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1.
Based on experimental data it is shown that samples in a solid solution series of the system Li7[VN4]–Li2O with partial Li–V order can be obtained.  相似文献   

2.
In the reaction conditions leading to γ‐Li7VN4, no ordered solid solution γ‐Li7VN4–Li2O seems to exist but rather a mixture of two phases: γ‐Li7VN4 and a lithium vanadium oxynitride with the disordered anti‐fluorite structure. Even though the trend may be different in the case of β‐Li7VN4–Li2O, neutron diffraction experiments would be desirable to confirm/dismiss these assumptions, as they would allow to determine the number of phases and polymorphs present and the degree of Li/V or N/O order, if any.  相似文献   

3.
A novel synthetic approach is presented leading to hitherto unknown nitridosilicates, oxonitridosilicates, oxonitridoaluminosilicates, carbidonitridosilicates, as well as nitridoborates and oxonitridoborates of rare earth elements, alkali, and alkaline earth metals. Typically, the respective metals were reacted with silicon diimide, aluminum nitride, or poly(boron amide imide), respectively, under pure nitrogen atmosphere utilizing a radiofrequency furnace. Usually, the compounds are obtained within short reaction periods as coarsely crystalline products. Zink nitridophosphates of the sodalite structure type were obtained by the reaction of phosphorus nitride imide with zinc or zinc chalcogenides, respectively. Several molecular metal silylamides and imides containing nitridobridges between the metals and silicon were obtained by the reaction of differently chlorinated disilazanes with metal chlorides. During these investigations hitherto unknown bis(trimethylsilyl)ammonium salts have been discovered. Furthermore, we report about the synthesis of N‐silyl metal hydrazides.  相似文献   

4.
New tetra‐ and octasubstituted nitrido(phthalocyaninato)metal(V) complexes RnPcMN (M = Re, Mo, W) were synthesized to obtain soluble nitrido‐bridged phthalocyanines. Phthalocyanines with nitrido bridges between rhenium and boron, aluminium, gallium and indium, respectively, were synthesized from nitrido(tetra‐tert.‐butylphthalocyaninato)rhenium(V) complex, tBu4PcReN and suitable electrophilic reagents like BCl3, B(C6F5)3, BPh3, BEt3, AlCl3, GaCl3, GaBr3, InCl3, etc. The nitrido‐bridged compounds prepared show different stabilities depending on the substituents at the boron atom. Additionally, the possibility to increase the nucleophilicity of (C5H11)8PcWN by reducing this complex with C8K was studied. The reaction of the reduced complex with electrophiles, e.g. with tBuMeSiCl, Ph3SiCl and Me3GeCl indicates the formation of nitrogen‐bridged complexes.  相似文献   

5.
We report on the synthesis, optical and electrical properties of thin films of LaxSr(1−x)Ti(O,N)3, x = 0, 0.25, 0.50, 0.75 and 1. The films were grown by a soft chemistry process from polymeric precursor solutions, which were deposited by spin coating on 100-oriented SrTiO3 substrates. After drying, the organic matrix was burned at 400 °C. These steps were repeated six times to obtain a reasonable thickness of the films. Afterwards, the samples were heated in a tube furnace at 950 °C in flowing ammonia. The oxynitride films showed different colours from red-orange for LaTiO2N to greenish-blue for SrTiO3:N. The films were characterised by X-ray diffraction, scanning electron microscopy, atomic force microscopy, UV–vis spectroscopy, secondary ion mass spectrometry and electrical measurements. The results show that the films are polycrystalline and have the perovskite structure. Their thickness is about 440 nm and the average roughness value is 7.5 nm. UV–vis transmittance measurements showed a strong decrease in the band gap values for the oxynitrides compared to the respective oxides. The values change from approximately 3.2 eV for the oxides to an average value of 2.4 eV for the oxynitrides. The electrical measurements indicate a change in the electrical behaviour from insulator for LaTiO2N to semiconductor for SrTiO3:N.  相似文献   

