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11.
Jarosł Spychała 《Research on Chemical Intermediates》2007,33(6):481-486
Evidence for a stereoinduction profile of the reaction of N-methyl-1,3-diaminopropane with acyl chlorides has been provided. A possibility to engage in intramolecular CH2⋯HN and Cl⋯H-N interactions and the proton migration process to the methylamino group leads to the E secondary amides carrying the N⋯H+⋯N or N-H⋯N bridges, that show unusual spectroscopic images. Empirical relations between the Δδ
C chemical shift differences, the polarizability of the CO(S) groups and hydrogen bonding strength have been found. Both 1H-15N-GHSQC and GHMBC experiments provide insight into the nature of hydrogen bonding and confirm the cyclic array of atoms. 相似文献
12.
Two-component thermo-responsive hydrogels poly(N-isopropylacrylamide)-co-vinylbenzyltrimethylammonium chloride (NIPA-co-VBT) and poly(N-isopropylacrylamide)-co-p-sodium styrene sulphonate (NIPA-co-SSS) were prepared by using high energy gamma radiation. The gels were characterized by Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and sol-gel analysis. The presence of ionic monomers in NIPA leads to lower gel content. Introduction of ionic components in the matrix enhanced swelling extent but caused slower volume transition. The swelling studies in alcohol indicated that swelling extent was function of polarity of the swelling medium and all gels followed the order water > methanol > ethanol > iso-propanol. In mixed co-solvents (water-alcohol), they exhibit complex reentrant behavior. The co-polymer gels containing VBT swelled faster and to higher extent than those containing SSS. The dynamic swelling studies indicated that diffusion of water in PNIPA gel shifts from Fickian for PNIPA to anomalous for NIPA-co-ionic gels also the mean swelling time (MST) decreases for gels containing ionic monomers. 相似文献
13.
当离子蒸气冷凝形成团簇时,其结构表现出特定的规律。文中对不同大小不同形状的氯化钠团簇结构与结合能进行了计算,以求揭示离子蒸气冷凝形成团簇的一些规律,并与实验结果进行对照。 相似文献
14.
Xin Ying ZHANG Xue Sen FAN Hong Ying NIU Jian Ji WANGSchool of Chemical Environmental Sciences Henan Normal University Key Laboratory ofEnvironmental Science Engineering of Henan Education Department Xinxiang 《中国化学快报》2003,(10)
a, a'-Bis(substituted benzylidene)cycloalkanones were efficiently prepared from cycloalkanones and benzaldehydes in [bmim][BF4] by using iron(III) chloride hexahydrate as a catalyst. It is shown that [bmim][BF4] and iron(III) chloride hexahydrate can be quantitatively recovered and be reused effectively for many times. Compared with the known methods, this novel process has the advantage of being an envkonmentally benign process together with good yields and mild reaction conditions. 相似文献
15.
用溶胶-凝胶方法制备了钠快离子导体Na_5YSi_4O_(12)(简称NYS)的纯相,应用交流阻抗谱技术测定了样品的离子电导和离子导电活化能,用扫描电子显微镜对用不同方法制备的样品烧结体表面进行了观察。与传统固相反应法制备的NYS离子导体相比,用溶胶-凝胶方法制备的NYS烧结体具有较好的界面效应。 相似文献
16.
17.
采用分子量500万的聚氧化乙烯和无水溴化铜,通过混溶蒸发法制备成高聚物固体电解质P(EO)n-CuBr2薄膜,并在0.1~300MPa范围不同的流体静水压下详细测量其复平面阻抗谱,分别得到在不同压力下离子电导率和介电常数与测量频率的关系.进一步解谱准确地求出P(EO)n-CuBr2(n=12、16)薄膜离子电导率和介电常数的静水压效应,并结合X-光物相分析,根据离子迁移通道的物理图象和高聚物的极化机构进行了初步的讨论.添加20%的增塑剂碳酸丙烯酯,较大改进了压力下的导电性.120~300MPa的离子电导率提高一个数量级 相似文献
18.
Y. Adachi K. Aoki 《Colloids and surfaces. A, Physicochemical and engineering aspects》2003,230(1-3):37-44
Standardized mixing procedure was applied to the analysis of flocculation of polystyrene latex (PSL) particles with polyelectrolytes. After confirming the initial enhancement of flocculation rate in the very beginning followed by abrupt stop with excess dosage, attention was shifted to the system of moderate dosage. In the former, effects of ionic strength were further analyzed to find the consistency with adsorption isotherm. In the latter, flocculation started slowly in the beginning, sometime slower than salt-induced rapid coagulation, however, the rate gradually increases in the middle stage. Often, the increased rate exceeds that of salt-induced rapid coagulation. This behavior emerged more clearly in the case of lower ionic strength. This is the indication that the rate of relaxation of polymer on the colloidal surface is a function of surface coverage and ionic strength. The ultimate degree of flocculation is usually higher than that observed for excess dosage. The size distribution of flocs was also examined, however, no clear difference between different experimental conditions was confirmed for the same degree of flocculation. 相似文献
19.
Poly ionic liquid 1-ethyl 3-(2-methacryloyloxy ethyl) imidazolium iodide (PEMEImI) as a single-ion conductor was designed and synthesized. When appropriate amount of suitable plasticizers, I2 and polyacrylonitrile (PAN) were incorporated into it, the complex formed gel polymer electrolyte. Chemical structure, thermal behavior and ionic conductive properties of the gel polymer electrolyte were investigated by Raman spectra, UV-Vis spectra, differential scanning calorimetry (DSC), and complex impedance analysis, respectively. For the new gel polymer electrolyte, the ionic conductivity of about 1 × 10−3 S cm−1 at room temperature was achieved. 相似文献
20.
The room temperature ionic liquid n‐butylpyridinium tetrafluoroborate (BPyBF4) is used as a ‘green’ recyclable alternative to classical molecular solvents for the cyclocondensation of α‐tosyloxyketones with 1‐aminoisoquinoline to prepare imidazo[2,1‐a]isoquinolines in good yields. 相似文献