Synthesis of calcium titanate from [Ca(H2O)3]2[Ti2(O2)2O(NC6H6O6)2]·2H2O as a cheap single-source precursor

Calcium titanate (CaTiO₃) was conveniently synthesized by thermal decomposition of a single-source precursor [Ca(H₂O)₃]₂[Ti₂(O₂)₂O(NC₆H₆O₆)₂]·2H₂O at low temperature. This single-source precursor was characterized by elemental analysis, IR spectrum, thermal gravimetric analysis and X-ray single crystal diffraction. The calcined products at different temperature were further characterized by powder X-ray diffractions and IR spectra. The morphology, microstructure, and crystallinity of the resulting CaTiO₃ materials have been characterized by SEM and TEM. The BET measurement revealed that the CaTiO₃ powders had a surface area of 14.0 m²/g. In addition, the microwave dielectric properties of the resulting CaTiO₃ material have been measured.     

Syntheses and structures of p-HOOCC6F4COOH · H2O (H2L · H2O) and luminescent coordination polymers [Tb2(H2O)4(L)3 · 2H2O] n and Tb2(Phen)2(L)3 · 2H2O

Compounds p-HOOCC₆F₄COOH · H₂O (H₂L · H₂O), [Tb₂(H₂O)₄(L)₃ · 2H₂O] _n (I), and Tb₂(Phen)₂(L)₃ · 2H₂O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H₂L · H₂O is built of centrosymmetric molecules H₂L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb₂(H₂O)₄(L)₃] _n and molecules of water of crystallization. The ligands are the L^2? anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO₉ is a distorted three-capped trigonal prism. Acid H₂L manifests photoluminescence in the UV region (??_max = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb³⁺ ions, and the band with ??_max = 545 nm (transition ⁵ D ₄?? ⁷ F ₅) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I.     

Synthesis and Crystal Structure of a Cyano-bridged Bimetallic Complex [La(betaine)2(H2O)6Fe(CN)6]·2H2O

The title complex [La(betaine)2(H2O)6Fe(CN)6](2H2O (betaine = (CH3)3NCH2CO2) has been synthesized and characterized by X-ray single-crystal structure analysis. The crystal crystallizes in monoclinic, space group P21/n with a = 15.793(5), b = 8.927(3), c = 22.257(7) (A), β = 110.147(5)°, C16H38FeLaN8O12, Mr = 729.31, Z = 4, V = 2946.0(15) (A)3, Dc = 1.640 g/m3, μ(MoKα) = 1.988 mm-1, F(000) =1476, R = 0.0388 and wR = 0.0827 for 4237 observed reflections (I > 2σ(I)). The La3+ ion is nine-coordinated by one cyano nitrogen atom and eight oxygen atoms of two betaine and six water molecules. Each complex molecule is connected to form a 3D network structure by some O-H…O and O-H…N hydrogen bonds.     

Synthesis and crystal structure of [UO2(L)(OH)], (CN3H6)2[(UO2)2CrO4(L)4 · 2H2O and [UO2(H2O)5][(UO2)2Cr2O7(L)4] (where L is picolinate ion)

[[UO₂(L)(OH)] (I), (CN₃H₆)₂[(UO₂)₂CrO₄(L)₄] · 2H₂O (II), and [UO₂(H₂O)₅][(UO₂)₂Cr₂O₇(L)₄] (III) crystals, where L is picolinate ion C₅H₄NCOO^?, have been synthesized and studied by X-ray diffraction and IR spectroscopy. Complex I crystallizes in triclinic system with the unit cell parameters a = 6.2858(5) Å, b = 7.9522(5) Å, c = 8.3598(6) Å, α = 79.527(6)°, β = 87.760(6)°, γ = 79.126(6)°, space group P $\bar 1$ , Z = 2, R = 0.0306, and complexes II and III crystalize in monoclinic system with a = 8.8630(9) Å, b = 13.4540(13) Å, c = 31.266(3) Å, β = 93.118(3)°, space group C2/c, Z = 4, R = 0.0187 (II), and a = 7.3172(4) Å, b = 15.4719(8) Å, c = 16.6534(10) Å, β = 98.943(4)°, space group P2₁/m, Z = 2, R = 0.0588 (III). The structure of complex I is built of electronegative [UO₂(L)(OH)] chains, which belong to the AT¹¹M² crystallochemical group (A = UO ₂ ²⁺ , T¹¹ = L, M² = OH^?) of uranyl complexes. The structure of complexes II and III contains [(UO₂)₂(L′)(L)₄]^2? dimers (L′ = CrO ₄ ^2? or Cr₂O ₇ ^2? ), which belong to the A₂B²B ₄ ⁰¹ group (A = UO ₂ ²⁺ ,B² = L′, B⁰¹ = L). The specifics of intermolecular interactions in the structures of complexes I–III and some their analogues have been considered using molecular Voronoi-Dirichlet polyhedra.     

