高富勒烯的提取新方法

高富勒烯的提取新方法刘咏梅盛蓉生朱绫李俊（武汉大学分析测试中心４３００７２）１９９０年，Ｋｒａｔｓｃｈｍｅｒ和Ｈｕｆｍａｎ等［１］发明了克量级生产Ｃ６０的方法，使富勒烯成为９０年代研究的热门课题。Ｃ７０［２］的单柱克量级分离也有报道，高富勒烯Ｃｎ（ｎ...     

Effect of Addition Groups on the Redox Properties of Fullerenes

采用循环伏安法和微分脉冲伏安法对比地研究了包括五种Ｃ６０的衍生物及四种Ｃ７０的衍生物的电化学性质．结果表明，推电子基团的引入使得富勒烯的氧化还原电位负移，这种负移的程度与加成基团的性质、个数和富勒烯的性质有关．对于Ｃ６０和Ｃ７０的单加成产物，负移的范围是０．０８～０．２０Ｖ．而对于Ｃ６０的双加成和三加成产物负移的范围分别为０．３０～０．３２Ｖ和０．５３～０．５８Ｖ．同时由于电位的负移大部分衍生物在低于＋１．５Ｖ（ｖｓ．ＳＣＥ）观察到了氧化峰，而Ｃ６０和Ｃ７０本身的氧化高达＋１．７Ｖ（ｖｓ．ＳＣＥ）．特别是对于Ｃ７０的双加成产物在＋０．４５Ｖ（ｖｓ．ＳＣＥ）出现了一个不可逆氧化峰，但是，对于同样加成基团的Ｃ６０双加成产物的氧化却在＋０．９０Ｖ（ｖｓ．ＳＣＥ），说明由于推电子基团的双加成引入，明显改变了Ｃ７０的电负性．     

场解吸质谱法对富勒烯的定量分析研究

首次报道了用场解吸质谱法（ＦＤＭＳ）对富勒烯Ｃ_（６０）和Ｃ_（７０）同时进行定量分析的方法，方法的相对偏差为±１％。与ＨＰＬＣ法比较，两者的偏差在±０．５％以内。特点是不需任何标准样品，并可同时对多种富勒烯的组分进行定性和定量分析。     

107例高龄老人头发锰铜锌铬微量元素含量的探讨

对１０７例７０～８０岁高龄老人作头发８种微量元素含量测定，测定结果以Ｍｎ，Ｃｕ，Ｚｎ，Ｃｒ与长寿地区广西巴马县老人作比较，结果表明本组是低Ｍｎ、高Ｃｕ、低Ｚｎ、高Ｃｒ，差异极为显著（Ｐ＜０．００１），符合非长寿地区低Ｍｎ的现状．本组与４５～５９岁，６０～６９岁二个年龄组比较，本组为高Ｍｎ、低Ｃｕ、低Ｚｎ、高Ｃｒ，差异均显著（Ｐ＜０．０５），表明本组微量元素组合优于７０岁前老人．从本组男、女微量元素比较，女性表现为高Ｍｎ、高Ｓｒ、高Ｃａ、低Ｃｒ、低Ｃｕ，说明老年女性在抗衰防衰方面优于老年男性．     

C60化学修饰的PNVC材料的UV—VIS谱研究

本实验采用金属有机化学方法成功地将富勒烯分子引子到ＰＮＶＣ侧链形成ＣＢＰ型共聚功能材料，研究了其ＵＶ－ＶＩｓ谱行为。结果表明，Ｃ６０或Ｃ６０／Ｃ７０混合物化学修饰的产物其紫外可见谱明显向长波方向移动，谱峰范围由２８０ｎｍ扩展至８７０ｎｍ。     

色谱法分离富勒烯的研究

研究了用活性炭作固定相，ＣＳ２作流动相柱色谱法分离富勒烯混合物的方法，考察了用溶剂浸泡活性炭减活的时间、活性炭与富勒烯混合物配比、活性炭的粒度等因素对分离结果的影响，采用了索氏抽提器，可以很快地将固定相中的Ｃ７０等高级富勒烯提取出来，提高了回收率。     

可溶性悬垂［60］富勒烯－聚苯乙烯聚合物

可溶性悬垂［６０］富勒烯－聚苯乙烯聚合物最近，美国科学家ＹａＰｉｎｇＳｕｎ等人得到了一种溶于有机溶剂的悬垂［６０］富勒烯－聚苯乙烯聚合物。合成反应是以二硫化碳为溶剂，以三氯化铝为催化剂，利用Ｆｒｉｅｄｅｌ－Ｃｒａｆｔｓ反应进行。这种聚合物能够溶于氯仿...     

