Synthesis and crystal structure of KNa3[Fe3O(CH3COO)6(H2O)2]3 [α-P2W17Fe(H2O)O61]·32.5H2O

A complex of the composition KNa₃[Fe₃O(CH₃COO)₆(H₂O)₃]₃ [α-P₂W₁₇Fe(H₂O)O₆₁]·32.5H₂O (I) was obtained by interaction of FeCl₃·6H₂O and phosphotungstate K₁₀[α₂-P₂W₁₇O₆₁]·20H₂O in an acetate buffer with a yield of 52%. Compound I was characterized by single crystal X-ray phase analysis and IR spectroscopy. In the crystal structure, the Na and K cations bind [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ trinuclear cations and [α-P₂W₁₇Fe(H₂O)O₆₁]⁷⁻ heteropolytungstate anions into infinite zigzag chains. Original Russian Text Copyright ? 2005 by N. V. Izarova, M. N. Sokolov, A. V. Virovets, H. G. Platas, and V. P. Fedin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 1, pp. 149–155, January–February, 2005.     

Melting and thermal decomposition of [Ni(H2O)6](NO3)2

The two-stage melting process and the thermal decomposition of [Ni(H₂O)₆](NO₃)₂ was studied by DSC, DTA and TG. The first melting point at 328 K is connected with the small and the second melting point at 362 K with the large enthalpy and entropy changes. The thermal dehydration process starts just above ca. 315 K and continues up to ca. 500 K. It consists of three well-separated stages, but the sample mass loss at each stage depends on the experimental regime. However, irrespective of the chosen regime, the total of registered mass losses in stage one and two amounts to three H₂O molecules per one [Ni(H₂O)₆](NO₃)₂ molecule. The remaining three H₂O molecules are gradually freed in the temperature range of 440–500 K in the third stage of the dehydration. Above 580 K, anhydrous Ni(NO₃)₂ decomposes into NO and NiO. The gaseous products were identified by quadrupole mass spectrometer (QMS), and the solid product was identified by X-ray diffraction (XRD) analysis.     

Thermal decomposition of Cu(NO3)2·3H2O at reduced pressures

Thermolysis of Cu(NO₃)₂·3H₂O is studied by means of XRD analysis in situ and mass spectral analysis of the gas phase at P=1/10 Pa at low heating rate. It is shown that stage I of the dehydration (40-80 °C) results in the consecutive appearance of crystalline Cu(NO₃)₂·2.5H₂O and Cu(NO₃)·H₂O. Anhydrous Cu(NO₃)₂ formed during further dehydration at 80-110 °C is moderately sublimed at 120-150 °C. Dehydration is accompanied by thermohydrolysis, leading to the appearance of Cu₂(OH)₃NO₃ and gaseous H₂O, HNO₃, NO₂, and H₂O. The higher pressure in the system, the larger amount of thermohydrolysis products is observed. The formation of the crystalline intermediate CuO_x(NO₃)_y was observed by diffraction methods. Final product of thermolysis (CuO) is formed at 200-250 °C.     

[H3N(CH2)4NH3]2[Al4(C2O4)(H2PO4)2(PO4)4]·4[H2O]: A new layered aluminum phosphate-oxalate

A new layered inorganic-organic hybrid aluminum phosphate-oxalate [H₃N(CH₂)₄NH₃]₂[Al₄(C₂O₄)(H₂PO₄)₂(PO₄)₄]·4[H₂O](AlPO-CJ25) has been synthesized hydrothermally, by using 1,4-diaminobutane (DAB) as structure-directing agent. The structure has been solved by single-crystal X-ray diffraction analysis and further characterized by IR, ³¹P MAS NMR, TG-DTA as well as compositional analyses. Crystal data: the triclinic space group P-1, a=8.0484(7) Å, b=8.8608(8) Å, c=13.2224(11) Å, α=80.830(6)°, β=74.965(5)°, γ=78.782(6)°, Z=2, R_1[I>2σ(I)]=0.0511 and wR_{2(all data)}=0.1423. The alternation of AlO₄ tetrahedra and PO₄ tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO₆ octahedra to form the layered structure with 4,6-net sheet. Interestingly, oxalate ions are bis-bidentately bonded by participating in the coordination of AlO₆, and bridging the adjacent AlO₆ octahedra. The layers are held with each other through strong H-bondings between the terminal oxygens. The organic ammonium cations and water molecules are located in the large cavities between the interlayer regions.     

