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1.
四氢键二聚体和分子组装   总被引:4,自引:0,他引:4  
介绍了最近几年新的四氢键有机二聚体研究的进展及其在分子自组装和分子聚 集体化学研究中的应用。  相似文献   
2.
A novel vanadate decamer, involving all vanadium atoms present in +5 oxidation and one formhydroxamic acid dimer cation readical, has been synthesized. The single-crystal X-ray diffraction shows that the orange crystal is formed in the triclinic system, space group Pi, a = 8. 4960 (17), b = 10.447 (2), c = 11.299 (2) A, α= 68. 82 (3)°,β= 87.35 (3)°, γ = 66.97(3)°. V = 855. 3(3) A3, Z = 8, R1 = 0. 0857, wR2=0. 2551. X-ray crystallographic and packing in superlattice studies showed that the crystal structure was constructed by electrostatic attraction of O-H…O hydrogen bonds between formhydroxamic acid dimer cation and decavanadate polyanion. Formhydroxamic acid dimer is got through controlling the condition of the reaction using formhydroxamic acid.  相似文献   
3.
以二聚酸和不同链长的醇为原料,合成了一系列二聚酸酯并对其结构进行表征;考查了其流变学性能以及摩擦磨损性能和抗磨剂在二聚酸二异辛酯为基础油中的摩擦感受性,并对其磨损表面主要元素进行分析;按照DIN-51828-1,2标准对各种试样进行生物降解性测试.结果表明:所合成的二聚酸系列酯的粘温性能良好,醇基烷链越长,二聚酸酯的粘度越高,倾点越低,尤其是异构体的倾点更低;醇基烷链越长,二聚酸酯的抗磨性越优良,承载能力越强;链长相同的二聚酸酯的承载能力和抗磨性随分子支链化(异构化)程度增加略有增加;所合成的二聚酸二异辛酯具有最佳综合性能,其流变学性能和摩擦磨损性能优于季戊四醇酯,是一种性能优良的基础油,并可以生物降解.  相似文献   
4.
We present a distribution that generalizes the Bose-Einstein distribution. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 159, No. 2, pp. 318–320, May, 2009.  相似文献   
5.
聚对苯二甲酸乙二酯(PET)的荧光光谱已经得到了相当广泛和深入的研究,当激发光波长位于310~360nm时,可以观察到位于360~390nm范围的荧光发光,这部分荧光的来源有很多争议,至今未取得一致的看法,有作者认为,此处的荧光发光是PET链段上苯环之间的相互作用形成的基态二聚体(ground-state dimer)引起的发光;还有人认为这是苯环基团之间相互作用形成的激基缔合物的发光(excimeric emission)。  相似文献   
6.
使用MP2/6-311G方法得到了四硫富瓦烯自由基正离子二聚体(TTF·^+ -TTF·^+)能量极小点的结构.这显示这种正离子间的吸引作用存在.这种新的吸引作用是望远镜形状的20中心2电子分子间共价π/π键.这种共价π/π键的键能约为-21kcal·mol^-1,它被正离子间的库伦排斥作用掩盖.有负离子围绕的四硫富瓦烯自由基正离子二聚体(TTF·^+ -TTF·^+)体系是稳定的.  相似文献   
7.
Two carbazole dimers (1 and 10) were synthesized from 9-ethyl-9H-carbazole-3-carbaldehyde and 6-bromo-9-ethyl-9H-carbazole-3-carbaldehyde by McMurry C-C coupling reaction. Palladium(0)-catalyzed C-N coupling reactions of 10 and various diarylamines result in the formation of stable carbazole derivatives in good yields. These compounds are fluorescent in blue to yellow region with moderate to good quantum yields. Also, they are thermally stable and capable of hole-transporting due to the presence of the carbazole moieties. The electroluminescent devices fabricated using 1, 2, and 3 as hole-transporters/emitters with a bilayer structure ITO/Cpd/TPBI or Alq3/LiF/Al (Cpd=1, 2, and 3) exhibit good performance (e.g., ηext=1.0-2.1%; ηp=0.9-1.9 lm/W; ηc=2.4-4.8 cd/A at a current density of 100 mA/cm2).  相似文献   
8.
荧光素二聚体荧光探针测定卡那霉素的研究   总被引:2,自引:0,他引:2  
基于卡那霉素对荧光素二聚体具有良好的荧光增强作用,以现场形成的荧光素二聚体作为荧光探针,建立了卡那霉素定量分析的新方法。在碱性条件下(pH=9.0),当溴化十六烷基三甲基铵(CTAB)浓度为0.4-1.0 mmol/L时,荧光素(FL)在CTAB作用下形成弱荧光现场二聚体,导致荧光猝灭。加入卡那霉素,体系荧光明显增强,且荧光强度与卡那霉素浓度呈良好的线性关系。在优化条件下,卡那霉素的测定线性范围为2.5×10^-3 - 0.1 g/L,检出限(3σ/K)为1.4×10^-4g/L。用于实际样品分析,测定回收率为101%-116%,RSD为1.9%-2.6%。  相似文献   
9.
1 INTRODUCTION Schiff base complexes containing sulfur and com- plexes of amino acid Schiff bases[1~5] have recently aroused increasing interest because of their antiviral, anticancer and antibacterial activities. Taurine, an amino acid containing sulfur, is indispensable to human beings and has important physiological func- tions. Recently, we have found that the Shiff base derived from taurine has manifold coordination modes[4~10]. Aromatic-ring stacking interaction is an important …  相似文献   
10.
A new Ni(Ⅱ) complex [Ni2(salen)2]·(NCS)·NH4 (salen = N,N'-bis(salicylidenea-mino)ethanato) has been prepared and structurally characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. It crystallizes in the orthorhombic system, space group Pbca with a = 16.8725(13), b = 19.0046(15), c = 20.0583(16) (A), Z = 8, V = 6431.8(9) (A)3, C33H32N6Ni2O4S1, Mr= 726.13, Dc = 1.500 g/cm3, F(000) = 3008, μ = 1.284 mm-1, the final R = 0.0394 and wR = 0.0767 for 4449 observed reflections with Ⅰ>2σ(Ⅰ). The complex involves a N,N'-ethylene-bis(salicylaldiminato) Schiff base, an isothiocyanato anion and an ammonium cation. The nickle(Ⅱ) ion adopts a distorted square coordination geometry with N2O2 set of Schiff base ligand. The complexes are linked into a dimmer via intermolecular hydrogen bonds and the [Ni(salen)] moieties are connected together to form a 2-D layer structure by intermolecular N-H…O hydrogen bonds and π-π stacking. Cyclic-voltammetry method was used to characterize electrochemically the complex.  相似文献   
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