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Zusammenfassung Bei röntgenographischen Untersuchungen im System GeO2-P2O5 wird eine Verbindung der Zusammensetzung 2 GeO2·P2O5 aufgefunden. Einkristallaufnahmen ergeben eine hexagonale (trigonale) Elementarzelle mita=7,998 undc=24,86 Å. Die schon beschriebene Verbindung 2 SiO2·P2O5 erweist sich als isotyp:a=7,862 undc=24,13 Å.  相似文献   

3.
本文提出一种Gibbs-Dubem关系的变通形式。应用該式可以从已知的二元系中二个组元的活度系数之此,分别求出二个組元的活度。将該式应用于PbCl_2-SnCl_2及PbCl_2-CdCl_2系,証明这二熔盐体系对Raoult定律仅呈較小的正偏差。此外,对反应Sn+PbCl_2→Pb+SnCl_2和Cd+PbCl_2→Pb+CdCl_2的标准自由能变化(△F°)作了修正。  相似文献   

4.
粱映秋  赵文运  徐蔚清  张致贵 《化学学报》1985,43(12):1126-1130
本文测定了原子簇化合物[Mo2O2S2(S2)2][2-]的红外和拉曼光谱,并在乙腈溶液中测得其共振拉曼光谱和退偏振比。利用X光晶体结构数据,对此阴离子的伸缩振动作了简化的正则坐标分析计算。所得结果可以帮助分析和归属一些Mo-Fe-S原子簇化合物的振动光谱。  相似文献   

5.
2MgO·2B2O3·MgCl2·14H2O-MgCl2-H2O体系30℃相平衡   总被引:2,自引:0,他引:2  
用相平衡方法研究2MgO@2B2O3@MgCl2@14H2O在30℃不同质量分数MgCl2水溶液中的溶解转化产物及其溶解度.结果表明,该复盐在MgCl2的质量分数0~2%浓度范围,发生不同步溶解并转化为多水硼镁石(2MgO@3B2O3@15H2O);在MgCl2的质量分数2%~13.8%浓度范围,转化为柱硼镁石(MgO@B2O3@3H2O),这一结果比文献报导的该硼酸盐的形成温度低了13℃,为盐湖硼酸镁矿物柱硼镁石形成的解释提供了物理化学依据;而在MgCl2质量分数大于13.8%时,同步溶解,不发生转化.提出了溶解相转化反应机理.  相似文献   

6.
韩维屏  王潍平  陈宏 《催化学报》1987,8(3):328-332
P_2O_5-V_2O_5-TiO_2(简写为P-V-Ti)对芳烃氧化有良好的催化效果.丁烷氧化催化剂P-V体系的体相和表面结构已有一些报道.但P_2O_5对V-Ti的影响文献较少报道.本文用XRD,IR,TPD和ESR考察了P-V-Ti体系. 1.试剂和催化剂:草酸、偏钒酸铵、二氧化钛均为化学纯.将V_2O_5:TiO_2=11:89(重量)样品分别按 P/V原子比为0.1,0.3,0.6,1.0,1.5和2.5制成编号为P-0.1,P-0.3,P-O.6,P-1.0,P-1.5和P-2.5的催化剂.  相似文献   

7.
Na2WO4·2H2O-H2O2催化氧化苯甲醛制备苯甲酸   总被引:4,自引:0,他引:4  
以30%H2O2为氧源,Na2WO4·2H2O催化氧化苯甲醛制备苯甲酸.考察了H2O2用量,反应时间,催化剂和酸性添加物(硫酸氢钠)对苯甲酸收率的影响和在非酸性环境下,表面活性剂对苯甲酸收率的影响.结果表明,加入非离子表面活性剂能有效的提高苯甲酸的收率,特别是添加β-环糊精,苯甲酸的收率达90.03%.  相似文献   

8.
关于过渡金属Pd,Pt对C_2H_2的吸附和氢化实验研究前人已作了不少工作,但有关Pd,Pt与C_2H_2之间成键问题的理论研究还尚不多见。为了了解Pd,Pt d轨道对炔键的活化行为和成键特性,本文以MC_2H_2(M=Pd,Pt)为模型,用赝势计算方法,对Pd,Pt与C_2H_2键的相互作用进行了研究。一、计算方法由于重原子的内层轨道对形成分子贡献很小,内层电子的相对论效应极为严重。本文采用Ps—HONDO程序,选取Hay的有效核芯势和价轨道Gaussian基组,对重原子Pd和Pt进行了价电子从头计算,对C和H进行了全电子从头算.部分地消除重原子内层电子相对论效应所引起的误差。  相似文献   

