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1.
Specific features of the textures (the preferred orientation of the nanometer building blocks) in the structures of mixed-anion compounds—rare-earth borogermanates, germanophosphates, and borotungstates that arise from the acid-base interaction in the Ln2O3-B2O3-GeO2, Ln2O3-GeO2-P2O5, and Ln2O3-B2O3-WO3 systems (Ln = La-Gd)—have been studied. Based on characteristic texture traits, the mixed-anion compounds of early rare-earth elements can be divided into three groups: (i) Ln2O3: ExOy > 1, (ii) Ln2O3: ExOy = 1, and (iii) Ln2O3: ExOy < 1. Because of the dominant structural effect of the basic oxide Ln2O3 in the compounds of the first group, the structures of Nd14O8(BO3)6(GeO4)2 and Pr11O10(GeO4)(PO4)3 are composed of infinite [LnOn] bands and layers and discrete groups [EOm] located in the interband and interlayer spaces. The dominant structural effect of the acid oxides [ExOy] in the compounds of the third group leads to the appearance of ring textures composed of [LnOn], as well as to the appearance of chains and networks composed of [EOm], in the structures of Ln(BGeO5) and Ln(BO2)(WO4). Original Russian Text ¢ G.A. Bandurkin, N.N. Chudinova, G.V. Lysanova, K.K. Palkina, E.V. Murashcva, V.A. Krut’ko, G.M. Balagina, 2006, published in Zhurnal Neorganicheskoi Khimii, 2006, Vol. 51, No. 2, pp. 334–347.  相似文献   

2.
In the Sc2O3---Ga2O3---CuO, Sc2O3---Ga2O3---ZnO, and Sc2O3---Al2O3---CuO systems, ScGaCuO4, ScGaZnO4, and ScAlCuO4 with the YbFe2O4-type structure and Sc2Ga2CuO7 with the Yb2Fe3O7-type structure were obtained. In the In2O3---A2O3---BO systems (A: Fe, Ga, or Al; B: Mg, Mn, Fe, Ni, or Zn), InGaFeO4, InGaNiO4, and InFe3+MgO4 with the spinel structure, InGaZnO4, InGaMgO4, and InAlCuO4 with the YbFe2O4-type structure, and In2Ga2MnO7 and In2Ga2ZnO7 with the Yb2Fe3O7-type structure were obtained. InGaMnO4 and InFe2O4 had both the YbFe2O4-type and spinel-type structures. The revised classification for the crystal structures of AB2O4 compounds is presented, based upon the coordination numbers of constituent A and B cations.  相似文献   

3.
The cloud points (CPs) of the copolymers 17R4 and L64 were first measured, and then the effects of salts ((NH4)3C6H5O7, K3C6H5O7) on 17R4 and L64 were researched. After finishing the work described above, the temperature (278.15, 283.15, and 288.15) K of aqueous two-phase systems was determined, which consist of 17R4-(NH4)3C6H5O7, 17R4-K3C6H5O7, L64-(NH4)3C6H5O7, and L64-K3C6H5O7. Finally, the liquid–liquid equilibrium (LLE) data of binodal curve and the tie line for 17R4-(NH4)3C6H5O7 aqueous two- phase systems (ATPSs) 17R4-K3C6H5O7 ATPSs, L64-(NH4)3C6H5O7 ATPSs, and L64-K3C6H5O7 ATPSs were obtained. Nonlinear fitting of the empirical equation was used for making the diagram. The results showed that the change in the size of the two-phase areas increases with the increase of temperature. The capacity of the salts to induce phase segregation follows the Hofmeister series, that is, K3C6H5O7?>?(NH4)3C6H5O7. In addition, the findings also showed that the phase separation ability of 17R4 is better than that of L64.  相似文献   

