C_(60)负离子化学的研究进展

中性的C60是很强的缺电子体,主要和亲核试剂进行化学反应。与之不同的是C60经还原生成负离子后,由缺电子变为富含电子,具有很强的亲核性质,可与亲电试剂进行反应。由于这种电子结构的变化,C60负离子进行的反应从机理至产物均有可能与中性富勒烯不同,从而丰富了富勒烯的反应方式和富勒烯产物的类型。结合我们的工作综述了C60负离子化学的研究进展,对丰富富勒烯化学、扩展富勒烯衍生物的种类及制备方法具有一定意义。

Effects of fullerene solubility on the crystallization of poly(3-hexylthiophene) and performance of photovoltaic devices

The substantial crystallization suppression of poly(3-hexylthiophene) (P3HT) in the untreated P3HT:C60 composite film prepared from o-dichlorobenzene (ODCB) solution has been revealed. Besides, the effective conjugation length of P3HT in this composite has been nearly maintained to that in the solution. The different crystallization behaviors of P3HT in its composites with C60 and [6,6]-phenyl C-61 butyric acid methyl ester (PCBM) are mainly attributed to the relative solubility of C60 and PCBM with respect to P3HT in ODCB. The solution to overcome this disadvantage of chain conformation and crystallinity of P3HT in the composite with C60 is thus proposed and finalized by resorting to the addition of low volatile solvent with much higher solubility of C60 than P3HT into the main solvent used, so as P3HT can crystallize before C60 forms crystallites in the solution. The feasibility of this approach has been proven by the improved efficiency of devices based on composites of P3HT and the low cost C60 without resorting to post-treatments.

Effective enhancement of peroxydisulfate electrochemiluminescence on C-60/DDAB films

Effective enhancement of electrochermluminescence (ECL) of peroxydisulfate on a C-60/didodecyldimethyl ammonium bromide (C-60/DDAB) film coated glassy carbon electrode (GCE) surface is reported in this paper. The C60/DDAB film gave lower cathodic current in the presence of peroxydisulfate than that from a bare GCE. To our surprise, electrochemiluminescent intensity from peroxydisulfate reduction was effectively enhanced on the C60/DDAB film, which was 50 times and 250 times higher than those from a DDAB film coated and bare GCE, respectively. Moreover, the ECL onset potential on the C60/DDAB film was about -0.9 V, which positively shifted 200 mV compared with that from the bare GCE. Dissolved oxygen and the applied potential also affected the electrochemiluminescent intensity. The presence of oxygen decreased the intensity, and the intensity reached maximum at the applied potential of -1.7 V. The unique property will greatly enrich ECL studies and applications based on fullerenes.

环糊精／富勒烯[60]超分子包合物研究进展

以环糊精(cyclodextrin)作为主体与C60形成超分子包合物不仅提高了C60在水中的溶解度,实现了C60分子在生物领域的应用,而且还保持了C60分子的电子结构,使其在温和的条件下可以发生固氮反应,以及对C=C、C=0和N—N+键进行还原。合成环糊精／C60包合物的方法虽然很多,如回流法、搅拌法、固相合成等,但其制备的环糊精／C60包合物多限于使用孔径较大的γ-环糊精分子,而难以实现小孔径环糊精分子,如α-、β-环糊精与C60形成包合物。最近本课题组发展了一种新颖的以C60负离子为客体合成环糊精／C60超分子包合物的方法,可以有效的合成包括小孔径环糊精分子的α-、β-以及γ-环糊精／C60包合物。在总结前人研究的基础上,综述了近年来水溶性环糊精／C60超分子包合物衍生物合成的研究进展。

笼内金属富勒烯的合成与分析

自1985年,Smalleyr等人首次在飞行时间质谱仪中检测到C60以来,富勒烯碳原子族的研究便不断深入,最初发现的激光蒸发含稀土化合物的石墨只能得到微量的金属富勒烯,仅限于质谱检测,直到1990年,Kratschmer等人采用石墨电子弧放电首次得到宏观量的富勒烯,才使得富勒烯研究进入了实质性的研究阶段。富勒烯及其化合物的分子结构确定对于研究这类化合物无疑是非常重要的,红外光谱、核磁共振、X射线衍射、质谱以及电化学方法都是非常重要的手段。在富勒烯研究中,质谱是相当重要的,在80年代中期的富勒烯以及富勒烯衍生物如金属富勒烯多面体都在质谱中首次发现的。电弧法成功地得到富勒烯后,质谱因其灵敏度高、用量少、简便、快速等优点,成为富勒烯化合物物理化学性能研究以及结构表征工具,其中激光解吸电离为软电离技术只给出化合物分子质量而不产生碎片离子,已成为研究富勒烯首选的重要工具。

