Synthesis and structure of a three-dimensional lanthanide complex [Tm2(C5H3N(COO)2)3(H2O)3)]·H2O

A new three-dimensional complex [Tm₂(C₅H₃N(COO)₂)₃(H₂O)₃)]·H₂O (PDC?=?3,5-pyridinedicarboxylate), has been synthesized and its structure determined by x-ray single crystal diffraction methods. Complex 1 crystallizes in the monoclinic space group P2(1)/n with a?=?14.579(4), b?=?11.193(3), c?=?14.839(5)?Å, β?=?94.009(6)°, U?=?2415.5(13)?ų. Two independent PDC ligands bridge Tm^III ions from different orientations to form a network. Thermogravimetric analyses on compound 1 show its high structural stability to 410°C.     

Synthesis and Crystal Structure of Mn(phen)(CF3COO)(H2O)3·NO3

The mononuclear manganese complex Mn(phen)(CF3COO)(H2O)3(NO3 (C14H14O8N3F3Mn) has been synthesized, where phen = 1,10-phenanthroline. The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 8.8550(3), b = 10.6529(3), c = 19.8763(2) A, β = 97.762(2)o, V = 1857.78(8) A3, Z = 4, Mr = 464.22, Dc = 1.660 g/cm3, μ = 0.789 mm-1, F(000) = 940, T = 293(2) K, R = 0.0764 and wR = 0.2441 for 1995 observed reflections with I > 2σ(I). In the crystal the manganese atom is six-coordinated by two chelated nitrogen atoms from phenanthroline, three oxygen atoms from water molecules and one oxygen atom from trifluoroacetate, completing an octahedral geometry.     

Synthesis and structure of [Cr3O(CH3COO)6(H2O)3][UO2 (CH3COO)3] · 3H2O

Crystals of [Cr₃O(CH₃COO)₆(H₂O)₃][UO₂(CH₃COO)₃]·3H₂O (I) were synthesized for the first time and studied by X-ray crystallography. The crystals of I are orthorhombic: a = 8.3561(3) ?, b = 16.8421(5) ?, c = 25.7448(9) ?, V = 3623.2(2) ?³, space group P2₁2₁2₁, Z = 4, R = 0.0409. The structure is composed of trinuclear [Cr₃O(CH₃COO)₆(H₂O)₃]⁺ complexes and mononuclear [UO₂(CH₃COO)₃]^? complexes classified with crystal-chemical groups A₃M³B ₆ ² M ₃ ¹ (A = Cr³⁺, M³ = O^2?, B² = CH₃COO^?, M¹ = H₂O) and AB ₃ ⁰¹ (A = UO ₂ ²⁺ , B⁰¹ = CH₃COO^?), respectively. The complexes are bound to each other by electrostatic interactions and hydrogen bonds involving outer-sphere water molecules. The results of IR spectroscopic study of I are in good agreement with the structural data for the crystal.     

Synthesis and Structure of a Novel Rare Earth Complex: Eu3(dpa dioxide)4·(CF3COO)5·H2O

The novel europium complex Eu3(dpa dioxide)4·(CF3COO)5·H2O (dpa dioxide = di-2-pyridylamine N,N'-dioxide) was prepared by the reaction of Eu(CF3CO2)3 with Dpa dioxide in acetonitrile under 95 ℃ and determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic system, space group C2/c with a = 41.632(8), b = 14.662(3), c = 23.300(4)(A),β= 100.862(5)°, Z = 8, D = 1.775 g/cm3, V = 13968(4)(A)3, F(000) = 7232, the final R = 0.0464 and wR = 0.1168. In this tri-nuclear complex, each europium(Ⅲ) is nine-coordinated to adopt an unequal sphere geometry.     

