共查询到18条相似文献,搜索用时 62 毫秒
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综述了芳香环状低聚体结构表征的发展过程及最新进展,以高效液相色谱、快原子(离子)轰击质谱、激光质谱、电喷雾质谱为主结合其他辅助方法分别做以介绍并比较了各种表征方法的特点及应用范围。 相似文献
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用核磁共振方法表征芳香酯环状二聚体 总被引:1,自引:0,他引:1
用^1H,^13CNMR方法研究了芳香酯环状二聚体的结构,并讨论了芳香酯环状二聚体的^1H谱和^13C谱各谱峰的归属,为同类化合物的表征提供了一个依据。 相似文献
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报道了酚酞芳香酯环状二聚体核磁共振氢 和碳谱,通过与模型化合物标准谱图的比较以及化学位移取代基效应的计算,归属了其碳谱和氢谱峰。 相似文献
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含酚酞结构的聚芳醚酮环状齐聚物的激光质谱表征 总被引:6,自引:0,他引:6
在“拟高稀”条件下,以酚酞与甲基酚酞为双羟基型单体,与活性双氟基芳香化合物合成了聚芳醚酮环状齐聚物。通过基质辅助激光解吸电离飞行时间质谱对其环状结构进行了表征。 相似文献
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应用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)技术对系列环状预聚体进行了表征,分别确定了系列环状预聚体各自不同的聚合度,同时对它们的结构进行了确认,获得了满意的结果。实验结果表明MALDI-TOF-MS是分析环状预聚体准确、快速工具之一。 相似文献
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设计合成可作为碳纳米管片段的共轭芳烃大环近年来吸引了化学家们广泛的研究兴趣,人们希望从这些共轭芳烃大环出发,通过利用“自下而上”的策略合成单壁碳纳米管。需要指出的是,传统制备碳纳米管的方法,如电弧法、化学气相沉积法等,都很难形成均一的单壁碳纳米管。而这种“自下而上”的策略为高效合成尺寸均一的单壁碳纳米管提供了可行的方法,这种合成方法因此成为了当下合成单壁碳纳米管的热点,但也仍是一大挑战。本文从二维碳纳米环、碳纳米带和三维碳纳米笼三个方面概述关于这类共轭芳烃大环研究的新进展,着重介绍了共轭碳纳米环的设计原则和合成方法,并突出介绍了多环芳烃碳纳米环。多环芳烃通常具有优良的光电性质,以其为基元构筑的共轭碳纳米结构不仅可以作为碳纳米管的合成前体,而且其自身也会表现出新的光电性质。 相似文献
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Yi-Feng Wang Martino Paventi Kwok P. Chan Allan S. Hay 《Journal of polymer science. Part A, Polymer chemistry》1996,34(11):2135-2148
Preparation of novel high Tg (220–280°C) macrocyclic oligomers in high yield by the reaction of 1,2-dihydro-4-(4-hydroxyphenyl)(2H)phthalazin-1-one with activated difluoro-monomers is described. The reaction, conducted under pseudo-high dilution conditions, produces cyclic oligomers in 90–97% isolated yield. Detailed structural characterization of these novel oligomers by the combination of NMR, MALDI–TOF–MS, GPC, and reverse-phase HPLC confirm the cyclic nature and reveal the composition of these cyclic oligomers. MALDI–TOF–MS which enables the detection of oligomers with mass up to 6000 Da, is shown to be a very powerful tool for determination of and the proof of the cyclic nature of the cyclic oligomers. The MALDI results provide answers to the possible combinations of monomer units in the cyclic oligomeric components for random co-cyclic oligomers. Rheological measurement of cyclic oligomers 3c shows that the cyclic oligomers are thermally stable in the melt and the molten cyclic oligomers essentially behave like Newtonian fluids. At 340°C and 100 s−1 the steady-state shear viscosity of the molten cyclic oligomers 3c is only about 14 poise. Ring-opening polymerization of the co-cyclic oligomers 4 to a high molecular weight polymer with Mw = 87,000 is achieved by heating at 340°C for 45 min in the presence of a nucleophilic initiator. © 1996 John Wiley & Sons, Inc. 相似文献
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Jia-qing Xie Fa-mei Feng Shen-xin Li Fuan Liu 《Journal of Dispersion Science and Technology》2013,34(9):1311-1318
The intramolecular nucleophilic substitution of an activated phosphate diester, bis(p-nitrophenyl) phosphate (BNPP) as the nucleic acids substitute, was investigated. A macro-cyclic ligand and the corresponding Cu (II) and Ni (II) complexes were synthesized and characterized. The metallomicelles made up of macrocyclic divalent metal complex and micelle, as mimic hydrolytic metalloenzyme, was used in BNPP catalytic hydrolysis. The metallomicelles displayed higher catalytic activity although they do not attain the catalytic efficiency of enzymes. The analysis of specific absorption spectra showed that the course of the BNPP catalytic reaction was different from that of the BNPP spontaneous hydrolysis, and was an intramolecular nucleophilic substitution reaction. Based on the analytic result of the specific absorption spectrum, an intramolecular nucleophilic substitution mechanism of BNPP catalytic hydrolysis was proposed and a correlative kinetic mathematical model was established, and the corresponding thermodynamic and kinetic constant was calculated. The result of this study proved validity of the mechanism and mathematical model proposed in the article. 相似文献
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Nizam M. El‐Ashgar Mohamed M. Chehimi Carole Connan Florence Babonneau Jacques Livage 《Journal of Dispersion Science and Technology》2013,34(3):445-453
A new porous solid macrocyclic 1,4,7,10,14,17,20‐heptaazadocosane‐3,21‐dione polysiloxane ligand system of the general formula P‐(CH2)3‐C15H32O2N5, (where P represents [Si‐O]n siloxane network) has been prepared by the reaction of immobilized iminobis(N‐diethylenediamineacetamide)polysiloxane with 1,3 dibromopropane. The new macrocyclic polysiloxane ligand system exhibits high potential for the uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+). Complexation with copper ions exhibits a high selectivity in which two copper ions were involved per one macrocyclic ligand group. 相似文献