Novel C 60 -Based Building Blocks Derived from C 60 2- Anion (original) (raw)
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C602- Chemistry: C60 Adducts Bearing Two Ester, Carbonyl, or Alcohol Groups
ChemInform, 2003
) ester, ketone) with C 60 2anion give rise to C 60 (CH 2 -A) 2 adducts (major products) along with unexpected methanofullerenes C 60 >CH-A and monosubstituted dihydrofullerenes C 60 (H)(CH 2 -A) (minor products). Methanofullerenes are shown to come from side reactions with X 2 CH-A traces.
Functionalization of C60 via organometallic reagents
Tetrahedron, 2008
The reaction of [60]fullerene with organolithium and Grignard reagents carrying orthoester, acetal or other end groups yielded adducts 3-5 at the 6-6 bond of C60 after quenching with trifluoroacetic acid. The adducts could be easily methylated or benzylated with methyl iodide or benzyl bromide in the presence of potassium tert-butoxide to yield exclusively the 1,4-disubstituted C60 6 and 7a,b. Cleavage of the orthoester, acetal and silylether groups gave the corresponding carboxylic acid 9, aldehydes 10a,b and 11 and alcohols 12 and 13a,b. The carboxylic acid 9 readily reacted with alanine ethyl ester under standard peptide coupling conditions to give 14 in 55% yield. Attempts to generate a silyl enol ether from the reaction of aldehyde 10b with TIPSOTf and triethylamine failed. Instead the reaction led to a cyclized ether 16a (or alcohol 16b in the absence of silylating agent) resulting from the addition of an initially formed fulleride anion to the aldehyde group. The corresponding acetal 4b reacted similarly. The reaction of aldehyde 10b with aniline also gave a cyclized product 19. Surprisingly, aldehyde 11, which no longer carried an acidic fullerene proton reacted with aniline to give a product 20 resulting from an intramolecular Diels-Alder reaction followed by aromatization of a primarily formed N-phenylimine. Alcohol 13b could be readily converted to the corresponding bromide using tetramethyl-a-bromoenamine. The bromide was reacted with the carbanion derived from the protected glycine derivative to yield the diastereomeric fullerene amino acid derivatives 1-benzyl-4-[a-propyl-tert-butylglycinate benzophenone imine] 1,4-dihydro[60]fullerenes 24a and 24b.
International Journal of Mass Spectrometry and Ion Processes, 1996
ABSTRACT Alkylation of C60 in tetrahydrofuran with tert-butyl chloride and lithium gives a variety of products. Adducts of general formula C60Hn(t-Bu)qOx(thf)y (where t-Bu is the tert-butyl group and thf the tetrahydrofuryl group (C4H7O)) have been detected by mass spectrometry, with n ≤ 8, q + y ≤ 18 and x = 0, 1, 2 depending on experimental conditions. IR and NMR spectra of products confirm these assignments.
New Journal of Chemistry, 2003
Functionalized mixed dihydrofullerenes C 60 RH and C 60 RR 0 are easily obtained from reactions between C 60 2À anion and halo derivatives RX and R 0 X. The key step consists in the selective reaction of the intermediate [C 60 R] À ion, as soon as it is formed, with either CF 3 CO 2 H or R 0 X. This process is made possible thanks to the very fast single electron transfer (SET) reaction between C 60 2À and RX. Functionalized dihydrofullerenes C 60 RH thus prepared are also shown to be very good starting compounds for obtaining various C 60 RR 0 derivatives. y Present address:
The Beautiful Molecule: 30 Years of C60 and Its Derivatives
ECS Journal of Solid State Science and Technology, 2017
In 1996 Sir Harold W. Kroto, Robert F. Curl and Richard E. Smalley were honored with the Nobel Prize in Chemistry for the discovery of fullerenes. The advent of these new forms of carbon heralded a race to understand the physical and chemical properties. C 60 is virtually insoluble in polar solvents but is partially soluble in benzene, toluene, and carbon disulfide. This made the processing of fullerenes for new applications fairly problematic. However, the physical and chemical properties of these cage structures may be tailored for a wide range of applications. Some of the difficulties in processing have been overcome by using novel fullerene derivatives. The functionalization of the fullerene core with different chemical moieties provided a vector toward potential applications in drug delivery, optoelectronics, electrochemistry and organic photovoltaics. In this review, we will take a closer look at the features of some of the fullerene derivatives that have reinvigorated the field of fullerene research. Water-soluble polyhydroxylated fullerenes such as fullerenol have demonstrated the potential for good electron transfer and optical transmission, while hydrophobic fullerene derivatives have shown promising avenues for catalytic applications. 2015 marked the 30 th anniversary of the discovery of fullerenes, with celebrations around the world including an event by the Royal Society of Chemistry, bringing together many of Sir Harold Kroto's former students. The event also coincided with the recent discovery of C 60 + in space after a complex twenty-year search. It is with sadness that we, Harry's Research Group at Florida State University, and his international collaborators, reflect on the passing of Sir Harold Kroto. His dedication to science and commitment to science communication through the VEGA Science Trust and the Global Educational Outreach for Science Engineering and Technology (GEOSET) initiative help to raise awareness of the challenges for science in the modern world. We will continue to inspire young students through outreach activities he initiated.
Crucial Role of Alkyl-Substituted Benzenes in the Formation of Intercalate Derivatives of C 60
Materials Science Forum, 2004
Intercalates of C 60 were obtained by a direct synthesis of C 60 solution in xylene, ethylbenzene, n-propylbenzene, n-butylbenzene and terc-butylbenzene with methanol, ethanol and isopropanol, respectively -"guest". Alcohol-solvent system interacts with C 60 and forms binary and ternary isostructure intercalate products. Infrared spectra of all derivatives showed no change compared to the pure C 60 . Binary intercalates are isostructural with the C 60 crystal structure , the same as ternary intercalates synthesized from a saturated solution of C 60 in xylene, n-butylbenzene and terc-butylbenzene. Intercalates do not have stoichiometric relation alcohol : C 60 . The presence of more voluminous solvents (terc-butylbenzene, xylene and n-butylbenzene) in ternary intercalates of C 60 affects the changes in intermolecular space of the C 60 crystal structure as well as the formation of new intermolecular interactions. In all cases of binary and ternary intercalated systems, alkyl-substituted benzene played the role of "donor" of the intercalating agent -"guest" in the C 60 crystal structures.
Arkivoc, 2014
The regioselective synthesis of an e,e,e trisadduct of C 60 via the Diels-Alder reaction with orthoquinodimethanes has been attempted employing the tether-directed remote functionalization approach. Opened-structure tether 10 and macrocyclic tethers 16 and 21 were synthesized for this purpose. The functionalization of C 60 afforded inseparable mixtures of regiomeric trisadducts and the regioselective formation of the e,e,e trisadduct was not feasible even when the more preorganized tethers 16 and 21 were employed. The in situ thermal generation of orthoquinodimethanes from the 1,2-bis(bromomethyl)benzene precursors requires high temperatures and is followed by fast, irreversible cycloaddition with C 60 to afford thermally stable products, which prevents the achievement of high regioselectivities.