Synthesis of nanosized bismuth ferrite (BiFeO3) by a combustion method starting from Fe(NO3)3·9H2O-Bi(NO3)3·9H2O-glycine or urea systems

Two bismuth ferrite potential precursors systems, namely Fe(NO₃)₃·9H₂O-Bi(NO₃)₃·9H₂O-glycine/urea with different metal nitrate/organic compound molar ratios have been investigated in order to evaluate their suitability as BiFeO₃ precursors. The presence into the precursor of both reducing (glycine and urea) and oxidizing (NO₃⁻) components, modifies dramatically their thermal behaviour comparative with the raw materials, both from the decomposition stoichiometries and temperature occurrence intervals points of view. Also, the thermal behaviour is dependent on the fuel nature but practically independent with the fuel content. The fuel nature influences also some characteristics of the resulted oxides (phase composition, morphologies). In the case of the oxides prepared using urea as fuel, a faster evolution toward a single phase composition with the temperature rise is evidenced, the formation of the BiFeO₃ perovskite phase being completed in the temperature range of 500–550°C.     

trans-dinitro- and trans-dinitratoruthenium complexes [RuNO(NH3)2(NO2)2(OH)] and [RuNO(NH3)2(H2O)(NO3)2]NO3·H2O

Methods for the synthesis of trans-diammino complexes [RuNO(NH₃)₂(NO₂)₂(OH)] (I) and [RuNO(NH₃)₂(H₂O)(NO₃)₂](NO₃)·H₂O (II) are suggested. The compounds were studied by IR spectroscopy and X-ray phase and X-ray structural analyses. Crystal data: space group P-1; a = 6.2328(2) ?, b = 11.0488(3) ?, c = 11.0981(4) ?, α = 71.942(1)°, β = 83.291(1)°, γ = 86.877(1)° (I); space group P2₁; a = 6.6290(2) ?, b = 13.4389(5) ?, c = 7.0180(2) ?, β 114.281(1)° (II). Complex II readily lost some part of crystal water on storage in open air. Original Russian Text Copyright ? 2009 by M. A. Il’in, E. V. Kabin, V. A. Emel’yanov, I. A. Baidina, and V. A. Vorob’yov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 341–348, March–April, 2009.     

Crystal structure of metal-organic coordination polymers [Cu(bpy)2(H2O)2](NO3)2·4.5C2H5OH and [Cu2(bpy)(H2O)(L-pha)2](NO3)2·H2O

Two metal-organic coordination polymers [Cu(bpy)₂(H₂O)₂](NO₃)₂·4.5C₂H₅OH (1) and [Cu₂(bpy)(H₂O)(L-pha) ₂](NO₃)₂·H₂O (2) (L-Hpha = L-phenylalanine, bpy = 4,4′-bipyridyl) are prepared by slow evaporation of an aqueous alcoholic solution of copper nitrate, L-phenylalanine, and 4,4′-bipyridyl. The structure and composition of the obtained compounds are determined by single crystal XRD. The framework of compound 1 is positively charged and forms two types of intersecting channels. Compound 2 is a homochiral metal-organic coordination polymer whose structure contains L-phenylalanine anions.     

Crystal structure of [Pd(NH3)4]3[Ir(NO2)6]2·H2O

A single crystal of [Pd(NH₃)₄]₃[Ir(NO₂)₆]₂·H₂O double complex salt is studied by X-ray diffraction. Crystallographic characteristics are as follows: a = 21.0335(5) ?, b = 8.0592(2) ?, c = 21.3452(5) ?, β = 91.254(1)°, V = 3617.43(15) ?³, P2₁/c space group, Z = 4, d _x = 2.714 g/cm³. Single-layer pseudohexagonal packing of complex anions is determined along the [−1 0 1] direction in the structure. Complex cations and crystallization water molecules are located between the mentioned layers.     

X-ray structure of KCs[Pd(NO3)4]·0.5H2O

A new Pd nitrate complex KCs[Pd(NO₃)₄]·0.5H₂O is synthetized. Its crystal structure contains isolated complex anions [Pd(NO₃)₄]²⁻, cations K⁺, Cs⁺, and crystallization water. Square-planar coordination around Pd is achieved by oxygen atoms of monodentate nitrate ligands. The coordinated nitrate ligands are all oriented in the same way, in a “basket”-like arrangement. The coordination around Pd is completed to 4+1 by forming Pd...Pd contacts of 3.564 ?. Original Russian Text Copyright ? 2009 by S. P. Khranenko, I. A. Baidina, N. V. Kuratieva, and S. A. Gromilov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 1, pp. 173–176, January–February, 2009.     

