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由相应的碲盐生成的某些碲ylide,能顺利地和1,4-双(3-取代苯基-3-酮-1-丙烯基)苯,1,5-二取代苯基-1,4-戊二烯-3-酮反应生成双环丙烷衍生物,反应具有高立体选择性,产率为61.8-88.8%。  相似文献   

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本文对甘氨酸、1,10-邻菲咯啉铜(Ⅱ)固体配合物进行了合成和表征,并利用X射线分析研究了其晶体结构。  相似文献   

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The paper describes a four-step synthesis of ethyl (2E, 4Z)-2, 4-decadienoate (pear ester) from propargyl alcohol with a 50% total yield. It also gives the synthesis of ethyl (2E, 4E)-2, 4-decadienoate. In both cases arsenic ylides were used to give the satisfactory results.  相似文献   

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In a new synthetic approach phenylcyanamide (Hpca) was synthesized by methylation of phenylthiourea followed by a basic work‐up. All products along the synthetic route have been fully characterized by means of NMR, IR, and X‐ray studies. The first structural report of neutral mixed crystals of phenylcyanamide containing monomeric and trimeric Hpca is presented. Examination of these intriguing mixed crystals revealed the formation of distinct layers of monomeric and trimeric Hpca. These layers are interconnected by weak hydrogen bonds. The trimer represents triphenylisomelamine, which readily isomerizes to the triphenylmelamine in the melt, in accord with computations at the B3LYP level, indicating an exothermic process (ΔH=?49.4 kcal mol?1). Pure trimeric Hpca (triphenylisomelamine) was obtained either by recrystallization of the mixed crystals from boiling water or by trimerization of monomeric Hpca in isopropanol for 12 h under reflux conditions. For comparison tritylcyanamide (Htca) and potassium phenylcyanamide as an [18]crown‐6 complex [K([18]crown‐6)pca] have been synthesized, and the solid‐state structures were determined using X‐ray diffraction techniques. The thermal behavior was studied by thermo‐analytical experiments. In agreement with the experimental results, computations predict an exothermic cyclotrimerization process for Hpca (ΔH=?41.3 kcal mol?1).  相似文献   

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The reaction of the title ylide {PhCOCHP(p-tolyl)3} with Pd(II), Pt(II). Hg(II), and Ag(I) in equimolar ratios using CH3CN, CH3OH, and CH2Cl2 as solvents have yielded [{(p-tolyl)3PCHCOC6H5} PdCl2]2 (I), [{(p-tolyl)3 PCHCOC6H5} PtCl2]2(2), [Hg(NO3)2 {(p-tolyl)3 PCHCOC6H5}](3), and [Ag{(p-tolyl)3 PCHCOC6H5 < eqid1 > 2]+ (4). The IR, 1H 13C, and 31P NMR together with micro analysis data of the products were obtained.  相似文献   

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Mixture formed from sonicating TiCI4 and Si(OEt)4 in the absence of water is used as precursor and hydrolyzed by using a long-chain organic ammonium bromide as a structuredirecting agent. The product, titania-silica, is of mesoporous structure and characterized with SEM, FT-IR, BET, XRD and so on.  相似文献   

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合成了5种新型镧系四元混合阴离子配合物,用X射线四圆衍射仪测定了[Pr(CH3COO)2(NO3)(bipy)]2的晶体结构,四个醋酸根呈两种配位方式,测定了铕和钆配合物的荧光和ESR谱.  相似文献   

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应用乙酸锰、高锰酸钾和丙酸(或氯乙酸)混酸体系合成,得到了2个基于Mn12O12核心的十二核锰配合物,分子式分别为[Mn12O12(O2CMe)8(O2CEt)8(H2O)4].2H2O(1)和[Mn12O12(O2CMe)12(O2CCl3)4(H2O)4].4MeCO2H.8H2O(2)。X射线单晶衍射分析表明配合物1结晶于四方晶系I4空间群,晶胞参数为:a=b=2.650 5(3)nm,c=1.349 7(3)nm,Z=4;配合物2结晶于四方晶系I41/acd空间群,晶胞参数为:a=b=2.7067(1)nm,c=2.5880(2)nm,Z=8。这2个配合物结构都具备Mn12O12核心,与其他经典Mn12明星分子的核心相似。中心的Mn4O4立方核通过μ3-氧桥被非共面的Mn8O8环聚集在一起,而16个η2-μ-混合羧酸以不同方向在外围充当连接桥,同时提供了酸性环境。文中还分析了混酸体系的pKa值对配合物结构形成的影响。  相似文献   

