共查询到18条相似文献,搜索用时 93 毫秒
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本文全面综述了多种[60]富勒烯衍生物的结构,阐述了(13)~C NMR谱在[60]富勒烯衍生物结构表征中的应用,重点讨论了不同对称性[60]富勒烯衍生物的(13)~C NMR谱图特征.通过[60]富勒烯部分(13)~C共振线的化学位移、数目和相对强度,可以确定[60]富勒烯衍生物的对称结构和加成方式.对于C_s、C_(2v)和C_(3v)对称性的[60]富勒烯衍生物,镜面上的碳原子的相对化学位移很大程度上取决于他们距加成位置的距离.因此,(13)~C NMR谱在碳笼具体结构的确定中具有不可替代的作用. 相似文献
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采用AM1的方法优化了翡翠绿[60]富勒烯C60[C(CH3)(CO2-t-Bu)2]6的结构.利用CI-ZINDO方法计算了基于晶体结构参数和优化结构的化合物及其衍生物的吸收光谱.计算结果与实验值吻合得很好. 相似文献
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将常用的有机催化剂如N,N′-二环乙基碳二亚胺、4-二甲氨基吡啶和1-羟基苯并三唑用于亚甲基「60」富勒烯羧酸的经典酯化反应,没有得到所期待的哑铃形偶联物,而得到单亚甲基富勒烯乙基酯,用柱色谱分离的产物经MALPI和FT-IR证实,并提出可能的反应机理。 相似文献
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通过Diels-Alder环加成反应,发现可控制反应条件,使1,1′-联茚与C60反应,并高产率地得到具有新颖结构的单加成物.用HPLC,FT-IR,FD-MS及1H NMR,13C NMR,HMQC,HMBC等多种波谱技术对其结构进行表征,测得它的两个sp3杂化的桥头碳的化学位移为δC:70.91,证明生成的衍生物为[6,6]闭式环加成.13C NMR谱共给出38个信号,表明C601,1′-联茚衍生物分子具有Cs对称性;此外,还发现单加成衍生物C601,1′-联茚热稳定性好,在四氢呋喃、丙酮等极性溶剂中溶解性好,很适合于在LB膜及光限幅性能方面的研究. 相似文献
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利用~(13)C-NMR 图谱研究各种类型有机化合物的分子结构与性质,已成为实验室的常规方法。若不考虑实验条件的影响,有机物中的~(13)C 化学位移值主要取决于化合物的分子结构。不同的结构效应有不同程度的影响。因此,在一定条件下,人们可以通过分子的~(13)C- 相似文献
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(1)H and (13)C NMR chemical shift predictions of homo- and methano[60]fullerenes containing chiral centers in attached fragment were made using the two-dimensional NMR technique (HH COSY, (1)H-(13)C HSQC and HMBC) and the quantum chemistry GIAO calculation method in the PBE/3ζ approach. The influence of a chiral substituent on the (13)C chemical shifts of diastereotopic fullerene carbons was estimated by comparing the calculated and experimental (13)C NMR spectra. The resonances of the fullerene carbons in α-, β- and δ-positions relative to the position of the substituent exhibit the greatest diastereotopic splitting. 相似文献
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QianRongLI LiQunLI ShaYANG 《中国化学快报》2005,16(6):729-732
Photochemical [2 2] cycloaddition of C60 with podophyllotoxin derivative containing a cyclohexadienone group in o-dichlorobenzene afforded an isomeric mixture of adducts and a pure adduct of C60-fused podophyllotoxin derivatives. The structures of the products were characterized by MS, NMR and IR spectra. 相似文献
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Masaru Kawaguchi Atsushi Ikeda Seiji Shinkai Ion Neda 《Journal of inclusion phenomena and macrocyclic chemistry》2000,37(1-4):253-258
[60]Fullerene (C60)-calix[n]areneinteractions were studied in toluene:MeCN = 10:1 (v/v)using an electrochemical method. In the presence ofhomooxacalix[3]arenes and calix[5]arenes, bothEpc and pa shifted to the negativepotential, whereas they were scarcely affected by theaddition of calix[4]arenes. The2values electrochemically determined forthe association with C60
- are generallysmaller than the 1 valuesspectroscopically determined for the association withC60. The tendency indicates that thecharge-transfer-type interaction is one of thedriving forces for C60 inclusion.thanks|Author for correspondence 相似文献
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Solvent-free organic reactions have been attracting great interest of chemists due to the elimination of the usage of harmful organic solvents,low costs,and simplicity in the procedure1.Solvent-free mechanochemical reactions of fullerenes were explored and are significant for the reactions of fullerenes because the low solubility of fullerenes in common organic solvents requires large quantity of organic solvents and some novel fullerene reactions could only occur in the solid-state reaction2.… 相似文献
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Khalilov LM Tulyabaev AR Yanybin VM Tuktarov AR 《Magnetic resonance in chemistry : MRC》2011,49(6):378-384
The (1)H and (13)C NMR chemical shifts of spiro-cycloalkylidene[60]fullerenes were assigned using experimental NMR data and the Density Functional Theory (DFT)-Gauge Independence Of Atomic Orbitals method (GAIO) calculation method in the Perdew Burke Ernzerhof (PBE)/3z approach. The calculated values of the (13)C NMR chemical shifts adequately reproduce the experimental values at this quantum chemistry approach. Similar assignments will be helpful for (13)C NMR spectral analysis of homo- and methano[60]fullerene derivatives for structure elucidation and to determine the influence of fullerene frames on substituents and the influence of substituents on fullerene cores. 相似文献
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Guohua Xu Jingjing Song Junbo He Qingyun Ren Wenyan Mo Hui Xu Shannan Sun Hongwu He Yanfang Cui 《Magnetic resonance in chemistry : MRC》2012,50(9):646-650
The complete 1H and 13C NMR assignments of four series pyrido[4,3‐d]pyrimidine derivatives were achieved by combination of one and two‐dimensional NMR experiments, and the NMR signals of these compounds were analyzed and compared. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献