Inorganic-organic hybrid materials with different dimensions constructed from copper-fluconazole metal-organic units and Keggin polyanion clusters

Inorganic-organic hybrid materials based on Keggin polyoxometalate building blocks combined with Cu(II)/Cu(I) and flexible fluconazole ligand [1-(2,4-difluorophenyl)-1,1-bis[(1H-1,2,4-triazol-1-yl)methyl]methanol] (Hfcz) have been obtained by hydrothermal methods, namely, [Cu(II)(2)(Hfcz)(4)(SiW(12)O(40))].3H(2)O (1), [Cu(II)(4)(fcz)(4)(H(2)O)(4)(SiMo(12)O(40))].6H(2)O (2), [Cu(II)(2)(fcz)(2)][Cu(II)(4)(fcz)(4)(SiW(12)O(40))][Cu(II)(2)(fcz)(2)(H(2)O)(2)(SiW(12)O(40))].6H(2)O (3), (Et(3)NH)(2)[Cu(I)(2)(Hfcz)(2)(SiW(12)O(40))].2H(2)O (4), (Et(3)NH)(2)[Cu(I)(2)(Hfcz)(2)(SiW(12)O(40))].H(2)O (5) and [Cu(I)(4)(Hfcz)(4)(SiMo(12)O(40))] (6). Their structures have been determined by single-crystal X-ray diffraction analyses, and the compounds are further characterized by elemental analyses, IR spectra and thermogravimetric (TG) analyses. In 1, Cu(II) cations are bridged by fluconazole ligands to form a 3D lvt coordination polymeric network, which is connected by (SiW(12)O(40))(4-) anions to form a complicated 3D (4,6)-connected framework with the topology of (4(2).6(4))(4(6).6(7).8(2))(2). In 2, two fcz(-) anions chelate two Cu(2+) cations to form a [Cu(fcz)](2)(2+) dimer, which is bridged by (SiW(12)O(40))(4-) polyanions to generate a 2D (4,4) grid. Compound 3 is formed by three types of co-crystallizing subunits including a dimer [Cu(fcz)](2)(2+), a dumbbell molecule [Cu(4)(fcz)(4)(SiW(12)O(40))] and an infinite chain {[Cu(2)(fcz)(2)(H(2)O)(2)(SiW(12)O(40))](2-)}(infinity). In compounds 4 and 5, Hfcz ligands link Cu(+) cations to generate 1D coordination polymeric units, and (SiW(12)O(40))(4-) polyanions connect these metal-organic units to form two types of (6(3)) sheets which are topological isomerism. In compound 6, (SiMo(12)O(40))(4-) polyanions fixed in Cu(I)-Hfcz square rings are further extended into a 2D sheet via linking Cu(I) atoms of different rings. By carefully inspection of the structures of 1-6, it is believed that various transition-metal organic units and Keggin polyanions with different coordination modes are important for the formation of the different structures. In addition, electrochemical behaviors of compounds 1, 2, 5 and 6 have been investigated.     

Electroactive chain-like compounds constructed from trimetallic clusters and 4,4'-bipyridine spacers: one-pot synthesis, characterization and surface binding

This paper reports the synthesis and characterization of a novel series of chain-like compounds where oxo-centered triruthenium cluster moieties are bridged by 4,4'-bipyridine (4,4'-bpy) spacers. A reaction of solvent-coordinated triruthenium "monomer" precursor [Ru(3)O(CH(3)CO(2))(6)(CO)(CH(3)OH)(2)] with a 0.1 equimolar amount of 4,4'-bpy in CH(3)OH gave mixture of chain-like compounds containing "dimers" to "tetramers" which were cleanly separated by column chromatography and characterized by spectroscopic and electrochemical methods. Cyclic voltammetry revealed that all chain-like compounds exhibit reversible and stepwise redox processes in solution with very weak intramolecular coupling between the triruthenium components across the 4,4'-bpy bridge. Photo-induced dissociation of CO from the compounds and electrode surface binding were also investigated.     

