Preparation,Structural Determination,and Characterization of Electronic Properties of [5,6]‐ and [6,6]‐Carbosilylated Sc3N@Ih‐C80

Photochemical carbosilylation of Sc₃N@I_h ‐C₈₀ with silirane 1 afforded two corresponding [5,6]‐adducts, 2 and 3 , and a [6,6]‐adduct, 4 . The structural and electronic properties of these products were characterized by means of spectroscopic, electrochemical, and theoretical methods. The structure of 2 was disclosed by means of single‐crystal X‐ray crystallographic analysis. Thermal isomerization of 3 to 2 was observed, whereas that of 2 to 3 proceeded less efficiently at 100 °C. Upon heating under the same conditions, adduct 4 underwent facile decomposition to afford Sc₃N@I_h ‐C₈₀, or isomerized into small amounts of 2 and 3 . The relative stabilities of 2 , 3 , and 4 were rationalized through the results of theoretical calculations. In contrast, adducts 2 , 3 , and 4 were stable under the photolytic conditions employed for carbosilylation. The photochemical functionalization of Sc₃N@I_h ‐C₈₀ represents a convenient synthetic method to obtain thermally labile fullerene‐based products.