Энергетический спектр и спектр оптического поглощения эндоэдральных фуллеренов Lu-=SUB=-3-=/SUB=-N@C-=SUB=-80-=/SUB=- и Y-=SUB=-3-=/SUB=-N@C-=SUB=-80-=/SUB=- в модели Хаббарда

Anticommutator Green’s functions and energy spectra of fullerene C80, endohedral fullerenes Lu3N@С80 and Y3N@С80 with the Ih symmetry groups have been obtained in an analytical form within the Hubbard model and static fluctuation approximation. The energy states have been classified using the methods of group theory, and the allowed transitions in the energy spectra of molecules C80, Lu3N@С80 and Y3N@С80have been determined. On the basis of these spectra, an interpretation of experimentally observed optical absorption bands endohedral fullerenes Lu3N@С80 and Y3N@С80.

Methods for the Synthesis of Endohedral Fullerenes

In the present manuscript the authors show the progress recorded regarding the main synthesis methods of metal endo-fullerenes. Shown, that nowadays, the most productive and common method of producing endohedral fullerenes is the electric arc process due to the fact that (a) it is simple enough to introduce atoms into the plasma from solids and gases; (b) its performance is the highest among other methods; (c) gives a wide range of produced types of metallofullerenes in an inert atmosphere-mono-, di-, tri-metalfullerenes, metal carbide clusters, in a reactive atmosphere (N2, NH3)-metal nitride and cyanide clusters, heterofullerenes; (d) provides the greatest energy potential, which is likely to allow the introduction into the cells of fullerene molecules metal atoms with higher ionization energies than titanium (≥7 eV). The yield of metal endofullerenes is substantially higher than the “empty” fullerenes. In this case, the stabilization of both metal atoms and fullerene cells occurs. The quantitative and qualitative output of MEF is significantly affected by: (a) conditions of the process in the reactor: the gas pressure, its flow rate, temperature, amperage; the distance between the electrodes, and others, that is, those factors that determine the plasma temperature and the residence time of the reaction particles in it; (b) the composition of solid additives (salts, oxides, metal alloys) in the graphite anode and their quantitative (mol) ratio with carbon; (c) replacement of the inert atmosphere of the synthesis with the active one (helium-with nitrogen, ammonia, water vapor, CO and other gases).

Density Functional Theory Reactivity Studies on X3N@C80 (X = Sc, Gd, Lu) Fullerenes

Density functional theory studies have been performed to reveal the reactivity of the sites in Sc3N@C80, Gd3N@C80 and Lu3N@C80 endohedral fullerenes. The condensed Fukui functions have been calculated using Mulliken atomic charges. The calculations show that the carbon atom sites are in direct contact with the endohedral cluster favourable nucleophilic attack. Similarly, the carbon atoms which are away from the direct bonding with the cluster are favourable for the electrophilic attack. This is also confirmed from the charge transfer analysis. It is noted that the spin multiplicity decides the reactivity sites and stability of the Gd3N@C80 system. The HOMO-LUMO gap value indicates that Gd3N@C80 with S = 7 is stable than the S = 21 system. Finally, present studies indicate that the charge transfer between the C80 cage and X3N plays a major role to determine the reactivity of the sites in the C80 cage.

Creation of Mo/Tc@C60 and Au@C60 and molecular-dynamics simulations

The formation of Mo, Au-incorporated fullerenes was investigated using radionuclides produced by nuclear reactions and using AIMD simulations. The possibility of the formation of endohedral fullerenes containing Mo/Tc and Au atoms is verified.