金属富勒烯La＠C_（2n）的合成、提取及其ESR和MS表征

采用对掺入Ｌａ_２Ｏ_３的石墨棒原位活化并结合交换电极回放方法制备了产率较高的金属富勒烯，并用甲苯高温热提取的方法有效地提取出Ｌａ＠Ｃ_（２ｎ），其中Ｌａ＠Ｃ_（７４）为可溶性金属富勒烯增加了新成员．同时，首次采用解吸电子轰击质谱对提取物进行了表征，讨论了提取物的ＥＳＲ谱．     

加成基团对富勒烯电化学性质的影响

采用循环伏安法和微分脉冲伏安法对比地研究了包括五种Ｃ６０的衍生物及四种Ｃ７０的衍生物的电化学性质。结果表明，推电子基团的引入使得富勒烯的氧化还原电位负移，这种负移的程度与加成基团的性质，个数和富勒烯的性质有关。     

低温基体隔离Mn2（CO）10的紫外激光光解

采用２８０ｎｍ和３５５ｎｍ的脉冲激光作光解光源，由ＦＴＩＲ进行初级产物探测，研究了Ｍｎ２（ＣＯ）１０在低温基体隔离条件下的光解反应。结果表明，在Ａｒ基体中，Ｍｎ２（ＣＯ）１０经２８０ｎｍ激光光解的初级产物主要是Ｍｎ２（ＣＯ）９；而在Ｘｅ基体中还观察到了Ｍｎ（ＣＯ）５的生成；与２８０ｎｍ激光相比，采用３５５ｎｍ激光光解Ｍｎ２（ＣＯ）１０，Ｍｎ２（ＣＯ）９的产率较低。     

C60大量、快速分离和电喷雾电离质谱检测

本文用配合沉淀和活性炭吸附相结合的方法，从高级富勒烯含量较高的混合物中，大量、快速分离Ｃ６０，并用电喷雾电离质谱对分离产物进行检测     

一些高碳富勒烯的光谱及HPLC特征

利用对叔本基杯「８」芳烃对烟炱中Ｃ６０的选择性配合作用 烟炱邻二氯苯（ＯＤＣＢ）提取筘的高碳成份得到富集,用高效液相色谱（ＨＰＬＣ）分离,得到Ｃ７０,Ｃ７６,Ｃ７８,Ｃ８４和五种高碳富勒烯及相应的ＵＶ－Ｖｉｓ光谱,实验中发现,ＯＤＣＢ提取物中Ｃ７８的比例与其它溶剂提取物略有差别,富勒烯的保留时间的对数与富勒烯的碳原子数之间的良好的线性关系,随着富勒烯对称性的降低,ＵＶ－Ｖｉｓ光谱吸收极值增多,谱带     

Selective extraction of higher fullerenes using cyclic dimers of zinc porphyrins

Higher fullerenes (>/=C76) were selectively extracted from a fullerene mixture obtained from a combustion-based industrial production source by cyclic dimers of beta-unsubstituted porphyrin zinc complexes 2C5-2C7 with C5-C7 alkylene spacers as host molecules. Results of single extraction of the fullerene mixture with 2C5-2C7 together with a beta-substituted analogue of 2C6 (1C6) and spectroscopic titration of 2C6 and 1C6 with C60, C70, and C96 indicated that the host selectivity toward higher fullerenes is much dependent on the structure of the porphyrin units and the size of the host cavity. Sequential three-stage extraction of the fullerene mixture with the best-behaved 2C6 resulted in considerable enrichment in very rare fullerenes C102-C110 (<0.1 abs %) up to 82 abs % (C76-C114, 99 abs %) (356 nm) of total fullerenes.     

煤基富勒烯烟灰萃取产物的质谱分析

用甲苯等有机溶剂对由煤制得烟灰(soot)进行索氏萃取，用时间飞行质谱及气相色谱-质谱联用（GCMS）技术对所得的萃取产物进行了分析，结果发现，煤基粗富勒烯中除含有大量的C60和C70外，高碳富勒烯（如C74、C78，C82、C84、C100及C106等）的丰度也较高。在煤基粗富勒烯的伴生副产物中存在一些含有苯环结构的芳香性碳氢化合物和少量的长烷烃化合物，由此推测煤基富勒烯的形成过程可能遵循着一条与以石墨为原料时的机制完全不同的途径。     

DFT study on electronic properties of single- and double-shell icosahedral fullerenes

Multi-shell fullerenes are widely studied for their interesting properties although comparative studies on single- and multi-shell structures remain scarce. In this work, important electronic features of single- and double-shell icosahedral fullerenes as a function of their sizes were calculated in the framework of the density functional theory. Fully optimized structures were used to get the gap between the highest occupied molecular and the lowest unoccupied molecular orbital (H-L gap), electronegativity, softness and density of the electronic states. This work shows that the H-L gap of the single-shell fullerenes decreases nonlinearly as the nanoparticles size increases, whereas for the double-shell fullerenes an opposite trend is obtained. A decrease of the H-L gap is found going from single- to double-shell fullerenes with similar external sizes, up to a diameter of 3.13 nm. The electron density of states revealed that isolated peaks give way to more dense electronic states for nanoparticles with diameters above 2 nm.     

