共查询到20条相似文献,搜索用时 15 毫秒
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《高等学校化学学报》1999,20(7):3
(R)-乙基-2-吡啶亚砜与(4R,5R)-二(羟基-二苯基-甲基)-2,2-二甲基-1,3-二氧戊环(TADDOL)可以形成物质的量比为1∶1的手性包结晶体,X射线衍射分析确定该晶体属单钭晶系, P2 相似文献
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标题化合物是通过(NH_4)_2WS_4, CuCl_2·2H_2O在吡咤溶液中反应制得。晶体呈蓝色, 属三斜晶系, 空间群P1, 晶胞参数为:a=1.3555(7), b=1.3666(5), c=1.7860(13) nm, α=69.08(4)°, β=87.39(5)°, γ=70.72(4)。V=2.907(3) nm, Z=1, D_m=2.56 g cm~(-3)。结构由Patterson法和Fourier法测出。对5692个收集到的独立衍射数据进行计算, 最后R=0.046。结构测定表明, 晶体由W_(10)O_(32)~(4-), [CuCl(C_5H_5N)_4]~+, C_5H_5N和H_2O所组成。W_(10)O_(32)~(4-)的结构见图1, W原子处在O原子的八面体配位中, 彼此共边和共顶点相连。[CuCl(C_5H_5N)_4]~+的结构见图2, Cu原子由1个Cl和4个N原子配位, 呈略有变形的四方锥形, 这种离子是首次报导。C_5H_5N和H_2O填入正负离子堆积的空隙中。 相似文献
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由N-甲基吡咯烷酮和H3PW12O40·nH2O反应得到了标题化合物,并以元素分析,红外光谱,质谱和X射线单晶衍射对其结构进行了表征.结构解析表明,该化合物属于三斜晶系,Pi空间群,晶胞参数为:α=1.335(2)nm,b=1.374(2)nm,c=1.826(2)nm,α=98.92(2)°,β=107.7(2)°,γ=109.9(2)°,V=2.873(1)nm^3,Z=2,Dc=3.840Mg/m^3,μ=24.05mm^-1,F(000)=2926,R1=0.0632,wR2=0.1403.在该化合物中,杂多阴离子仍保持其Keggin结构,通过静电引力与阳离子作用. 相似文献
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在乙腈-水混合溶剂中培养得到了聚金属氧酸盐[(C4H9)4N]6[PMo12O40]2.0.5H2O的单晶.X射线衍射结构分析表明,该晶体属于单斜晶系,C2/c空间群,晶胞参数:a=4.996(10)nm,b=1.411(3)nm,c=2.633(5)nm,β=114.804(4)°,V=16.844 nm3,Z=1,R1=0.0843,wR2=0.2546.化合物分子由两个多阴离子[PMo12O40]3-,6个四丁基胺阳离子[n-Bu4N]+和0.5个结晶水组成. 相似文献
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《Journal of Coordination Chemistry》2012,65(3):427-439
The binuclear complexes [Cu2L2(H2O)4] · 5H2O (1) and [Ni2L2(H2O)4] · 2H2O (2) (where L = C11H11NO5S, H 2 L = 2-[(3-formyl-5-methyl-2-hydroxy-benzylidene)-amino]ethanesulfonic acid) have been synthesized and characterized by IR, elemental analysis and X-ray diffraction. The crystals belong to the monoclinic system, space group P21/c. Complex 1: a = 16.8902(12), b = 11.2829(6), c = 17.4249(11) Å; β = 106.709(4)°; S = 1.131; V = 3180.5(3) Å3; Z = 4; D Calcd = 1.729 g cm?3; F(000) = 1712; μ = 1.554 mm?1; R 1 = 0.0519, wR 2 = 0.1349; complex 2: a = 11.399(2), b = 19.985(3), c = 7.3694(10) Å; β = 108.664(7)°; S = 1.157; V = 1590.6(4) Å3; Z = 2; D Calcd = 1.604 g cm?3; F(000) = 800; μ = 1.388 mm?1; R 1 = 0.1859, wR 2 = 0.4346. The geometry around each metal(II) center can be described as slightly distorted octahedral. Water-sulfonic clusters and (H2O)4 water clusters can be observed for 1 from the crystal packing diagram, while cavity and offset face-to-face π–π stacking can be observed for 2. The complexes have been tested for the antibacterial activities which show antibacterial activities of 1 for β-hemolytic streptococcus, Staphylococcus aureus and Escherichia coli, and the antibacterial activity of 2 only for β-hemolytic streptococcus. 相似文献
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The paper describes the synthesis, characterization and thermal decomposition of nickel(II) bis(tartrato) nickelate(II) heptahydrate [Ni2(C4H4O6)2]·7H2O. The complex was characterized by elemental analysis, magnetic moment measurement, infrared, ESR and electronic spectroscopy. The experimental evidences indicate that complex is likely to have metal bonding. The thermal decomposition of the complex produced NiO in air at about 360°C and in nitrogen at about 380°C as the final product. Some of the intermediates produced during the thermolysis were isolated by temperature arrest technique and identified by analytical and spectroscopic methods. A tentative reaction mechanism is proposed for the thermal decomposition of the complex in air and nitrogen.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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X. F. Wang X. Zh. Liu J. Wang Zh. H. Zhang W. Sun Y. M. Kong X. D. Zhang 《Russian Journal of Coordination Chemistry》2008,34(2):134-145
The three title complexes, NH4[HoIII(Edta)(H2O)3] · 1.5H2O (I) (H4Edta = ethylenedianine-N,N,N′,N′-tetraacetic acid), (NH4)4[Ho 2 III (Dtpa)2] · 9H2O (II) (H5Dtpa = diethylenetriamine-N,N,N′,N″,N″-entaacetic acid), and (NH4)3[HoIII(Ttha)] · 5H2O (III) (H6 Ttha = triethylenetetramine-N,N,N′,N″,N?,N?-hexaacetic acid), have been prepared and characterized by FT-IR, elemental analyses, and single-crystal X-ray diffraction technique. Complex I has a nine-coordinate mononuclear structure with distorted monocapped square antiprismatic conformation and its crystal structure belongs to orthorhombic system and Fdd2 space group. The crystal data are as follows: a = 19.343(9), b = 35.125(17), c = 12.364(6) Å, V = 8400(7) Å3, Z = 16, M = 552.26, ρcalcd = 1.747 g cm?3 μ = 3.828 mm?1, and F(000) = 4368. Complex II has a binuclear nine-coordinate pseudomonocapped square antiprismatic conformation and its crystal structure belongs to triclinic system and space P1 group. The crystal data are as follows: a = 9.7637(16), b = 9.9722(16), c = 12.945(2) Å, α= 85.853(2)°, β = 77. 140(2)°, γ = 77.140(2)°, V = 1198.4(3) Å3, Z = 1, M = 1340.80, ρcalcd = 1.858 g cm?3, μ = 3.380 mm?1, and F(000) = 674. As for complex III, it also has nine-coordinate mononuclear structure with distorted tricapped trigonal prism and its crystal structure belongs to monoclinic system andP21/c space group. The crystal data are as follows: a = 10.349(3), b = 12.760(4), c = 23.142(7) Å, β = 91.020(6)°, V = 3055.6(16) Å3, Z = 2, M = 797.55, ρcalcd = 1.734 g cm?3, μ = 2.674 mm?1, and F(000) = 1624. The results showed that although the ligands are different from one another in the shape and the numbers of coordination atoms, they all have nine-coordinate structures. However, one of them has binuclear structure and the other two have mononuclear structures because of the difference of the ligands. 相似文献