Synthesis,Magnetic Property and Crystal Structure of a Ytterbium-Copper Mixed Metal Complex:Yb_2Cu_3L_6·6H_2O (L=O(CH_2COO)_2)

1INTRODUCTIONThesynthesisofpolynuc1earmixedcopper-lanthanoidcomplexesisofinterestforseveralreasons[l-4i.Thesecomplexesareimportanttotheunderstandingofthenature0fthemagneticexchangeinteractionsbetweenrareearthandtransiti0n-metalions,andtheycanpossib1ybeusedasmagneticmaterialst2'33andhightemperaturesuperconductors"'.Itwasbelievedthatthemultidentatepoly-carboxylateacidsisgoodligandsforthepreparationoftheLn-Cumixedmetalcomplexesasthemetalionscanbebridgedbythebidentatecarboxylategroups.Thedig…     

Synthesis and Crystal Structure of a Cyano-bridged Bimetallic Complex[La(betaine)_2(H_2O)_6Fe(CN)_6]·2H_2O

1 INTRODUCTION In the last decade, cyano-bridged Prussian Blueanalogues[1] have been intensively studied from theviewpoint of application as functionalized molecule-based magnets[2], chemical sensor materials[3], fluo-rescent materials[4] and zeolitic-type materials[5, , 6]etc. In 1976, a series of cyano-bridged three-dimen-sional rare earth hexacyanometalates(IIILnM(CN)6?nH2O (M = Fe or Cr, n = 4 or 5) were crystallized andsubjected to single-crystal X-ray analysis[7]. …     

Outer-sphere addition compounds of MoO2Br2(H2O)2 with ethers. Molecular structure of MoO2Br2(H2O)2·L (L=2,5,8-trioxanonane; 2,5,8,11,14-pentaoxapentadecane)

Outer-sphere addition compounds of MoO₂Br₂(H₂O)₂ with diethyl ether, dioxane, glyme, diglyme, triglyme and tetraglyme have been readily prepared by crystallizing diethyl ether extracts of a solution of sodium molybdate in concentrated hydrobromic acid in the presence of the corresponding ether. The molecular structures of MoO₂Br₂(H₂O)₂·L (L=2,5,8-trioxanonane; 2,5,8,11,14-pentaoxapentadecane) have been established by X-ray diffraction analysis.     

Synthesis and crystal structure of a coordination polymer {[Cu2(L)2(Phen)2] · 8H2O} n

A novel metal coordination polymer, {[Cu₂(L)₂(Phen)₂] · 8H₂O} _n (I), has been synthesized by the reaction of Cu(NO₃)₂ with 2,2′-bipyridyl-4,4′-dicarboxylic acid (L) and 1,10-phenanthroline (Phen) at room temperature. The polymer was characterized by IR, elemental analyses and X-ray diffraction. Single-crystal structural analysis reveals that the center Cu²⁺ ions have two coordinated types. The Cu(1) atom has the five-coordinate mode, and Cu(2) forms an is octahedron of the six-coordinate mode. Two Cu²⁺ ions are connected by the O atom of carboxylate group bridges. Complex I contains eight molecules of water clusters and constructed a 1D tape structure.     

Synthesis,Structure and Characterization of a New Complex: [Mn(C_6H_(12)N_4)_2(H_2O)_4][Mn(H_2O)_6][SO_4]_2·6H_2O

A novel complex,[Mn(C_6H_(12)N_4)_2(H_2O)_4][Mn(H_2O)_6][SO_4]_2·6H_2O,was synthesized and hexagonal single crystals with centimeter-scale sizes were obtained by the method of solvent evaporation.It was characterized by elemental analysis,infrared spectrum,thermogravimetric analysis and X-ray single-crystal diffraction.The complex belongs to triclinic crystal system,space group P■ with a=9.3390(8),b=13.3520(13),c=16.3207(13)?,α=100.7160(3)°,β=90.1020(10)°,γ=109.9490(5)°,V=1874.9(3)?~3,Z=2,D_c=1.542 g/cm~3,M_r=870.64,μ=0.876 mm~(-1),T=293(2) K,F(000)=916 and S=0.990.The crystal structure determination displayed a distorted octahedral geometry around the manganese atom,which is bound to two nitrogen atoms from hexamethylenetetramine,acting as monodentate ligands,and to four aqua ligands.Variable-temperature magnetic measurements of the complex indicate the presence of weak antiferromagnetic interaction between manganese centers.     