Highly enhanced luminescence from single-crystalline C-60 center dot 1m-xylene nanorods

Single-crystalline C-60 center dot 1m-xylene nanorods with a hexagonal structure were successfully synthesized by evaporating a C-60 solution in m-xylene at room temperature. The ratio of the length to the diameter of the nanorods can be controlled in the range of approximate to 10 to over 1000 for different applications. The photoluminescence (PL) intensity of the nanorods is about 2 orders of magnitude higher than that for pristine C-60 crystals in air. Both UV and Raman results indicate that there is no charge transfer between C-60 and m-xylene. It was found that the interaction between C-60 and m-xylene molecules is of the van der Waals type. This interaction reduces the icosahedral symmetry of C-60 molecule and induces strong PL from the solvate nanorods.

Photoluminescence of aggregated C-60 in nano-size at room temperature

When the aggregation of C-60 is arranged in mono-dispersed state on the ITO substrate, the photoluminescence (PL) spectra are observed clearly. These emission peaks are attributed to recombination of self - trapped excitons, the zero-phonon exciton (R-0) and its phonon replicas.

Gas-phase ion - Molecule reactions of neutral C-60 with the plasmas of alkyl methyl ethers and primary alcohols

The gas-phase ion-molecule reactions of C-60 with the methoxymethyl ion [CH3O=CH2](+) and the 1-hydroxyethyl ion [CH3CH=OH](+) generated under the self-chemical-ionization (self-CI) conditions of alkyl methyl ethers and primary alcohols were studied in the ion source of a mass spectrometer. The adduct ions [C60C2H5O](+) and protonated molecules [C60H](+) were observed as the major products of C-60 with the plasma of alkyl methyl ethers. On the contrary, the reactions of C-60 With the plasmas of primary alcohols produced few corresponding adduct ions. The AM1 semiempirical molecular orbital calculations were carried out on 14 possible structures. The calculated results showed that the most stable structure among the possible isomers of [C60C2H5O](+) is the [3+2] cycloadduct. According to experimental and theoretical results, the pathway for the formation of the adduct was presented.

Gas-phase ion-molecule reactions of C-60 with methyl ethers CH3OCnH2n+1

Gas-phase ion-molecule reactions of buckminsterfullerene (C-60) with the ion systems generated from the self-chemical-ionization of alkyl methyl ethers(CH3OCnH2n+1, n =2 , 3, 4) were studied in the ion source of a mass spectrometer. The adduct cation [C60C2H5O](+) and protonated molecular ion [C60H](+) were observed as the major products, The former was produced by the reactions.of C-60 with the methoxymethyl ion [CH3O = CH2](+) , the latter corresponded to the proton transfer reactions from the protonated alkyl methyl ethers to C60 It is suggested that the [3+2] cycloadduct is the most favorable structure among the probable isomers with special chemical properties, Our investigation provides the guidance for the synthesis of this compound in condensed phase.

Gas-phase ion-molecule reactions of neutral C-60 with alkyl methyl ethers under chemical ionization conditions

Gas-phase ion-molecule reactions of buckminsterfullerene (C-60) with the ion systems generated from the self-chemical ionization of alkyl methyl ethers (CH3OR, R = n-C2H5, n-C3H7, n-C4H9) were studied in the ion source of a mass spectrometer. The adduct cation [C60C2H5O](+) and protonated molecule [C60H](+) were observed as the major products. The former adduct ion was produced by the reactions of C-60 with the methoxymethyl ion [CH3OCH2](+), and the latter resulted from the proton transfer reactions from protonated alkyl methyl ethers to C-60 It is suggested that the [3+2] cycloadduct to a 6-6 bond of C-60 (a C-C bond common to two annulated six-membered rings) is the most favorable structure among the probable isomers of [C60C2H5O](+). (C) 1998 John Wiley & Sons, Ltd.

