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排序方式: 共有201条查询结果,搜索用时 281 毫秒
101.
Clovis Peppe Melina De Azevedo Mello Felipe Terra Martins Jaqueline Pinto Vargas Felipe Christoff Wouters Robert Alan Burrow 《Journal of Coordination Chemistry》2018,71(6):813-827
AbstractBromomethyl-dibromo-indium(III), Br2InCH2Br, obtained from indium monobromide and methylene dibromide, reacts with hard and soft donor ligands to afford the corresponding indium(III) organometallic complexes. In this work, we investigated the conditions to prepare adducts of Br2InCH2Br using bis(diphenylphosphino)alkane dioxides acting as hard ligands. We report here the synthesis and crystal structures of two 1-D coordination polymers with the hard donor ligands Ph2P(O)(CH2)mP(O)Ph2 (m = 2, dppeO2 and m = 6, dpphO2). Compounds 1 and 2 with formulas [Br2In(CH2Br)(dppeO2)]n (1) and [Br2In(CH2Br)(dpphO2)]n (2) were characterized by IR and Raman spectroscopy and elemental analysis. We also obtained an ionic indium(III) compound with dppeO2 acting as a chelating ligand with formula [InBr2(dppeO2)2][InBr3(CH2Br)] (3). The crystal structures were determined for 1–3 using single crystal X-ray diffractometry. The geometry around the In(III) can be described as a trigonal bipyramid in 1 and 2, and the chains were packed onto the plane giving layers that are stabilized mainly by intermolecular interactions. Compound 3 has a square bipyramidal In(III) cation with formula [Br2L2In]+ and tetrahedral organoindium(III) anion with formula [Br3InCH2Br]–. Hirshfeld surface analysis employing 2-D fingerprint plots have been used to analyze intramolecular and intermolecular interactions present in the solid state of the structures. 相似文献
102.
通过对Nist107标准物质中饱和脂肪烃的质谱数据进行挖掘,发现了新的饱和脂肪烃的谱图特征。利用这些特征设置分步问答,使用MatLab编程实现并优化建立了自动识别饱和脂肪烃的方法。利用库内分子量小于450的标准质谱数据和本实验室测定的齿叶铁线莲(根)挥发油数据进行检验。库内检验结果表明:第一类错误(弃真错误)率为0.503%,第二类错误(存伪错误)率为0.008%。正构烷烃的误识率为0。实验数据验证结果表明:此法能准确识别饱和脂肪烃,用于识别正构烷烃时可克服因夹角余弦相似匹配中相似度接近而无法正确定性的缺点,为植物挥发成分测定、汽油样品的PONA分析和空气颗粒物中饱和脂肪烃的识别和总量的测定提供了一种新的快速的方法。 相似文献
103.
Vapor pressures for the benzene+n-tetradecane system have been measured using a static apparatus. The excess Gibbs free energy was calculated using a modified Barker method and a Pade approximant equation. The selection of the most adequate approximation is discussed. Results are compared with those corresponding to other thermodynamic properties. The activity coefficient of benzene at infinite dilution calculated from these data agrees well with the value obtained from the literature. 相似文献
104.
H. Wilczura B. Semeniuk A. Myslinski T. Kasprzycka-Guttman 《Journal of Thermal Analysis and Calorimetry》1992,38(9):2011-2018
The molar excess enthalpies measured for binary mixtures of 2-, 3-, 4-picoline +n-alkane (C6H14-C10H22) at 298.15 K have been compared with the Prigogine-Flory-Patterson theory and the Extended Real Associated Solution model estimations.
Zusammenfassung Die bei 298.15 K gemessenen molaren Zusatzenthalpien binärer Mischungen aus 2-,3-,4-Picolin und einemn-Alkan (C6H14-C10H22) wurden mit den nach der Prigonine-Flory-Patterson-Theorie und den nach dem erweiterten Modell real assoziierter Lösungen (ERAS) berechneten Weiten verglichen.相似文献
105.
分子结构/性质相关性的研究:一种新的拓扑指数及其应用 总被引:12,自引:1,他引:11
本文以图论为基础,提出一种新的表征有机化合物分子结构特征的拓扑指数,并将其用于研究饱和链烃类化合物的物理化学性质,得很了满意的结果。与已有的拓扑指数相比较,表明该指数具有良好的唯一性和相关性。 相似文献
106.