9.
The decomposition kinetics of peroxide products contained in the liquid phase of the LiOH-H2O2-H2O ternary system were studied, and the applicability of the solubility method to studying this system was demonstrated for hydrogen peroxide concentrations in the liquid phase from 2 to 6 wt % and temperatures of 21–33°C. The stabilizing influence of solid Li2O2 · H2O on hydrogen peroxide decomposition was demonstrated. The temperature and concentration boundaries of existence were determined for the Li2O2 · H2O phase, whose identity was verified by chemical analysis and qualitative X-ray powder diffraction analysis.  相似文献   

10.
Crystal structure of the title complex was determined by X-ray diffraction method. It crystallizes in space group P21/n with cell dimensions:α=10. 041(5) , b=10. 719(4) , c= 1. 5671(6) nm, β=104. 36(3)°. The structure was solved by Patterson method. The final residual factor is R=0. 050.  相似文献   

11.
A novel heteropoly compound, containing two kinds of coordinated cations, [K(H2O)2Ni(H2O)6]2[V10O28], has been synthesized through routine process and characterized by elemental analyses, IR, 51V NMR and single crystal X-ray diffraction. It crystallizes in the triclinic system, space group P1 with a=0.87382(17) nm, b=1.075 4(2) nm, c=1.111 1(2) nm, α=65.10(3)°, β=75.01(3)°, γ=70.63(3)°, V=0.884 8(3) nm3 and Z=1. The X-ray analysis reveals that the two kinds of coordinated cations are linked by three shared coordinated water molecules, and K+ cations coordinate with ten oxygen atoms: five of which come from V10O286- anion, the other five from water molecules. The title compound exhibits extended 2D array building up of V10O286- groups connected by ten-coordinated K+ cations. The hexahydrated nickel cations Ni(H2O)62+ lie in neat apposition to three adjacent V10O286- clusters. CSD: 413271.  相似文献   

12.
The superconducting phase(Bi_(1.7)Pb_(0.2)In_(0.1))Sr_2Ca_2Cu_3O_(10) with on-set T_c near 112K and zero resistivity at 95K has been prepared. The Unit cell is. body-centered tetragonal, space group I4/mmm, a=0.3.817(1) nm, c=3.704(1) nm. Chemical substitution of Pb and In in Bi—Sr—Ca—Cu—O series results in the growth of 2223 phase. The superconductivity and the formation mechanism are associated with the structural features.  相似文献   

13.
我们已制备出Tl_2 Ca Ba_2 Cu_2O_8(2122)和Tl_2Ca_2 Ba_2 Cu_3 O_(10)(2223)两个纯相,并对它们的晶体结构和性质进行了研究。现在我们又制备出一种新的超导相,它的组成为Tl_2 Ca_3 Ba_2 Cu_4 O_(120(2324),并进一步研究了它的超导性质和晶体结构。  相似文献   

14.
In the SrS-Ga2S3 system, there exist two individual compounds: SrGa2S4 (a = 2.084 nm, b = 2.050 nm, c = 1.220 nm; congruent melting at 1530 K) and Sr2Ga2S5 (a = 1.253 nm, b = 1.203 nm, c = 1.117 nm; peritectic melting at 1330 K); both are orthorhombic. We discovered a compound of composition Sr4Ga2S7; this compound crystallizes in cubic system with the unit cell parameter a = 0.6008 nm, space group Pa3, and decomposes by a solid-phase reaction at 870 K. Eutectic compositions are 42 and 73 mol % Ga2S3; eutectic melting temperatures are 1210 and 1170 K, respectively. The SrS solubility in γ-Ga2S3 at 1070 K reaches 4 mol %.  相似文献   

15.
利用水热法在均苯三甲酸、六水氯化钴、甲酸铵和水的体系中合成了四水合均苯三甲酸二氢钴。该化合物晶体属于单斜晶系,对应的空间群为P21/c。磁性测量表明该化合物的钴离子之间存在反铁磁的相互作用,但直至2 K时也没有观察到磁有序。  相似文献   

16.
层状类钙钛矿结构新铌酸盐KSr2Nb3O10   总被引:3,自引:0,他引:3  
A new niobate compound KSr2Nb3O10 was synthesized for the first time. The chemical compositions, crystal structure, optical property, density and melting point of the new compound were characterized by EPMA, TEM, XRD, DTA and so on. KSr2Nb3O10 crystallizes the orthorhombic system with unit cell parameters a=0.7816(1) nm, b=0.7764(2) nm, c=2.9995(2) nm, V=1.8114(4) nm3, and space group P212121, Z=8. The structure may be described as treble perovskite sheets [Sr2Nb3O10- interleaved with K+. Further, it was found that KSr2Nb3O10 has intercalation phenomenon. Na+, Li+, H+, NH+4 could exchange the interlayer cations K+ of KSr2Nb3O10, and n-hexylamine also could intercalate into the place between the layers of [Sr2Nb3O10-.  相似文献   