Dinuclear copper(II) complexes with ferromagnetic and antiferromagnetic interactions mediated by a bridging oxalato group: structures and magnetic properties of [Cu2L4(μ-C2O4)](PF6)2(H2O)2 and [Cu2L2(μ-C2O4)(NO3)2((CH3)2NCOH)2] (L = di-2-pyridylamine)

Two dinuclear Cu^II complexes of formula [Cu₂(dpyam)₄(μ-C₂O₄)](PF₆)₂(H₂O)₂ (1) and [Cu₂(dpyam)₂(μ-C₂O₄)(NO₃)₂(DMF)₂] (2) (dpyam=di-2-pyridylamine) have been synthesized and their spectroscopic and magnetic properties characterized. Complex (1) crystallizes in the non-centrosymmetric monoclinic space group Pc, while (2) crystallizes in the non-centrosymmetric triclinic space group P1. Compound (1) involves the compressed octahedral Cu^II environment, whereas (2) exhibits an elongated octahedral Cu^II geometry. Both complexes contain six-coordinate metal centers bridged by planar bis-didentate oxalate group. The geometry, spectroscopic properties and the effective magnetic moment of (1) are very close to those of the recently published [Cu₂(dpyam)₄ (μ-C₂O₄)](ClO₄)₂(H₂O)₃ and [Cu₂(dpyam)₄(μ-C₂O₄)](BF₄)₂(H₂O)₃. Thus (1) is expected to exhibit a very weak ferromagnetic interaction between the Cu^II centers which is confirmed by EPR spectrum. Those of (2) are comparable to those of the recently published [Cu₂(dpyam)₂(μ-C₂O₄)(NO₃)₂(DMSO)₂]. Therefore a strong antiferomagnetic interaction is expected. The effective magnetic moment at room temperature of (1) was measured to be 2.55 BM/dimer, which agrees with the spin only value of Cu^II, 2.45BM calculated for two uncoupled spin=1/2 centers. In (2) the room temperature effective magnetic moment of 2.16 BM/dimer indicates the partial spin paring by antiferromagnetic coupling. This is confirmed by the e.p.r. spectrum and is explained as a result of the magnetic interaction between the coplanar ${\rm d}_{x^2-y^2}$ orbitals on the two copper atoms.     

Crystal structure of a tantal cluster with tetraphenylborate-anion: [Ta6Br12(H2O)6](BPh4)2·4H2O

The crystal structure of the [Ta₆Br₁₂(H₂O)₆](BPh₄)₂·4H₂O salt (1), obtained from Ta₆Br₁₄·7H₂O and NaBPh₄, is determined by X-ray crystallographic analysis. The structure contains a network of hydrogen bonds, which organizes the cluster cations into layers.     

Tansition metal complexes with 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL): Synthesis and crystal structure of [Co(L)2(H2O)4] · 6H2O and [Cu(L)2(H2O)2] · 4H2O

Transition metal complexes of 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL), namely [Co(L)₂(H₂O)₄] · 6H₂O (I) and [Cu(L)₂(H₂O)₂] · 4H₂O (II), have been synthesized by a hydrothermal procedure and characterized by X-ray crystallography, CIF files CCDC nos. 1007524 (I), 1007525 (II). Both I and II are mononuclear molecules. In I, the Co²⁺ ion is in octahedral coordiantion environment and surrounded by four O atoms from water molecules and two carboxylate O atoms of two deprotonated ligand (L^?) occupied six culmination. While in II, the Cu²⁺ ion is located in a square-planar geometry, bounded to two aqua O atoms and two carboxylate O atoms from L^?.     

Synthesis and Structure Characterization of a Tetranuclear Manganese(Ⅲ) Complex:[Mn4O2(O2CMe)6(MeOH)2(dbm)2]·2MeCOOH·2CH2Cl2

The title compound, [Mn4O2(O2CMe)6(MeOH)2(dbm)2]·2MeCOOH·2CH2Cl2 (Hdbm = dibenzoylmethane), has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P(-l), with a = 10.729(3), b = 12.269(3), c =13.085(4) (A), a = 106.367(3), β = 107.643(2), γ = 94.771(2)°, V = 1547.9(7) (A)3, Z = 1,C50H64Cl4Mn4O24, Mr= 1410.57, Dc= 1.513 g/em3, F(000) = 724, Rint = 0.0147, T = 293(2) K and μ = 1.046 mm-1. The fimal R = 0.0359 and wR = 0.0938 for 5791 observed reflections with I ＞ 2( )I).The structure of the complex consists of one [Mn4(μ3-O)2]8+ core with four coplanar Mn atoms disposed in an extended "butterfly-like" arrangement and two O atoms triply bridging each "wing",and the peripheral ligation is provided by six μ2-MeCO2-, two terminalμ2-dbm- groups at the two hydrogen bonding interactions are found within the structure of the compound.     