6.
Three new complexes with the ligand 3,5‐diamino‐1,2,4‐triazole (Hdatrz), [Co32‐Hdatrz)6(H2O)6]·(NO3)8·4H2O ( 1 ), [Cu32‐Hdatrz)42‐Cl)2(H2O)2Cl2]·Cl2·4H2O·2C2H5OH ( 2 ) and {[Zn22‐SO4) (μ3‐datrz)2]·2H2O}n ( 3 ) have been synthesized and structurally characterized. Complex 1 has a linear trinuclear mixed‐valence cobalt structure with six neutral triazole ligands in the N(1), N(2)‐bridging mode. The central cobalt atom, Co(1), is coordinated to six nitrogen atoms (octahedral) whereas the terminal cobalt atom, Co(2), is coordinated to an N3O3 moiety (octahedral). In complex 1 , the uudd cyclic water clusters, nitrate anions and the trimeric cations are linked to a supramolecular structure. Complex 2 features a linear trinuclear copper(II) core, with four N(1), N(2)‐bridging triazole ligands and two chlorido bridges. The central copper atom is coordinated to an N4Cl2 moiety (octahedral) whereas the terminal copper is coordinated to an N2Cl2O moiety (square‐pyramidal). In complex 2 , tetrahedral hydrogen bonding interactions play an important role to form a supramolecular network. Complex 3 exhibits a polymeric structure, with N(1), N(2), N(4)‐bridging triazolate ligands and sulfate bridges, in which zinc is coordinated to an N3O moiety (tetrahedral). In complex 3 , water molecules and sulfate anions construct the sulfate‐water supramolecular chain with hydrogen bonding interactions. In addition, the complexes were investigated by elemental analyses, IR spectroscopic, and thermogravimetric measurements.  相似文献   

7.
采用密度泛函方法对MX(M=Sc,Ti,V;X=C,N,O)固体的体相电子结构和力学性质进行了系统研究.计算结果表明,对于金属原子相同的同一系列化合物,氮化物具有最大的体模量;进一步的研究可知,随着外界压力的增大,化合物由NaCl构型向CsCl构型转变由易到难的顺序依次是氧化物、氮化物和碳化物.本文还首次用密度泛函方法系统地计算了各化合物的能带结构和态密度,并对该类型化合物的导电性能进行了探讨.  相似文献   

8.
Electrochemical oxidation of cadmium in an acetonitrile solution of N‐2‐pyridyl‐sulfonamides (HL) afforded cadmium coordination compounds of composition [CdL2]. Heteroleptic complexes of composition [CdL2L′] (L′ = 2, 2′‐bipyridine or 1, 10‐phenanthroline) were obtained when the coligand L′ was added to the electrolytic phase. The crystal structures of several compounds have been determined by X‐ray diffraction. In all cases the cadmium atom is hexacoordinated, but the coordinative behaviour of the N‐2‐pyridyl‐sulfonamide ligand depends on the location of the substituents in the pyridyl ring. When the substituent is in position 3, the ligands act as N, O‐donors. In all other cases, the ligands act as N, N′‐bidentate systems.  相似文献   

9.
The synthesis and characterization of Zr‐POSS and Hf‐POSS coordination polymers were reported. The IR data and the solid‐state 29Si MAS NMR indicated the existence of Si? O? M linkage. The polarized optical microscopy images and the XRD data suggested their crystalline nature.  相似文献   

10.
11.
Some new N‐carbonyl, phosphoramidates with formula C6H5C(O)N(H)P(O)R2 (R = NC3H6 ( 1 ), NC6H12 ( 2 ), NHCH2CH=CH2 ( 3 ), N(C3H7)2 ( 4 )) and CCl3C(O)N(H)P(O)R′2 (R′ = NC3H6 ( 5 ), NHCH2CH=CH2 ( 6 )) were synthesized and characterized by 1H, 13C, 31P NMR and IR spectroscopy and elemental analysis. The structures were determined for compounds 1 and 2 . Compound 1 exists as two crystallographically independent molecules in crystal lattice. Both compounds 1 and 2 produced dimeric aggregates via intermolecular ‐P=O…H‐N‐ hydrogen bonds, which in compound 2 is a centrosymmetric dimer. In compounds with four‐membered ring amine groups, 3J(P,C)>2J(P,C), in agreement with our previous studies about five‐membered ring amine groups. Also, 3J(P,C) values in compounds 1 and 5 are greater than in compounds with five‐, six‐ and seven‐membered ring amine groups.  相似文献   