Formation of Co nanoparticles in the process of thermal decomposition of the cobalt complex with hexamethylenetetramine (NO3)2Co(H2O)6(HMTA)2 · 4(H2O)

The thermal decomposition of the cobalt complex with hexamethylenetetramine (NO₃)₂Co(H₂O)₆(HMTA)₂ · 4(H₂O) was studied by the methods of differential thermal analysis, thermogravimetry, mass spectrometry, X-ray diffraction analysis, and by the magnetic method. It was established that the thermal decomposition of the complex in a current of an inert gas is accompanied by a pronounced exothermic process and formation of Co nanoparticles. It was shown that the kinetics of this process and the chemical nature of the decomposition products depend on the initial density of the sample under study.     

Crystal structures of barium bis(iminodiacetato)cobaltates(III): [Ba(H2O)6][Co(Ida)2]2 · H2O and Ba4(H2O)14][Co(Ida)2]5(ClO4)3 · 5.46H2O · 2CH3OH

The structures of the crystals of Ba₄[trans(N)-Co(Ida)₂]₃[cis-(N)-Co(Ida)₂]₂(ClO₄)₃ · 19.46H₂O · 2CH₃OH (I) and Ba[trans-(N)-Co(Ida)₂]₂ · 7H₂O (II) (H₂Ida is iminodiacetic acid) were determin by X-ray diffraction. The crystals of I containing two geometric isomers of the complex anions [Co(Ida)₂]⁻ were obtained by a slow cooling of a hot solution, which contained initially only the cis-isomer. One Ba atom in I interacts with the trans-complex and with two cis-complexes to give a three-dimensional framework in crystal I. The positive charge of the last framework is compensated by one more trans-complex and by the perchlorate ions, one of which acts as a bidentate ligand with respect to the Ba atom. The crystals of II are built of the chains with the alternating Ba atoms and the trans-(N)-[Co(Ida)₂]⁻ anions. The other anions of the same structure are each “suspended” to the Ba atoms of the chain. Original Russian Text ? M. Zabel, A.I. Poznyak, V.I. Pawlowskii, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 11, pp. 831–836.     

配合物[Cr3(μ3-O)(Tc)6(H2O)3]·(NO3)·4H2O的水热合成及晶体结构

通过有限个过渡金属离子如Fe,Ni,Cr,Mn与O、OH、-O或-O2CR等桥联原子或基团键合形成的具有不同尺寸的环形轮状金属离子簇合物或分子簇合物是近年来的研究热点之一[1,2].它们不仅具有独特的结构,而且在催化、非线性光学、分子自组装等方面具有潜在的应用价值[3～5].特别是具有三角型结构的过渡金属-氧轮簇化合物由于可以作为单分子磁体的磁性交换和电子耦合的研究体系,引起了研究人员的极大地兴趣[6,7].研究表明,具有[M(μ3-O)(O2CR)6L3]0/+,(M=Fe3+或Mn3+,L为水或吡啶,R为烷基或芳香基团)结构的化合物具有反铁磁作用[8,9].     

Hydrothermal synthesis and crystal structure of [Zn(pytpy)2][NO3]2·2H2O

The title compound, [Zn(pytpy)₂][NO₃]₂·2H₂O (pytpy = 4′-(4-pyridyl)-2,2′: 6′,2″-terpyridine), has been synthesized by the reaction of Zn(NO₃)₂·6H₂O with pytpy, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to tetragonal space group P4₃ with a = 0.90873(8) nm, b = 0.90873(8) nm, c = 4.4741(6) nm, V = 3.6946(7) nm³, Z = 4, D _c = 1.521 g/cm⁻³, μ = 0.736 mm⁻¹, F(000) = 1744, R = 0.0871, wR = 0.1302 for 5553 observed reflections with I > 2σ(I). X-ray analysis has revealed that the Zn^II ion is surrounded by six N atoms from two pytpy ligands leading to a distorted octahedral geometry. In the crystal structure there are numerous strong intermolecular and intramolecular H-bonds and π-π interactions.     

LaL3(NO3)3·(H2O)2·(C2H5OH)2的晶体结构和生成反应焓变

0 引言 稀土是一类具有特殊结构和性质的元素,稀土元素不仅大量用于工业,而且在农业和医学领域也有广泛应用 [1,2].其中,镧系离子以其独特的光、电、磁、催化和分析等性能而受到人们的广泛关注,并进行了大量的研究.镧系离子本身发光效率低,目前,设计并合成含有稀土离子La3+和Eu3+的超分子配合物,作为发光分子器件和荧光探针成为稀土配位化学,材料科学,超分子化学,分析化学和生物化学等研究领域的热点课题之一 [3～8].但对它们的热化学行为的研究鲜见文献报道.     