Synthesis and X-ray diffraction study of cs3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)] and Cs5[UO2(CH3COO)3]3[UO2(NCS)4(H2O)] · 2H2O

Cs₃[UO₂(CH₃COO)₃]₂[UO₂(CH₃COO)(NCS)₂(H₂O)] (I) and Cs₅[UO₂(CH₃COO)₃]₃[UO₂ (NCS)₄(H₂O)] · 2H₂O (II) have been synthesized via the reaction between uranyl acetate and cesium thiocyanate in aqueous solution. According to single-crystal X-ray diffraction data, both compounds crystallize in monoclinic system with the unit cell parameters a = 18.7036(5) Å, b = 16.7787(3) Å, c = 12.9636(3) Å, β = 92.532(1)°, space group C2/c, Z = 4, R = 0.0434 (I); and a = 21.7843(3) Å, b = 24.6436(5) Å, c = 13.1942(2) Å, β = 126.482(1)°, space group Cc, Z = 4, R = 0.0273 (II). Uranium-containing structural units of compound (I) are mononuclear [UO₂(CH₃COO)₃]^? and [UO₂(CH₃COO)(NCS)₂(H₂O)]^? moieties, which correspond to the AB ₃ ⁰¹ and AB⁰¹M ₃ ¹ crystallochemical groups (A = UO ₂ ²⁺ , B⁰¹ = CH₃COO^?, M¹ = NCS^? and H₂O). The structure of compound II is built of [UO₂(CH₃COO)₃]^? and [UO₂(NCS)₄(H₂O)]^2? complexes, which belong to the AB ₃ ⁰¹ and AM ₅ ¹ crystallochemical groups, respectively. Uranium-containing complexes in both structures are linked into a framework by hydrogen bonds and electrostatic interactions with cesium cations. The IR spectra of compounds I and II agree well with X-ray diffraction data.     

Cu(CH3COO)2·H2O脱水反应动力学探讨

水合乙酸铜;;脱水动力学;热分析;等温等转化率法;Cu(CH3COO)2·H2O脱水反应动力学探讨     

Dimeric Structure and Electronic Conformation of Tb(CF3COO)3⋅3H2O According to Luminescence Data

The results of X-ray diffraction and luminescence analyses of Tb(CF₃COO)₃3H₂O are presented. According to X-ray diffraction analysis, the compound is a centrosymmetric dimer. The electronic structure of this compound was established from the luminescence and excitation spectra. The energies of the singlet and triplet levels of the molecule were estimated and their positions in the structure of the terms of the terbium(III) ion as well as the nepheloxetic shift values were determined. It follows from the analysis of the luminescence spectra that the dimer molecule of the compound in the excited state is not centrosymmetric.     

Synthesis and structures of Pb3O2(CH3COO)2·0.5H2O and Pb2O(HCOO)2: two corrosion products revisited

Reactions of carboxylic acids with lead play an important role in the atmospheric corrosion of lead and lead-tin alloys. This is of particular concern for the preservation of lead-based cultural objects, including historic lead-tin alloy organ pipes. Two initial corrosion products, Pb(3)O(2)(CH(3)COO)(2)·0.5H(2)O (1) and Pb(2)O(HCOO)(2) (2), had been identified through powder diffraction fingerprints in the Powder Diffraction File, but their structures had never been determined. We have crystallized both compounds using hydrothermal solution conditions, and structures were determined using laboratory and synchrotron single-crystal X-ray diffraction data. Compound 1 crystallizes in P1, and 2 in Cccm. These compounds may be viewed as inorganic-organic networks containing single and double chains of edge-sharing Pb(4)O tetrahedra and have structural similarities to inorganic basic lead compounds. Bond valence sum analysis has been applied to the hemidirected lead coordination environments in each compound. Atmospheric exposure experiments contribute to understanding of the potential for conversion of these short-term corrosion products to hydrocerussite, Pb(3)(CO(3))(2)(OH)(2), previously identified as a long-term corrosion product on lead-rich objects. Each compound was also characterized by elemental analysis, thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), and Raman spectroscopy.     

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.     

