Polar and tropical regioisomeric decanuclear cuprofullerenes

Abstract

Achieving exohedral metallofullerenes (ExMFs) with metal atoms selectively binding at specific spatial positions on the surface of a C₆₀ molecule remains a considerable challenge. In this study, we report the synthesis of two decanuclear, regioisomeric cuprofullerenes with polar and tropical coordination patterns. Complex 1 features 10 Cu^I atoms coordinated to the CC bonds of two polar zones, stabilized by Cl⁻ anions and protonated 4-methoxybenzylamine countercations. Complex 2 involves coordination of 10 Cu^I atoms in the tropical zone, utilizing trifluoroacetate (L_F) and 5-methylpicolinate (L_mpic) as auxiliary ligands. Notably, complex 2 forms a typical pcu topology MOF, linking tropical cuprofullerenes through Cu^II(L_mpic)₂ units. Theoretical calculations reveal intricate charge transfer processes that significantly influence the electronic properties of these cuprofullerenes.