[U(CO3)3(H2O)2]·2H2O配合物的合成及晶体结构

A uranylcontaining compound [U(CO₃)₃(H₂O)₂]·2H₂O has been synthesized under hydrothermal condition and characterized by X-ray single-crystal analysis. Crystal structural analysis indicates that this compound consists of three CO₃^2- molecules, one U⁶⁺. The results reveal that the title compound presents a 3D frame work built up by O-H…O week hydrogen bonds interactions. The central uranium atom is eight-coordinated through three CO₃^2- molecules and two H₂O. The compound shows a coplanar hexagonal network structure, each hexagon containing a hexagonal hole with a water moleculet. CCDC: 737313.     

Synthesis and crystal structure of [Fe4O2(H2O)10(C5H5NCOO)4](NO3)8 · 2H2O

Crystals of the tetranuclear complex [Fe₄O₂(H₂O)₁₀(C₅H₅NCOO)₄](NO₃)₈ · 2H₂O are obtained by the slow evaporation of an aqueous solution of iron(III) nitrate and isonicotinic acid. According to the X-ray diffraction data, four metal atoms lie in the same plane and together with two μ₃-O oxygen atoms form the fragment [Fe₄(μ₃-O)₂]¹⁰⁺. The [Fe₄O₂(H₂O)₁₀(C₅H₅NCOO)₄]⁸⁺ cation has been obtained and structurally characterized for the first time.     

Synthesis and structures of nine-coordinate K[SmIII (Edta)(H2O)3] · 2H2O and Ten-Coordinate K2[SmIII(Pdta)(H2O)2]2 · 4.5H2O complexes

The title complexes, K[Sm^III(Edta)(H₂O)₃] · 2H₂O(I)(H₄Edta = ethylenediamine-N,N,N′,N′-tetraacetic acid) and K₂[Sm^III(Pdta)(H₂O)₂]₂ · 4.5H₂O (II) (H₄Pdta = propylenediamine-N,N,N′,N′-tetraacetic acid), were prepared and their compositions and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques, respectively. Complex I has a mononuclear structure, and the Sm³⁺ ion is nine-coordinated by an Edta ligand and three water molecules, yielding a pseudo-monocapped square antiprismatic conformation, and the complex crystallizes in the orthorhombic crystal system with space group Fdd2. The crystal data are as follows: a = 19.84(5), b = 35.58(9), c = 12.15(3) ?, V = 8580(38) ?³, Z = 16, ρ _c = 1.925 g/cm³, μ = 3.010 mm⁻¹, F(000) = 4976, R = 0.0252, and wR = 0.0560 for 3510 observed reflections with I ≥ 2σ(I). Complex II has a binuclear structure and the Sm³⁺ ion is ten-coordinated by a Pdta ligand, two oxygen atoms from a carboxylic group of adjacent Pdta ligand and two water molecules, yielding a distorted bicapped square antiprismatic prism. The complex crystallizes in the triclinic crystal system with space group P $ \bar 1 $ \bar 1 . The crystal data are as follows: a = 8.9523(15), b = 10.7106(15), c = 11.6900(19) ?, α = 80.613(5)°, β = 80.397(5)°, γ = 76.530(4)°, V = 1065.7(3) ?³, Z = 1, ρc = 1.970 g/cm³, μ = 2.532 mm⁻¹, F(000) = 1620, R = 0.0332 and wR = 0.0924 for 5390 observed reflections with I ≥ 2σ(I).     

Crystal structure of K2[Mo3(PdPPh3)S4(C2O4)3(H2O)3]·0.5H2O

By the reaction of [Mo₃S₄(C₂O₄)₃(H₂O)₃]²⁻ with PdCl₂ and NH₄H₂PO₂ as a reducing agent, followed by the addition of PPh₃, a new oxalate cuboidal cluster complex [Mo₃(PdPPh₃)S₄(C₂O₄)₃(H₂O)₃]²⁻ is obtained. It was isolated and structurally characterized as K₂[Mo₃(PdPPh₃)S₄(C₂O₄)₃(H₂O)₃]·0.5H₂O. Original Russian Text Copyright ? 2008 by A. L. Gushchin, M. N. Sokolov, D. Yu. Naumov, and V. P. Fedin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 4, pp. 775–778, May–June, 2008.     