A new sodium hydroxygallophosphate containing tetrameric gallium units: Na3[Ga4O(OH)(H2O)(PO4)4]·H2O

A new sodium hydroxygallophosphate, Na₃Ga₄O(OH)(H₂O)(PO₄)₄·H₂O, has been prepared by hydrothermal synthesis. Its structure has been determined from a single-crystal X-ray diffraction study. It crystallizes in the P2₁/c space group with the cell parameters a=9.445(2) Å, b=9.028(1) Å, c=19.209(3) Å, β=102.08(2), V=1603.4(4) Å³. Its three-dimensional framework can be described from PO₄ monophosphate groups sharing their apices with original Ga₄O₁₆(OH)(H₂O) tetrameric building units, which result from the assembly of one GaO₄ tetrahedron, one GaO₅ trigonal bipyramid and two octahedra: GaO₅(OH) and GaO₄(OH)(H₂O). The sodium cations and one water molecule are located in tunnels running along b.     

Spectroscopic study of the trinuclear complex salt [Cr3O(CH3COO)6(H2O)3]Cl†6H2O

The presence of two sets of inequivalent trimeric clusters in [Cr₃O(CH₃COO)₆(H₂O)₃]Cl†6H₂O at low temperature has been confirmed by luminescence and luminescence excitation spectroscopy. Assignments of the four lowest level of the lowest electronically excited state have been made. The ground state parameters have been determined.     

Preparation and characterization of pure single-phase BiFeO3 nanoparticles through thermal decomposition of the heteronuclear Bi[Fe(CN)6]·5H2O complex

The heteronuclear Bi[Fe(CN)₆]·5H₂O complex was synthesized and single-phase perovskite-type BiFeO₃ nanoparticles with an average size of 30 nm were obtained by its decomposition at 600 °C. The complex and its decomposition products were analyzed using elemental analysis, thermal analysis (TGA/DTA/DSC), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), UV–Vis spectroscopy, BET specific surface area measurement, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and magnetic measurements. The magnetic measurement confirms that the product shows a ferromagnetic order at room temperature, which may be ascribed to the size confinement effect. The DTA and DSC results confirm the multiferroic nature of the BiFeO₃ nanoparticles with Neel and Curie points at 372 and 825 °C, respectively. The BiFeO₃ prepared by this method could be an appropriate visible-light photocatalytic material due to its strong absorption band in the visible region. This method is simple, low-cost, safe and also suitable for industrial production of high purity perovskite-type BiFeO₃ nanoparticles for electromagnetic applications.     

混合价四核锰配合物[Mn4O2(ClCH2COO)7(bipy)2]•H2O的合成、晶体结构及性质研究

在乙腈溶液中, 由混合价三核锰配合物[Mn₃O(ClCH₂COO)₆(py)₂]•(H₂O) (py为吡啶)与2,2′-联吡啶(bipy)反应合成了混合价(Mn₃^IIIMn^II)四核锰配合物[Mn₄O₂(ClCH₂COO)₇(bipy)₂]•H₂O. 采用元素分析、红外光谱、热分析和X射线单晶衍射法确定了其组成和结构. 标题化合物晶体属于三斜晶系, 空间群P-1, 晶胞参数: a＝0.89854(13) nm, b＝1.4027(2) nm, c＝1.9037(3) nm, α＝93.518(3)°, β＝96.736(3)°, γ＝94.875(3)°, V＝2.3680(6) nm³, Z＝2, D_c＝1.734 g/cm³, F(000)＝1238, GOF＝1.036, R₁＝0.0592, wR₂＝0.1162 [I＞2σ(I)]. 在标题化合物中, 配位结构单元中心为一蝶型[Mn₄(μ₃-O)₂]^7＋多核簇, 含有2个Mn₃(μ₃-O)单元, 具有近似C₂对称轴. 4个Mn离子均为六配位, 外围配体为7个氯乙酸根和2个2,2′-联吡啶, 处于变形的八面体环境. 变温磁化率研究表明标题化合物在整体上表现为反铁磁性耦合作用, 但在低温下的磁相互作用较为复杂.     

