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1.
价电子能级连接性指数及其应用   总被引:46,自引:2,他引:44  
价电子能级连接性指数( fE)被定义为: fE=Σ(mi·mj…)-0.5,m为价电子能级值。其中0、1阶指数公式分别为: 0E=Σ(mi)-0.51E=Σ(mi·mj)-0.50E1E与化合物的总键能(ΔE)、晶格能(U)、标准生成焓(ΔfH?m)以及非金属氢化物的pKa呈现高度相关性。它们的线性回归方程为:ΔE=-48.0095+1402.94631E,r=0.9474, U=-328.0770+1541.9351 1E, r=0.9801,-ΔfH?m=-266.9299+1324.6461 1E, r=0.9509, pKa=-20.9723+28.1756 1E, r=0.98884, pKa=-14.6102-7.835 0E+40.6461 1E, R=0.9933。mfE具有物理意义明确、计算方法简单等优点,而且预测结果令人满意。  相似文献   

2.
Treatment of the lithium β-diketiminate [Li{N(R)C(NMe2)C(H)C(NMe2)N(R)}]2 (1) (R=SiMe3) with KOBut, KOH·H2O and CoCl2 in tetrahydrofuran gave in good yields the RO bridged β-diketiminato Co(Ⅱ) complex [Co{N(H)C(NMe2)C(H)C(NMe2)N(R)-( μ-OR)}]2 (2) at ambient condition. The crystal data of (2) are as follows: crystal system, monoclinic; space group, P121/n1; a=0.963 9(3) nm, b=1.077 2(3) nm, c=2.025 0(6) nm, V=2.102 5(10) nm3, Z=2, Dc=1.186 g·cm-3, F(000)=804, μ(Mo )=0.934 mm-1, R1=0.047 8, wR2=0.097 9. In solid state, complex (2) is a dimer bridged by RO (R=SiMe3) group and the two Co2+ are in distorted tetrahedron. CCDC: 249253.  相似文献   

3.
[Zn(DMF)6]H2SiW12O40·(CH3)2NH的合成,晶体结构及性质   总被引:1,自引:0,他引:1  
The title compound [Zn(DMF)6]H2SiW12O40·(CH3)2NH was synthesized in mixed solvent of aqueous and acetonitrile, and its crystal structure had been determined using single crystal X-ray diffraction. The crystal belongs to monoclinic, space group C2/m, a=2.0654(4)nm, b=1.3306(3)nm, c=1.3194(3)nm, β=119.59(3)°, V=3.1531(11)nm3, Dc=3.606Mg·m-3, Z=2, R=0.0462, Rw=0.0836. The title compound comprises of a [Zn(DMF)6]2+ unit, a polyanion and a free (CH3)2NH molecule. The ESR spectrum of the title compound shows that charge-transfer between organic groups and polyanion takes place under irradiation of the sunlight in solid state. The TG study of the title compound shows that it had four stages of the weight loss, and the increase of the de-composition temperature for the polyanion shows that the stability of the polyanion was enhanced due to the influence of Zn2+ ion. CCDC:175866.  相似文献   

4.
Two new mononuclear Mn(Ⅱ) complexes Mn(phen)2(N3)2 (1) and [Mn(phen)2(N3)(H2O)]ClO4·H2O (2) have been synthesized and structurally characterized, where phen is 1,10-phenanthroline. Complex 1 crystallizes in the P1 space group, with lattice parameters a=8.1688(2)?, b=11.1218(2)?, c=12.6881(2)?, α=83.558(3)°, β=82.287(3)°, γ=73.643(3)°, V=1092.7(4)?3, Dc=1.518Mg·m-3, Z=2, F(000)=510, R1=0.0620, wR2=0.0958 (based on F2), S=0.981. Complex 2 crystallizes in the P1 space group, with lattice parameters a=8.6543(2)?, b=8.9767(2)?, c=17.5915(4)?, α= 93.399(3)°, β=102.806(3)°, γ=106.234(3)°, V=1268.7(4)?3, Dc=1.552Mg·m-3, Z=2, F(000)=606, R1=0.0672, wR2=0.1781 (based on F2), S=1.047. In complex 1, the Mn atom is coordinated by six nitrogen atoms of two phen molecules and two N3- ions with the Mn-N distances ranging from 2.142(4) to 2.318(4)?. The coordinated phen molecules of the adjacent Mn(phen)2(N3)2 moieties experience π-π stacking which is responsible for the crystal packing. In complex 2, the Mn atom is coordinated by five nitrogen atoms of two phen molecules and one N3- ion with the Mn-N distances ranging from 2.152(5) to 2.291(5)?. The approximately octahedral environment was completed by the oxygen atom of the coordinated water molecule with the Mn-O distance of 2.180(5)?. The hydrate water molecule is hydrogen-bonded to one of the O atoms of free ClO4- anion. ?  相似文献   