4.
Reactivity, in the solid state between Ag2S and Ag2CrO4, was investigated by DTA, XRD and IR methods. It was found that, according to a composition of an initial Ag2S/Ag2CrO4 mixture, the products of a reaction of Ag2S with Ag2 CrO4 can be: solid solution with Ag2CrO4 structure (Ag2Cr1–xSxO4) and AgCrO2; or solid solution Ag2Cr1–xSxO4, Ag2SO4, AgCrO2 and metallic silver; or Ag2S, β-Ag8S4O4, Ag, AgCrO2, Ag2SO4 and Ag2Cr1–xSxO4 solid solution. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

5.
Ternary Rare-Earth Halides of the A2MX5 Type (A = K, In, NH4, Rb, Cs; X = Cl, Br, I) Ternary rare-earth (=M) chlorides, bromides, and iodides In2MCl5, (NH4)2MCl5, Rb2MCl5, Cs2MCl5, CsRbMCl5, K2MBr5, Rb2MBr5, K2MI5, and Rb2MI5 have been synthesized. Single crystals of In2PrCl5, Rb2PrCl5, K2PrBr5, and K2PrI5 were grown and the structures refined. The other halides were characterized by x-ray powder patterns. They are isotypic either with K2PrCl5(orthorhombic, Pnma, Z = 4, hexagonal arrangement of chains of edge-connected polyhedra [PrX7]) or with Cs2DyCl5 (orthorhombic, Pbnm, Z = 4, hexagonal arrangement of cis-corner-connected octahedra [DyCl6]) which may be discriminated in structure field diagrams. The thermal expansion was investigated für Cs2LuCl5 and Rb2PrX5 (X = Cl, Br, I).  相似文献   

6.
A 480 L evacuable reaction chamber, equipped with FT-IR spectroscopy on-line and ion chromatography off-line, has been used to study the gas phase reaction between the nitrate radical, NO3, and the reduced organic sulphur compounds CH3CH2SH, (CH3CH2)2S, (CH3CH2)2S2, and CH3CH2SCH3 in air. The products CH3CH2SO3H, SO2, H2SO4, CH3CHO, and CH3CH2ONO2 were identified and quantified in the reactions of the first three compounds, CH3CH2SH, (CH3CH2)2S, and (CH3CH2)2S2. The reaction products were CH3CH2SO3H, CH3SO3H, SO2, H2SO4, CH3CHO, and CH2O in the reaction of CH3CH2SCH3. On the basis of identified reaction products and intermediates observed in the infrared spectra, mechanisms are proposed for the reactions between the NO3 radical and the four reduced organic sulphur compounds. The results of this study, together with those from previous experiments performed in this laboratory on CH3SCH3, CH3SH, and CH3SSCH3 lead to the conclusion that all these species, in the reaction with the NO3 radical, follow a similar degradation mechanism producing SO2, H2SO4, R? SO3H, R? CHO, and R? CH2ONO2, as the main reaction products. The inital step of the reaction of NO3 with R? S? R and R? S? H type (R = CH3, CH2CH3) reduced organic sulphur compounds was found to be H-atom abstraction, probably after the formation of an initial adduct. For the reaction between NO3 and R? S? S? R type compounds, evidence for an addition-decomposition reaction, as the initial steps, was obtained. R? S·, R? S(O)·, and R? S(O)2· appear to be formed as intermediates in all the reactions. © John Wiley & Sons, Inc.  相似文献   

7.
The Courses of the Ammonolyses of the Ammonium Hexafluorometalates of Aluminum, Gallium, and Indium, (NH4)3MF6 (M = Al, Ga, In) The courses of the ammonolysis reactions of the ammonium hexafluorometalates (NH4)3MF6 (M = Al, Ga, In) were investigated with the aid of in‐situ powder diffractometry and differential thermal analysis. Under these conditions, the reaction of (NH4)3AlF6 with gaseous ammonia yields at about 360 °C AlF3 via the intermediates NH4AlF4, Al(NH3)2F3 and Al(NH3)F3. The ammonolysis of (NH4)3GaF6 produces GaN at about 400 °C. Depending upon the actual reaction conditions, the intermediates NH4GaF4 and Ga(NH3)F3 as well as their ammonia adducts NH4GaF4 · NH3 and Ga(NH3)2F3 and the amide‐ammoniate Ga(NH3)(NH2)F2 are observed. In the case of (NH4)3InF6 the intermediates (NH4)3InF6 · NH3 and In(NH3)F3 may exist; there are also indications for the reduction of In(III) to In(I) and for the existence of In(NH3)2F and InF as products of the ammonolysis of (NH4)3InF6.  相似文献   

