Singly Bonded Monoadduct rather than Methanofullerene: Manipulating the Addition Pattern of Trimetallic Nitride Clusterfullerene through One Endohedral Metal Atom Substitution

Abstract

Bingel-Hirsch reactions of trimetallic nitride clusterfullerenes (NCFs) generally yield methanofullerene (cyclopropane) adducts instead of singly bonded derivatives, which have been reported for monometallofullerenes. Herein, we report the synthesis and characterization of the Bingel-Hirsch derivative of a mixed metal nitride clusterfullerene (MMNCF) TiY2 N@Ih -C80 . Surprisingly, in contrast to the reported Bingel-Hirsch cyclopropane adducts of the analogous NCF Y3 N@Ih -C80 , the Bingel-Hirsch derivative of TiY2 N@Ih -C80 is the first singly bonded monoadduct (labeled as TiY2 N@C80 -Mono) to be reported, which was determined unambiguously by single-crystal X-ray crystallography. Besides, the reactivity of TiY2 N@Ih -C80 was found to be significantly improved relative to that of Y3 N@Ih -C80 . Upon substituting one endohedral yttrium (Y) atom of Y3 N@Ih -C80 with titanium (Ti), the Bingel-Hirsch derivative changes from the cyclopropane to the singly bonded monoadduct, revealing that not only the reactivity but also the addition pattern of NCFs can be manipulated simultaneously through one endohedral metal atom substitution.

Keywords: Bingel-Hirsch reaction; cycloaddition; fullerenes; rare earths; structure elucidation.