-bipyridine] have been successfully synthesized and characterized by single-crystal X-ray diffraction study, elemental analysis, IR spectra, TGA and powder X-ray diffraction (PXRD). This work presents a comparative study on the tuning of structural topologies by using two N-donor ligands with different lengths as auxiliary ligands. The structural determination reveals that complex 1, incorporating bpe ligands, features a three-dimensional (3D) 4-connected 4-fold dia interpenetrating architecture with the point symbol of 6⁶, while 2, containing bipy ligands, exhibits a two-dimensional (2D) sql layer structure with a 4-connected (4⁴·6²) topology. Moreover, the magnetic properties for 1 and 2 were also measured and compared on account of their different structures.     

A new lamellar solid trapping water clusters and intercalated organosulfonate guests

The synthesis and X-ray crystal structure of a lamellar framework with water clusters and organosulfonate guests trapped in the interlamellar region, [Co(H₂O)₂(4,4′-bpy)₂] · (ps)₂ · 10H₂O 1 (4,4′-bpy = 4,4′-bipyridine; Hps = pyridine-4-sulfonic acid), are presented. The structure is made up of cationic square-grid cobalt-4,4′-bipyridine layers with lamellar separation of ca. 8 Å, which is comparable to the hydrotalcite-like solids. The structure also contains intercalated charge-compensating ps⁻ anions and water molecules defining it a hydrotalcite analog.     

Synthesis,crystal structure and third-order non-linear optical properties of two-dimensional supramolecular polymer [Co2(μ2-4,4′- bipy)2(μ2-be)2(be)2]n

Two-dimensional (2D) metal-organic supramolecular polymer [Co₂(μ₂-4,4′-bipy)₂(μ₂-be)₂(be)₂]_n 1 (4,4′-bipy = 4,4′-bipyridine, be = benzoate) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, TGA, IR spectra and UV–visible spectra. The 2D structure is built from the linkage of secondary building units of binuclear [Co₂(μ₂-4,4′-bipy)₂(μ₂-be)₂(be)₂] clusters by a mixed connector of 4,4′-bipyridine and benzoate. The third-order non-linear optical (NLO) properties of the 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 8.30 × 10⁻³⁰ esu for 1 in a 2.70 × 10⁻⁴ mol dm⁻³ DMF solution.     

Selective sensing of 2,4,6-trinitrophenol and detection of the ultralow temperature based on a dual-functional MOF as a luminescent sensor

A novel 3D Cd(II) MOF, {[Cd(Ccbp⁻)(4.4′-bpy)·H₂O]·(ClO₄⁻)·2H₂O} (1), (Ccbp⁻ = 3-carboxy-1-(4-carboxybenzyl)pyridin-1-ium, 4.4′-bpy = 4.4′-bipyridine), has been successfully synthesized and characterized. Complex 1 possesses a 3D 4-fold interpenetrating dia network with a pyridine cation basic skeleton. This Cd-MOF 1 can be applied as the first potential dual-functional luminescent sensing material for high selective and recyclable sensing of 2,4,6-trinitrophenol and quantitatively detecting the ultralow temperature from 10 to 60 K.     

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.     

Synthesis,crystal structure and photoluminescent properties of a 3D Zn(II) coordination polymer

A new 3D coordination polymer [NH₂(CH₃)₂]₂[Zn₇L₄(DMF)₂(H₂O)₃]·19H₂O (1) (L = 2,3′,5,5′-biphenyl tetracarboxylic acid) has been solvothermally synthesized and structurally characterized by IR, elemental analysis and single-crystal X-ray diffraction. Single-crystal X-ray diffraction studies indicate that 1 exhibits 3D framework with a one-dimensional (1D) channel. The luminescence properties have been studied, and the results showed that 1 displays strong fluorescent emissions both in the solid state and in methanol suspension at room temperature. More interesting, the addition of Fe^3 + causes the fluorescence intensity of 1 to be weakened, which implies that it may be used as luminescent probes of Fe^3 +.