8.
On Dialkali Metal Dichalcogenides β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 and Rb2Te2 The first presentation of pure samples of α- and β-Rb2S2, α- and β-K2Te2, and Rb2Te2 is described. Using single crystals of K2S2 and K2Se2, received by ammonothermal synthesis, the structure of the Na2O2 type and by using single crystals of β-Na2S2 and β-K2Te2 the Li2O2 type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na2O2 type to the Li2O2 type will be explained by means of the examples α-/β-Na2S2 and α-/β-K2Te2. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb2S2 is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence.  相似文献   

9.
The mass spectra of the following acetylenic derivatives of iron, ruthenium and osmium carbonyls are reported: the iron compounds Fe2(CO)6[C2(C6H5)s2]2, Fe2(CO)6[C2(CH3)2]2 and Fe2(CO)6[C2(C2H5)2]2, the ruthenium compounds Ru2(CO)6[C2(C6H5)2]2, and Ru2(CO)6[C2(CH3)2]2 and the osmium compounds Os2(CO)6[C2(C6H5)2]2, Os2(CO)6[C2HC6H5]2 and Os2(CO)6[C2(CH3)2]2. Iron compounds exhibit breakdown schemes where binuclear, mononuclear and hydrocarbon ions are present. On the other hand, ruthenium and osmium compounds fragment in a similar way and give rise to singly and doubly charged binuclear ions. Phenylic derivatives of ruthenium and osmium also give weak triply charged ions. The results are discussed in terms of relative strengths of the metal-metal and metal-carbon bonds.  相似文献   

10.
When heated with Group V and Group VI elements, the phenylenemercurials (C6H4Hg)3, (C6F4Hg)3 and (C6Cl4Hg)3 form heterocycles of formulae (M2(C6X4)3 and M′2(C6X4)2 where M = As, Sb, Bi and M′ = S, Se, Te. The compounds Te2(C6Cl4)2 and M2(C6Cl4)3 (M = As, Sb, Bi) were also obtained by heating the elements with 1,2-I2C6Cl4, which was prepared by mercuration of 1,2-H2C6Cl4 followed by iododemercuration. Octachlorothianthrene has been obtained by heating sulphur with Te2(C6Cl4)2, C6Cl6 or C6Cl5I, and from the reaction between 1,2-H2C6Cl4, AlCl3, and S2Cl2.  相似文献   

11.
On the refluxing ofM(II) oxalate (M=Mn, Co, Ni, Cu, Zn or Cd) and 2-ethanolamine in chloroform, the following complexes were obtained: MnC2O4·HOCH2CH2NH2·H2O, CoC2O4·2HOCH2CH2NH2, Ni2(C2O4)2·5HOCH2CH2NH2·3H2O, Cu2(C2O4)2·5HOCH2CH2NH2, Zn2(C2O4)2·5HOCH2CH2NH2·2H2O and Cd2(C2O4)2·HOCH2CH2NH2·2H2O. Following the reaction ofM(II) oxalate with 2-ethanolamine in the presence of ethanolammonium oxalate, a compound with the empirical formula ZnC2O4·HOCH2CH2NH2·2H2O1 was isolated. The complexes were identified by using elemental analysis, X-ray powder diffraction patterns, IR spectra, and thermogravimetric and differential thermal analysis. The IR spectra and X-ray powder diffraction patterns showed that the complexes obtained were not isostructural. Their thermal decompositions, in the temperature interval between 20 and about 900°C, also take place in different ways, mainly through the formation of different amine complexes. The DTA curves exhibit a number of thermal effects.  相似文献   

