Hydrothermal syntheses, crystal structures and magnetic properties of two copper(II) complexes involved in situ ligand synthesis

The hydrothermal reaction of Cu(NO(3))(2), isophthalate (ip) and 2,2'-bipyridine (2,2'-bpy) without or with K(2)Cr(2)O(7) affords different complexes, whose structures are controlled only by the addition of the K(2)Cr(2)O(7). The reaction of Cu(NO(3))(2), isophthalate and 2,2'-bipyridine yields a novel one-dimensional double-chain coordination polymer [Cu(3)(ip)(2)(Hipa)(2)(bpy)(2)](n) (1). However, with the addition of K(2)Cr(2)O(7) in the above reaction at the same hydrothermal conditions, a discrete hexanuclear Cu(II) complex [Cu(6)(ipO)(4)(2,2'-bpy)(2)(H(2)O)(2)].6H(2)O (2) (ipOH = 2-hydroxyisophthalate) was isolated. It is interesting to find that the in situ reaction of isophthalate (ip) oxidized to 2-hydroxyisophthalate (ipOH) occurs. K(2)Cr(2)O(7) acts as an oxidant. The magnetic properties of 1 and 2 have been investigated by variable-temperature magnetic susceptibility and magnetization measurements, and the results reveal that intramolecular ferromagnetic interactions exist with weak intermolecular antiferromagnetic interactions at very low temperature in 1 and weak antiferromagnetic interactions admixture with strong ferromagnetic interactions in 2.     

Synthesis, structure and optical properties of rare-earth benzene carboxylates

Two series of rare-earth isophthalates of the general formula, [M(2)(H(2)O)][{C(6)H(4)(COO)(2)}(2){C(6)H(4)(COOH)(COO)}(2)].H(2)O, M=La (I), Pr (Ia), and Nd (Ib) and [M(2)(H(2)O)(2)][{C(6)H(4)(COO)(2)}(3)].H(2)O, M=Y (II), Gd (IIa), and Dy (IIb) have been prepared by the reaction of the corresponding trivalent lanthanide salts and isophthalic acid under mild hydrothermal conditions. The La (I), Pr (Ia) and Nd (Ib) have MO(9) polyhedra connected to the isophthalate anions forming a two-dimensional structure, whereas Y (II), Gd (IIa) and Dy (IIb) have MO(7) and MO(8) polyhedral units connected to the isophthalate anions forming a different, but related two-dimensional structure. Both the structures are stabilized by hydrogen bonding and pi...pi/CH...pi interactions. Partial substitution of Eu and Tb (2 and 4%) at the La (I) and Y (II) sites give rise to characteristic red/pink or green luminescence, indicating a ligand-sensitized metal-centered emission. The Nd (Ib) compound shows interesting UV and blue emission through an up-conversion process.     

A 3D Co(II) framework with alternating vertex- and edge-sharing Δ-ribbons showing a two-step field-induced magnetic transition

A novel 3D framework with vertex- and edge-sharing Δ-ribbons extended by ip(2-) connectors, {[Co(7)(H(2)O)(2)(μ(3)-OH)(4)(atz)(2)(ip)(4)]·5H(2)O}(n) (atz(-) = 5-amino-tetrazolate and ip(2-) = isophthalate), exhibits a two-step field-induced metamagnetic transition from an antiferromagnetic ordering to a weak spontaneous magnetization state by spin-competition at 2.0 KOe, followed by a spin-flop transition at 22.5 KOe.     