BN-Substituted fullerenes C60−2x (BN) x : a computational 11B and 15N NMR study

Density functional theory has been used to investigate the ¹⁵N and ¹¹B NMR parameters of heterofullerenes C_60?2x (BN) _x (x = 1, 2, 3, 6, 9, 12, 15, 18, 21, and 24). Geometry structures of all the BN-substituted fullerenes have been optimized at the B3LYP/6-31+G* level of theory. Afterward, ¹¹B and ¹⁵N chemical shielding isotropy and anisotropy (CSI, CSA) parameters have been calculated at the same level. The obtained results illustrate the electrostatic environment divisions of the nuclei into few layers, which have been then confirmed by calculating natural charges at B and N sites. A good correlation has been seen between the layers of CSI and CSA values and three local structures around boron and nitrogen atoms. The effects of curvature of fullerene structure on chemical shielding (CS) parameters of heterofullerenes have also been investigated by computing CS tensors for curved and relaxed structures of a set of small fragments separated from the heterofullerenes, suggesting high sensitivity of CS parameters to the curvature of fullerene structure.     

A novel LIF-CE method for the separation of hyaluronan- and chondroitin sulfate-derived disaccharides: Application to structural and quantitative analyses of human plasma low- and high-charged chondroitin sulfate isomers

The report describes a rapid and simple CE method using LIF detection for the analysis of unsaturated disaccharides obtained from enzymatic depolymerization of plasma chondroitin sulfate (CS) isomers. The disaccharide reducing groups were labeled with 2-aminoacridone (AMAC). The fluorotagged products can be separated by reversed-polarity CE using a sodium acetate buffer, pH 3.8, in the presence of 0.05% methylcellulose. The choice of the appropriate electrophoretic conditions was performed after a deep analysis of the most important parameters affecting analyte separation. In particular, the effect of both run buffer concentration and pH on resolution, efficiency, migration times, and peak area was evaluated. The selected electrophoretic conditions allowed us to separate the CS isomers-derived Delta-disaccharides in less than 12 min, also resolving the nonsulfated disaccharides released from CS isomers from those released from hyaluronan (HA). Moreover, these conditions gave a good reproducibility of both the migration times (CV%, 0.25) and the peak areas (CV%, 1.4). Intra- and interassay CV were 5.37 and 7.23%, respectively, and analytical recovery was about 86%. The applicability of the above method to the quantitative and structural disaccharide analyses of plasma CS isomers was investigated. Data obtained from 44 healthy human subjects were compared with those obtained by a fluorophore-assisted carbohydrate electrophoresis (FACE) reference assay, by using the Passing and Bablok regression and Bland-Altman tests. The developed method could represent a good tool for an ultrasensitive analysis of CS isomers in biological samples from different sources, particularly when samples are available in very low amounts.     

Dielectric parameters of polystyrene films modified with fullerenes

The frequency dependences of the electrophysical parameters (capacitance, dielectric constant, dielectric loss tangent, and resistivity) of polystyrene films doped with small (up to 1 wt % C₆₀) additions of fullerenes were determined by dielectrometry. The composite materials obtained were concluded to be nonpolar. The dielectric constant as a function of the film composition passes through a minimum at 0.035 wt % C₆₀. The polymer preserves good insulating properties on doping with fullerenes.     

Nonchromatographic "stir and filter approach" (SAFA) for isolating Sc3N@C80 metallofullerenes

Separation difficulties have led to a paucity of purified metallic nitride fullerenes (MNFs). Fundamental research and application development has been hampered with limited sample availability. Separation techniques designed to remove contaminant empty-cage fullerenes (e.g., C(60), C(70)...C(2)(n)) and classical metallofullerenes (e.g., non-MNFs) traditionally require expensive and tedious chromatographic methods. Our motivation is an alternative purification approach to minimize dependence on HPLC. Herein we report the use of cyclopentadienyl (CPD) and amino functionalized silica to selectively bind contaminant fullerenes. This "Stir and Filter Approach" (SAFA) provides purified MNF samples at ambient and reflux conditions. Under reflux conditions, purified MNFs (80% recovery, 41 h) are obtained using CPD silica. However, at room temperature, there is an equilibrium established between fullerenes and CPD silica, and no purified MNF samples are obtained using SAFA. In contrast, purified MNF samples (99+%) are readily obtained at room temperature using amino, diamino, and triamino silica at recoveries of 93% (11 h), 76% (9 h), and 50% (6 h), respectively.