pH effect on the assembly of metal-organic architectures

Crystal engineering is the rational design and assembly of solid-state structures with desired properties via the manipulation of intermolecular interactions, hydrogen bonding and metal ligand complexation in particular. The heart of crystal engineering is to control the ordering of the building blocks, be they molecular or ionic, toward a specific disposition in the solid state. The relatively weak strength of intermolecular forces with respect to chemical bonding renders the assembly of supramolecular constructs sensitive to external physical and chemical stimuli, with pH condition of the reaction mixture being arguably the most prominent and extensively observed. Using selected examples of constructing metal-organic architectures from recent literature, the influences of pH on the specific ligand forms, the generation and metal coordination of hydroxo ligands, ligand transformation promoted by pH condition changes, pH-dependent kinetics of crystallization of a number of metal-organic architectures are discussed. Current status of this particular areas of research in supramolecular chemistry and materials are assessed and personal perspectives as to toward what directions should this chemistry head are elaborated.NNSFC [20825103, 20721001, 90922031]; 973 project [2007CB815304]; MSTC ; Natural Science Foundation of Fujian Province of China [2008J0010

Recent advances in polyoxometalate-based lanthanide–oxo clusters

Polyoxometalate (POM)-based lanthanide-oxo clusters (LnOCs) are a class of polynuclear lanthanide–oxygen complexes formed by polyoxometalate stabilization through oxygen bridges in which POMs can be viewed as multidentate inorganic ligands. POM-based LnOCs have received interest owing to their interesting structures and potential applications. In this paper, we summarize the classification, synthesis strategies, and properties of POM-based LnOCs. POM-based LnOCs are classified into three main categories according to their metal core element type and quantity: pure 4f clusters, 5d–4f clusters, and 3d–4f clusters. Their synthetic strategies are divided into four categories based on the source of the POM involved in the structural assembly: the lacunary POMs ligand-directed method, the in-situ transformation of lacunary POMs ligand-directed method, the in-situ generation of lacunary POMs ligand-directed method, and mixed synthesis strategies. In addition, the single-molecule magnets of POM-based LnOCs and their proton conduction properties are summarized

1,2,3,4,4b,4c,6,7,8,9,9b,9c-Dodecachloro-4b,4c,9b,9c-tetrahydrocyclobuta[1,2-a;3,4-a']diindene-5,10-dione

The title compound, C18Cl12O2, was synthesized by a solvothermal reaction between sodium and carbon tetrachloride; the oxygen may come from air. The mol­ecule has crystallographic C2 symmetry and contains a four-membered ring, two five-membered rings and two six-membered rings. The five-membered rings are attached to opposite sides of the cyclo­butane group and the six-membered rings are fused to the five-membered rings. In the solid state, the mol­ecule adopts a boat form

A four-shell, 136-metal 3d-4f heterometallic cluster approximating a rectangular parallelepiped

通讯作者地址: Long, LS (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surface, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surface, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 3. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA 4. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA 电子邮件地址: [email protected], [email protected] nanosized heterometallic cluster containing 60 La(III) and 76 Ni(II) ions, which are arranged into a four-shell, nest-like framework structure, was obtained by the hydrolytic reaction of the mixed La(NO3)(3)-Ni(NO3)(2) system using iminodiacetate as an ancillary ligand to control the hydrolysis.NSF CAREER CHE-0238790 NNSFC 20531050,20721001 MSTC 2007CB81530

Crystal Structure of Hexacyanoferrato(III)bis(µ-cyano){1,3-bis-[(4-methyl-5-imidazol-1-yl)ethylideneamino]propan-2-olcopper(II) Hexacyanoferrato(III)-µ-cyano-1,3-bis[(4-methyl-5-imidazol-1-yl)-ethylideneamino]propan-2-olcuprate(II) Tetradecahydrate