Synthesis and structural characterization of a novel organic-inorganic supermoleculer of [FeII(Phen)3]L2 · 2H2O complex

A new organic-inorganic complex [Fe^II(Phen)₃]L₂ · 2H₂O (Phen = 1,10-phenanthroline, L = 2-mercaptonicotinic acid) was synthesized and characterized. The crystal structure of the complex was determined by single-crystal X-ray diffraction, crystallizing in orthorhombic crystal system, space group Pba2 with the unit cell parameters a = 13.4711(11), b = 17.0021(14), c = 11.7026(9) Å, and Z = 2. The Fe(II) atom was six-coordinated with N(1), N(1A), N(2), N(2A), N(3), and N(3A) from three Phen ligands and formed a slightly distorted octahedral geometry. The base units form a one-dimensional chain via π-π-stacking interaction between 2-mercaptonicotinic acid fragments. A new 3D layered compound was obtained through hydrogen bonding.     

Synthesis,Structure and Biological Activities of a Novel Anionic Organotin(Ⅳ) Complex {[(pClC_6H_4CH_2)Sn(H_2O)(Cl)_2OCOCH(O)CH(O)CO_2Sn(H_2O)(Cl)_2(p-ClC_6H_4CH_2)]·2(HNEt_3)}

A novel anionic organotin(Ⅳ) complex {[(pClC_6H_4CH_2)Sn(H_2O)(Cl)_2OCOCH(O)CH(O)CO_2Sn(H_2O)(Cl)_2(p-ClC_6H_4CH_2)]·2(HNEt_3)}(1) was synthesized by the reaction of di(p-chlorobenzy)tin dichloride with the D-tartaric acid in 2:1 molar in the presence of an organic base triethylamine. The structure was characterized by elemental analysis, IR, TG, XRD and single-crystal X-ray diffraction. It crystallizes in triclinic, P1 space group, with a = 0.7067(1), b = 1.9762(3), c = 2.2383(3) nm, α = 91.544(2)°, β = 90.075(2)°, γ = 90.110(2)°, V = 3.1247(7) nm~3, Z = 3, Dc = 1.621 g/cm~3, m(Mo Kα) = 16.29 cm–1, F(000) = 1530, R = 0.0394, wR = 0.1092,(Δρ)max = 1224 and(Δρ)min = –840 e/nm~3. The stabilities, orbital energies and composition characteristics of some frontier molecular orbitals of 1 have been carefully investigated with quantum chemistry calculation. In addition, the in vitro antitumor activity suggested that 1 had stronger inhibitory activity on H460, MCF7 than on A549.     

Synthesis and Crystal Structure of a Palladium(Ⅱ)Coordination Polymer [Na2Pd(2,6-pydc)2(H2O)6]n

A novel coordination polymer [Na2Pd(2,6-pydc)2(H2O)6]n (2,6-H2pyde = 2,6-pyri-dinedicarboxylie acid) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinie system, space group P21/c,with a = 11.962(2), b = 6.5552(13), c = 12.673(3) A, β = 91.72(3)°, V= 993.3(3) A3,Z = 2, Mr=590.68, Dc = 1.975 g/cm3,μ=1.059 mm-1, F(000) = 592, the final R = 0.0211 and wR = 0.0454. In the crystal the Pd(Ⅱ) ion adopts a distorted four-coordinated square-planar geometry and bonds to two bidentate 2,6-pyridinedicarboxylate molecules through caronyl oxygen and pyridine nitrogen atoms. The title complex exhibits a novel three-dimensional network structure.     

FeCl3·6H2O catalyzed diastereoselective synthesis of (L)-menthyl 4-oxo-2-arylpiperidine-3-carboxylates

An efficient diastereoselective synthesis of substituted piperidines is accomplished by using catalytic amount of FeCl₃·6H₂O via intramolecular aza-Michael addition of carbamate on alkylidene β-keto (L)-menthyl esters in a very short time.     

Synthesis and crystal structure of a novel tartrate copper(II) two-dimensional coordination polymer: {[Cu2(C4H4O6)2(H2O)2]·4H2O}∞

A new 2D coordination polymer, {[Cu₂(C₄H₄O₆)₂(H₂O)₂]·4H₂O}_∞ has been synthesized by the hydrothermal method and characterized by X-ray single crystal diffraction. Every copper(II) atom adopts a distorted octahedral geometry and coordinates with six oxygen atoms from one water molecule and three tartrate acid ions. The two tartrate acid ions have different coordination modes, one provides four oxygen atoms to coordinate with Cu(II) and another coordinates with all six oxygen atoms. Such a coordination mode generates a two-dimensional coordination polymer. In the solid state, the title compound forms a 3D network structure through hydrogen bonds.