用图示法和非线性规划的方法对直链烷烃同系物最高成键分子轨道能级、最低成键分子轨道能级,电离电位,氧化半波电位,正常沸点,正常熔点、临界压力、临界温度、密度、折光率、表面张力和粘度和12种结构型性质和凝聚型性质的变化规律进行研究,结果发现,直链烷烃结构型性质和凝聚型性质一般能遵守同系对数递变规律,各种结构型性能和凝聚型性能均与对数递变函数呈优良的相关性,相关系数均大于0.99,用同系对数递变规律对直 相似文献
107.
应用分子电性距离矢量预测烷烃和一元醇的折光指数 总被引:5,自引:0,他引:5
应用分子电性距离矢量对81个烷烃、22个一元醇进行了结构表征,通过多元线性回归与逐步回归的方法建立了分子电性距离矢量与折光指数的定量结构性质模型,模型的相关系数分别为0.980和0.979.采用留一法对模型进行交互检验复相关系数R2cv分别为0.927和0.898.说明定量结构性质模型具有很好的稳定性和预测功能. 相似文献
108.
J. J. Moura Ramos 《Journal of solution chemistry》1989,18(10):957-975
A recently proposed method for calculating the energy of cavity formation in liquids is presented in which the cavity formation process is described as work against the surface forces of the solvent, at the microscopic scale. The energy involved in the cavity formation process is, on the other hand, viewed as a strictly interaction potential energy and the reference cavity, which has the size and the shape of the space occupied by each molecule in the liquid, is considered as having short-range orientational order characteristic of the pure liquid. The method is successfully applied to binary alkane mixtures at infinite dilution whose components have different chemical structure (linear, cyclic and branched alkanes). The importance of the changes in the molecular order of the solute and the solvent occuring in the mixing process is emphasized. 相似文献
109.
Dr. Fengkai He Dr. Christophe Gourlaouen Prof. Dr. Huan Pang Prof. Dr. Pierre Braunstein 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(41):e202200507
We report the first examples of metal-promoted double geminal activation of C(sp3)−H bonds of the N−CH2−N moiety in an imidazole-type heterocycle, leading to nickel and palladium N-heterocyclic carbene complexes under mild conditions. Reaction of the new electron-rich diphosphine 1,3-bis((di-tert-butylphosphaneyl)methyl)-2,3-dihydro-1H-benzo[d]imidazole ( 1 ) with [PdCl2(cod)] occurred in a stepwise fashion, first by single C−H bond activation yielding the alkyl pincer complex [PdCl(PC HP)] ( 3 ) with two trans phosphane donors and a covalent Pd−C bond. Activation of the C−H bond of the resulting α-methine C H−M group occurred subsequently when 3 was treated with HCl to yield the NHC pincer complex [PdCl(PCNHCP)]Cl ( 2 ). Treatment of 1 with [NiBr2(dme)] also afforded a NHC pincer complex, [NiBr(PCNHCP)]Br ( 6 ), but the reactions leading to the double geminal C−H bond activation of the N−CH2−N group were too fast to allow identification or isolation of an intermediate analogous to 3 . The determination of six crystal structures, the isolation of reaction intermediates and DFT calculations provided the basis for suggesting the mechanism of the stepwise transformation of a N−CH2−N moiety in the N−CNHC−N unit of NHC pincer complexes and explain the key differences observed between the Pd and Ni chemistries. 相似文献
110.
用均根拓扑指数与路径数预测链烷烃的沸点和热力学性质 总被引:17,自引:0,他引:17
以距离矩阵为基础,建构调和均根拓扑指数(K),以表征链烷烃分子的大小 和分支情况,85种链烷烃的沸点(T_b)、标准生成焓(Δ_rH_m~θ)、标准熵(S_m~θ )、标准生成自由能(Δ_fG_m~θ)与K及路径数(P_2, P_3)的回归方程为: ln(793- T_b) = 6.48346-0.10092K + 0.00131P_2-0.01110P_3, R = 0.9996; -Δ_fH_m~θ = 62.664 + 25.331 K + 6.597 P_2 - 0.678 P_3, R = 0.9984; S_m~θ = 170. 691 + 67.425 K - 4.712P_2 + 5.251 P_3, R = 0.9989; Δ_fG_m~θ = -45.677 + 10.060 K + 0.555 P_2 + 2.342P_3, R = 0.9935。它们的计算值与相应实验值 都非常吻合。结果表明,K对链烷烃具有良好的结构选择性和性质相关性。 相似文献