碱式氯化镁5Mg(OH)2·MgCl2·3H2O的制备与表征

以氨水和盐湖盛产的水氯镁石为原料经过两步反应制备碱式氯化镁。第一步,水氯镁石和氨水反应制备氢氧化镁;第二步,利用氢氧化镁和水氯镁石,通过水热反应得到了具有纤维形貌、结晶较好的碱式氯化镁。应用化学分析、XRD、SEM和FIIR等手段对产物进行测试与表征。化学分析结果表明产物组成为5Mg(OH)₂·MgCl₂·3H₂O。将得到的5Mg(OH)₂·MgCl₂·3H₂O和碱式氯化镁系列标准XRD图对照,未有较好的匹配,且结合化学分析和已报道碱式硫酸镁具有5Mg(OH)₂·MgSO₄·3H₂O物相,因而推测其为新物相;SEM图中5Mg(OH)₂·MgCl₂·3H₂O纤维直径约为0.4 μm,平均长度大于24 μm,长径比大于60;FTIR图谱中3 419 cm^-1附近出现了氢键的O-H伸缩振动吸收峰,1 635 cm^-1附近出现了游离水中H-O-H的弯曲振动吸收峰。水热合成的5Mg(OH)₂·MgCl₂·3H₂O和常压下的产物相比直径较小,晶形更完整,强度更高。     

Crystal and Molecular Structures of Barium cis(NO2)-trans(N)-Bis(glycinato)dinitrocobaltate(III) Hydrate [Ba(H2O)4][Co(Gly)2(NO2)2]2 · 1.43H2O

Crystals of [Ba(H₂O)₄][Co(Gly)₂(NO₂)₂]₂ · 1.43H₂O (a=8.1917(6) , b=8.4440(4) , c=19.444(1) , =98.189(9)°, Z=2, space group P2/n) contain infinite strips of alternating axially symmetric [Ba(H₂O)₄]²⁺ fragments and two dinitro-bis(glycinato)cobaltate(III) ions. In addition to four oxygen atoms of water molecules, the nearest environment of Ba includes six oxygen atoms of the carboxyl groups of four anions, two of which are also coordinated by the cobalt atoms (Ba-O, 2.77–3.01 ). The nitrite ions do not interact with the Ba²⁺ ions.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 5, 2005, pp. 329–332.Original Russian Text Copyright © 2005 by Zabel, Poznyak, Pawlowski.     

Syntheses of the eight-coordinate NH4[ErIII(Cydta)(H2O)2] · 4.5H2O and (NH4)2[Er 2III (Pdta)2(H2O)2] · 2H2O complexes and their structural investigation

In this work, the title complexes, NH₄[Er^III(Cydta)(H₂O)₂] · 4.5H₂O (I) (H₄Cydta = trans-1,2-cyclo-hexanediamine-N,N,N′,N′-tetraacetic acid) and (NH₄)₂[Er₂^III(Pdta)₂(H₂O)₂] · 2H₂O (II) (H₄Pdta= propylene-diamine-N,N,N′,N′-tetraacetic acid), were prepared, respectively, and their composition and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques. Complex I selects a mononu-clear structure with pseudosquare antiprismatic geometry crystallized in the triclinic crystal system with space group $ P\bar 1 $ P\bar 1 and the central Er³⁺ ion is eight-coordinated by the hexadentate Cydta ligand and two water molecules. The crystal data are as follows: a = 8.568(3), b = 10.024(3), c = 14.377(4) ?, α = 88.404(4)°, β = 75.411(4)°, γ = 88.332(4)°, V = 1194.2(6) ?³, Z = 1, ρ _c = 1.793 g/cm³, μ = 3.586 mm⁻¹, F(000) = 648, R = 0.0257, and wR = 0.0667 for 4169 observed reflections with I ≥ 2σ(I). Complex II is eight-coordinated as well, which selects a binuclear structure with two pseudosquare antiprismatic geometry and crystallizes in the monoclinic crystal system with space group P2₁/n. The central Er³⁺ ion is coordinated by two nitrogens and four oxygens from one hexadentate Pdta ligand. Besides, two oxygens come from one carboxylic group of the neighboring Pdta ligand and one water molecule, respectively. The crystal data are as follows: a = 12.7576(8), b = 9.3151(6), c = 14.3278(9) ?, β = 96.1380(10)°, V = 1692.93(19) ?³, Z = 4, ρ _c = 2.054 g/cm³, μ = 5.015 mm⁻¹, F(000) = 1028, R= 0.0228, and wR = 0.0534 for 2984 observed reflections with I ≥ 2σ(I).     