[Pb2(TNR)2(CHZ)2(H2O)2]4H2O的结构及热分解机理

The coordination compound of [Pb 2(TNR) 2(CHZ) 2(H 2O) 2]•4H 2O was prepared by using the aqueous solution of carbohydrazide, lead nitrate and sodium styphnate. The molecular structure of [Pb 2(TNR) 2(CHZ) 2(H 2O) 2]•4H 2O(C 7H 13 N 7O 12 Pb, Mr=594.43) was determined by using a single crystal diffraction analysis .The thermal decomposition mechanism of the title compound was studied by TGDTG, DSC and IR techniques. The crystal belongs to monoclinic with space group P2 1/n.The unit cell parameters are as follows: a=0.64700(10)nm, b=1.6074(3)nm, c=1.4883(3)nm,β=97.42(2)°,V=1.5349(5)nm3, Z=2, DC=2.572g•cm -3 ,μ(Mo, Kα)=11.080cm -1 , F(000)=1128. R=0.0422, Rw=0.0735. The binuclear lead coordination compound is bridged by two carbohydrazide molecules. The molecule has a symmetrical center. TNR 2- ,CHZ and H 2O coordinate with the central ions simultaneously.     

[Co(en)3][In3(H2PO4)6(HPO4)3]·H2O: A new layered indium phosphate templated by cobalt complex

A new layered indium phosphate [Co(en)₃][In₃(H₂PO₄)₆(HPO₄)₃]·H₂O (1) has been synthesized solvothermally by using a racemic mix of chiral metal complex Co(en)₃Cl₃ as a template. Its structure is determined by single-crystal X-ray diffraction analysis and further characterized by X-ray powder diffraction, ICP, NMR and TG analyses. The inorganic layer is built up by alternation of In-centred octahedra (InO₆) and P-centered tetrahedra (PO₃(OH), PO₂(OH)₂, PO₂(=O)(OH) and PO(=O)(OH)₂) forming a 4.12-net. The metal complex cations locate in the interlayer region and interact with the host network through H-bonds. It is the first indium phosphate compound templated by a transition-metal complex and is isostructural with GaPO-CJ14. Crystal data: 1, monoclinic, space group P2₁/m (No. 11), a=9.1700(18) Å, b=22.6923(5) Å, c=9.9116(2) Å, β=107.87(3)°, Z=4, R_1[I>2σ(I)]=0.0287 and wR_{2(all data)}=0.0939.     

Investigation of phase transitions of a pseudo-hexagonal phase of [Rh(NH3)5Cl]2[Re6S8(CN)6]·3H2O during thermal decomposition

A general motif of the crystal structure of [Rh(NH₃)₅Cl]₂[Re₆S₈(CN)₆]·3H₂O is examined, and the cluster anions are found to form a pseudo-hexagonal sublattice. The thermal decomposition of [Rh(NH₃)₅Cl]₂[Re₆S₈(CN)₆]·3H₂O is studied, and it is shown that in helium atmosphere thermolysis occurs through the formation of intermediate amorphous phases. The final product obtained at 1200°C is a disordered single-phase solid solution of Re_0.75Rh_0.25 based on the structure of rhenium. Powder X-ray diffraction data for solid solutions in the system of Rh-Re are surveyed. It is demonstrated that the data for phases prepared by the thermal decomposition of coordination compounds better match the theoretical state diagram than the experimental one. The dependence of atomic volume on the composition of solid solutions of Re_xRh_1−x is derived. Original Russian Text Copyright ? 2007 by S. A. Gromilov, K. V. Yusenko, and E. A. Shusharina __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No.5, pp.957–962, September–October, 2007.     

Thermal decomposition course of Eu(CH3COO)3·4H2O and the reactivity at the gas/solid interface thus established

The thermal decomposition course of europium acetate tetrahydrate (Eu(CH₃COO)₃·4H₂O) was probed on heating up to 1000 °C in a dynamic atmosphere of air by thermogravimetry and differential thermal analysis. The solid- and gas-phase decomposition products were identified by X-ray diffractometry, ex- and in situ infrared spectroscopy and mass spectrometry. Results obtained showed the acetate to dehydrate stepwise at 145-283 °C, and then decompose stepwise to yield eventually cubic-Eu₂O₃ at ≥663 °C encompassing the formation of intermediate oxycarbonate (Eu₂O(CO₃)₂/Eu₂O₂(CO₃) solid products (at 347-466 °C)) and H₂O, (CH₃)₂CO and CO₂ as primary gaseous products. A considerable enhancement of the production of the primary gas phase products at 400-450 °C and the emergence of (CH₃)₂CCH₂, CH₄ and CO molecules in the gas phase are ascribed to reactions occurring at the gas/solid interface at the expense of some of the primary products. These interfacial activities impart application-worthy adsorptive and catalytic functions for the associated solid products.     