12.
The title complexes [M(ImH)4(tfbdc)(H2O)] ( 1 : M=Co; 2 : M=Ni) (ImH=imidazole, tfbdc=2,3,5,6‐tetrafluoroterephthalate) were synthesized by the reaction of M(OAc)2·4H2O, H2tfbdc and ImH in water solution. The complexes were characterized by elemental analysis, IR spectra, thermogravimetric analysis, cyclic voltammetry and X‐ray single crystal structure analysis. Structural analysis reveals that 1 and 2 possess isostructure: monoclinic, P21/c, Z=4. M(II) ion in complexes 1 and 2 has a distorted octahedral geometry coordinated by one oxygen atom from water, one oxygen atom from tfbdc2? and four nitrogen atoms from ImHs. They are discrete zero‐dimensional molecular complexes. And the adjacent monomeric components are connected by hydrogen bonds to form a supramolecule. Electrochemical properties of the complexes 1 and 2 show that electron transfer of M(II) between M(III) in electrolysis is a quasi‐reversible process.  相似文献   

13.
冯传启  张克立 《中国化学》2003,21(3):287-290
Li-Mn-spinel was synthesized using the rheological phase recation method,First,the precursor was prepared by rheological phase reaction.The it was decomposed to form Li-Mn-spine,which was characterized by X-ray diffraction analysis and IR spectra.The particle size of Li-Mn-spinel was determined by the method of the transmission electron microscopy.The synthesized materials are of nanometer size with 30-100nm in the average diameter.The electrochemical properties of the Li-Mn-spinel were also studied.It proved that this method not only provided a simple practicable and effective route for the synthesis of Li-Mn-spinel,but also had many advantages such as lower sintering temperature,shorter sintering time,fine particles and particularly excellent electrochemical performances.  相似文献   

14.
Averievite-type compounds with the general formula (MX)[Cu5O2(TO4)], where M = alkali metal, X = halogen and T = P, V, have been synthesized by crystallization from gases and structurally characterized for six different compositions: 1 (M = Cs; X = Cl; T = P), 2 (M = Cs; X = Cl; T = V), 3 (M = Rb; X = Cl; T = P), 4 (M = K; X = Br; T = P), 5 (M = K; X = Cl; T = P) and 6 (M = Cu; X = Cl; T = V). The crystal structures of the compounds are based upon the same structural unit, the layer consisting of a kagome lattice of Cu2+ ions and are composed from corner-sharing (OCu4) anion-centered tetrahedra. Each tetrahedron shares common corners with three neighboring tetrahedra, forming hexagonal rings, linked into the two-dimensional [O2Cu5]6+ sheets parallel to (001). The layers are interlinked by (T5+O4) tetrahedra (T5+ = V, P) attached to the bases of the oxocentered tetrahedra in a “face-to-face” manner. The resulting electroneutral 3D framework {[O2Cu5](T5+O4)2}0 possesses channels occupied by monovalent metal cations M+ and halide ions X. The halide ions are located at the centers of the hexagonal rings of the kagome nets, whereas the metal cations are in the interlayer space. There are at least four different structure types of the averievite-type compounds: the P-3m1 archetype, the 2 × 2 × 1 superstructure with the P-3 space group, the monoclinically distorted 1 × 1 × 2 superstructure with the C2/c symmetry and the low-temperature P21/c superstructure with a doubled unit cell relative to the high-temperature archetype. The formation of a particular structure type is controlled by the interplay of the chemical composition and temperature. Changing the chemical composition may lead to modification of the structure type, which opens up the possibility to tune the geometrical parameters of the kagome net of Cu2+ ions.  相似文献   

15.
王金月  胡常伟  李平  向明礼  肖慎修 《化学学报》2004,62(23):2313-2318
使用密度泛函理论的离散变分方法(DFT-DVM)研究了双帽Keggin型杂多阴离子[PM12O40(VO)2]n--(M=Mo,n=5; M=V,n=9),即[PMo12O40(VO)2]5- (a)和[PV12O40(VO)2]9- (b)的电子结构,讨论了双帽的形成对Keggin型杂多阴离子的电子结构和催化性质的影响,并与其Keggin型杂多阴离子(PM12O40)n-(M=Mo,n=3; M=V,n=15)的计算结果进行了对比分析,计算结果表明,双帽的形成对Keggin型杂多阴离子的电子结构产生了很大的影响,因而它们在催化活性上可能会表现出较大的差异.  相似文献   

16.
水热条件下,合成了三个新的配合物[Ni(en)3] (ndt) ·H2O 1, [Co(en)3] (ndt) ·H2O 2 和[Mn(en)3] (ndt) ·H2O 3。晶体结构通过X-射线单晶衍射进行了表征。三个配合物均属于单斜晶系,Cc空间群。[M(en)3]2+阳离子、ndt阴离子和结晶水分子通过氢键自组装出相同结构的三维网。通过紫外-可见-近红外漫反射光谱对这三个配合物的光吸收性能和能带进行了测定。  相似文献   