The crystal structure of hexacyanoferrato(III)bis(µ-cyano){1,3-bis[(4-methyl-5-imidazol-1-yl)ethylideneamino]propan-2-ol}copper(II) hexacyanoferrato(III)-µ-cyano-{1,3-bis[(4-methyl-5-imidazol-1-yl)ethylideneamino]propan-2-ol}cuprate(II) tetradecahydrate consists of trinuclear cations and dinuclear anions whose copper atoms show square pyramidal and iron atoms octahedral coordination. The cations and anions are linked by hydrogen bonds involving 14 lattice water molecules in a network architecture. Crystals of the C51H82Cu3Fe2N30O17 belong to the triclinic P1̅ space group [a = 13.700(2), b = 13.881(2), c = 21.431(3) Å; α = 76.96(1), β = 83.07(1), γ = 74.70(1)°]

Magnetooptical Properties of Chiral [Co2Ln] Clusters.

Two pairs of enantiomeric 3d-4f metal clusters, [Co2Ln[( R )/( S )-L]4]·Cl5·(H2O)2·CH3OH·CH3CH2OH [ Co 2 Ln ; Ln = Gd ( 1S and 1R ), Dy ( 2S and 2R )], were synthesized by the reaction of chiral Schiff-base ligand ( R )/( S )-3-[(2-hydroxybenzylidene) amino]propane-1,2-diol [( R )/( S )-HL] with CoCl2·6H2O and LnCl3·6H2O. The circular dichroism spectra of ( S )/( R )-Co 2 Ln display a mirror-symmetry effect with seven peaks at 210-800 nm, which can be ascribed to π-π* transitions, exciton coupling, charge-transfer transitions between ligands and Co3+, and characteristic d-d transitions of Co3+ ions. Interestingly, the chiral Co 2 Ln metal clusters display strong magnetic circular dichroism signals at room temperature. This work suggests that the chiromagnetic metal cluster is expected to show a strong magnetooptical response

Structures, magnetic and catalytic properties of three sandwich-type silicotungstates containing tetranuclear copper(II) clusters

Three sandwich-type silicotungstates. formulated as [Cu-4(H2O)(2)(SiW9O34)(2)] 12NH(4) 22H(2)O (1), [Cu-4(H2O)(2)(SiW9O34)(2)] 12NH(4) 11H(2)P (2) and {[Cu(NH3)(4)](2)[Cu(H2O)(4)][Cu-4(H2O)(2)(SiW9O34)(2)]} 2[Cu(NH3)(4)(H2O)] 2NH(4) 6H(2)O (3), were synthesized by microwave irradiation and hydrothermal reaction Crystal structural analysis reveals that 1-3 possess the same dimeric polyoxoanions [Cu(2)StW(9)O(34) (H2O)(2)(12-) featuring tetranuclear copper(II) clusters Magnetic studies indicate that the Cu., clusters exhibit ferromagnetic coupling interactions Investigation on their catalytic activity for the oxidation of ethylbenzene suggests that catalytic activity of 1-3 is closely related to the acidity of complexes and the existence of unsaturated coordination sites in the complexNNSFC [20825103, 20721001, 90922031]; MSTC [200703815304]; Natural Science Foundation of Fujian Province of China [2008J0010

A lanthanide-based metal-organic framework with a dynamic porous property

NNSFC [20721001]; MSTC [2007CB815304

Influence of halide ions on the chirality and luminescent property of ionothermally synthesized lanthanide-based metal-organic frameworks

Four lanthanide-based metal-organic frameworks, [Emim][Ln(1.5) (2,5-tdc)(2)]Cl(1.5-x)Br(x)(Ln = Nd 1, Eu 2) and [Emim][Ln(2,5-tdc)(2)] (Ln = Nd 3, Eu 4) (2,5-tdc = thiophene-2,5-dicarboxylate, Emim = 1-methyl-3-ethylimidazolium), were synthesized under ionothermal conditions. Compounds 1 and 2 crystallize in the polar space group P2(1)2(1)2, while 3 and 4 crystallize in the central symmetry space group P2(1)/c. Luminescence studies revealed a significantly higher quantum yield of 4 than that of 2, with similar lifetimes. It is clear that the coordination of the halide ions has profound effects on the structures and properties of these lanthanide-based metal-organic frameworks.NNSFC[20825103, 90922031, 21021061]; MSTC[2007CB815304