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.     

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.     

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.     

Synthesis,crystal structure and luminescence of novel two-dimensional interpenetrating frameworks

Two novel metal coordination polymers, [Zn(nic)(isonic)]_n (1) and [Cu(nic)(isonic)]_n (2) (H₂nic = nicotinic acid, H₂isonic = isonicotinic acid), have been hydrothermally synthesized and characterized by elemental analysis, IR, and single crystal X-ray diffraction. X-ray single-crystal structural analyses reveal that 1 and 2 are isomorphous, two-dimensional interpenetrating (4, 4) frameworks bridged by nic and isonic ligands, and further assembled into a three-dimensional supramolecular structure via π–π stacking interaction. Moreover, 1 displayed photoluminescent properties in the blue range at room temperature.     

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 2D metal–organic frameworks based on 2,2′-bibenzimidazole ligand with (6,3) net topology

Two 2D metal–organic frameworks (MOFs), {[Zn₄(Hbbim)₄(bbim)₂] 2H₂O}_n (1) and [Cd₂(Hbbim)₂(bbim)]_n (2) (H₂bbim = 2,2′-bibenzimidazole) were obtained by solvothermal reaction and characterized by single crystal X-ray diffraction analysis. Different metal ions, Cd(II)/Zn(II), adopt very different coordination geometries though two title compounds both have a 2D honeycomb network with (6,3) topology. The frameworks of compounds 1 and 2 are stable below 360 °C and 475 °C, respectively. Solid-state luminescent spectroscopy of compound 2 exhibits an emission peak at 407 nm.     

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.     

Blue emission of a 2D non-interpenetrated zinc coordination polymer constructed through saturated fatty acid ligand

We report a new non-interpenetrated 2D zinc coordination polymer, [Zn(AA)(BPHY)]_n (1) (H₂AA = adipic acid, BPHY = 1,2-bis(4-pyridyl)hydrazine), which is a mixed ligand complex. The solid-state sample of 1 exhibits tunable blue emission excited by UV light with the wavelengths from 320 nm to 380 nm. The luminescent mechanism of 1 has been studied by theoretical calculation.     

Syntheses and characterizations of two-dimensional polymers based on tetraimidazole tetraphenylethylene ligand with aggregation-induced emission property

Two new coordination polymers [Co(TIPE)(H₂O)₂]·Hbtc·CH₃CN·3H₂O (1) and [Cd(TIPE)_0.5(m-bdc)(H₂O)]·CH₃OH·H₂O (2) (TIPE = tetra(3-imidazoylphenyl)ethylene, H₃btc = 1,3,5-benzenetricarboxylate, m-H₂bdc = 1,3-benzenedicarboxylate) have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, IR, TGA, and PXRD. Furthermore, the luminescent properties of complexes 1, 2 and TIPE ligand have also been investigated in the solid at room temperature.     

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.     

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.     

Template-assisted self-assembly: Synthesis,structures, and magnetic properties of lanthanide(III)-cobalt(II) coordination complexes constructed with deprotonated 3,5-pyridinedicarboxylic acid ligand

Two new 3d-4f complexes, [LnCo(3,5-pdc)₂(3,5-Hpdc) (H₂O)₇]·H₂O (Ln = Gd 2, La 3; 3,5-pdcH₂ = pyridine-3,5-dicarboxylic acid), have been synthesized by the self-assembly of Ln(III) oxides, 3,5-pdcH₂ and the template molecule [Co(3,5-pdc)(H₂O)₅]·H₂O (1) under hydrothermal conditions. Heterometallic complexes 2 and 3 are isostructural with supracyclic units containing four Ln(III) ions and two Co(II) ions, in which Co(II) and Ln(III) are linked by the deprotonated 3,5-pdcH₂ ligands in three kinds of bridging modes. The weak antiferromagnetic coupling of complex 2 and 3 imply that the large 3,5-pdc bridges with the greater separation ( > 7 Å) cannot lead to long range magnetic ordering, the strength of d_n-f_n exchange coupling increasing with decreases the size of the lanthanide ion.     