配合物[Mn(2,2''-bipy)(H2O)4]·(m-phth)的水热合成和晶体结构

A mononuclear manganese complex [Mn(2,2'-bipy)(H2O)4]·(m-phth) (2,2'-bipy=2,2'-bipyridine, m-phth=isophthalate) has been synthesized by hydrothermal methods. The crystal structure was determined by singlecrystal X-ray diffraction. The crystal is of orthorhombic, space group Pnna with a=0.766 8(8) nm, b =2.050 2(2)0.027 0, R=0.028 0 and wR=0.075 5. In the crystal the manganese atom is six-coordinated by two nitrogen atoms from 2,2'-bipyradine and four oxygen atoms from water molecules, completing an octahedral coordination geometry. The isophthalate molecules are included in the lattice and connected to Mn(2,2'-bipy)(H2O)4 by hydrogen bonding interactions to form a three-dimensional supramolecular structure. CCDC:286965.     

Magnetic nanosized {M(II)24}-wheel-based (M = Co, Ni) coordination polymers

Two 3D coordination polymers, [Co(24)(OH)(12)(SO(4))(12)(ip)(6)(DMSO)(18)(H(2)O)(6)]·(DMSO)(6)(EtOH)(6)(H(2)O)(36) (1·guests, ip = isophthalate) and [Ni(24)(OH)(12)(SO(4))(12)(ip)(6)(DMSO)(12)(H(2)O)(12)]·(DMSO)(6)(EtOH)(6)(H(2)O)(20) (2·guests), constructed with nanosized tetraicosanuclear Co(II) and Ni(II) wheels are solvothermally synthesized. Both complexes show intra- and interwheel dominant antiferromagnetic interactions.     

Syntheses, topological analyses, and NLO-active properties of new Cd(II)/M(II) (M = Ca, Sr) metal-organic frameworks based on R-isophthalic acids (R = H, OH, and t-Bu)

Solvothermal syntheses of Cd(NO(3))(2)·4H(2)O and R-isophthalic acids (R = H, OH and t-Bu) in the presence of Ca(II) or Sr(II) lead to four new three-dimensional Cd(II)/Ca(II) or Cd(II)/Sr(II) heterometallic frameworks: [CdCa(m-BDC)(2)(DMF)(2)] (1), [CdSr(2)(m-BDC)(2)(NO(3))(2)(DMF)(4)] (2), [CdCa(OH-m-BDC)(2)(H(2)O)(2)]·2Me(2)NH (3), and (Me(2)NH(2))(2)[Cd(2)Ca(Bu(t)-m-BDC)(4)] (4) (m-H(2)BDC = isophthalate, OH-m-H(2)BDC = 5-hydroxyisophthalate and Bu(t)-m-H(2)BDC = 5-butylisophthalate). All of these compounds except for 4 crystallize in acentric (or chiral) space groups and the bulk materials for 1 and 3 display strong powder SHG efficiencies, approximately 1.54 and 2.31 times than that of a potassium dihydrogen phosphate (KDP) powder. Topological analyses show that 1 and 2 have structures with sxb and dia topologies, respectively, while both 3 and 4 exhibit pcu topological nets when the metal carboxylate clusters are viewed as nodes. The fluorescence properties and thermal stabilities for these compounds are also investigated.     

Self-assembly of lanthanide mixed-carboxylates coordination polymers

Two new mixed-ligands lanthanide coordination polymers, [Ln(Ac)(ip)(H₂O)₂]·0.5H₂O (Ln=La (1); Ln=Eu (2); Ac=acetate; ip=isophthalate) have been synthesized under hydrothermal condition. Single-crystal X-ray analyses show that complexes 1 and 2 are three-dimensional structure in which lanthanide ions are bridged by monocarboxylate ligand, acetate or dicarboxylate ligand, isophthalate. And the central lanthanide ions, La³⁺ and Eu³⁺, are both nine-coordinate with oxygen atoms. The thermogravimetric analysis was carried out to examine the thermal stability of the title complexes. And the photoluminescence property of complex 2 was also investigated.     