Ligand dynamics and reactivity in trimetallic clusters

The general relationships between trinuclear cluster reactivity and the ligand dynamical processes in these systems are explored. Three specific mechanistic studies are presented: (1) the rate and stereochemistry of ligand addition to ₃-imidoyl complexes, (2) the factors influencing the rate of carbon-hydrogen bond activation in ₃-alkyne complexes, and (3) the origin of anomalously large kinetic deuterium isotope effect in metal to ligand and ligand to metal hydrogen transfer in trinuclear and binuclear complexes. In all three cases, the current state of the mechanistic studies are summarized and the possible rate of specific ligand dynamical processes in controlling the mechanism are put forth.     

New two-dimensional metal-organic networks constructed from 1,2,4,5-benzenetetracarboxylate and chelate ligands

Two novel nickel coordination polymers [Ni(2)(2,2'-bipy)(2)(OH)(2)(H(2)btec)](3)(n)(1) and [Ni(2)(1,10'-phen)(2)(H(2)O)(2)(btec)](n)(2) (btec = 1,2,4,5-benzenetetracarboxylate) have been hydrothermally synthesized and characterized by elemental analyses, IR and XPS spectra, TG analysis, X-ray powder diffraction, and single crystal X-ray diffraction. Crystal data for 1: C(90)H(66)N(12)O(30)Ni(6), monoclinic P2(1)/c, a = 10.905(2) A, b = 18.006(4) A, c = 20.551(4) A, beta = 94.91(3) degrees, Z = 2. Crystal data for 2: C(34)H(22)N(4)O(10)Ni(2), monoclinic P2(1)/n, a = 10.122(2) A, b = 9.3106(19) A, c = 15.690(3) A, beta = 92.03(3) degrees, Z = 2. Compound 1 exhibits a novel one-dimensional chainlike structure, in which the dinuclear Ni centers are linked by the btec ligands. Furthermore, the adjacent chains are linked into a 2-D wavelike layer via the strong OH.O hydrogen bonding interactions. Compound 2 possesses an unusual two-dimensional steplike network with interesting rhombic grids. Both compounds exhibit unprecedented metal-organic ligand construction modes in [M/btec/L] (M = transition metal; L = chelate ligands) systems. The magnetic behaviors of compounds 1 and 2 have been studied.     

Rod packings and metal-organic frameworks constructed from rod-shaped secondary building units

The principal structure possibilities for packing infinite rod-shaped building blocks are described. Some basic nets derived from linking simple rods (helices and ladders) are then enumerated. We demonstrate the usefulness of the concept of rod secondary building units in the design and synthesis of metal-organic frameworks (MOFs). Accordingly, we present the preparation, characterization, and crystal structures of 14 new MOFs (named MOF-69A-C and MOF-70-80) of 12 different structure types, belonging to rod packing motifs, and show how their structures are related to basic nets. The MOFs reported herein are of polytopic carboxylates and contain one of Zn, Pb, Co, Cd, Mn, or Tb. The inclusion properties of the most open members are presented as evidence that MOF structures with rod building blocks can indeed be designed to have permanent porosity and rigid architectures.     

Porous metal-organic truncated octahedron constructed from paddle-wheel squares and terthiophene links

A metal-organic truncated octahedron (termed MOP-28) has been constructed from six rigid square-shaped Cu2(CO2)4 paddle-wheel building units and twelve 2,2':5',2' '-terthiophene-5,5' '-dicarboxylate (TTDC) linkers. TTDC linker in the cis,cis conformation provides the critical 90 degrees linkage for this unique construction. The porous structure of MOP-28 is maintained even after the removal of guest species, as evidenced by this compound's nitrogen sorption isotherm of Type I characteristics and unprecedented surface area (Langmuir surface area 1100 m2/g, BET surface area 914 m2/g) among materials composed of discrete molecules.     

