A new, simple, and rapid photochemical reaction of o‐phthalaldehyde with C60 has been disclosed. This reaction afforded exclusively the unanticipated C60‐phthalide derivative 11 in good yield. The formation of this product is consistent with the intervention of a key free‐radical intermediate –a benzylic radical– in the course of the reaction. The structure of 11 has been determined by the combined use of experimental and theoretical NMR studies. In the course of this study we further disclosed a new mode of radical reactivity of C60 with a series of substituted phthalides (2, 15–17) catalyzed by tetrabutylammonium decatungstate.

Although the functionalization and modification of single‐walled carbon nanotubes (SWCNTs) has been advanced for two decades, their chemical transformation via catalytic processes has yet to be explored and further facilitate their industrial utility. Here, the decatungstate‐photocatalyzed acylation is described of semiconducting (7,6)SWCNTs and the scope of the reaction is investigated by employing alkyl, aromatic, and organometallic aldehydes. The success of the methodology is confirmed by diverse spectroscopic, thermal, microscopy imaging, and redox techniques. The developed catalytic process for the functionalization of SWCNTs is environmetal friendly, since the catalyst and unreacted aldehydes can be recovered and reused, while the modified SWCNTs can be easily isolated and purified by membrane filtration. It is believed that the current findings will open new avenues for the catalytic functionalization of SWCNTs and the approach is intended to extend for modifying 2D nanomaterials.

A new, one step functionalization of C60 with lactones has been developed. This photochemical approach utilizes a variety of lactonyl radicals deriving from lactones through a hydrogen atom abstraction process mediated by tetrabutylammonium decatungstate [(n-Bu4N)4W10O32]. This reaction provides access to a previously unknown class of materials, namely 1-lactonyl-2-hydro[60]­fullerenes. A mechanism for this new reaction has been proposed based mainly on the structure of reaction products and deuterium-incorporated experiments.

An innovative, efficient, regioselective functionalization of C60 with 9H‐fluorenes has been disclosed. This efficient photochemical approach uses certain fluorenyl radicals in 9‐position deriving from fluorenes through a hydrogen‐atom transfer (HAT) process mediated by tetrabutylammoniumdecatungstate [(n‐Bu4N)4W10O32]. The single addition of these fluorenyl radicals to C60 proceeded to produce [60]fullerene‐fluorene dyads in a single step. The scope and mechanism of this new reaction have been examined. The primary kinetic isotope effect measurements signify the presence of a stepwise mechanism in which the C−H (D) bond scission is the rate‐limiting step of the reaction.

Photoexcited o‐alkyl‐substituted benzaldehydes add to C60through their photoenol reactive intermediates producing stable [4 + 2] fullerene adducts. A mechanistic approach for this reactivity of C60 is provided, based mainly on intra‐ and intermolecular kinetic isotope effects (KIEs) studies. It is demonstrated that the rotation of Caromatic–Ccarbonyl single bond in the excited triplet state of o‐alkyl carbonyl compounds, is the rate‐determining step (rds), whereas C‐H(D) bond scission during the photoenolization step, occurs relatively fast.