Synthesis,crystal structure and magnetic properties of the helical oxalate-bridged copper(II) chain {[(CH3)4N]2[Cu(C2O4)2] · H2O}n

The preparation, crystal structure and magnetic properties of a new oxalate-containing copper(II) chain of formula {[(CH₃)₄N]₂[Cu(C₂O₄)₂] · H₂O}_n (1) [(CH₃)₄N⁺ = tetramethylammonium cation] are reported. The structure of 1 consists of anionic oxalate-bridged copper(II) chains, tetramethylammoniun cations and crystallization water molecules. Each copper(II) ion in 1 is surrounded by three oxalate ligands, one being bidentate and the other two exhibiting bis-bidenate coordination modes. Although all the tris-chelated copper(II) units from a given chain exhibit the same helicity, adjacent chains have opposite helicities and then an achiral structure results. Variable-temperature magnetic susceptibility measurements of 1 show the occurrence of a weak ferromagnetic interaction through the oxalate bridge [J = +1.14(1) cm⁻¹, the Hamiltonian being defined as H = –J ∑_nmS_i · S_j]. This value is analyzed and discussed in the light of available magneto-structural data for oxalate-bridged copper(II) complexes with the same out-of-plane exchange pathway.     

Zn3(HPO3)4·Zn(H2O)6: a purely inorganic open-framework zincophosphite with octahedral zinc complex [Zn(H2O)6] encapsulating in the channels

The hydrothermal synthesis and single crystal structure of Zn₃(HPO₃)₄·Zn(H₂O)₆ are reported. The structure is built-up from vertex linking ZnO₄ tetrahedral and HPO₃ pseudo-pyramids units, giving rise to a three-dimensional framework with large 8, 16-membered ring channels. The zincophosphite is purly inorganic with the octahedral zinc complex filled in the channel. The synthesis of system required the presence of the organic amine which is not incorporated into the structure of the product. The framework-metal complex encapsulating in the channel is the first time appeared in open-framework zincophospates and zincophosphites. Crystal data: Zn₃(HPO₃)₄·Zn(H₂O)₆, M=689.52, orthorhombic, Fddd (No. 70), , , , , Z=8, , , R=0.0265, R_w=0.0406.     

The synthesis and crystal structure of vanadium complexes: [VO2(phen)2]·6H2O and [2,2′-(bipy)2VO2](H2BO3)·3H2O

The organic-inorganic hybrid materials vanadium oxide [V^IVO₂(phen)₂]·6H₂O (1) and [(2,2′-bipy)₂V^VO₂](H₂BO₃)·3H₂O (2) have been conventional and hydrothermal synthesized and characterized by single crystal X-ray diffraction, elemental analyses, respectively. Although the method and the ligand had been used in the syntheses of the compounds (1) and (2) are different, they almost possess similar structure. They all exhibit the distorted octahedral [VO₂N₄] unit with organonitrogen donors of the phen and 2,2′-bipy ligands, respectively, which coordinated directly to the vanadium oxide framework. And they are both non-mixed-valence complexes. But the compound (1) is isolated, and the compound (2) consists of a cation of [(2,2′-bipy)₂V^VO₂]⁺ and an anion of (H₂BO₃)⁻. So the valence of vanadium of (1) and (2) are tetravalence and pentavalence, respectively. Meanwhile it is noteworthy that π-π stacking interaction between adjacent phen and 2,2′-bipy groups in compounds 1 and 2 also play a significant role in stabilization of the structure. Thus, the structure of [V^IVO₂(phen)₂]·6H₂O and [(2,2′-bipy)₂V^VO₂](H₂BO₃)·3H₂O are both further extended into interesting three-dimensional supramolecular. Crystal data: (1) Triclinic, a=8.481(4), b=12.097(5), and α=66.32(2), β=82.97(3), and γ=82.59(4)°, Z=2, R₁=0.0685, wR₂=0.1522. (2) Triclinic, a=6.643(13), b=11.794(2), and α=101.39(3), β=101.59(3), and γ=97.15(3)°, Z=2, R₁=0.0736, wR₂=0.1998.     

