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1.
采用熔融硼酸法合成了一种具有层状结构的新型水合稀土多硼酸盐, La[B5O8(OH)(H2O)]NO3•2H2O, 并利用单晶X射线衍射技术确定了它的结构. 它属于单斜晶系, P21/n空间群. 其基本构建单元 (fundamental building block, 简称FBB)是由三个BO4和两个BO3基团所构成的一个双三元环[B5O12]基团. 结构中每一个FBB通过共顶点氧原子与周围四个同样的单元连接成具有九元环窗口的二维[B5O10]层, La3+位于九元环中心附近. [B5O10]层沿着b方向进行堆积, 硝酸根离子和结构中部分结晶水分子位于相邻的[B5O10]层之间.  相似文献   

2.
通过三核铁盐[Fe3O(O2CCH3)6(H2O)3]C1在吡啶溶液中水解聚合得到铁氧簇合物[Fe11O6(OH)6(O2CCH3)15](C5H5N)6。晶体结构表明11个铁离子(Ⅲ)中6个位于扭曲的三棱柱的顶点上,其余5个分别位于三棱柱的每个面之外。铁离子(Ⅲ)之间以氧桥或者羟基氧桥相连。变温磁化率证实铁离子(Ⅲ)之间是反铁磁耦合的。  相似文献   

3.
合成了2个新的希土冠醚配合物Ln(NO3)3·C26H38N2O4(Ln=La、Ce; C26H38N2O4=1, 7, 10, 16-四氧-4,13-二氮杂-N,N′-二苄基环十八烷)。通过元素分析,红外光谱,拉曼光谱及其 1H核磁共振谱进行表征。用四圆衍射仪测定了La(NO3)3·C26H38N2O4·CH3CN的晶体结构。晶体属三斜晶系,P1空间群,晶胞参数:a=1.2869(4) nm, b=1.5868(6) nm, c=0.9147(2) nm; α=101.89(2)°, β=105.38(2)°, γ=71.96(3)°; Z=2。dcald.=1.58 g·cm-3, μ(Mo)=13.25 cm-1。中心镧离子与冠醚配体中的4个氧原子和2个氮原子配位,3个硝酸根中的6个氧原子也与La3+配位,形成配位数为12的配合物。  相似文献   

4.
在硼酸介质中合成了一种新的具有层状结构的多硼酸铍H2BeB4O8,并利用多晶X射线衍射方法确定了晶体结构。H2BeB4O8的空间群为P21/n,晶胞参数a=17.7564(2)?,b=4.2948(1)?,c=7.1532(1)?,β=96.8797(9)°。H2BeB4O8的层状结构由双三元环[BeB4O11]构成,层之间通过垂直于层平面的羟基所形成的氢键连接成三维结构。  相似文献   

5.
利用水热合成技术成功制备出一种新型多钒硼氧化合物, 用X射线单晶衍射分析技术对其晶体结构和分子结构进行了确定。结果表明在该化合物中多钒硼氧阴离子具有一个新颖的三明治结构。上下两个结构单元都是由六个VO5四角锥交替地通过顺式和反式共边的方式连接起来构成的一个钒氧三角形结构。中间的结构单元是由BO3平面三角形和BO4四面体以共角的方式相互连接形成的一个折叠型的B18O36(OH)6环。三明治结构中层与层之间通过桥氧相连。一个水分子处于它的核心位置上,与每个VO5四角锥中的钒原子都保持几乎相等的距离。该化合物及其晶体中存在着丰富的化学结构和成键信息,同时也有作为氧化还原反应催化剂的潜能。  相似文献   

6.
张爱芸  姚燕 《化学学报》2006,64(6):501-507
测定了298.15 K下, 无液接电池Li-ISE│Li2B4O7 (mA)(aq.), MgCl2(mB)(aq.)│AgCl/Ag的电动势, 利用测定结果计算了Li2B4O7-MgCl2-H2O体系离子强度在0.05~3 mol•kg-1范围内, 不同MgCl2离子强度分数的溶液中LiCl的平均活度系数, 并给出了其随离子强度I, B4O72-和Mg2+浓度的变化规律. 结合以往关于该体系和Li2B4O7-LiCl-H2O, Li2B4O7-H2O体系的等压研究结果, 用迭代和多元线性回归方法对Li-Mg2+-Cl-B4O72--H2O体系的离子相互作用模型进行了研究. 具体方法为考虑了该体系在不同的总硼浓度范围H3BO3, B(OH)4, B3O3(OH)4和B4O5(OH)42-四种含硼化合物的存在以及各硼化合物间的化学平衡, 以修正了的Pitzer渗透系数方程和活度系数方程为基础, 对该体系的等压法和电动势法研究结果进行最小二乘拟合, 拟合的标准偏差为0.0167, 用该模型计算的该体系的渗透系数、活度系数与实验值基本一致.  相似文献   