An isomorphous series of cubic, copper-based triazolyl isophthalate MOFs: linker substitution and adsorption properties

An isomorphous series of 10 microporous copper-based metal-organic frameworks (MOFs) with the general formulas (∞)(3)[{Cu(3)(μ(3)-OH)(X)}(4){Cu(2)(H(2)O)(2)}(3)(H-R-trz-ia)(12)] (R = H, CH(3), Ph; X(2-) = SO(4)(2-), SeO(4)(2-), 2 NO(3)(2-) (1-8)) and (∞)(3)[{Cu(3)(μ(3)-OH)(X)}(8){Cu(2)(H(2)O)(2)}(6)(H-3py-trz-ia)(24)Cu(6)]X(3) (R = 3py; X(2-) = SO(4)(2-), SeO(4)(2-) (9, 10)) is presented together with the closely related compounds (∞)(3)[Cu(6)(μ(4)-O)(μ(3)-OH)(2)(H-Metrz-ia)(4)][Cu(H(2)O)(6)](NO(3))(2)·10H(2)O (11) and (∞)(3)[Cu(2)(H-3py-trz-ia)(2)(H(2)O)(3)] (12(Cu)), which are obtained under similar reaction conditions. The porosity of the series of cubic MOFs with twf-d topology reaches up to 66%. While the diameters of the spherical pores remain unaffected, adsorption measurements show that the pore volume can be fine-tuned by the substituents of the triazolyl isophthalate ligand and choice of the respective copper salt, that is, copper sulfate, selenate, or nitrate.     

Chemical bonding topology of ternary transition metal-centered bismuth cluster halides: from molecules to metals

The bismuth polyhedra in ternary transition metal-centered bismuth cluster halides may form discrete molecules or ions, infinite chains, and/or infinite layers. The chemical bonding in many of these diverse structures is related to that in deltahedral boranes exhibiting three-dimensional aromaticity by replacing the multicenter core bond in the boranes with two-center two-electron (2c-2e) bonds from the central transition metal to the nearest neighbor bismuth vertices. Examples of discrete molecules or ions include octahedral MBi(6)(micro-X)(12)(z)()(-) (X = Br, I; M = Rh, Ir, z = 3; M = Ru, z = 4) with exclusively 2c-2e bonds and pentagonal bipyramidal RhBi(7)Br(8) with a 5c-4e bond in the equatorial pentagonal plane indicative of M?bius aromaticity. The compound Ru(3)Bi(24)Br(20) contains a more complicated discrete bismuth cluster ion Ru(2)Bi(17)(micro-Br)(4)(5+), which can be dissected into a RuBi(5) closo octahedron and a RuBi(8) nido capped square antiprism bridged by a Ru(2)Bi(4)(micro-Br)(4) structural unit. In RuBi(4)X(2) (X = Br, I), the same Ru(2)Bi(4)(micro-Br)(4) structural unit bridges Bi(4) squares similar to those found in the known Zintl ion Bi(4)(2)(-) to give infinite chains of Ru(2)Bi(4) octahedra. The electron counts of the RuBi(5), RuBi(8), and Ru(2)Bi(4) polyhedra in these structures follow the Wade-Mingos rules. A different infinite chain structure is constructed from fused RhBi(7/2)Bi bicapped trigonal prisms in Rh(2)Bi(9)Br(3). This Rh(2)Bi(9)Br(3) structure can alternatively be derived from alternating Rh(2/2)Bi(4) octahedra and Rh(2/)(2)Bi(5) pentagonal bipyramids with electron counts obeying the Wade-Mingos rules. Related chemical bonding principles appear to apply to more complicated layer structures such as Pt(3)Bi(13)I(7) containing Kagomé nets of PtBi(8/2) cubes and Ni(4)Bi(12)X(3) containing linked chains of NiBi(6/3)Bi capped trigonal prisms.     