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α-Metallated ylides have revealed themselves to be versatile reagents for the introduction of ylide groups. Herein, we report the synthesis of the thiophosphinoyl and piperidyl (Pip) substituted α-metallated ylide [Ph2(Pip)P=C−P(S)Ph2]M (M=Li, Na, K) through a four-step synthetic procedure starting from diphenylmethylphosphine sulfide. Metallation of the ylide intermediate was successfully accomplished with different alkali metal bases delivering the lithium, sodium and potassium salts, the latter isolable in high yields. Structure analyses of the lithium and potassium compounds in the solid state with and without crown ether revealed different aggregates (monomer, dimer and hexamer) with the metals coordinated by the thiophosphoryl moiety and ylidic carbon atom. Although the piperidyl group does not coordinate to the metal, it significantly contributes to the stability of the yldiide by charge delocalization through negative hyperconjugation.  相似文献   

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合成了联苯甲酰双缩氨基脲硫氰酸根、硝酸根混合配位的钕(Ⅲ)配合物。在此配合物中只有1个链状配体,另有2个硫氰酸根、1个硝酸根和1个水分子参与配位。总配位数是9。晶体结构分析表明,该配合物晶体属三斜晶系,P空间群。晶胞参数a=10。866(2),b=13.687(3),c=15.433(3),α=98.75(4)°,β=107.64(5)°,γ=112.14(5)°。最终偏差因子R=0.075。用INDO方法计算结果表明:NCS对Nd(Ⅲ)的配位比=C基对Nd(Ⅲ)的配位强。  相似文献   

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杨上峰  刘富品  陈传宝  章文峰 《化学进展》2010,22(10):1869-1881
内嵌混合金属氮化物原子簇富勒烯的发现极大地扩展了内嵌富勒烯家族。内嵌混合金属氮化物原子簇富勒烯是一类新型的内嵌富勒烯,其内嵌物为由2-3种不同的金属组成的氮化物原子簇。本文首先介绍了新型内嵌混合金属氮化物原子簇富勒烯的发现、合成和分离方法,并对目前所分离出来的内嵌混合金属氮化物原子簇富勒烯进行了分类。然后总结了目前所报导的内嵌混合金属氮化物原子簇富勒烯的结构表征手段,对于不同的内嵌混合金属氮化物原子簇富勒烯的分子结构分别进行了阐述。最后着重讨论了内嵌混合金属氮化物原子簇富勒烯的特殊电子性质以及物理和化学性质。本文还对内嵌混合金属氮化物原子簇富勒烯潜在的应用前景作了展望,在内嵌具有不同物理性质的两到三种金属原子的基础上,所形成的内嵌混合金属氮化物原子簇富勒烯有可能兼具不同金属原子各自的性质,从而成为多功能综合的功能材料。  相似文献   

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芳香多羧酸根阴离子作为一类多齿配位试剂能够在阴离子和阳离子之间形成一维,二维,和三维的无限连续^[1],从而通过这种方式构建链状,层状和网状结构的化合物^[2]。此类化合物不仅有独特的结构,而且有广泛的用途,从灭火剂,催化剂到分子磁体等都有文献报道^[3,4],因而成为近年来无机材料化学和配位化学研究的热点之一,1,2,4,5-苯四甲酸根阴离子(TCB)作为一种对称性芳香多羧酸根阴离子,已表现出很强的桥联能力和为顺磁金属离子提供磁交换路径的能力^[5],本文以TCB为桥联配体,以咪唑(Him)为协同配体,合成了一种镍(Ⅱ)配位聚合物{[Ni(Him)4][Ni(TCB)2/2(Him)2(H2O)2].6H2O}n,并表征了其结构。  相似文献   

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高分散纳米二氧化钛混合晶体的合成、结构与光催化性能   总被引:11,自引:0,他引:11  
Using TiCl4 and urea as the raw materials and nanometric carbon black as plate, nanometric mix-crystals of rutile and anatase TiO2 were prepared at 100 ℃ for 10~180 min by homogeneous precipitation method. The effects of pH on the ratio of nanometer TiO2 mix-crystals were also discussed. TEM measurement indicates that the TiO2 is spherical particles, and the average diameter of the particles is 20 nm. XRD and TG-DTA were also used to characterize the nanometer mix-crystal materials. The photocatalytic experiment show that the mix-crystal material has the best photocatalytic reactivity. After being irradiated under the sunlight for 40 min, the compound can completely degrade the acid-red 3R.  相似文献   

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