[en] The endohedral metallofullerenols Me@C_2_n(OH)_3_8_–_4_0 + C_2_n(OH)_3_8_–_4_0 (Me = Tb, Sc, Gd, Fe, Pr, Mo) have been obtained and their radiation resistance under irradiation by a neutron flux of 8 × 10"1"3 cm"–"2 s"–"1 has been studied. The factors affecting the radiation resistance of endohedral metallofullerenols are discussed.

[en] The parameters of an electric-arc facility for the synthesis of fullerenes and endohedral metallofullerenes are optimized. The resistance of C_6_0 and C_7_0 fullerenes and C_6_0(OH)_3_0 and C_7_0(OH)_3_0 fullerenols against neutron irradiation is studied. It is established that the radiation resistance of the fullerenes is higher than that of the fullerenols, but the radiation resistance of the Gd@C_2_n endometallofullerenes is lower than that of the corresponding Gd@C_2_n(OH)_3_8 fullerenols. The radiation resistance of mixtures of Me@C_2_n(OH)_3_8 (Me = Gd, Tb, Sc, Fe, and Pr) endometallofullerenes with C_6_0(OH)_3_0 is determined. The factors affecting the radiation resistance of the fullerenes and fullerenols are discussed.

[en] Endohedral lanthanide metallofullerenes and their water-soluble biocompatible derivatives have been synthesized. The effect that fast-neutron irradiation has on the stability and nuclear physical properties of endohedral metallofullerenes that are used as magnetocontrast materials (⁴⁶Sc, ¹⁴⁰La, ¹⁴¹Nd, ¹⁵³Sm, ¹⁵²Eu, ¹⁵⁴Eu, ¹⁵³Sm, ¹⁶⁰Tb, ¹⁶⁹Yb, ¹⁷⁰Tm (isomers I and III), and ¹⁷⁷Lu) is studied. Our hypothesis, according to which carbon-shell relaxation is based on the fast nonradiative processes of an electron shake-off type, is confirmed.

[en] Endohedral metallofullerenes Me@C_2n (n = 30–50), their hydroxylated derivatives Me@C_2n(OH)_38–40 (Me = Tm, Ho, Eu, Sm, Co), and fullerenol С₆₀(OH)₃₈ have been synthesized The radiation resistance of these structures under irradiation in reactor by thermal and fast neutron fluxes in the fluence range of 1018–1019 cm^–2 (cadmium ratio of ~10) has been analyzed. Endofullerenols are shown to be more stable in comparison with initial endohedral fullerenes; the molecules containing Eu and Sm (atoms characterized by the largest slow-neutron absorption cross section) turned out to be most stable. The mechanism of the formation of secondary Eu and Sm endofullerenols is discussed taking into account the neutron capture and emission of γ quanta by excited nuclei, which acquire the recoil energy.

[en] The nuclear magnetic resonance (NMR)-relaxation characteristics of protons in pure aqueous and buffer solutions of highly hydroxylated endofullerenols with paramagnetic gadolinium ions at ambient temperature have been studied. These systems were thoroughly characterized by SANS and examined by NMR at various resonance frequencies: f = 2 kHz–500 MHz. In all the cases, we have discovered much higher longitudinal and transversal relaxation rates as compared to the reference salt solutions with Gd⁺³ ions in the same range of concentrations (0.1–10.0 mM/l). We suppose that this effect is due to the fact that the objects studied reveal well-manifested abilities to the self-assembly in acidic conditions. As a result, the transversal relaxation rate (1/T₂) increases greatly, and also the longitudinal relaxation rate (1/T₁) demonstrates a broad maximum at resonant frequencies f ~ 20–100 MHz that are determined by the time of fullerenol diffusive rotations. The relaxation rates, which increase linearly with fullerenol content (0.1–10.0 mM/l), testify the stable assembly. The studied features of fullerenol assembly and its strong influence on the proton relaxation make it possible to suppose good prospects of these metal–carbon structures for biomedical applications, in particular, as contrast agents in MRI.