12.
通过高温固相法对醋酸镧(C6H9O6La·xH2O)与高钼酸铵((NH46Mo7O24·4H2O)在一定条件下热解制备非Pt催化剂La2Mo2O7(La2O3-2MoO2)。进一步采用2种方法将La2Mo2O7与多壁碳纳米管(MWCNTs)进行复合,一种是将La2Mo2O7喷涂到MWCNTs表层之上得到La2Mo2O7/MWCNTs,另一种是将两者均匀混合掺杂得到La2Mo2O7@MWCNTs,再将上述2种复合材料应用于染料敏化太阳能电池对电极进行相应研究。通过扫描电子显微镜(SEM)表征了复合催化材料的微观形貌,X射线衍射(XRD)确定了微观结构。采用电流密度-光电压曲线、循环伏安,交流阻抗以及塔菲尔极化分析了材料的光电性能。实验结果表明在电解液I3-/I-中,基于La2Mo2O7/MWCNTs与La2Mo2O7@MWCNTs的对电极,相同的条件下在光电池中获得的光电转换效率分别为6.09%和4.84%,明显高于MWCNTs的3.94%和La2Mo2O7的0.87%。电极性能的提高可归因于La2Mo2O7复合催化剂相对大的比表面积和高导电性。  相似文献   

13.
Zinc phosphites ZnPHO3·2.5 H2O, Zn2H2P3H3O9·H2O, Zn3H4P5H5O15·1.5 H2O, ZnH2H2P2H2O6 have been studied at higher temperatures and by X-rays and molecular spectroscopy. Hydrates ZnPHO3·2.5 H2O and Zn2H2P3H3O9·H2O, when heated, yield an anhydrous salt. Thermal decomposition of dihydrogen triorthophosphite and tetrahydrogen pentaorthophosphite leads, before oxidation of the anion, to a mixture of zinc phosphite ZnPHO3 and dihydrogen diorthophosphite ZnH2P2H2O6 and then after loss of water of constitution dihydrogen diorthophosphite converts to zinc diphosphite ZnP2H2O5. The results of the thermal decomposition study were confirmed by X-ray investigation. Anhydrous zinc dihydrogen triorthophosphite Zn2H2P3H3O9 and zinc diphosphite ZnP2H2O5 were hitherto unknown. Infrared spectra confirmed the existence of hydrogen bonding in all the phosphites studied and in the case of zinc phosphite ZnPHO3·2.5 H2O exhibited a symmetry decrease of the anion PHO3 2– from the point group C3v to Cs. In the crystal lattice of ZnPHO3·2.5 H2O hydrogen bonding by water molecules participates, with polyorthophosphites hydrogen bonding shares in the production of anions and in the case of their hydrates there is in addition hydrogen bonding by water molecules.

Mit 3 Abbildungen  相似文献   

14.
Several vertical sections are investigated in the HgBr2-PbBr2-CsBr system by the methods of physicochemical analysis. Six compounds, namely, CsHg2Br5, CsHgBr3, Cs2HgBr4, CsPb2Br5, CsPbBr3, and Cs4PbBr6, are formed in the bordering binaries of the ternary system. By the results of investigation, the projection of the liquidus surface of the HgBr2-PbBr2-CsBr system on the composition triangle is constructed, and the fields of primary crystallization of nine phases are plotted, namely, HgBr2, PbBr2, CsBr, CsHg2Br5, CsHgBr3, Cs2HgBr4, CsPb2Br5, CsPbBr3, and Cs4PbBr6. An immiscibility region is found in the system. This region occupies a considerable part of the primary crystallization field of PbBr2. The coordinates of invariant points are determined, and isotherms are plotted.  相似文献   