5.
三唑酮氯化锌配合物的合成和晶体结构研究   总被引:3,自引:0,他引:3  
The new compound was synthesized by the reaction of ZnCl2 and triadimefon(ratio 1∶2) in ethanol solution refluxing for 6 hours. The crystal used for X-ray analysis was obtained by slow evaporation of the solution at room temperature. It crystallizes in the monoclinic system, space group P2/n. The lattice parameters are: a=1.58916(6)nm, b=0.60634(2)nm, c=1.83566(8)nm, β=93.979(2)°, V=1.7645(1)nm3, Z=2, Dc=1.362g·cm-3, F(000)=744.00, μ(Mo Kα)=1.038mm-1, R1=0.042, wR2=0.106. In the complex, the Zn(Ⅱ) cation is tetrahedrally coordinated to two triadimefon ligands and two chloride in cis disposition. The title complex was also characterized by elemental analysis, molar conductance, IR and TG-DTA. CCDC: 207413.  相似文献   

6.
A mononuclear Cobalt(Ⅱ) complex [CoL(H2O)2]n (H2L: 4,4′,6,6′-Tetrabromo-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol), has been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction single crystal structure analysis. The crystal of the complex belongs to monoclinic space group P21/c with a=2.516 8(3) nm, b=1.023 43(18) nm, c=0.789 17(14) nm, β=91.375(2)°, V=2.032 1(5) nm3, Z=4, Dc=2.317 Mg·m-3, μ(Mo Kα)=8.747 mm-1, F(000)=1 356, R1=0.049 7, wR2=0.110 4. The crystal structure of [CoL(H2O)2]n indicates that the complex consists of one cobalt(Ⅱ) atom, one L2- unit and two coordinated water molecules, and the coordination number of the cobalt(Ⅱ) atom is six. One-dimensional chain supramolecular structure is formed by intermolecular hydrogen bonds and π-π stacking of neighboring benzene rings. CCDC: 652649.  相似文献   

7.
A novel coordination polymer, [Cu(m-BDOA)(bipy)·H2O]n (m-BDOA2-=benzene-1,3-dioxyacetate), was synthesized and characterized by elemental analysis, IR spectra, X-ray single crystal structure analysis. Crystallographic data are as follows: orthorhombic, space group Pna21, a=1.606 9(3) nm, b=1.685 9(3) nm, c=0.699 7(1) nm, V=1.8955(7) nm3, Z=4, Dc=1.619 g·cm-3, μ=1.200 mm-1, F(000)=948,R=0.038 1, wR=0.038 6. The copper atom is five-coordinated involving two oxygen atoms of different m-BDOA2- ligand, two nitrogen atoms of 2,2′-bipy ligand and one coordinated water, there is a distorted square pyramidal environment. Two copper atoms are bridged by m-BDOA2- ligand, forming a one-dimensional chain along a axis. The adjacent distance of Cu…Cu atoms is 0.877 3nm. The crystal network was formed by the intermolecular hydrogen bond and π-packing interactions.  相似文献   

8.
The title complex Cu[C5H3N(CCH3=N-C6H5)2]2(PF6)2 has been synthesized by reaction of Schiff base C5H3N(CCH3=N-C6H5)2 and cupric sulfate in toluene solution. The crystal structure was determined by X-ray diffraction method and the chemical formula weight of the complex is 1041.85. The crystal structure belongs to triclinic system with space group P1 and cell parameters: a=12.6470(10)?, b=14.123(2)?, c=15.613(2)?;α=66.150(10)°,β=79.470(10)°,γ=78.290(10)°, V=2481.6(5)?3, Z=2, Dc=1.394Mg·m-3 and F(000)=1064. The final R[I >2σ(I)]:R1=0.0668, wR2=0.1927; R(all data): R1=0.1133, wR2=0.2357. The Cu(Ⅱ) was coordinated by six nitrogen, at the same time the Cu(Ⅱ) formed a distorted octahedron, besides the angles and planes of this compound were discussed . The result of kinetics of the thermal decomposition indicated that the first step of it is 2 series chemical reactions, the function of machanism is f(a)=(1-a)2, and the activation energy is 144.64E/kJ. CCDC: 180872.  相似文献   