On the thermal decomposition of [Fe2NiO(CH3COO)6(H2O)3]·2H2O

The heteronuclear-oxoacetate with the composition [Fe₂NiO(CH₂COO)₆(H₂O)₃]·2H₂O decomposed on heating, forming nickel ferrite NiFe₂O₄ and (depending on the decomposition conditions) in part other solid phases. H₂O, CH₃COOH, acetone and CO₂ were also formed in the decomposition. A reaction scheme is given for the decomposition. The products were porous powders with grain diameters between 3 and 10m. On increase of the temperature of decomposition from 300 to 800 C, the BET surface area and the surface area of the pores decreased, but only a small alteration in grain size was observed. As a result of thermal treatment in the temperature region abone 800C, larger aggregates of grains were formed in sintering processes.

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Zusammenfassung Heteronukleare-Oxoazetate der Zusammensetzung [Fe₂NiO(CH₃COO)₆(H₂O)₃]·2H₂O werden durch Erhitzen zersetzt, wobei Nickelferrite NiFe₂O₄ und — in AbhÄngigkeit von den Bedingungen der Zersetzung — mit einem Teil anderer fester Phasen gebildet wird. In der Zersetzungsreaktion werden auch H₂O, CH₃COOH, Azeton und CO₂ gebildet. Es wird ein Reaktionsschema für die Zersetzung angegeben. Die Produkte sind poröse Pulver mit einem Korndurchmesser zwischen 3 und 10 m. Wird die Zersetzungstemperatur von 300 auf 800C erhöht, nimmt die BET-OberflÄche und die PorenoberflÄche ab, wobei sich die Korngrö\e aber nur wenig verÄndert. Im Ergebnis der WÄrmebehandlung im Temperaturbereich oberhalb 800C werden durch Sinterprozesse grö\ere Partikelaggregate gebildet.

     

Synthesis and Structure of Trinuclear Iron Acetate [Fe3O(CH3COO)6(H2O)3][AuCl4]·6H2O

Iron acetate of composition [Fe₃O(CH₃COO)₆(H₂O)₃][AuCl₄]·6H₂O (I) was synthesized and investigated by X-ray diffraction analysis and Mössbauer spectroscopy. The [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ complex cation has a structure typical for ₃-O bridged trinuclear ferric compounds with iron atoms lying at the vertices of a regular triangle with an oxygen atom at the center. The iron atoms are each coordinated by 4 oxygen atoms of the four bridging carboxylic groups, the ₃-O bridging atom, and the coordinated water molecule in the trans-position to the latter. In the trinuclear cation, the Fe(III) ions are coupled by antiferromagnetic exchange interactions with the exchange parameter J = -29.0 cm ^–1 (HDVV model for D _3h symmetry). The specific role of the solvate water molecules in structure formation is discussed.     

Crystal,molecular, and electronic structure of carboxylate [Fe3O(CH3COO)6(H2O)3]NO3·4H2O

Results of X-ray structural analysis, IR spectroscopy, and quantum chemical study of the [Fe₃O(CH₃COO)₆(H₂O)₃]NO₃·4H₂O complex are reported. The crystal belongs to the monoclinic system with a=15.688(3), b=11.767(2), c=15.318(4) Å, γ=92.54(3)^o, space group P2₁/a, R=0.078. The molecule has a trinuclear structure: three iron atoms occupy the vertices of an equilateral, triangle with an Fe−Fe distance of 3.29 Å and are bonded by the μ₃-oxo and μ-CH₃COO⁻ (O,O′) ligands. To each iron atom, one water molecule is coordinated. Using the obtained values of populations on 3d AO of Fe (d _xy ^1.34 ; d _xz ^1.39 ; d _yz ^1.46 ; ; ) and charges on oxygen atoms (O _c ^−0.5 ; O _ac ^−0.31 ; O _w ^−0.31 ), we estimated the values of isomeric shift and quadrupole splitting (0.75 and 0.70 mm/sec, respectively; these are close to the experimental values of 0.75 and 0.58 mm/sec, (300 K)). Institute of Chemistry, Moldovian Academy of Sciences. Moldovian State University. Institute of Applied Physics, Moldovian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii., Vol. 35, No. 2, pp. 112–120, March–April, 1994. Translated by T. Yudanova     