Hydrothermal Syntheses and Crystal Structures of Two Layered Nickel(II) Coordination Polymers Based on 1,2,3‐Benzenetricarboxylic Acid

The hydrothermal reactions of Ni(II), 1,2,3‐benzenetricarboxylic acid (1,2,3‐H₃btc) and 4,4′‐bipyridine (4,4′‐bpy)/1,2‐bis(4‐pyridyl)ethane (bpa) yield two layered nickel(II) coordination polymers, [Ni₂(1,2,3‐btc)(OAc)‐(4,4′‐bpy)₂(H₂O)]·2H₂O ( 1 ) and [Ni(ip)(bpa)] ( 2 ) (ip=isophthalate), respectively. Both complexes are 2‐D coordination network based on 1‐D Ni‐carboxylate chains. The 1,2,3‐btc ligand adopts 3‐bridging mode in complex 1 , but transformed to isophthalate (ip) ligand through decarboxylation in 2 . The formation of the two complexes indicates that hydrothermal conditions andin‐situ ligand reaction have significant effect on constructing coordination polymers.     

Double-stranded helices and molecular zippers assembled from single-stranded coordination polymers directed by supramolecular interactions

Using three nonlinear dicarboxylates, isophthalate (ipa), 4,4'-oxybis(benzoate) (oba), and ethylenedi(4-oxybenzoate) (eoba), we have prepared five neutral infinite copper(II) dicarboxylate coordination polymers containing lateral aromatic chelate ligands, namely [Cu(ipa)(2,2'-bpy)]n.2nH2O (1), [Cu2(ipa)2(phen)2H2O]n (2), [Cu(oba)(phen)]n (3), [Cu(oba)(2,2'-bpy)]n (4), and [Cu(eoba)(phen)]n (5; 2,2'-bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline) by hydrothermal synthesis. X-ray single-crystal structural analyses of these complexes reveal that the nonlinear flexible or V-shaped dicarboxylates can induce the helicity or flexuousity of the polymeric chains and aromatic chelate ligands are important in providing potential supramolecular recognition sites for pi-pi aromatic stacking interactions. An appropriate combination of the bridging dicarboxylate and aromatic chelate can induce a pair of single-stranded helical or flexuous chains to generate a double-stranded helix or molecular zipper through supramolecular interactions, respectively.     

Occurence of an octanuclear motif of uranyl isophthalate with cation-cation interactions through edge-sharing connection mode

An uranyl isophthalate has been hydrothermally synthesized at 200 °C for 24 h, from a mixture of uranyl nitrate, isophthalic acid, and hydrazine in water. It was characterized by single-crystal analysis [triclinic, P ?1, a = 7.3934(3) ?, b = 13.3296(5) ?, c = 15.4432(5) ?, α = 111.865(2)°, β = 90.637(2)°, γ = 104.867(2)°, V = 1355.49(9) ?(3)] and different spectroscopic techniques (Raman, IR-ATR, UV-visible). The 3D structure of the phase (UO(2))(8)O(2)(OH)(4)(H(2)O)(4)(1,3-bdc)(4)·4H(2)O (1,3-bdc = 1,3-benzenedicarboxylate) reveals octanuclear units based on the association of 7-fold coordinated uranyl cations (pentagonal bipyramid) involving a rare case of cation-cation interaction together with edge-sharing polyhedral connection mode. UV-visible absorption spectroscopy confirmed that uranium was only involved in the structure as uranyl forms (excluding the presence of tetravalent or pentavalent uranium). Additionally, μ-Raman and IR-ATR experiments allowed assigning four uranyl contributions to the four types of uranyl entities in the structure, in agreement with the XRD analysis.     

Synthesis and Crystal Structure of a 1-D Coordination Polymer {[Cu(NIT4py)2(ip)]·6H2O}n

A new complex {[Cu(NIT4py)2(ip)]·6H2O}n (NIT4py=2-(4'-pyridinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and ip = isophthalate dianion) has been synthesized and structurally characterized by X-ray diffraction. It crystallizes in orthorhombic, space group Cmcm with a = 25.161(3), b =10.045(1), c = 15.450(2)(A), C32H48N6O14Cu, Mr = 804.30, V = 3904.8(8)(A)3, Z = 4, Dc = 1.368 g/cm3,μ(MoKα) = 0.630 mm-1, F(000) = 1692, the final R = 0.0326 and wR = 0.0787 for 1843 independent reflections with Rint = 0.0372. Each Cu(II) ion is four-coordinated by two carboxylate oxygen atoms and two pyridyl-N atoms from NIT4py radicals to furnish a rhombus geometry. The central Cu(II) ion is located at an inversion center and a crystallographic two-fold axis. Each isophthalate dianion binds two Cu(II) ions in bis-monodentate mode, leading to a 1-D chain, and these 1-D chains are further linked into a 2-D network via hydrogen-bonding interactions.     

