Synthesizing 1,23‑C60 Adducts with Improved Efficiency: A Type of Stable and Highly Soluble C60 Derivatives

In addition to the 1,9- and 1,7-C60 adducts, the 1,23-C60 adducts are an important type of C60 derivatives, where the property of the fullerene compounds is significantly affected by the addition pattern. However, much less is known on the adducts due to the less availability of the compounds. Herein, the hydroxide-promoted reactions of C60 with 2-alkylmalonates are reported, which produce the 1,23-C60 adducts with improved efficiency. The reactions were studied with the in situ vis–NIR spectral measurement in order to probe into the reaction mechanism. The obtained 1,23-C60 adducts exhibited good thermal stability and better solubility with respect to the 1,7-isomers.