15.
在γ-Al2O3载体上用等体积浸渍法浸渍Pd、MnOx活性组分,然后涂覆于堇青石基体上制备Pd-MnOx/γ-Al2O3整体式催化剂.分别用X射线衍射(XRD)、H2-程序升温还原(H2-TPR)、低温N2吸附-脱附及X射线光电子能谱(XPS)对制备的催化剂进行表征.研究了Pd、MnOx浸渍顺序对催化剂活性、氧化还原性能及织构性质的影响.实验结果表明,Pd、MnOx共浸渍较分别浸渍制备的催化剂活性好,Pd和MnOx之间存在一定的协同作用.考察了不同载体如La-Al2O3、SiO2、γ-Al2O3和Zr-Al2O3对催化剂活性、氧化还原性能、织构性质及表面电子性能的影响.研究表明,以La-Al2O3或SiO2为载体的催化剂活性最好,即,14°C时O3转化率为82%,完全转化温度为36°C.γ-Al2O3载体次之,Zr-Al2O3载体较差.不同载体制备的催化剂中MnOx的氧化还原性能顺序为:PdMnOx/SiO2Pd-MnOx/La-Al2O3Pd-MnOx/γ-Al2O3Pd-MnOx/Zr-Al2O3.  相似文献   

16.
Three samples, LiNi0.5Mn1.5O4, LiNi0.4Mn1.4Co0.2O4, and LiNi0.4Mn1.4Cr0.15Co0.05O4, were prepared by sol–gel method and characterized by powder X-ray diffraction, Fourier transformed infrared spectroscope, scanning electron microscopy, Brunauer–Emmett–Teller surface area, four-probe resistance, cyclic voltammetry, electrochemical impedance spectroscopy, and charge–discharge test. It is found that the co-doped sample LiNi0.4Mn1.4Cr0.15Co0.05O4 exhibits an improved performance compared with the Co-doped sample LiNi0.4Mn1.4Co0.2O4 and the undoped sample LiNi0.5Mn1.5O4, especially at elevated temperature. At 25 °C, the discharge capacity of LiNi0.4Mn1.4Cr0.15Co0.05O4 is 130 mAh g?1 at 0.1 C and 103 mAh g?1 at 10 C. At an elevated temperature (55 °C), its 1 C discharge capacity is 136 mAh g?1 and maintains 95.6 % of its initial capacity after 100 cycles. Compared with the reported results of LiNi0.4Mn1.4Co0.2O4 and LiNi0.475Mn1.475Co0.05O4, the co-doped sample LiNi0.4Mn1.4Cr0.15Co0.05O4, with least content of Co, 0.05, possesses not only the high C-rate capacity but also the structural stability. The mechanism on the electrochemical performance improvement of LiNi0.5Mn1.5O4 by the co-doping was discussed.  相似文献   

17.
Syntheses and Crystal Structures of the Phosphaneimine Complexes MCl2(Me3SiNPMe3)2 with M = Zn and Co, and CoCl2(HNPMe3)2 The molecular complexes MCl2(Me3SiNPMe3)2 (M = Zn, Co) have been prepared by the reaction of the dichlorides of zinc and cobalt with Me3SiNPMe3 in CH3CN and CH2Cl2, respectively, whereas the complex CoCl2(HNPMe3)2 has been prepared by the reaction of CoCl2 with NaF in boiling acetonitrile in the presence of Me3SiNPMe3. All complexes were characterized by IR spectroscopy and by crystal structure determinations. The complexes MCl2(Me3SiNPMe3)2 crystallize isotypically. ZnCl2(Me3SiNPMe3)2: Space group P212121, Z = 4, 2677 observed unique reflections, R = 0.024. Lattice dimensions at ?70°C: a = 1243.6; b = 1319.0; c = 1464.7 pm. CoCl2(Me3SiNPMe3)2: Space group P212121, Z = 4, 3963 observed unique reflections, R = 0,071. Lattice dimensions at ?80°C: a = 1236.3; b = 1317.4; c = 1457.6 pm. CoCl2(HNPMe3)2 · CH2Cl2: Space group Pbca, Z = 8, 1354 observed unique reflections, R = 0.055. Lattice dimensions at ?80°C: a = 1247.3; b = 998.4; c = 2882.4 pm. All complexes have monomeric molecular structures, in which the metal atoms are coordinated in a distorted tetrahedral fashion by the two chlorine atoms and by the nitrogen atoms of the phosphaneimine molecules.  相似文献   