Synthesis,Structure and Characterization of Three Metal Molybdate Hydrates: Fe(H2O)2(MoO4)2·H3O,NaCo2(MoO4)2(H3O2)and Mn2(MoO4)3·2H3O

Three metal molybdate hydrates,Fe(H2O)2(MoO4)2·H3O(FeMo),NaCo2(MoO4)2(H3O2)(CoMo)and Mn2(MoO4)3·2H3O(MnMo),were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray...     

Synthesis and structure of (NH4)2[(UO2)2(C2O4)(CH3COO)4] · 2H2O

Single crystals of (NH₄)₂[(UO₂)₂C₂O₄(CH₃COO)₄] · 2H₂O have been synthesized and studied. The compound crystallizes in the orthorhombic system with the unit cell parameters a = 6.9225(14) Å, b = 12.327(3) Å, c = 14.619(3) Å, space group Immm, Z = 2, and V = 1247.6(5) ų. The main structural units of the crystals are the isle binuclear groups [(UO₂)₂C₂O₄(CH₃COO)₄]^2? belonging to the crystal-chemical group A₂K⁰²B ₄ ⁰¹ (A = UO ₂ ²⁺ , K⁰² = C₂O ₄ ^2? , B⁰¹ = CH₃COO^?) of the uranyl complexes. The uranium-containing groups are linked into a three-dimensional framework due to electrostatic interaction with the ammonium cations and through a system of hydrogen bonds involving atoms of the water molecules, oxalate and acetate ions, and ammonium and uranyl cations.     

Rb[C6H3(COOH)2(COO–)] · [C6H3(COOH)3] · 2H2O: Synthesis,Crystal Structure,and Properties

The salt Rb[C₆H₃(COO)₂(^–)] · [C₆H₃(COOH)₃] · 2H₂O (I) of trimesic acid was synthesized and its thermal stability and conductivity (10^–11 ohm^–1 cm^–1 at 298 K) were measured. Molecular and crystal structures of I were established by X-ray diffraction analysis. Hydrogen bonding system in complex I was detected by IR and Raman spectroscopies. X-ray diffraction data agree with vibration spectroscopy data.     

The complexation of cadmium acetate and propionate by phenanthroline. Structure and properties of [Cd(CH3COO)2(C12H8N2)(H2O)] · H2O and [Cd(CH3CH2COO)2(C12H8N2)]2 · 2CH3CH2COOH

The coordination compounds [Cd(CH₃COO-κO ¹,O ²)₂(phenanthroline-kN ¹ N ²)(H₂O)] · H₂O (1) and [Cd{μ-(CH₃CH₂COO-κO ¹,O ²)}₂(phenanthroline-κN ¹,N ²)]₂ · 2CH₃CH₂COOH (2) were synthesized and characterized by elemental and thermal analysis and IR spectroscopy. Crystal and molecular structures of both compounds were determined. The complexes are air stable and fairly soluble in water. In both compounds the cadmium is seven-coordinate and contains chelating phenanthroline and two chelating carboxylate groups in the inner coordination sphere. The seventh coordinating oxygen belongs to water in 1 and to bridging carboxylate in 2. All carboxylate groups are bonded unsymmetrically to the central atom. The coordination polyhedra can be described as distorted pentagonal bipyramid (compound 1) and distorted capped tetragonal bipyramid (compound 2). In the structure of 1 intermolecular O(water)–H ··· O (water/carboxylate) hydrogen bonds create a two-dimensional net along the crystallographic a0c plane. Each molecule of 2 is connected to two propionic acid molecules via hydrogen bonds. In both compounds exist π-stacking interactions.     