[NEt~4][Mn(salophen)(H~2O)~2]~2[Fe(CN)~6]·H~2O· CH~3OH超分子化合物的 合成和结构

室温下将[NEt~4]~3[Fe(CN)~6]和[Mn(salophen)(H~2O)(CH~3OH)]ClO~4反应,得到了超分子化合物[NEt~4][Mn(salophen)(H~2O)~2]~2[Fe(CN)~6]·H~2O·CH~3OH(salophenH~2=双水杨醛缩邻苯二胺),并对其进行了晶体结构测定。结果表明,该晶体属三斜晶系,空间群P1,晶胞参数a=1.2150(4)nm,b=1.4834(6)nm,c=1.6625(6)nm,α=81.896(7)°,β=76.980(8)°,γ=81.120(6)°,V=2.872(2)nm^3,Z=2,D~c=1.388g·cm^-^3。晶体的各部分间以氢键连接成网状超分子体系。     

一维链状铜配位聚合物[Cu(bpb)0.5(CH3COO)2]n的合成与晶体结构

A coordination complex of [Cu(bpb)_0.5(CH₃COO)₂]_n (bpb=1,4-bis(pyridine-3-aminomethyl)benzene) has been synthesized and characterized by elemental analysis, IR spectra, TG and X-ray single crystal diffraction. The title complex crystallizes in triclinic with space group P1, a=0.771 98(15) nm, b=0.827 62(17) nm, c=1.116 0(2) nm, α=96.71(3)°, β=90.03(3)°, γ=105.39(3)°, and V=0.682 4(3) nm³, Z=2, R=0.042 4, wR=0.091 1. The title complex is composed of dicopper tetracarboxylate units. Copper(Ⅱ) atom asumes a square-pyramidal coordination geometry formed with one pyridyl N atom from bpb and four O atoms from four bridging acetate anions. Two adjacent dicopper tetracarboxylate units are linked into a 1D chain by the bpb ligands, which were further connected by inter-chain hydrogen bonds to form a 2D network structure. CCDC: 667605.     

The role of anhydrous zinc nitrate in the thermal decomposition of the zinc hydroxy nitrates Zn5(OH)8(NO3)2·2H2O and ZnOHNO3·H2O

The steps associated with the thermal decomposition of Zn₅(OH)₈(NO₃)₂·2H₂O and ZnOHNO₃·H₂O are re-examined. Previous reports have suggested that Zn₅(OH)₈(NO₃)₂·2H₂O decomposes to ZnO via two intermediates, Zn₅(OH)₈(NO₃)₂ and Zn₃(OH)₄(NO₃)₂ whereas ZnOHNO₃·H₂O has been reported to decompose to ZnO via a Zn₃(OH)₄(NO₃)₂ intermediate. In this study, we demonstrate using TG, mass spectral analysis of evolved gases and in situ variable temperature powder X-ray diffraction analysis that, in fact, in the decomposition of Zn₅(OH)₈(NO₃)₂·2H₂O an anhydrous zinc nitrate intermediate is also involved. We, additionally, show that the decomposition of ZnOHNO₃·H₂O to ZnO also involves the formation of an anhydrous zinc nitrate intermediate. The anhydrous zinc nitrate formed in both cases is poorly crystallised and this observation may explain why this phase could not be observed by PXRD analysis in the previous studies.     

Synthesis, crystal structure and thermal decomposition study of a new barium acetato-propionate complex

The present study reports on a novel barium acetato-propionate complex, obtained by the reaction of barium acetate with propionic acid, used as an oxide precursor with applications in superconducting thin films deposition. The molecular structure has been determined by X-ray diffraction on single crystals and demonstrated to be [Ba₇(CH₃CH₂COO)₁₀(CH₃COO)₄·5H₂O]. The barium acetato-propionate is a three-dimensional channel-type polymer. The thermal decomposition of the barium precursor has been studied by simultaneous differential thermal analysis-thermogravimetry-mass spectrometry (DTA-TG-MS) in air at a heating rate of 10 °C/min. Based on these analyses, infrared spectroscopy was further used to characterize the precursor solution by the step-wise addition of the reagents. The X-ray diffraction on the precursor powder at different temperatures was performed.