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Fullerene Core (fullerene + core)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Sugar Balls: Synthesis and Supramolecular Assembly of [60]Fullerene Glycoconjugates

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2007
Haruhito Kato
Abstract The synthesis and characterization of fully deprotected C60 glycoconjugates 4 and 17 is reported. Bis(,- D -mannopyranosyl)malonamide 4 was obtained by using nucleophilic cyclopropanation chemistry, which in general is a very versatile method for fullerene functionalization. Fullerene sugar 17 contains two dendritic ,- D -mannopyranosides that are connected through two adjacent imino bridges to the all-carbon framework. In this adduct-type of C60, which represents a 1,9-dihydro-1a-aza-1(2)a-homo(C60 - Ih)[5,6]fullerene derivative, the entire 60-,-electron system of the fullerene core is retained. This architecture allows the basic cleavage of the acetyl protection groups of precursor adduct 16 without destruction of the core structure of the fullerene sugar. Dendritic glycoconjugate 17 containing six deprotected sugar building blocks is very soluble in water. The amphiphilic nature of 17 with its cone-shaped structure forces the formation of small supramolecular aggregates in aqueous solutions to shield the hydrophobic fullerene units from the water subphase. DOSY NMR spectroscopy and TEM investigation reveal micellar sugar balls with an extremely narrow size distribution of around 4 nm.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

Chiral Ruthenium,Allenylidene Complexes That Bear a Fullerene Cyclopentadienyl Ligand: Synthesis, Characterization, and Remote Chirality Transfer

CHEMISTRY - AN ASIAN JOURNAL, Issue 3 2007
Yu-Wu Zhong Dr.
Abstract Ruthenium complexes that bear both a fullerene and an allenylidene ligand, [Ru(C60Me5)((R)-prophos)=CCCR1R2]PF6 (prophos=1,2-bis(diphenylphosphanyl)propane), were prepared by the reaction of [Ru(C60Me5)Cl((R)-prophos)] and a propargyl alcohol in better than 90,% yields, and characterized by 1H, 13C, and 31P,NMR, IR, and UV/Vis/NIR spectroscopy and MS. Cyclic voltammograms of these complexes showed one reversible or irreversible reduction wave due to the allenylidene part, and two reversible reduction waves due to the fullerene core. Nucleophilic addition of RMgBr or RLi proceeded regioselectively at the distal carbon atom of the allenylidene array. The reaction took place with a 60:40,95:5 level of diastereoselectivity with respect to the original chirality in the (R)-prophos ligand, which is located six atoms away from the electrophilic carbon center. [source]

Gene Delivery by Aminofullerenes: Structural Requirements for Efficient Transfection

CHEMISTRY - AN ASIAN JOURNAL, Issue 1-2 2006
Hiroyuki Isobe Dr.
Abstract A series of aminofullerenes that share a common structural motif have been synthesized and subjected to a systematic investigation of structure activity relationship regarding their ability for transient transfection and cytotoxicity. DNA-binding tests indicated that any water-soluble fullerene-bearing amino group would bind to double-stranded DNA. For these molecules to be effective transfection reagents, however, they require additional structural features. First, the molecule must be capable of producing submicrometer-sized fullerene/DNA aggregates that can be internalized into mammalian cells through endocytosis. Second, the molecule must be capable of releasing DNA as the aggregates are transferred into the cytoplasm. This can be achieved in at least two ways: by loss of the DNA-binding amino groups from the fullerene core, and by transformation of the amino groups to neutral groups such as amides. The screening experiments led us to identify the best reagent, a tetrapiperidinofullerene, that can be synthesized in two steps from fullerene, piperazine, and molecular oxygen, and that is more efficient at transfection than a commonly used lipid-based transfection reagent. [source]

Synthesis, Characterization, and Electrochemical Properties of Novel Transition Metal,Fullerene Complexes Containing Di- and Tetraphosphane Ligands

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2006
Li-Cheng Song
Abstract This paper reports the synthesis, characterization, and some properties of transition metal,fullerene complexes containing trans -1,1,-bis(diphenylphosphanyl)ethylene (dppet, trans -Ph2PCH=CHPPh2) and N,N,N,,N,-tetra(diphenylphosphanylmethyl)ethylene diamine (dppeda, [(Ph2PCH2)2NCH2]2), including [(,2 -C60M)(dppet)2] (M = Pt 1, Pd 2), [(,2 -C60M)(dppet)]2 (M = Pt 3, Pd 4), [(,2 -C60Pd)(,2 -C60Pt)(dppet)2](5), [(,2 -C60Pd)(,2 -C70Pd)(dppet)2] (6), [(,2 -C70Pd)(dppet)]2 (7), [(,2 -C60M)(dppeda)] (M = Pt 8, Pd 9), and [(,2 -C60M)2(dppeda)] (M = Pt 10, Pd 11). Interestingly, while complexes 1, 2, 8, and 9 are the first examples of metallacyclopropafullerene diphosphane ligands containing fullerene cores, complexes 3,7, 10, and 11 are the first group 10 metal-containing, dumbbell-shaped bisfullerenes. All the complexes 1,11 were characterized by elemental analysis, spectroscopy, and, particularly for 4 and 5, by X-ray crystallography and cyclic voltammetry. Pathways for the formation of 1,11 are suggested. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]