17.
In this paper we describe the molecular and crystal structures of the K3[Y(NTA)2(H2O)]· 6H2O(H3NTA=nitrilotriacetic acid). The crystal data are as followsmonoclinic system, C2/c space group, a=1.5268(3)nm,b=1.2833(3)nm,c=2.6079(5)nm,β =96.03(3)°,V=5.0815(18)nm3,Z=8,M=708.68,Dc=1.852gcm-3,μ =2.875mm-1,F(000)=2880.The final R1 and wR2 are 0.0636 and 0.1523 for 4264 [I >2.0σ (I)] unique reflections and 0.1178 and 0.1651 for all 4364 reflections,respectively.In the title complex, the anion [Y(NTA)2(H2O)]3- has a nine-coordination structure with distorted monocapped square antiprism. Each group acts as a tetradentate ligand with three Oatoms and one Natom and a H2O molecule caps a quadrilateral face as a ligand.It can be known that the Y(Ⅲ) ion can form a high-coordinate compound with aminopolycarboxylic acid ligands because it has a larger ionic radius (0.104nm).  相似文献   

18.
Phase equilibria in the EuS-Cu2S-Nd2S3 system were studied in an isothermal (970 K) section and NdCuS2-EuS and Cu2S-EuNdCuS3 polythermal sections. The complex sulfide EuNdCuS3 has an orthorhombic crystal lattice (space group Pnma; a = 1.10438(2) nm, b = 0.40660(1) nm, c = 1.14149(4) nm), is isostructural to BaLaCuS3, and melts incongruently at 1470 K: EuNdCuS3 (0.50 EuS; 0.50 NdCuS2) ai 0.18 EuS ss (0.88 EuS; 0.12 NdCuS2) + 0.82 L (0.415 EuS; 0.585 NdCuS2); ΔH = 17.8 kJ/mol. Within the range 0.5 mol % EuS, EuNdCuS3-based solid solutions were not found. At 970 K, the tie lines pass from the compound EuNdCuS3 to Cu2S, EuS, NdCuS2, and EuNd2S4 phases and lie between the NdCuS2 phase and solid solutions (ss) of γ-Nd2S3 with EuNd2S4. Eutectics are formed between the compounds NdCuS2 and EuNdCuS3 at 32.0 mol % EuS T = 1318 K and between the compounds Cu2S and EuNdCuS3 at 20.5 mol % EuNdCuS3 and T = 1142 K. Five main subordinate triangles were identified in the system.  相似文献   

19.
利用三苄基氧化锡与2-噻吩甲酸和2-唑甲酸反应,合成了六聚体苄基锡氧2-噻吩甲酸酯(1)和六聚体苄基锡氧2-唑甲酸酯(2)鼓形簇合物.通过元素分析、红外光谱和X射线单晶衍射对其结构进行了表征.测试结果表明:化合物1属三斜晶系,空间群p1,a=1.2760(3)nm,b=1.3056(3)nm,c=1.3343(3)nm,α=105.65(3)°,β=96.27(3)°,γ=97.20(3)°,Z=1,V=2.0997(7)nm3,Dc=1.809g/cm3,μ=2.097mm-1,F(000)=1116,R=0.0651,wR=0.1292.化合物2属三斜晶系,空间群p1,a=1.2240(4)nm,b=1.3673(4)nm,c=1.3744(4)nm,α=107.760(4)°,β=98.069(5)°,γ=91.480(5)°,Z=2,V=2.1631(12)nm3,Dc=3.373g/cm3,μ=3.799mm-1,F(000)=2136,R=0.0382,wR=0.079.它们均为鼓形簇状结构,锡原子呈畸变的八面体构型.化合物1通过分子间S…S近距离作用,形成一维链状结构.  相似文献   

20.
Li_(0.025)Na_(0.975)NbO_3 undergoes a ferroelectric-ferroelectric phase transition at 180K (on cooling) or 260 K (on heating). The structure determinations of both phases have been carried out by single crystal diffraction analysis. The ferroelectric room-temperature phase is orthorhombic, with space group Pc2_1b; the cell parameters are a=0.5508(3), b=1.5521(6), c=0.5568(2) nm. The structure is same with Li_(0.02)Na_(0.98)NbO_3. The ferroelectric low-temperature phase is also orthorhomhie, a=0.5497(7), b=0.7913(18), c=0.5565(10) nm, V=0.2421 nm, Z=4. There is disordernal position distribution of O(2) atomes in the low-temperature phase. Its “apparent space group” is P2/n2/n2/n. The relation of the ferroelectric properties to the low-temperature phase structure is discussed.  相似文献   

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