Construction of three new mixed-ligand Zn(II) coordination polymers based on nitrogen-containing heterotopic ligands and carboxylate co-ligands

Reactions of Zn(II) salts, presynthesized 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and various carboxylate ligands result to three new coordination polymers (CPs), namely, [Zn₂[(IPT)₂(ox)]}_n (H₂ox = oxalic acid, 1), [Zn₂(IPT)₂(mNBDC)]_n (H₂mNBDC = 5-nitroisophthalic acid, 2), and [Zn₂(IPT)(CA)(H₂O)]_n (H₃CA = citric acid, 3). Compound 1 can be seen as constructed from 2D [Zn(IPT)]_n layers with (6,3) topology and pillared by ox^2 −. It is a 3D (3,4)-connected framework with InS topology. Compound 2 has 2D bilayer structure based on 2D [Zn(IPT)]_n single layer and mNBDC^2 − linkers. Compound 3 is a 3D pillar-layer framework built by Zn–CA bilayers and IPT⁻ pillars. The results showed that the coordination modes, configurations of IPT⁻, and the structure of carboxylate co-ligands have great influence on the structures of the final network. The choice of carboxylate can decide the result of CPs in Zn–IPT chains/net subunits plus carboxyl linkers or Zn–carboxylate chains/net subunits plus IPT⁻ linkers. The thermal stabilities and luminescent properties of selected compounds have also been studied.     

Three new d10 coordination polymers based on 2-(2-pyridyl)benzimidazole ligand: Synthesis,structures and properties

Three coordination polymers containing 2-(2-pyridyl)benzimidazole (PyHBIm) ligand, namely {[Zn₃(PyBIm)₃(PyHBIm)₂(tma)(H₂O)]?H₂O}_n (1), [Zn(PyHBIm)(oba)]_n (2), [Cd(PyHBIm)(oba)]_n (3), (tma = trimesate, oba = 4,4′-oxybis-(benzoate)), have been prepared through hydrothermal reaction. Compound 1 exhibits one-dimensional (1D) helical structure. However, compounds 2 and 3 display 1D meso-helical structure. These 1D structures are further assembled into three-dimensional (3D) networks through aromatic π–π stacking interactions and hydrogen bonding interactions. Moreover they all exhibit strong photoluminescence at room temperature and may be good candidates for potential luminescence materials.     

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.     

Synthesis and chemical reactivity of an Fe(III) metallacrown-6 towards N-donor Lewis bases

The iron(III) 18-azametallacrown-6 [Fe(ashz)(EtOH)]₆ (1) (ashz^3 − = trianionic derivative of N-acetylsalicylhydrazide), prepared upon reaction of [Fe₃(μ₃-O)(Piv)₆(H₂O)₃](Piv) (Piv = Bu^tCOO⁻) with H₃ashz, reacts with N-heterocyclic Lewis bases (B = pyridine, 4-methyl pyridine, 3-amino pyridine or imidazole), leading to the stable adducts [Fe(ashz)(B)]₆ (2 to 5, respectively) upon replacement of the labile ethanol ligand. All the compounds were characterized by elemental analysis, IR and ESI–mass spectroscopies and, for complexes 1 and the 3-amino pyridine adduct 4, also by X-ray crystallography. In both 1 and 4, the stereochemistry of the ligand imposes a propeller configuration of the metal cation which exhibits alternating Λ/Δ forms.     

Synthesis of diiron sulfur clusters containing thiolato-1,8-naphthalene imide ligand

Three diiron sulfur clusters containing thiolato-1,8-naphthalene imide ligand, [Cp*Fe(μ-4,5-S₂-ⁿBu-NMI)(μ-CO)FeCp*] (3a), [Cp′Fe(μ-4,5-S₂-ⁿBu-NMI)(μ-CO)FeCp′] (3b), [CpFe(ⁿBu-NMI-S)]₂ (4) (3a: Cp* = η⁵-C₅Me₅; 3b: Cp′ = η⁵-C₅HMe₄; 4: Cp = η⁵-C₅H₅; ⁿBu-NMI = N-butyl-1,8-naphthalene imide) were synthesized via the reaction of N-butyl-4,5-disulfide-1,8-naphthalene imide and [Cp2Fe(μ-CO)CO]₂ (Cp2 = Cp*, Cp′, Cp). A partially desulfurated product [CpFe(ⁿBu-NMI-S)]₂ was determined in the reaction of [CpFe(μ-CO)CO]₂ with ⁿBu-NMI 4,5-dithiolate. The new complexes were structurally characterized by X-ray analysis.     

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.     

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.