Unprecedented (3,10)-connected 2-D metal-organic framework constructed from octanuclear cobalt(II) clusters and a new bifunctional ligand

A metal-organic framework with the highest connectivity of 2-D topology was first assembled from an octacobalt(II) cluster as a 10-connected node and a new bifunctional ligand 1-(3,5-dicarboxy-phenyl)-4-phenyl-1H-1,2,3-triazole as a 3-connected node as well as "double bridge" linkers.     

Microporous metal-organic framework constructed from heptanuclear zinc carboxylate secondary building units

A novel, three-dimensional, noninterpenetrating microporous metal-organic framework (MOF), [Zn7O2(pda)5(H2O)2]5 DMF4 EtOH 6 H2O (1) (H2PDA=p-phenylenediacrylic acid, DMF=N,N-dimethylformamide, EtOH=ethanol), was synthesized by constructing heptanuclear zinc carboxylate secondary building units (SBUs) and by using rigid and linear aromatic carboxylate ligands, PDA. The X-ray crystallographic data reveals that the seven zinc centers of 1 are held together with ten carboxylate groups of the PDA ligands and four water molecules to form a heptametallic SBU, Zn7O4(CO2)10, with dimensions of 9.8 x 9.8 x 13.8 A3. Furthermore, the heptametallic SBUs are interconnected by PDA acting as linkers, thereby generating an extended network with a three-dimensional, noninterpenetrating, intersecting large-channel system with spacing of about 17.3 A. As a microporous framework, polymer 1 shows adsorption behavior that is favorable towards H2O and CH3OH, and substantial H2 uptake. In terms of the heptanuclear zinc carboxylate SBUs, polymer 1 exhibits interesting photoelectronic properties, which would facilitate the exploration of new types of semiconducting materials, especially among MOFs containing multinuclear metal carboxylate SBUs.     

A one-dimensional coordination polymer constructed from planar pentanuclear copper(II) clusters with a flexible tripodal ligand

A one-dimensional coordination polymer based on planar pentanuclear copper(II) clusters has been assembled from a flexible tripodal ligand, which exhibits a quite strong antiferromagnetic coupling between Cu(II) ions.     

A zeolitic porous lithium-organic framework constructed from cubane clusters

Reported here is a lithium cubane based zeolitic framework possessing a multi-dimensional channel system. The unique design strategy of adopting the ditopic ligand 4-pyridinol leads to a rigid porous framework with high thermal stability. It has a BET surface area of 440.3 m(2) g(-1) and a H(2) uptake capacity of 108.7 cm(3) g(-1) at 77 K.     

Two triazole-based metal-organic frameworks constructed from nanosized Cu20 and Cu30 wheels

Two metal-organic frameworks constructed from nanosized Cu(20) and Cu(30) wheels have been obtained under hydrothermal conditions based on 1,2,3-triazole and 1-H-1,2,3-benzotriazole, respectively. Crystal structure analysis shows that their differences in the size and nuclearity of Cu(20) and Cu(30) wheels are attributed to the steric effect of ligands.     

Photoluminescent coordination polymer bulk glasses and laser-induced crystallization

We synthesized luminescent coordination polymer glasses composed of d¹⁰ metal cyanides and triphenylphosphine through melt-quenching and mechanical milling protocols. Synchrotron X-ray total scattering measurements and solid-state NMR revealed their one-dimensional chain structures and high structural dynamics. Thermodynamic and photoluminescence properties were tunable by the combination of heterometallic ions (Ag⁺, Au⁺, and Cu⁺) in the structures. The glasses are moldable and thermally stable, and over centimeter-sized glass monoliths were fabricated by the hot-press technique. They showed high transparency over 80% from the visible to near-infrared region and strong green emission at room temperature. Furthermore, the glass-to-crystal transformation was demonstrated by laser irradiation through the photothermal effect of the glasses.

Over centimeter-sized luminescent coordination polymer glasses were fabricated. They showed high transparency (over 80%) and strong green emission at room temperature. The glass-to-crystal transformation by laser irradiation was demonstrated.     