Enhancing U(eff) in oxime-bridged [Mn(III)6Ln(III)2] hexagonal prisms

The first 3d-4f clusters built using derivatised salicylaldoximes (R-saoH(2)) describe unusual hexagonal prisms. Replacement of the paramagnetic Gd(III) ions with diamagnetic Ln(III) ions allows for a more thorough understanding of the magnetic properties, whilst replacement with Tb(III) doubles U(eff).     

The optical properties of ZnO hexagonal prisms grown from poly (vinylpyrrolidone)-assisted electrochemical assembly onto Si (111) substrate

ZnO hexagonal prisms have been grown from poly (vinylpyrrolidone)-assisted electrochemical assembly onto p-type Si (111) substrate. These ZnO prisms arrays are highly (0002) orientated. The (0001) end facets and {1010} side facets of the hexagonal prisms are well defined. The photoluminescence (PL) spectrum of these ZnO prisms shows an intense ultraviolet near band-gap emission with a full width at half maximum of 86 meV at room temperature. The low-temperature PL spectrum is split into well-resolved free and bound exciton emission lines. The temperature dependence of the exciton emission intensities shows a nonmonotonic decaying behavior, which can be explained by the existence of interfacial states.     

Hydrothermal preparation of nickel(II)/uranium(IV) fluorides with one-, two-, and three-dimensional topologies

A modified compositional diagram for the reactions of Ni(C(2)H(3)O(2))(2).4H(2)O with UO(2)(C(2)H(3)O(2))(2).2H(2)O and HF in aqueous media under mild hydrothermal conditions (200 degrees C) has been completed to yield three Ni(II)/U(IV) fluorides, Ni(H(2)O)(4)UF(6).1.5H(2)O (1), Ni(2)(H(2)O)(6)U(3)F(16).3H(2)O (2), and Ni(H(2)O)(2)UF(6)(H(2)O) (3). The structure of 1 consists of one-dimensional columns constructed from two parallel chains of edge-sharing dodecahedral [UF(8)] units. The sides of the columns are terminated by octahedral Ni(II) units that occur as cis-[Ni(H(2)O)(4)F(2)] polyhedra. In contrast, the crystal structure of 2 reveals a two-dimensional Ni(II)/U(IV) architecture built from edge-sharing tricapped trigonal prismatic [UF(9)] units. The top and bottom of the sheets are capped by fac-[Ni(H(2)O)(3)F(3)] octahedra. The structure of 3 is formed from [UF(8)(H(2)O)] tricapped trigonal prisms that edge share with one another to form one-dimensional chains. These chains are then joined together into a three-dimensional network by corner sharing with trans-[Ni(H(2)O)(2)F(4)] octahedra. Crystallographic data: 1, orthorhombic, space group Cmcm, a = 14.3383(8) A, b = 15.6867(8) A, c = 8.0282(4) A, Z = 8; 2, hexagonal, space group P6(3)/mmc, a = 7.9863(5) A, c = 16.566(1) A, Z = 2; 3, monoclinic, space group C2/c, a = 12.059(1) A, b = 6.8895(6) A, c = 7.9351(7) A, beta = 92.833(2) degrees, Z = 4.     