［Mn2(CHZ)4(H2O)2］(PA)4·10H2O的制备和分子结构研究

本文论述了苦味酸(PA,三硝基苯酚)锰与碳酰肼(CHZ, NH₂NHCONHNH₂)反应制备目标配合物的方法及该配合物的晶体结构。该配合物的结构式为［O,O′-μ-Mn₂(CHZ)₄(H₂O₂)］(PA)₄·10H₂O。晶体属三斜晶系,P1 空间群。晶体学参数为：a=0.8269(1) nm, b=1.2812(1) nm, c=1.5915(1) nm; α=109.58(1)°, β=95.19(1)°, γ=92.76(1)°, V=1.5765(2)nm³; Z=1, Dc=1.580 g·cm^-3, μ(Mo K_α)=520 m^-1。晶体结构经全矩阵最小二乘法修正,最终偏离因子R=0.0557。该化合物为具有中心对称的双核配合物,以两个碳酰肼分子中羰基氧为桥原子将两个锰离子结合起来,与锰离子形成配位键的原子是碳酰肼分子第一、五氮原子,羰基氧原子和水分子中的氧原子,锰离子的配位数为七。若味酸根作为外界离子以库伦力和氢键与内界离子结合成配合物分子。     

Synthesis, thermogravimetric analysis, IR spectrum, and the crystal structure of sodium hexatunstomanganate [Na2(H2O)10][Na(H2O)3]2[MnW6O18(OH)6] · 6H2O

The complex [Na₂(H₂O)₁₀][Na(H₂O)₃]₂[MnW₆O₁₈(OH)₆] · 6H₂O was synthesized and studied by mass spectrometry, thermogravimetry, IR spectroscopy, X-ray diffraction. The crystals are monoclinic, space group P2₁/n, a = 11.698(2), b = 11.670(2), c = 14.652(3) ?, β = 102.52(3)°, V = 1952.7(7) ?³, ρ(calcd.)= 3.45 g/cm³, Z = 2.     

Structural determination of new eight-coordinate NH4[EuIII(Cydta)(H2O)2]·4.5H2O and K2[Eu 2III (pdta)2(H2O)2]·6H2O complexes

The NH₄[Eu^III(Cydta)(H₂O)₂]·4.5H₂O (I) (H₄Cydta = trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid) and K₂[Eu₂^III(pdta)₂(H₂O)₂]·6H₂O (II) (H₄pdta = propylenediamine-N,N,N′,N′-tetraacetic acid) complexes are prepared by heat-refluxing and acidity-adjusting methods respectively, and their composition and structures are determined by elemental analyses and single crystal X-ray diffraction techniques. The complex I has a mononuclear structure, crystallizes in the triclinic crystal system with the P[`1]P\bar 1 space group; the central Eu^III ion is eight-coordinated by a hexadentate Cydta ligand and two water molecules. The crystal data are as follows: a = 8.653(4) ?, b = 10.041(4) ?, c = 14.405(6) ?, α = 88.469(6)°, β = 74.892(6)°, γ = 88.256(7)°, V = 1207.5(9) ?³, Z = 1, D _c = 1.731 g/cm³, μ = 2.669 mm⁻¹, F(000) = 638, R = 0.0257, and wR = 0.0667 for 3807 observed reflections with I ≥ 2σ(I). The EuN₂O₆ part in the [Eu^III(Cydta)(H₂O)₂]⁻ complex anion forms a pseudo-square antiprismatic polyhedron. The complex II is eight-coordinate as well; it is a binuclear structure that crystallizes in the monoclinic crystal system with the C ₂/c space group; half of the central Eu^III ion is coordinated by two nitrogen atoms from one hexadentate pdta ligand and six oxygen atoms from the same pdta ligand, one water molecule and carboxylic group from the neighboring pdta ligand respectively. The crystal data are as follows: a = 19.866(3) ?, b = 9.1017(12) ?, c = 21.010(3) ?, β = 104.972(2)°, V = 3670.1(9) ?³, Z = 8, D _c = 2.046 g/cm³, μ = 3.710 mm⁻¹, F(000) = 2240, R = 0.0213 and wR = 0.0460 for 4183 observed reflections with I ≥ 2σ(I). Otherwise, the two EuN₂O₆ parts in the [Eu₂^III(pdta)₂(H₂O)₂]²⁻ complex anion form a pseudo-square antiprismatic polyhedron.