C_(60)与甲基醚CH_3OC_nH_(2n+1)的气相离子分子反应研究

自宏观量合成和分离Ｃ６０以来，人们不断地合成各种功能化的Ｃ６０衍生物［１］．在对Ｃ６０化学性质的认识过程中，气相离子化学一直起着十分重要的作用．Ｂｏｈｍｅ等［２］在ＳＩＦＴ质谱仪上，研究了Ｃ６０的单、双、三电荷离子与水、醇、醚、醛、酮、酯和胺等的气相…

Probe beam deflection combined with cyclic voltammetry studies of C-60-modified electrode film

C-60 films, prepared by solution casting, were studied by means of in situ probe beam deflection (PBD) combined with cyclic voltammetry (CV). PBD is a powerful technique for investigation of phenomena at the electrode/electrolyte interface in acetonitrile with quaternary ammonium and alkali metal salts as supporting electrolytes. In tetra-n-butylammonium (TBA(+)) salt solution, a stable CV can be obtained during the first two reduction/reoxidation waves. On reduction, injection of cations to maintain charge balance and dissolution of small amount of C-60(-) (TEA(+)) and/or C-60(2-) (TBA(+))(2) are detected. During the reoxidation process ejection of cations and injection of anions occur simultaneously, especially for the second reoxidation wave. In the case where TBABr is the supporting electrolyte, the accompanied behavior is more complicated than in TBABF(4), TBAClO(4), and TBAPF(6) solutions. A small pair of prewaves in CV are proposed due to oxidation/reduction of C-60 domains but not dissolution/redeposition of C-60 film. Extending the potential scan range to the third reduction wave, no apparent corresponding reoxidation wave is related to the third reduction wave, the electroactivity of the film disappears rapidly and dissolution of C-60 film is observed. In tetraethylammonium (TEA(+)) and NAClO(4) solutions, the electrochemistry of the C-60 films is unstable, and potential scans lead to dissolution of flaking of the film.

Reactions of C-60 with R(3)SnH: A new synthetic route to C-60(RH)(n) and the property of C-60 to catalyze radical reactions

A new method for the preparation of polyalkyl and polyarenefullerene derivatives C-60(RH)(n)(R=Bu,n=1-3; R=Ph,n=1-10) by the reaction of C-60 with organotin hydride in toluene is described. Another series of products of stannanes R(a)Sn(b)H(c) (R=Bu, a=3-8, b=1-4, c=0-3 R=Ph, a=3-11, b=1-5, c=0-4) were also obtained, which shows that C-60 can catalyze polymerization of organic-tin. These products were determined by mass and infrared spectrometry. And the possible reaction mechanisms are discussed.

A study of the radical reaction of C-60 with n-Bu(3)SnH

The reaction of buckministerfullerene (C-60) with tri-n-blltyltin hydride(n-Bu(3)SnH) in toluene solution has been investigated. According to mass spectrometry analysis, the products of above reaction are C-60(BuH)(n)(n = 1 similar to 3) and Bu(x)Sn(y)H(x) (x = 3 similar to 8, y = 1 similar to 4,approximate to = 0 similar to 3). The reaction maybe provide a new method for the synthesis of alkylated fullerene derivatives. Where C-60 also takes a role of a catalysis of organtic-tin polymerization. The radical reaction mechanism has been discussed.

GAS-PHASE ION-MOLECULE REACTIONS OF BUCKMINSTERFULLERENE C-60 WITH SOME SMALL ORGANIC-COMPOUNDS IN MASS-SPECTROMETER

In chemical ionization mass spectrometry (CIMS) gas phase C-60(+) or C-60 can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions. A dozen of gas-phase adduct ions of C-60 are observed, and most of them contain chlorine atoms. The results of the comparison and analysis show that the relative intensities of adductions are not directly proportional to the corresponding fragment ions in the MS of reagents,which implies that some fragment ions containing radicals are more reactive with C-60(+) or C-60. This indicates that the alkene-like C-60(+) or C-60 can act as a radical sponge in addition reactions.