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1.
用过氧化物法合成了新体系[ Co( 3, 3-tri)( ibn) CI][ ZnCl4]( 3, 3-tri= N-( 3-Aminopropyl)- 1, 3-propanedia-mine; ibn=1, 2-diamino-2-methylpropane)中的一经式异构体[Co(3, 3tri)(ibn)CI][ZnCl4]·2H2O,解析了其晶体结构。晶体学参数:三斜晶系,空间群P1(#2),a=99.58(2)nm,b=114.83(2)nm,c=98.81(1)nm,a=96.79(2)°,β=97.243(10)°,y=96.89(1)°,V=1.1055(3)X 106nm3,De=1.678g·cm-3,Z=2,F000=572.00,μ( Mo Ka)= 24. 59cm-1, R= 0. 025, Rw= 0. 034。晶胞中含 2个配位阳离子, 2个 [ZnCl4]2-阴离子及 4个水分子。  相似文献   

2.
冯亚青  张晓东 《合成化学》1997,5(3):269-272
由螺[5.5]十一烷-3-酮与硫脲在碘的存在下反应,生成了4,5-二氢螺[苯并[d]噻唑-6-(7H),1′-环己烷]-2-胺(3),3与溴甲基苯基甲酮在苯中缩合得到相应的酮4a~4c,然后在醇中加热环化生成二氢螺[咪唑并[2,1-b]苯并[d]噻唑]化合物5a~5c。新化合物5a~5c的分子组成及结构经元素分析、1HNMR、13CNMR证实,其中产物5b的分子结构经X-射线衍射晶体分析确认。  相似文献   

3.
SynthesisandStructureoftheHexanuclearDiazenido-oxomolybdate[(n-C_4H_9)_4N]_3[Mo_6O_(18)(N_2C_6H_4-p-NO_2)]LiHai-Lian;YouXiao-Zeng;...  相似文献   

4.
在不同条件下合成了[Co(phen)mXp]Y1·nH2O型配合物,(m=1,2;p=1,2;1=1-3;n=0-4;phen=邻菲绕啉;X=Cl-,H2O,酒石酸(tart),甘氨酸(gly),α-皮可林酸(pic).DL-两氨酸(ala),L-亮氨酸(leu),L-脯氨酸(pro);Y=Cl-,]并进行了元素分析,热重分析,电子光谱,红外光谱和磁化率测定,计算它们的10Dq和B值.X-ray单晶衍射实验证明:[Co(Phen)2(H2O)2](NO3)3·2H2O,[Co(Phen)2(gly)]Cl2·4H2O均为顺式结构.[Co(Phen)(ala)2]Cl·3H2O,[Co(Phen)(pro)2]ClO4·4/3H2O均为trans(N)结构.在[Co(phen)2X2](n+)型配合物中,X反位的键长均长于顺位键长,其反位效应的顺序为:Cl->羧基,NH2>H2O。  相似文献   

5.
吴鼎铭  黄小荥 《结构化学》1994,13(5):385-388
SynthesisandStructureof[HOCH_2CH_2N(CH_3)_3]_4[Cu_4OCl_(10)]WuDing-Ming;HuangXiao-Ying;ZhuangHong-Hui(StateKeyLaboratoryofStruct?..  相似文献   

6.
卢绍芳  黄建全 《结构化学》1996,15(6):415-421
[Mo3(μ3-O)(μ-S)3(μ-OAc(dtp)3(py)]和[Mo3(μ-S)3(μ-OAc(dtp)3-(py)](dtp=S2P(OC2H5)2^-)族合物分别与金属化合物BiI3和SbBr3进行原子簇反应均能获得意外产物{[Mo3(μ3-S)(μ-S2)2(dtp)3](μ3-S)(η^3-S2)[Mo2(μ3-S)(μ-S)3(μ-OAc)(dtp)2]}六核钼簇。其结构实际上是由  相似文献   

7.
研究了1-芳基-4-乙氧羰基-5-氨基-1,2,3-连三唑(1)同甲酰胺、异氰酸磺酰氯以及内酰亚胺醚等的反应,制得5-H-1-芳基-1,2,3-连三唑[4,5-e]嘧啶-4-酮(2a-c)、5-N-甲基-1-芳基-1,2,3-连三唑[4,5-e]嘧啶-4-酮(3a-c)、1-芳基-4-乙氧羰基-5-脲基-1,2,3-连三唑(4a,b)、5-H-1-芳基-1,2,3-连三唑[4,5-e]嘧啶-4,6-二酮(5_(a,b))、1-苯基-1,2,3-连三唑[4,5-e]哌啶[1,2-b]嘧啶-4-酮(6a)、1-苯基-1,2,3-连三唑[4,5-e]氢化吖辛因[1,2-b]嘧啶-4-酮(7a),并经元素分析、红外、核磁共振以及质谱等方法确认了它们的结构,初步筛选了其代表特的生物活性.  相似文献   