17.
Metal-encapsulated silicon cage clusters are a new class of clusters and are opening up new avenues for silicon-based nanoscale materials. We present experimental evidence for a highly stable cluster corresponding to M@Si16 (M = Sc, Ti, and V). Mass spectrometry and anion photoelectron spectroscopy show that the cluster features an electronically closed TiSi16 neutral core which undergoes a change in the number of valence electrons involving (i) substitution of neighboring metals with Sc and V, or (ii) addition of a halogen atom to the TiSi16 anion, and that VSi16F is predicted to form an ionically bound superatom complex.  相似文献   

18.
王金月  胡常伟  李平  向明礼  肖慎修 《化学学报》2004,62(23):2313-2318
使用密度泛函理论的离散变分方法(DFT-DVM)研究了双帽Keggin型杂多阴离子[PM12O40(VO)2]n-(M=Mo, n=5; M=V, n=9),即[PMo12O40(VO)2]5- (a)和[PV12O40(VO)2]9- (b)的电子结构,讨论了双帽的形成对Keggin型杂多阴离子的电子结构和催化性质的影响,并与其Keggin型杂多阴离子(PM12O40)n-(M=Mo, n=3; M=V, n=15)的计算结果进行了对比分析,计算结果表明,双帽的形成对Keggin型杂多阴离子的电子结构产生了很大的影响,因而它们在催化活性上可能会表现出较大的差异.  相似文献   

19.
粟智  叶世海  王永龙 《化学学报》2009,67(21):2413-2420
用水热法合成了锂离子电池正极材料正交结构LiMnO2材料, 并对其进行S2-、大尺寸阳离子(Cu2+, Co3+, Ti4+)以及硫-金属离子复合掺杂改性. 用X射线衍射(XRD)、X光电子能谱分析(XPS)、透射电子显微镜(TEM)、恒电流充放电、交流阻抗谱(EIS)等测试技术进行表征. 实验结果表明: 当掺入离子的含量较低时, 得到的产物能保持完整的正交结构, 并表现出较好的电化学性能. S2-和非Jahn-Teller效应大尺寸阳离子的掺入使材料的循环稳定性能大幅度提高, 而这种提高是源于这些离子对LiMnO2结构的稳定作用. 电极材料Li1.02Mn0.988Ti0.012O1.989S0.011显示了最优的电化学性能, 在50 mA•g-1放电速率下, 其初始放电容量为142.6 mAh•g-1, 60次循环后放电容量为213.4 mAh•g-1. 硫-金属阳离子复合掺杂, 综合了大尺寸阳离子可以提高材料中Li+的扩散能力和S2-掺杂抑制Jahn-Teller畸变两方面优势, 使层状结构LiMnO2正极材料既保持了较高的容量又获得良好的循环性能.  相似文献   

20.
Four alkaline earth oxotellurate(IV) halides with common formula M3Te2O6X2 (M = Sr, Ba; X = Cl, Br) have been prepared as polycrystalline powders and/or in the form of single crystals. All compounds crystallize in the cubic space group Fd$\bar{3}$ m with cell parameters a = 15.9351(4) Å for Sr3Te2O6Cl2 (single‐crystal X‐ray data), 16.052(5) Å for Sr3Te2O6Br2 (powder X‐ray data), 16.688(2) Å for Ba3Te2O6Cl2 (single‐crystal X‐ray data) and 16.8072(3) Å for Ba3Te2O6Br1.64Cl0.36 (single‐crystal X‐ray data). The results of the crystal structure analyses reveal a rigid ${3}\atop{{\infty}}$ [M3Te2O6]2+ framework which can be described as being composed of regular octahedra of two types of chemically non‐bonded M6 octahedra that are capped by trigonal pyramidal [TeO3] anions located above every second face of one of the M6 octahedra. The halide X anions are situated in the voids of the ${3}\atop{{\infty}}$ [M3Te2O6]2+ framework. Dependent on the nature of the halogen, the anions show various kinds of occupational disorder which eventually led to a revision of the previous structure model of Ba3Te2O6Cl2. A comparative discussion with other structures of general formula M3Ch2O6X2 (M = divalent metal; Ch = Te, Se; X = Cl, Br) is presented.  相似文献   

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