In the present study, we report the systematic investigation of the effect of chemical oxidation on the structure of single-walled carbon nanotubes (SWNTs) by using different oxidants. The oxidation procedure was characterized by using infrared spectroscopy and transmission electron microscopy (TEM). The SWNTs were produced by chemical vapor deposition (CVD) and oxidized with three kinds of oxidants:  (1) nitric acid (2.6 M), (2) a mixture of concentrated sulfuric acid (98 wt %) and concentrated nitric acid (16 M) (v/v = 3/1) and (3) KMnO4. The results reveal that the different functional groups can be introduced when the SWNTs are treated with different oxidants. Refluxing in dilute nitric acid can be considered as a mild oxidation for SWNTs, introducing the carboxylic acid groups only at those initial defects that already exist. The abundance of the carboxylic acid groups generated with this oxidant remained constant along with the treating time. In contrast, sonication of SWNTs in H2SO4/HNO3 increased ...

Effect of Chemical Oxidation on the Structure of Single-Walled Carbon Nanotubes

Regarding the activation of chemical reactions, today’s chemist is used to thinking in terms of thermochemistry, electrochemistry, and photochemistry, which is reflected in the organization and content of the standard physical chemistry textbooks. The fourth way of chemical activation, mechanochemistry, is usually less well-known. The purpose of the present review is to give a survey of the classical works in mechanochemistry and put the key mechanochemical phenomena into perspective with recent results from atomic force microscopy and quantum molecular dynamics simulations. A detailed historical account on the development of mechanochemistry, with an emphasis on the mechanochemistry of solids, was recently given by Boldyrev and Tkáčová.1 The first written document of a mechanochemical reaction is found in a book by Theophrastus of Ephesus (371-286 B.C.), a student of Aristotle, “De Lapidibus” or “On stones”. If native cinnabar is rubbed in a brass mortar with a brass pestle in the presence of vinegar, metallic mercury is obtained. The mechanochemical reduction probably follows the reaction:1-3 * To whom correspondence should be addressed. Telephone: ++49-89-289-13417. Fax: ++49-89-289-13416. E-mail: martin.beyer@ch.tum.de (M.K.B.); Telephone: ++49-89-12651417. Fax: ++49-89-1265-1480. E-mail: clausen-schaumann@ fhm.edu (H.C.-S.). † Technische Universität München. ‡ Institut für Strahlenschutz. § Current address: Munich University of Applied Sciences. HgS + Cu f Hg + CuS (1) Volume 105, Number 8

http://depa.fquim.unam.mx/amyd/archivero/MECANOQUIMICA_3426.pdf

Mechanochemistry: the mechanical activation of covalent bonds.

http://www.crystallography.ru/MA/articles/!Self-sustaining_Takacs2002.pdf

Self-sustaining reactions induced by ball milling

The covalent functionalization of C 60 has developed vigorously over the past 5 years. Several methods are now available for the formation of C 60 monoadducts. Regioselective formation of multiple adducts has allowed study of the changes in chemical and physical properties that occur when the conjugated fullerene chromophore is reduced during an increase in functionalization. The systematic development of covalent fullerene chemistry provides an unprecedented diversity of tailor-made three-dimensional building blocks for technologically interesting materials.

http://science.sciencemag.org/content/sci/271/5247/317.full.pdf

Covalent Fullerene Chemistry

In spite of their importance in fundamental and applied studies, the preparation of endohedral fullerenes has relied on difficult-to-control physical methods. We report a four-step organic reaction that completely closes a 13-membered ring orifice of an open-cage fullerene. This process can be used to synthesize a fullerene C60 encapsulating molecular hydrogen, which can be isolated as a pure product. This molecular surgical method should make possible the preparation of a series of C60 fullerenes, encapsulating either small atoms or molecules, that are not accessible by conventional physical methods.