New mixed-anion zinc(II) complexes, [Zn(phen)2(CCl3COO)(H2O)](NO3) and [Zn(bpy)2(CH3COO)](ClO4) · H2O; synthesis,characterization and crystal structures

Zinc(II) complexes with 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy) containing two different anions have been synthesized and characterized by elemental analysis, IR-, ¹H?NMR-, ¹³C?NMR spectroscopy. The single crystal X-ray data of [Zn(phen)₂(CCl₃COO)(H₂O)](NO₃) show the complex to be monomeric and the Zn atom with an unsymmetrical six-coordinate geometry, coordinated by four nitrogen atoms of “phen”, one trichloroacetate and one water. The crystal structure of [Zn(bpy)₂(CH₃COO)](ClO₄)?·?H₂O shows each zinc atom chelated by the nitrogen atoms of “bpy” and also two oxygen atoms of acetate. From the infrared spectra and X-ray crystallography, it is established that coordination of the carboxylate group to zinc is different for trichloroacetate and acetate.     

Crystal structure of compounds [Ln(H2O)8]3+·4CCl3COO?·4H2O·2(4-bpy)·(4-bpyH)+(Ln(III) = Gd, Tb, Er, AND Tm)

Novel compounds of Gd(III), Tb(III), Er(III), and Tm(III) with 4,4??-bipyridine (4-bpy) and trichloroacetates are prepared. The title compounds are isomorphic and isostructural in the solid state. All atoms in the studied compound lie in general positions of the Cc space group. The coordination polyhedra around central atoms can be described as bicapped trigonal prisms slightly disordered towards a square antiprism. All 4-bpy molecules are located in the outer coordination sphere together with four trichloroacetate anions and four water molecules. One of the nitrogen atoms of one 4-bpy is protonated due to stoichiometry.     

Synthesis and properties of tetraalkylammonium chlorides peroxosolvates (CH3)4NCI·H2O2 and (C2H5)4NCl·H2O2

Tetraalkylammonium chlorides peroxosolvates (CH₃)₄NCl·H₂O₂ and (C₂H₅)₄NCl·H₂O₂ were synthesized. The composition of the solvates was proved by chemical analysis; their X-ray patterns, IR spectra, and thermograms were obtained. The solubility of the solvates in water and their stability in aqueous solutions were investigated.     

Ionic crystals based on Keggin anion and mixed-valent diruthenium tetracetate: [Ru2(CH3COO)4(H2O)2]2[HnXW12O40]·[Ru2(CH3COO)4(H2O)Cl]·12H2O (X = B,Si, Ge)

Three new ionic crystals based on Keggin anion and mixed-valent diruthenium tetracetate, [Ru₂(CH₃CO₂)₄(H₂O)₂]₂[H_nXW₁₂O₄₀]·[Ru₂(CH₃CO₂)₄(H₂O)Cl]·12H₂O {X = B, n = 3 (1); X = Si, n = 2 (2); X = Ge, n = 2 (3)}, have been prepared in acidic aqueous solution at about pH 3.0 by reaction of K₄BW₁₂O₄₀·mH₂O, K₈SiW₁₁O₃₉·mH₂O and K₈GeW₁₁O₃₉·mH₂O with diruthenium tetracetate Ru₂(CH₃COO)₄Cl, respectively, and their structures were determined by X-Ray diffraction analysis. They are isostructural structure with the ratio of heteropolytungstate anion, Ru₂(CH₃CO₂)₄⁺ cation and neutral molecular Ru₂(CH₃CO₂)₄Cl of 1:2:1. The cyclic voltammetry in 0.5 M KNO₃ aqueous solution at pH 3.0 show the respective electrochemical behaviors of the W-centers and Ru₂-centers for these three complexes. Magnetic data analysis shows that diruthenium units display the ground state electronic configuration π*²δ* with large positive D value.