9.
The tri(o-chlorobenzyl)tin chloride as well as the tri(o-fluorobenzyl)tin was treated with aqueous solution of NaOH to formed the μ-oxygen-bis[tri(o-chlorobenzyl)tin] and μ-oxygen-bis[tri(o-fluorobenzyl)tin], respectively. The crystal and molecular structures of compound were determined by X-ray diffraction. The crystal(1) belongs to triclinic space group P1 with a=1.0195(5), b=1.0951(6), c=1.0986(6)nm, α=118.250(7), β=104.923(7), γ=99.534(8)°, V=0.9827(9)nm3,Z=1, Dx=1.701g·cm-3, μ(MoKα)=17.12cm-1, F(000)=498, R1=0.0680, wR2=0.13014. The crystal(2) are triclinic, space group P1 with a=0.9635(3), b=1.0797(4), c=1.0852(3)nm, α =105.807(5), β=90.551(6), γ=116.382(5)°, V=0.9619(6)nm3, Z=2, Dx=1.595g·cm-3, μ(MoKα)=13.62cm-1, F(000)=458, R1=0.0268, wR2=0.0674. The bond lengths of Sn-C is 0.2128(9)~2.162(12)nm and 0.2155(4)~0.2162(3)nm, and the Sn-O is 0.1901nm and 0.19166(6)nm, respectively. The bond angle Sn-O-Sn is 180.0(0)°. The tin atom has a distorted tetrahedral geometry. The composition characteristics of some frontier molecular orbitals have been investigated by means of G98W package and taking Lanl2dz basis set. (1) CCDC:184751,(2) CCDC:187572.  相似文献   

10.
张淑华  蒋毅民  肖瑜 《无机化学学报》2003,19(12):1339-1342
A heteronuclear compound, K2[Co(Dipc)2]·7H2O (Dipc=pyridine-2,6-dicarboxylic acid) has been synthe- sized and characterized by IR, elemental analysis, and X-ray diffraction. Crystal data: orthorhombic system with space group Pnna and unite cell parameters: a=2.0645(3)nm, b=1.3484(2)nm, c=0.8204(1)nm; V=2.2838(6)nm3, Z=4, Dcald=1.726 g·cm-3, μ=1.193 mm-1, F(000)=1212, Gof=1.045, Δρ=339~-348 e·nm-3, the final R is 0.0295. In the molecule of the complex, Co(Ⅱ) ion is six-coordinate to form a dis-torted octahedron. The N atom and the carboxyl group of pyridine-2,6-dicarboxylic acid are coordinated with the central ions. One of the carboxyl groups of the pyridine-2,6-dicarboxylic acid connect K(Ⅰ) and Co(Ⅱ). The com- pound possesses approximate C2 symmetry. The compounds form a three-dimensional network of infinite length connection with crystal waters, potassium ions and hydrogen bonds. The result of kinetics of thermal decomposition indicated that the compound decomposition takes place in two steps. CCDC: 207078.  相似文献   

11.
分析恒电流库仑滴定过程中电气因素的影响,包括恒流源输出精度的影响、参考标准不确定度的影响、外部连接线路的影响、实验环境对电路的影响等,提出了减小这些影响的办法。  相似文献   

12.
白皎煤及其充甲烷样品电极化特征的研究   总被引:2,自引:0,他引:2  
研究了四川白皎无烟煤在交变和恒电场中的极化特征。结果表明,在恒电场中主要由于位移极化和空间极化的作用,使通过煤和充甲烷煤的电流随时间按下式:I=Is+aebt逐渐衰减至一稳定值,且高压电下达到稳定的时间比低电压时要长,a随外加电压的升高而增大,衰减系数λ随电压的升高有减小的趋势,高电压时常数b与甲烷平衡压力P的关系为:100b=10.115exp(0.3380P);在交变电场中,由于极化作用的影响,使得通过煤和充甲烷煤的电流不随时间而变。  相似文献   