https://science.sciencemag.org/content/sci/307/5707/238.full.pdf

Encapsulation of Molecular Hydrogen in Fullerene C60 by Organic Synthesis

The bulk synthesis of the [2 + 2] dimer of fullerene C60 was achieved by the solid-state mechanochemical reaction of C60 with KCN by the use of a high-speed vibration milling (HSVM) technique. This reaction took place also by the use of potassium salts such as K2CO3 and CH3CO2K, metals such as Li, Na, K, Mg, Al, and Zn, and organic bases such as 4-(dimethylamino)- and 4-aminopyridine. Under optimum conditions, the reaction afforded only the dimer C120 and unchanged C60 in a ratio of about 3:7 (by weight) regardless of the reagent used. The dimer C120 was fully characterized by IR, UV−vis, 13C NMR, and TOF MS spectroscopies, cyclic voltammetry, and differential scanning calorimetry. Comparison of the IR and 13C NMR spectral data of C120 with those reported for all-carbon C60 polymers implied that the [2 + 2] dimer C120 represents the essential subunit of these polymers. The dimer C120 underwent facile dissociation into two C60 molecules by heat, HSVM treatment, exposure to room light, or electrochemical re...

Mechanochemical Synthesis and Characterization of the Fullerene Dimer C120

The high electron affinity of fullerene (C{sub 60}) suggests that this important structure is a framework of highly stabilized carbanions. Recent studies of the controlled addition of organolithium and Grignard reagents to C{sub 60} demonstrated the formation of monosubstituted fulleride ions (RC{sub 60}{sup {minus}}) in high yields. Their regiospecific protonation to form 1-R-1,2-dihydrofullerenes as thermodynamically-controlled products has suggested that stepwise introduction of two different alkyl groups into distinct positions of the C{sub 60} framework can be achieved by using RC{sub 60}{sup {minus}} as a nucleophile. The reported high stability of t-BuC{sub 60}{sup {minus}} (1{sup {minus}}) toward electrophiles prompted the authors to synthesize new ionically-dissociative hydrocarbons by the carbocation-carbanion coordination of 1{sup {minus}} and highly stabilized hydrocarbon cations. Here, the authors report the synthesis of a disubstituted dihydro-fullerene 3 in isomerically pure form by the reaction of tert-butylfulleride ion (1{sup {minus}}), generated by deprotonation of t-BuC{sub 60}H, with 1,4-dicyclopropyltropylium ion (2{sup +}) and its reversible heterolysis to regenerate 1{sup {minus}} and 2{sup +} in highly polar solvents.

Regiospecific Coordination of tert-Butylfulleride Ion and 1,4-Dicyclopropyltropylium Ion. Synthesis of a Dialkyldihydrofullerene Having a Heterolytically Dissociative Carbon-Carbon .sigma. Bond

1,1′,2,2′-Tetrahydrobi[60]fulleren-1-yl C120H2 (9) and bis(1,2-dihydro[60]fulleren-1-yl)acetylene C122H2 (11) were prepared, and their structures were determined based on 1H and 13C NMR, MS, and UV–VIS spectroscopies. While the deprotonation of C120H2 with t-BuOK caused dissociation and resulted in the formation of the radical anion C60˙–, the generation of dianion C1222– (122–) from C122H2 (11) was confirmed by visible–near-IR and 13C NMR spectroscopies. The electrochemical studies indicated that dianion C1222– (122–) was formed also during the reduction process of C122H2 (11). The oxidation process of the dianion 122– was found to be irreversible suggesting that the radical species produced undergoes rapid coupling.

Synthesis of the singly bonded fullerene dimer C120H2 and the difullerenylacetylene C122H2, and generation of the all-carbon dianion C1222–

Ionically Dissociative hydrocarbons Containing the C60 Skeleton

The solid-state mechanochemical reaction of fullerene C60 by the use of a high-speed vibration milling technique has been applied to the nucleophilic addition of an organozinc reagent to C60, [4+2] cycloaddition of C60 with condensed aromatic hydrocarbons, 1,3-dipolar addition of C60 with organic azides, and dimerization of C60

Toru Tanaka

Papers

Mechanochemical Synthesis and Characterization of the Fullerene Dimer C120

Regiospecific Coordination of tert-Butylfulleride Ion and 1,4-Dicyclopropyltropylium Ion. Synthesis of a Dialkyldihydrofullerene Having a Heterolytically Dissociative Carbon-Carbon .sigma. Bond

Synthesis of the singly bonded fullerene dimer C120H2 and the difullerenylacetylene C122H2, and generation of the all-carbon dianion C1222–

Ionically Dissociative hydrocarbons Containing the C60 Skeleton

The Solid-State Mechanochemical Reaction of Fullerene C60