8.
用X射线衍射法测定了由η~5-MeO_2CC_5H_4)(CO)_3MoNa和[(η~5-MeO_2CC_5H_4)(CO)_2W]Fe-(CO)_3Co(Co)_3(μ_3-S)的等瓣置换反应所生成的手性簇合物──[(η~5-MeO_2CC_5H_4)(CO)_2Mo]-[(η~5-MeO_2CC_5H_4)(CO)_2W]Fe(CO)_3(μ_3-S)的分子结构及晶体结构。晶体属P1空间群,晶胞参数α=0.87162(5)nm,b=0.76218(4)nm,c=1.87111(8)nm;α=94.164(4)°,β=97.979(2)°,γ=99.108(2)°,Z=2,μ=5.9cm~(-1)。最终的一致性因子R=0.036,Rw=0.037.该簇合物含MoWFeS四面体簇核,其中Mo、W原子以1:1的比例无序地分占了四面体的2个顶点.  相似文献   

9.
Co3(CO)7(μ3—S)(μ,η^2—SCNR2)的合成和晶体结构   总被引:1,自引:0,他引:1  
Co2(CO)8与4个二硫代双(烷基硫代甲酰胺)类前配体[R2NC(S)S]2反应,得4个含烷基硫代甲酰胺基的三核钴羰基硫簇合物。通过元素分析、IR、^1HNMR和MS等方法表征了它们的结构,用X射线衍射法测定了其中一个簇合物Co3(CO)7(μ3-S)[μ,η^2-SCN(i-Pr)2](Ⅲ)的晶体结构。晶体属单斜晶系,P21/n空间群,晶胞参数a=1.1452(2)nm,b=1.5028(3)  相似文献   

10.
SynthesisandCrystalStructureof[(n-Bu)_4N]_2[Mo_4O_(10)(OC_(10)H_6O)_2(OCH_3)_2]¥LuXiao-Ming;ZhuHui-Ju;YangNing;LiuShun-Cheng;JinX?..  相似文献   

11.
The properties of Pbn(n=2―30) clusters including binding energies,second differences in energy,and HOMO-LUMO gaps,especially fragmentation energies and ionization potentials,have been studied by ab initio calculation.The main fragmentation products of Pbn+ are shown to be Pb+Pbn-1+ for n≤14 and two small cluster fragments for larger ones with n14.The Pb13+ appears frequently as the products in the fragmentations of large clusters.Also,the calculated ionization potentials of the clusters are consistent with the experiment data.  相似文献   

12.
The geometric and electronic structures of the Pbn+ clusters (n=2-15) have been investigated and compared with neutral clusters. The search for several low-lying isomers was carried out under the framework of the density functional theory formalism using the generalized gradient approximation for the exchange correlation energy. The wave functions were expanded using a plane wave basis set and the electron-ion interactions have been described by the projector augmented wave method. The ground state geometries of the singly positively charged Pbn+ clusters showed compact growth pattern as those observed for neutrals with small local distortions. Based on the total energy of the lowest energy isomers, a systematic analysis was carried out to obtain the physicochemical properties, viz., binding energy, second order difference in energy, and fragmentation behavior. It is found that n=4, 7, 10, and 13 clusters are more stable than their neighbors, reflecting good agreement with experimental observation. The chemical stability of these clusters was analyzed by evaluating their energy gap between the highest occupied and lowest unoccupied molecular orbitals and adiabatic ionization potentials. The results revealed that, although Pb13 showed higher stability from the total energy analysis, its energy gap and ionization potential do not follow the trend. Albeit of higher stability in terms of binding energy, the lower ionization potential of Pb13 is interesting which has been explained based on its electronic structure through the density of states and electron shell filling model of spherical clusters.  相似文献   

13.
In this work, the high-pressure behavior of Pmn2(1)-Li(2)MnSiO(4) and Pbn2(1)-Li(2)CoSiO(4) is followed by in situ X-ray diffraction at room temperature. Bulk moduli are 81 and 95 GPa for Pmn2(1)-Li(2)MnSiO(4) and Pbn2(1)-Li(2)CoSiO(4), respectively. Regardless of the moderate values of the bulk moduli, there is no evidence of any phase transformation up to a pressure of 15 GPa. Pmn2(1)-Li(2)MnSiO(4) shows an unusual expansion of the a lattice parameter upon compression. A density functional theory investigation yields lattice parameter variations and bulk moduli in good agreement with experiments. The calculated data indicate that expansion of the a lattice parameter is inherent to the crystal structure and independent of the nature of the transition-metal atom (M). The absence of pressure-driven phase transformation is likely associated with the incapability of the Li(2)MSiO(4) composition to adopt denser structures while avoiding large electrostatic repulsions.  相似文献   

14.
To simulate the changes in core-level binding energies in germanium-doped lead telluride, cluster calculations of the changes in the electrostatic potential at the corresponding centers have been performed. Different locations of the Ge atom in the crystal bulk have been considered: near vacancies, near another dopant site, and near the surface. For calculating the potential in the clusters that model the bulk and the surface of the lead telluride crystal (c-PbTe), the electron density obtained in the framework of the Hartree-Fock and hybrid density functional theory (DFT) methods has been used.  相似文献   