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《Journal of Coordination Chemistry》2012,65(21):3420-3437
Two Cu(II) hydroxo succinates [Cu3(H2O)2(OH)2(C4H4O4)2]?·?4H2O (1) and [Cu4(H2O)2(OH)4(C4H4O4)2]?·?5H2O (2) and one Cu(II) hydroxo glutarate [Cu5(OH)6(C5H6O4)2]?·?4H2O (3) have been prepared and structurally characterized by single crystal X-ray diffraction methods. They feature 1D and 2D copper oxygen connectivity of elongated {CuO6} octahedra in “4?+?1?+?1” and “4?+?2” coordination geometries. Within 1, linear trimers of three edge-sharing {CuO6} octahedra are connected into copper oxygen chains, which are bridged by the anti conformational succinate anions to generate 2D layers with mono terminally coordinating gauche succinate anions on both sides. The layers are assembled into a 3D framework by interlayer hydrogen bonds with lattice H2O molecules distributed in channels. Different from 1, the principal building units in 2 are linear tetramers of four edge-sharing {CuO6} octahedra. The tetramers are condensed into copper oxygen chains and the succinate anions interlink them into a 3D framework with triangular channels filled by lattice H2O molecules. The {CuO6} octahedra in 3 are edge-shared to form unprecedented 2D inorganic layers with mono terminally coordinating glutarate anions on both sides. Interlayer hydrogen bonding interactions are responsible for supramolecular assembly of the layers into a 3D framework with lattice H2O molecules in the channels. The inorganic layers in 3 can be described as hexagonal close packing of oxygen atoms with the Cu atoms in the octahedral cavities. The title compounds were further characterized by elemental analyses, IR spectra and thermal analyses. 相似文献
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Hugues Bienaym 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》1997,109(23):2785-2788
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Lukas Hintermann Antonio Togni 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2000,112(23):4530-4533
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Lukas Hintermann Antonio Togni 《Angewandte Chemie (International ed. in English)》2000,39(23):4359-4362
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Dr. Christian Schmitz Prof. Walter Leitner Dr. Giancarlo Franciò 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(30):10696-10702
A library of α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol (TADDOL)‐based phosphoramidites has been synthesized and applied in the Ni‐catalyzed cycloisomerization of different dienes. Through the systematic variation of the three structural motifs of the lead structure, that is, the amine moiety, the protecting group, and the aryl substituents, the ligand features could be optimized for the asymmetric cycloisomerization of the model substrate diethyl diallylmalonate. The substrate scope of the new catalytic system was extended to other diallylic substrates, including unsymmetrical dienes. Overall remarkably high activities of up to approximately 13 500 h?1, very high selectivities toward five‐membered exo‐methylenecyclopentanes, and enantioselectivities of up to 92 % ee have been achieved. 相似文献
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Jun LIU Qing Hua BIAN Ming An WANG Hong Chao GUO Min WANG 《中国化学快报》2006,17(5):606-608
Optically active TADDOL (α, α, α′, α′-tetraaryl-1, 3-dioxolane-4, 5-dimethanol) and the related ligands have played a significant role in asymmetric reactions1. Although several hundreds of different TADDOLs and TADDOL analogues have already been de 相似文献
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In model experiments, concerning the modulation of memory of chirality during the intramolecular alkylation of N-(p-methoxy)benzyl-N-chloroacetyl-Phe-OtBu derivative to the corresponding β-lactam, TADDOL was selected from a panel of different phase-transfer catalysts as the best chiral additive (ee up to 82%). We have demonstrated here that the degree and sign of the cyclization selectivity was virtually independent on TADDOL configuration, providing experimental proof that in this reaction this additive works as a memory of chirality enhancer and not as a real catalyst. The effect of TADDOL is strongly dependent on the starting amino acid derivative, the increase of selectivity being only observed for those with aromatic side chains. 相似文献