Specificity of carbon cages towards oxidation states of metal atoms in metallofullerenes

Abstract

The effect of transmutation of the metallic element encaged in C 82 through β − radioactive decay has been studied for two decay series of 155 Sm→ 155 Eu and 177 Yb→ 177 Lu , and the results were examined in combination with those reported for the decay series of 161 Gd→ 161 Tb . The metallofullerenes containing the β − decay progeny element are chemically stable if its oxidation state remains the same as that of the parent atom, namely, (+3→+3) and (+2→+2), whereas they become unstable if the oxidation state is changed like (+2→+3). This suggests that specific carbon cages can form stable metallofullerenes only with a metal atom of a given oxidation state: carbon cages for metal atoms of +2 oxidation are not the stable cage for atoms of the +3 oxidation state.