A new 1D chiral metal-organic coordination polymer constructed by Cu(II) with L-3-Cyanophenylalanine

A new 1D chiral metal-organic coordination polymer [Cu(Cphe)₂] · 3H₂O (I) (HCphe = L-3-Cyanophenylalanine) has been synthesized in an aqueous solution and characterized by elemental analysis, thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD), infrared spectroscopy (IR) and single crystal X-ray diffraction. The X-ray diffraction analysis reveals that I crystallizes in the monoclinic space group P2₁. The adjacent copper(II) atoms are linked by Cphe ligands to form a 1D zigzag chain, which is further connected via strong hydrogen bonds to form a 3D supramolecular framework. The unit cell parameters for I are: a = 12.0201(8), b = 6.1495(4), c = 14.8576(10) Å, β = 94.1720(10)°, V = 1095.00(13) ų, and Z = 2.     

Synthesis,structure, and thermal properties of 3-D coordination polymers constructed from asymmetrical carboxylates

Three new coordination polymers constructed from asymmetric ligands were synthesized under hydrothermal conditions and characterized with single crystal X-ray analysis, infrared, and thermal gravimetric methods. Complex 1 exhibits a 3-D network constructed from rod-shaped secondary building units. Pyrimidine-4-carboxylic acid (bpa) was used as the starting material, but under hydrothermal conditions bpa formed 2,2′-pyrimidine-4,4′-dicarboxylic acid (bpda) in situ, which further connected with Pb. 3-D two-fold interpenetration of complex 2 was obtained by the similar method as described for 1, except that Cd(NO₃)₂ · 6H₂O was used instead of Pb(NO₃)₂ · 6H₂O to react with bpa. Complex 3 shows a three-connected 3-D network. Furthermore, the photoluminescence properties of 1 and 2 were studied.     

A 12-connected metal-organic framework constructed from an unprecedented cyclic dodecanuclear copper cluster

A 12-connected metal-organic framework based on an unprecedented cyclic Cu(12) cluster with a large internal cavity has been prepared, and its cation exchange property was determined.     

Nanocage containing metal-organic framework constructed from a newly designed low symmetry tetra-pyrazole ligand

1368-Tetra(1H-pyrazol-4-yl)-9H-carbazole (H₄CTP), a tetra-pyrazole ligand with C_s symmetry, has been synthesized based on a carbazole core. A solvothermal reaction of this ligand with NiCl₂·6H₂O gave a three-dimensional (3-D) metal-organic framework (MOF), [Ni(H₄CTP)Cl₂]·nS (BUT-41), which crystallized in the cubic space group Pm-3 in spite of H₄CPT with a central carbazole core and four peripheral pyrazole rings has low symmetry. The framework of BUT-41 can be regarded as a four-connected 3-D net with the rhr topology when both the organic ligand and the metal center are considered as four-connected nodes. Nanocages with internal diameter of 2 nm are present in the framework of BUT-41, which are formed by interconnecting 12 H₄CTP ligands and 20 Ni(II) ions. Each nanocage connects with six adjacent cages through sharing hexagonal windows with diameter over 7 Å, resulting in 3-D intersecting channels of the MOF. Although the tetra-pyrazole ligand is not deprotonated after coordination with the metal ions, powder X-ray diffraction and N₂ adsorption experiments reveal that the framework of BUT-41 is rigid and permanently porous with the Brunauer-Emmett-Teller surface area up to 1551 m² g^?1. Furthermore, gas adsorption experiments show that this MOF selectively adsorbs CO₂ over N₂ and CH₄.     