7.
王天维 《无机化学学报》2009,25(12):2189-2192
The title linear trinuclear complexes, [Fe3L2(CH3COO)2](L=bis-(salicylidene)-1,3-diaminopropane (salpd) (1) and L=bis-(salicylidene)-1,4-diaminobutane (salbd) (2) were synthesized simply using solvothermal method in methanol and were characterized by X-ray single crystal diffraction. [Fe3L2(CH3COO)2](1) was obtained using salicylaldehyde, 1,3-diaminopropane and Fe(CH3COO)2·4H2O via the above method with monoclinic crystal system and space group of P21/c, and lattice parameters of a=0.945 0(8) nm, b=1.037 0(8) nm, c=1.830 5(14) nm, β=94.357(16)°. The [Fe3L2(CH3COO)2](2) was obtained using1,4-diaminobutane instead of 1,3-diaminopropane while keeping the other conditions the same as that for synthesis of [Fe3L2(CH3COO)2] (1). The [Fe3L2(CH3COO)2](2) was in monoclinic crystal system and space group of P21/c, and lattice parameters of a=0.919 0(5) nm, b=1.675 6(9) nm, c=1.270 0(7) nm, β=95.126(11)°. CCDC: 754930, 1; 754931, 2.  相似文献   

8.
水热法合成了新结构类型化合物CsIn[PO3(OH)]2,并通过单晶X-射线衍射表征结构。标题化合物空间群为P1 21/c 1 (No.14),晶体学参数为:Mr=439.69,mP56,a=0.532 86(6) nm,b=0.916 53(7) nm,c=1.478 39(14) nm,β=93.849(9)°,V=0.720 4(1) nm3,Z=4,Dx=4.054 g·cm-3,μ=8.713mm-1F(000)=800,R1= 0.032 5,wR2=0.087 4。在该化合物中,2个InO6八面体和4个PO4四面体形成交连的六元环柱,并沿a轴方向形成近六方密堆积并连接成Cs+离子占据的十二元环结构隧道,六元环和十二元环连接构筑了三维网络结构。与类似化学计量比化合物Na2In2[PO3(OH)]4·H2O比较,标题化合物中十二元环的形成明显取决于隧道阳离子的大小,其拓扑构造可看作扩展的6,3-网格连接,化合物 RbIn[PO3(OH)]2与之同构。  相似文献   

9.
采用XRD、N2吸附、 11B MAS NMR、NH3-TPD和催化性能评价等方法研究了B2O3/TiO2-ZrO2催化剂的结构、酸性及催化环己酮肟气相Beckmann重排反应性能间的关系。结果表明,催化剂中的B2O3同时以三配位的BO3和四配位的BO4结构单元存在;  相似文献   

10.
A hydrothermal reaction of NaVO3, Ce(NO3)3, H3BO3, 2,2′-bipyridine and water in a molar of 1∶2∶3∶2∶333 gives a yellow crystal [(C10H8N2)2VO2](H2BO3)·3H2O. It crystallizes in a triclinic with space group P1 and unit cell parameters a=0.6643(1)nm, b=1.1794(2)nm, c=1.4822(3)nm, α=101.39(3)°, β=101.59(3)°, γ=97.15(3)°, Z=2, Dc=1.542g·cm-3, μ=0.508mm-1, F(000)=528, R1=0.0736, wR2=0.1998,Goof=1.071. X-ray crystallographic study showed that the VN4O2 octahedron unit is distorted, in which the V1 atom is coordinated by two terminal O1 and O2 atoms, and N1, N2, N3 and N4 atoms from two 2,2′-bipy ligands. The hydrogen bonding are observed between 2,2′-bipy and adjacent terminal oxygen atom. It is noteworthy that π-π stacking interaction between adjacent 2,2′-bipy groups plays an significant role in stabilization of the structure of crystal. CCDC: 194327.  相似文献   