15.
A systematic theoretical study of the PbnM (M=C, Al, In, Mg, Sr, Ba, and Pb; n=8, 10, 12, and 14) clusters have been investigated to explore the effect of impurity atoms on the structure and electronic properties of lead clusters. The calculations were carried out using the density functional theory with generalized gradient approximation for exchange-correlation potential. Extensive search based on large numbers of initial configurations has been carried out to locate the stable isomers of PbnM clusters. The results revealed that the location of the impurity atom depends on the nature of interaction between the impurity atom and the host cluster and the size of the impurity atom. Whereas, the impurity atoms smaller than Pb favor to occupy the endohedral position, the larger atoms form exohedral capping of the host cluster. The stability of these clusters has been analyzed based on the average binding energy, interaction energy of the impurity atoms, and the energy gap between the highest occupied and lowest unoccupied energy levels (HLG). Based on the energetics, it is found that p-p interaction dominates over the s-p interaction and smaller size atoms interact more strongly. The stability analysis of these clusters suggests that, while the substitution of Pb by C or Al enhances the stability of the Pbn clusters, Mg lowers the stability. Further investigations of the stability of PbnM clusters reveal that the interplay between the atomic and electronic structure is crucial to understand the stability of these clusters. The energy gap analysis reveals that, while the substitution of Mg atom widens the HLG, all other elements reduce the gap of the PbnM clusters.  相似文献   

16.
胡盛志 《结构化学》2001,20(2):151-156
我们发表胡盛志教授的“札记” ,一是想提醒晶体结构工作者们在晶体结构测定过程对空间群的指定应十分小心 ,尽量减少差错 ;同时也想借此透露一些国外同行在纠正空间群测定差错这一方面的工作 ,引起国内同行关注和响应。至于胡教授“札记”的论证方法的客观性 ,论据的充分性等 ,因纯系个人的见解 ,十分欢迎有不同意见者结合实例来稿进行讨论。  相似文献   

17.
Four methods, including voltammetric measurement of double layer capacitance, surface oxides reduction, under potential deposition of Cu and carbon monoxide (CO) stripping have been applied to evaluate the real surface area of a polycrystalline Pd (pc-Pd) electrode. The results reveal that the second and third methods lead to consistent results with deviations below 5%. And from the determined double layer capacitance and CO stripping charge, it is deduced that the double layer capacity unit area is 23.1±0.4 μF/cm2 and the saturated CO adlayer should be ca. 0.66 ML in order to ensure that the real surface area as determined isconsistent with the other two techniques. The applicability as well as the attentions when applying these techniques for the determination of the real surface area of pc-Pd electrodes have been discussed.  相似文献   

18.
采用欠电位沉积法,以铅电极作基体制备了负载型Pt-Sn双金属催化电极。应用循环伏安法和电位阶跃法研究了各种因素对该电极的催化活性和稳定性的影响,并应用XPS和AES技术分析了该电极的表面物性。该电极对酸性介质中的甲醇氧化反应显示出高于Pt-Sn/Pt电极的催化活性和稳定性。  相似文献   

19.
铅及铅锑合金阳极膜中硫酸铅的氧化过程   总被引:2,自引:0,他引:2  
应用电位阶跃和交流阻抗法分别研究铅和Pb-5wt% Sb合金在4.5mol·dm^-^3H~2SO~4(30℃)中于1.3V(vs. Hg/Hg~2SO~4, 下同)生长20min后的阳极膜在0.9V还原5min后再在1.4V将膜中硫酸铅氧化的过程。实验结果表明在0.9V还原二氧化铅而得到的硫酸铅能在1.4V于1min内氧化为二氧化铅。这是由于此种硫酸铅处于硫酸铅颗粒表层的缘故。至于颗粒内部由铅直接生成的硫酸铅的氧化为二氧化铅就要缓慢得多。合金中的锑能使二氧化铅晶核形成和生长速率显著降低。  相似文献   

20.
The origin of the surface potential of calcium carbonate in aqueous dispersions and the dissolution of calcite in systems containing excess Ca(2+) and CO(3)(2-) have been the subjects of this study. In addition, stabilization of calcite particles with an anionic polyelectrolyte (sodium polyacrylate (NaPA)) and the effect on surface potential and dissolution of calcite have been studied. Preferential dissolution of either Ca(2+) or CO(3)(2-) from the surface, which is governed by the partial pressure of CO(2) in solution and the pH of the solution, mainly determines the surface potential. Both lattice ions (Ca(2+) and CO(3)(2-)) adsorb onto the surface and thus alter the surface potential. NaPA adsorbs strongly onto the calcite surface regardless of background electrolyte concentration, and reverses the surface potential to negative values. Chelation of the surface due to NaPA can be partly prevented by adding Ca(2+) to the dispersion.  相似文献   

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