Authors:Natalia Avramenko, M. Korobov, Aksana Parfenova, P. Dorozhko, Natalia Kiseleva, and P. Dolgov
In an effort to improve
understanding of dissolution behaviour of fullerenes and their simple chemical
derivatives the binary systems of C60, C70
and the piperazine monoadduct of  fullerene C60
with a series of aromatic solvents have been studied by means of DSC. In certain
systems solid solvates have been found to be the thermodynamically stable
phases relative to saturated solution at room temperature. Identified solid
solvates were characterized by their compositions, temperatures and enthalpies
of incongruent melting transitions. The regularities in thermodynamic stability
of the solvated crystals have been discussed along with dissolution properties
of fullerenes and the derivative. Certain correlations have been observed.
The positron density distributions in C60 and K6C60 have been evaluated using the positron lifetime and Doppler-broadening spectroscopy for the annihilation radiation.In C60, positrons are distributed in the interstitial sites between the C60 molecules,which has been demonstrated by measurements of the temperature dependence of the Doppler-broadening of the annihilation radiation. On the other hand, the positron density distribution must be greatly changed in K6C60, because positrons are repelled by Coulomb interactions by the positively charged K atoms. It has been observed that there is an extremely short lifetime and a small Doppler-broadening component for the positron annihilation in K6C60. This component is considered to reflect the positron annihilation inside a C60 molecule.
Authors:Li Yuguo, Zhang Xiaodong, Li Qingnuan, and Li Wenxin
In this paper water-soluble fullerene derivative C60(OH)xOy was radioiodinated with the iodogen method. The labeling yield was determined by radio-TLC. The effects of pH value, reaction time, temperature and amount of the iodogen on the labeling yield were studied. The labeled product was purified by Sephadex G-25 column chromatography and then the stability of 125I-C60(OH)xOy was examined . The results showed that the radiochemical purity of 125I-C60(OH)xOy solution with benzylalcohol remained 82.7% after 43 hours.
Authors:E. Kowalska, P. Byszewski, R. Diduszko, A. Huczko, and J. Mieczkowski
The crystalline solvates containing fullerenes and (di)methylnaphthalenes were investigated by thermal analyses and X-ray
diffraction methods. It was found that C60 with (di)methylnaphthalenes forms two types of stable solvates: either at the molar ratio 1:2 decomposing at temperatures
close to 100C or at 1:1 molar ratio decomposing in the temperature range 120–214C. Crystalline lattice and thermal stability
of the solvates depends on the structure of the solvent molecules. The strong solute-solvent interaction is also manifested
by the modification of the C60 absorption spectra in solution. The results are discussed using semiempirical quantum chemistry methods.
Authors:A. V. Markin, V. A. Ruchenin, N. N. Smirnova, G. V. Markin, S. Yu. Ketkov, V. A. Kuropatov, V. K. Cherkasov, G. A. Abakumov, and G. A. Domrachev
The discovery of the method for producing C60 fullerenes in macroquantities [ 1 ] has laid a new field of research. Thus, different properties of functional fullerene derivatives with valuable characteristics
Authors:P. Byszewski, E. Kowalska, and R. Diduszko
Iron in the fullerite lattice binds fullerences in a sandwich type C60FeC60 complexes. At the concentration C60Fe2 it crystallizes in the monoclinic lattice. The structure is thermally unstable, with the energy release of 606 kJ·mol−1 it returns to fee lattice. Two possible sites in the reconstructed fee lattice are discussed, Fe bond to C60 and Fe inside the C60 cage.
Compositions of the solid solvates of C60 with 1,2-dichlorobenzene and 1,3,5-trimethylbenzene were determined with the help of experimental procedures developed. Possible
correlations between compositions and thermodynamic properties were discussed.
Iron: fullerides were prepared by chemical methodes in the solution using nitric acid as activation agent. Experimental results
of thermal analyses, X-ray diffraction and Mössbauer spectroscopy of the products are presented. To interpret these results,
standard quantum chemistry calculations were used to determine the geometry and charge distribution in Fe:C60 complexes, which might be formed in the reaction.
Authors:Natalia V. Avramenko, E. B. Stukalin, and M. V. Korobov
The binary systems of C60with α-methyl- and α-chloronaphthalene have been studied by means of differential scanning calorimetry. C60was found to form the molecular complex of the van der Waals type with α-methylnaphthalene which melts incongruently below
the boiling point of the solvent at temperature 382.73.0 K. The enthalpy of the desolvation reaction is 14.10.5 kJ mol-1of C60. The molar ratio of fullerene to solvent in the solvate is 1:1.5. In the system C60-α-chloronaphthalene a two-stage incongruent melting process has been observed at temperatures 314.14.6 K and 375.77.4 K
with the enthalpies 8.12.6 kJ mol-1and 11.61.0 kJ mol-1, respectively. The composition of the most solvated phase equilibrated with the saturated solution at room temperature and
below the first of the incongruent melting transitions was determined as 1:1.5. Based on the results obtained the thermodynamic
characteristics of the incongruent melting reactions have been revealed and influence of solvate formation on solubility of
C60has been discussed.
Authors:E. Kowalska, P. Byszewski, Z. Klusek, M. Popławska, and J. Radomska
Molecules that may adopt various stable conformations might be applied to store information. The conformational changes could
be induced by suitable polarized tip of STM. For the STM experiments two types of fullerene:ferrocene cycloadducts (C60:Fn) were selected where ferrocene fragment is bound to C60 at the 6-6 bond by different heterocyclic pentagon rings. According to semiempirical quantum chemistry calculation one of
them may be used to STM observation without any modification, while the second cycloadduct must be exposed to thermal treatment
in order to obtain bistable molecule.