18.
Reaction of [M(NH3)6]Cl3 (M = Co, Rh, Ir) and [Ir(NH3)5(OH2)]Cl3 with (NH4)2C2O4 · H2O in aqueous solution resulted in the isolation of [M(NH3)6]2(C2O4)3 · 4 H2O and [Ir(NH3)5(OH2)]2(C2O4)3 · 4 H2O, respectively. The complexes have been characterized by X‐ray crystallography, IR and UV/VIS spectroscopy. The isomorphous compounds crystallize in the orthorhombic space group Pnnm (No. 58). Four molecules of crystal water are involved in an extended three‐dimensional hydrogen bonding network. The librational modes of the lattice water around 600 cm–1 allow the characterization of [Ir(NH3)6]2(C2O4)3 · 4 H2O and [Ir(NH3)5(OH2)]2(C2O4)3 · 4 H2O, respectively, by IR spectroscopy. The band around 600 cm–1 shows a significant frequency shift in the IR spectra of the hexaammine and aquapentaammine complex of iridium(III) and, by that, a distinction is possible.  相似文献   

19.
Reactivity in the solid state between CoWO4 and some rare-earth metal tungstates RE2WO6 (RE = Sm, Eu, Gd) was investigated by the XRD method. Two families of new isostructural cobalt and rare-earth metal tungstates, Co2RE2W3O14 and CoRE4W3O16, were synthesized. The Co2RE2W3O14 phases are formed by heating in air the CoWO4 and RE2WO6 compounds mixed at the molar ratio 2:1, while the CoRE4W3O16 phases are synthesized at the molar ratio of CoWO4/RE2WO6 equals to 1:2. The Co2RE2W3O14 phases as well as the CoRE4W3O16 compounds crystallize in the orthorhombic system. The Co2RE2W3O14 and CoRE4W3O16 compound melt above 1150 °C. A melting manner of the Co2RE2W3O14 and CoRE4W3O16 compounds was determined in an inert atmosphere. The formation of CoWO4−x phase was observed during heating in an inert atmosphere.  相似文献   

20.
Co-ordinative Properties of Chelating Ligands of the Type Me2XSi(Me2)CH2XMe2 (X ? N and/or P; Me ? CH3) The reactions of the ligands L ? Me2XSi(Me2)CH2XMe2 (X ? N and/or P; Me ? CH3) with M(CO)6 and M(CO)4norbor (norbor ? norbornadiene) (M ? Cr, Mo), respectively, yield derivatives of the types M(CO)5L, M(CO)4L, and M(CO)4L2, respectively. M(CO)5L compounds are formed from the hexacarbonyls with Me2NSiMe2CH2PMe2, whereas the ligand Me2NSiMe2CH2NMe2 does not afford analogous derivatives under the same conditions. Even on substitution of the diene-ligand in M(CO)4norbor by Me2NSiMe2CH2PMe2 the chelate complexes M(CO)4NMe2SiMe2CH2PMe2 are not obtained, but the cis-disubstituted products M(CO)4[PMe2CH2SiMe2NMe2]2 with phosphorus acting as donor atom are produced. The ligands Me2PSiMe2CH2XMe2(X ? N, P) give the chelate complexes M(CO)4PMe2SiMe2CH2XMe2 in high yields. The new compounds were identified by analytical and spectroscopic (PMR, IR, mass spectra) methods.  相似文献   

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