11.
Two single crystals[Ln(TBPO)4(NO3)2]NTf2 (Ln=Eu, Gd) were prepared and characterized by element analysis, single crystal X-ray diffraction, PXRD, FT-IR, TGA and fluorescence spectroscopy. The two compounds have similar coordinate structures, in which the central metal ion is coordinated by four TBPO (Tri-n-butylphosphine oxide) molecules and two bidentate nitrates, while NTf2-(bis(trifluor-(bis(trifluoromethylsulfonyl) imide anion) acts as the counter anion. The packing modes of the two crystals are same. The two single crystals are the focus on 8-coordinate tetra-TRPO complexes (TRPO is Trialkyphosphine oxides).  相似文献   

12.
Using an on-line solution-reaction isoperibol calorimeter, the standard molar enthalpies of reaction for the general thermochemical reaction: LnCl3·6H2O(s) + 2C9H7NO(s) + CH3COONa(s) = Ln(C9H6NO)2(C2H3O2)(s) + NaCl(s) + 2HCl(g) + 6H2O(l) (Ln: Nd, Sm), were determined at T=298.15 K, as  kJ mol−l, respectively. From the mentioned standard molar enthalpies of reaction and other auxiliary thermodynamic quantities, the standard molar enthalpies of formation of Ln(C9H6NO)2(C2H3O2)(s) (Ln: Nd, Sm), at T=298.15 K, have been derived to be: −(1494.7±3.3) and −(1501.5±3.4) kJ mol−l, respectively.  相似文献   

13.
A series of new complexes of formula Ln(acac)_s(Ph_3PO)_3 (where Ln~(3+)=Nd~(3+), Sm~(3+), Eu~(3+), Tb~(3+), Ho~(3+)) have been prepared and characterized. The coordination of two ligands with lanthanide ions are studied by IR spectra, ~1H, ~(13)C, ~(31)P-NMR and metal-ligand charge tranafer tranaition is also discussed via electronic adaorption and luminescence spectroscopy.  相似文献   

14.
Thermodynamic properties of rare-earth Ln2CuO4 (Ln = Nd, Sm, Eu), Ho2Cu2O5 and Ln2BaCuO5 (Ln = Nd, Sm, Eu, Ho, Yb) cuprates were determined using the electromotive force method with a fluorine-ion electrolyte in the temperature interval of 1000–1230 K. The thermodynamic data obtained by different experimental methods were compared.  相似文献   

15.
以乙酰丙酮(Hacac)、邻菲咯啉(phen)、硝酸根为配体,8-羟基喹啉为酸度调节剂合成出一个系列的镧系轻稀土四元配合物Ln(NO3)2(phen)2(CH3COCHCOCH3)(Ln=La,Ce,Pr,Nd,Sm)。配合物的结构与性质由元素分析,IR,1HNMR和TGA等表征。单晶Ce(NO3)2(phen)2(CH3COCHCOCH3)·H2O结构经由X射线衍射仪分析表明,晶体属单斜晶系,空间群P21/n,晶胞参数为a=1.11017(8)nm,b=0.98401(7)nm,c=1.34453(10)nm,β=102.0530(10)°,V=1.43641(18)nm3,Dc=1.715g·cm-3,Z=2,F(000)=742。配合物呈单核结构,中心离子Ce髥配位数为10。  相似文献   

16.
The enthalpies of dissolution in water of new ternary complexes of four late trivalent lanthanide ions Ln(Gly)4Im(ClO4)3·nH2O (Ln=Gd, Tb, Dy, Y; Gly: glycine; Im: imidazole and n=1 or 2) were measured by means of a Calvet microcalorimeter. Empirical formulae for the calculation of the enthalpies of dissolution (ΔdissH), relative apparent molar enthalpies (ΔdissH (app)), relative partial molar enthalpies (ΔdissH (partial)) and enthalpies of dilution (ΔdilH1,2) were obtained from the experimental data of the enthalpies of dissolution of these complexes. The plot of ΔdissHmΘ, ΔdissH (app) and ΔdissH (partial) versus the values of the ionic radius of the lanthanide element (r) showed a grouping effect of the lanthanide elements, indicating that the coordinated bond between the lanthanide ions and the ligands has some covalent character. The unknown value of the standard enthalpy of dissolution for the similar complex: Ho(Gly)4Im(ClO4)3·H2O was estimated according to the plot of ΔdissHmΘ versus r.  相似文献   