Two-dimensional metal-organic frameworks (MOFs) constructed from heterotrinuclear coordination units and 4,4'-biphenyldicarboxylate ligands

Three novel metal-organic frameworks (MOFs) formulated as [Zn(2)M(BPDC)(3)(DMF)(2)].4DMF (M = Co(II), Ni(II) or Cd(II); BPDC = 4,4'-biphenyldicarboxylate; DMF = N,N'-dimethylformamide) have been prepared via solvothermal synthesis from mixtures of the corresponding transition metal salts and 4,4'-biphenyldicarboxylic acid (H(2)BPDC). The framework structures are characterized by single-crystal X-ray diffraction analysis, IR and UV-vis diffuse reflectance spectroscopy, thermogravimetric analysis (TGA), and X-ray powder diffraction (XRPD). All three compounds possess essentially the same 2-D layered coordination framework consisting of linear heterotrinuclear secondary building units (SBUs) connected by rigid bridging BPDC ligands. Crystal data: for (C(60)H(66)CoN(6)O(18)Zn(2)): monoclinic, space group P2(1)/n, M = 1348.86, a = 20.463(4), b = 14.819(3), c = 23.023(5) A, beta = 111.75(3) degrees , V = 6484(2) A(3), Z = 4, D(c) = 1.382 Mg m(-3). For (C(60)H(66)N(6)NiO(18)Zn(2)): monoclinic, space group P2(1)/n, M = 1348.64, a = 11.670(2), b = 14.742(3), c = 19.391(4) A, beta = 102.29(3) degrees , V = 3259.5(11) A(3), Z = 2, D(c) = 1.374 Mg m(-3). For (C(60)H(66)CdN(6)O(18)Zn(2)): monoclinic, space group P2(1)/n, M = 1402.33, a = 11.491(2), b = 14.837(3), c = 19.386(4) A, beta = 101.53(3) degrees , V = 3238.3(11) A(3), Z = 2, D(c) = 1.438 Mg m(-3).     

A novel metal-organic ternary topology constructed from triangular, square and tetrahedral molecular building blocks

A novel metal-organic network [Cu(4)(5-NH(2)-1,3-bdc)(4)(pyridine)(2)(H(2)O)(2)](n), displaying an unprecedented topology has been constructed utilizing the different coordinating functional groups of 5-NH(2)-1,3-bdc to generate a ternary network based upon vertex-linked triangular, square and tetrahedral molecular building blocks (MBBs).     

A series of coordination polymers constructed from flexible bis(benzimidazole)ether ligands and different carboxylates

Six new coordination polymers constructed from two structurally related ligands, 2,2′-bis(2-methylbenzimidazole) ether (L1) and 2,2′-bis(2-ethylbenzimidazole)ether (L2), have been synthesized. They are [Cu(L1)(bz)₂] (1), [Cu(L2)(bz)₂] (2), [Zn₂(L1)(m-bdc)₂] (3), [Cd₂(L2)(m-bdc)₂(H₂O)]₂·H₂O (4), [Zn(L1)(OH-bdc)-(H₂O)] (5) and [Zn₂(L₂)(btca)] (6), where Hbz = benzoic acid, m-H₂bdc = 1,3-benzenedicarboxylic acid, OH-H₂bdc = 5-hydroxyisophthalic acid, and H₄btca = 1,2,4,5-benzenetetracarboxylic acid. In 1 and 2, the bidentate N-donor ligands (L1 and L2) bridge neighboring metal centers to form 1D single chains. The bz anions are attached on both sides of the chains. In 3 and 4, the N-donor ligands (L1 and L2) in cis conformations bridge two metal centers to generate a [M₂(L1)]⁴⁺ unit (M = Zn(II) and Cd(II)). The adjacent [M₂(L1)]⁴⁺ units are further linked via the dicarboxylate anions to form 1D double chain structures. In 5, the Zn(II) cations are bridged by OH-m-bdc anions to form an infinite polymeric chain. The L1 ligands are attached on one side of the chain in a monodentate mode. In 6, two Zn(II) cations are bridged by two L2 ligands to form a [ZnL2]₂ ⁴⁺ ring, which is further linked by btca anions to generate a 2D layer. The luminescent properties of the ligands and 3–6 in the solid state at room temperature were also studied.