V(III)(H2O)]3O(O2CC6H4CO2)3.(Cl, 9H2O) (MIL-59): a rare example of vanadocarboxylate with a magnetically frustrated three-dimensional hybrid framework

[V(III)(H2O)]3O(O2CC6H4CO2)3.(Cl, 9H2O) (denoted MIL-59) presents a three-dimensional framework built up from octahedral vanadium trimers joined via the isophthalate anionic linkers to delimit cages where water molecules and chlorine anions are occluded; the frustrated magnetic behaviour of MIL-59 is discussed.     

New organometallic single-source precursors for CuGaS(2)-polytypism in gallite nanocrystals obtained by thermolysis

The complex [((i)Pr(3)PCu)(2)(Me(2)Ga)(2)(SCH(2)CH(2)S)(2)] (4) was synthesized from trimethylgallium, [((i)Pr(3)PCu)(4)(SCH(2)CH(2)S)(2)] (1) and ethanedithiol by elimination of methane. The related monomethyl compound [((i)Pr(3)PCu)(2)(MeGaSPh)(2)(SCH(2)CH(2)S)(2)] (5) has been prepared from [((i)Pr(3)PCuSPh)(3)] (2) and [(MeGaSCH(2)CH(2)S)(2)] (3) by a ligand exchange reaction in tetrahydrofuran solution. The molecular structures of 1 and 3-5 were determined by single crystal X-ray diffraction. Thermolysis of 4 and 5 results in the formation of the ternary semiconductor CuGaS(2), gallite. The residue of 5 was characterized using X-ray powder diffraction, energy dispersive X-ray spectroscopy and transmission electron microscopy. The CuGaS(2) crystals obtained are mainly hexagonal plates of around 200 to 300 nm diameter and 10 to 30 nm thickness, exhibiting an unusual metastable hexagonal crystal structure, related to wurtzite. Partially, the usual tetragonal chalcopyrite structure or its disordered cubic zinc-blende analogue is realized by stacking faults, resulting in an overall similarity to the zinc-blende-wurtzite polytypism in ZnS and related compounds.     

VIII(OH)[O2C-C6H4-CO2].(HO2C-C6H4-CO2H)x(DMF)y(H2O)z(or MIL-68), a new vanadocarboxylate with a large pore hybrid topology: reticular synthesis with infinite inorganic building blocks?

V(III)(OH)[O(2)C-C(6)H(4)-CO(2)].(HO(2)C-C(6)H(4)-O(2)H)(x)(DMF)(y)(H(2)O)(z) or MIL-68 was solvothermally synthesised in a non-aqueous medium. Its structure, built up from octahedral chains connected by terephthalate linkers, exhibits large hexagonal channels containing different occluded moieties. Their irreversible removal releases a specific surface area of 603(22) m(2).g(-1)(BET).     

Synthesis, Structure and Luminescent Properties of a New Terbium（Ⅲ） Complex with 5-Bromoisophthalic Acid

The self-assembly of 5-bromoisophthalic acid (H2BIPA) with Tb(NO3)3·6H2O under hydrothermal conditions gives rise to a 3D coordination polymer, [Tb2(BIPA)3(CH3CH2OH)]n (1), which was characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal is of monoclinic system, space group P21/c with a = 19.2591(17), b = 8.2537(7), c = 18.5663(17), β = 104.4720(10)°, V = 2857.6(4)3, C26H15Br3O13Tb2, Mr = 1092.95, Dc = 2.540 g/cm3, F(000) = 2040, μ = 9.173 mm-1 and Z = 4. The final R = 0.0324 and wR = 0.0767 for 5299 observed reflections (I > 2σ(I)). Complex 1 displays an unusual three-dimensional (4,6)-connected network with (48.66.8)2(44.62)2(42.84) topology, which is different from [Tb(HBDC)(BDC)(H2O)4]·3.3H2O (BDC = isophthalate) because the -Br substituent of isophthalate results in different electronic effect and steric hindrance to change the coordination modes of carboxylate groups in the assembly process. Moreover, luminescent properties of 1 have also been investigated in the solid state.