17.
In this study, Lnx(SiO4)6O(1.5x–12) (Ln: Nd, La) materials as electrolytes for solid oxide fuel cells (SOFC) were prepared by the sol-gel process. It has been reported that the apatite structure of Lnx(SiO4)6O(1.5x–12) shows higher ionic conductivity than yttrium-stabilized zirconium oxide at the working temperature of the SOFC. Ln10(SiO4)6O3 is a major component of the Lnx(SiO4)6O(1.5x–12) system. Ln10(SiO4)6O3 consists of Ln9.33(SiO4)6O2 and a small amount of Ln2SiO5. It has been proposed that the ionic conductivity of Lnx(SiO4)6O(1.5x–12) decreases with increasing Ln2SiO5 with non-apatite structure. The object of the present study was to bring about this decrease by generating Ln2SiO5 in the system.Precursor solutions for synthesis of the powder were prepared using tetraethoxysilane (Si(OC2H5)4) and neodymium acetate monohydrate (Nd(CH3COO)3·H2O) or lanthanum acetate monohydrate (La (CH3COO)3·H2O) as raw materials and acetic acid (CH3COOH), 2-methoxyethanol (C2H5OCH2CH2OH), and triethanolamine (N(CH2CH2OH)3) as solvents. To obtain the powder, the solution was dried and heat-treated at 600 °C for 2 h. Disks made from the powder were heat-treated at temperatures between 1100 and 1500 °C for 10 h. The results of an XRD investigation indicate that almost all diffraction peaks of these samples could be assigned to Ln9.33(SiO4)6O2. The sample with x = 10.00 included a small amount of Ln2SiO5. The ionic conductivity of this latter sample was higher than that of other samples with similar values of x (x = 9.33 and 10.67).  相似文献   

18.
Compounds of the type (n-CnH2n+1NH3)2MCl4 with n = 12 or n = 16 and with M = Mn, Cu, Co, Fe, Hg, Zn show order-disorder solid-solid phase transitions in the temperature range 300–380 K. Three general types of thermal behaviour can be observed for compounds with different metals, but with the same n. The different thermal behaviour appears to be related to different coordination geometries at the metal atoms.  相似文献   

19.
用XPS测定了LnCu2O4(Ln=Gd, Nd)的内层和价层电子能谱,观察到LnCu2O4中稀土金属的3d电子结合能比相应的稀土金属简单氧化物的3d结合能低0.8~0.9 eV,而Cu的2p电子结合能比CuO的高0.4~0.5 eV,因此推断在LnCu2O4的Ln-O-Cu链中存在Cu→O→Ln电荷转移.XPS分析还表明LnCu2O4的Cu原子上有较低的电荷密度,但不存在混合价态.此外,通过比较价电子能谱,发现NdCu2O4的Ln 4f Cu 3d O 2p价带中心比GdCu2O4的价带中心向Fermi能级移近了3.4 eV,而且NdCu2O4的价带谱更窄.  相似文献   

20.
Two new potassium vanadium phosphates have been prepared and their structures have been determined from analysis of single crystal X-ray data. The two compounds, K3(VO)(V2O3) (PO4)2(HPO4) and K3(VO)(HV2O3)(PO4)2(HPO4), are isostructural, except for the incorporation of an extra hydrogen atom into the nearly identical frameworks. The structures consist of a three-dimensional network of [VO]n chains connected through phosphate groups to a [V2O3] moiety. Magnetic susceptibility experiments indicate that in the case of the di-hydrogen compound, there are no significant magnetic interactions between the three independent vanadium (IV) centers. Crystal data: for K3(VO)(V2O3)(PO4)2 (HPO4), Mr = 620.02, orthorhombic space group Pnma (No. 62), a = 7.023(4) Å, b = 13.309(7) Å, c = 14.294(7) Å, V = 1336(2) Å3, Z = 4, R = 5.02%, and Rw = 5.24% for 1238 observed reflections [I > 3σ(I)]; for K3(VO)(HV2O3)(PO4)2(HPO4), Mr = 621.04, orthorhombic space group Pnma (No. 62), a = 6.975(3) Å, b = 13.559(7) Å, c = 14.130(7) Å, V = 1336(1) Å3, Z = 4, R = 6.02%, and Rw = 6.34% for 1465 observed reflections [I > 3σ(I)].  相似文献   

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