13.
本文以实验为基础,运用计算机数值解解出双电层相互作用时平面胶体表面电位ψ随距离X的分布,依据作者导出的双电层相互作用时胶体表面阴离子负吸附方程,计算出胶体表面外Hclmhotz面(OHP)处的表面电荷密度σ_δ;讨论了双电层相互作用程度(ψ_d/ψ_δ)对胶体表面电位分布及其表面电荷密度的影响。  相似文献   

14.
Fukui提出的前线轨道理论在预测反应活性方面获得了极大的成功。在某些情况下,除了前线轨道之外,还必须考虑其它轨道之间的相互作用。本文提出赝轨道的概念,将所有内层轨道的作用包括在赝轨道参数之内。扩展了前线轨道理论的适用范围。并用硝基苯和苯睛的硝化反应的定位效应为例说明了赝轨道指数的应用。  相似文献   

15.
壳聚糖折光指数增量的研究   总被引:4,自引:1,他引:4  
王伟  薄淑琴 《应用化学》1991,8(2):56-59
本工作制备了具有不同胺基含量的系列壳聚糖样品,测定和研究了它们的脱乙酰度(D.D.)和溶液拆光指数增量(dn/dc)。发现不同D.D.壳聚糖的dn/dc值不同,而且两者间符合二元无规共聚物的dn/dc值与其化学组成之间的一般线性关系,从而建立了一种可从dn/dc值分析测定壳聚糖的脱乙酰度的新方法。  相似文献   

16.
介绍了恒电流库仑滴定装置的结构与原理,对电解电流的自动恒定以及利用计算机对库仑滴定过程进行自动控制做了探索。  相似文献   

17.
大功率温控设备KSY-12-16S可控硅温控SX2-6-13箱式电阻炉因接触电阻变大导致元件烧坏。对故障现象进行了分析,提出了排除办法,并通过更换元件对该设备作了改进。  相似文献   

18.
pH-敏感的疏水型凝胶在直流电场中的刺激响应   总被引:3,自引:0,他引:3  
合成了不同疏水链长的甲基丙烯酸酯、甲基丙烯酰胺及丙烯酸与 4 ,4′ 二 (甲基丙烯酰胺基 )偶氮苯交联共聚的聚电解质凝胶 .该凝胶在非接触电场中发生消溶胀 ,但疏水侧链较长的凝胶在发生消溶胀之前经历了一个溶胀过程 .凝胶在电场中首先弯向阴极 ,随着时间的延长或电压的升高弯向阴极 ;并出现弯曲的方向或弯曲的程度的波动 .当撤去电场后 ,凝胶又能恢复到初始的形态 .凝胶的这些性质既与电渗、电扩散及电解有关 ,亦与凝胶的疏水相互作用有关  相似文献   

19.
原子连接性指数与对镧系元素理化性质的预测   总被引:8,自引:1,他引:7  
以原子为研究对象的原子连接性指数( mAt)被定义为:mAt=Σ(Ei×Ej×Ek×…)-0.5,E为价电子的能级值。其中:0At=Σ(Ei)-0.5, 1At=Σ  相似文献   

20.
含硫杂环桥联的高折射率聚酰亚胺的合成与性能   总被引:1,自引:0,他引:1  
合成了两种含硫杂环桥联的芳香族二胺单体,2,5-双(4-氨基苯硫基)噻吩(APST)以及2,5-双(4-氨基苯硫基)-1,3,4-噻二唑(BATT).分别采用这两种二胺单体与含硫二酐单体4,4′-双(3,4-二羧基苯硫基)二苯硫醚二酐(3SDEA)通过两步聚合法制备了两种聚酰亚胺(PI),PI-1(3SDEA-APST)与PI-2(3SDEA-BATT).系统研究了含硫杂环对PI耐热性能以及光学性能的影响.研究结果表明,与苯环相比,含硫杂环的引入在一定程度上降低了PI薄膜在可见光区(400~700nm)的光学透明性以及耐热稳定性.PI-1与PI-2薄膜的起始热分解温度(T5%)分别为418℃与466℃.PI薄膜在450nm处的透光率低于50%.但是含硫杂环的引入可以显著提高PI薄膜的折射率.PI-1与PI-2的折射率分别为1.7527和1.7490.两种材料的双折射均小于0.01.  相似文献   

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