Highly Regioselective Derivatization of Tri metal lie Nitride Templated Endohedral Metallofullerenes via a Facile Photochemical Reaction

摘要

Photophemically generated benzyl radicals react with Sc3N@Cao-lh to produce a dibenzyl adduct Sc3N@C8o(CH2C6H5)2 in 82 yield and high regioselectivity, The adduct's 1H spectrum revealed high symmetry: only one AB pattern was observed for the methylene protons. The 13C NMR spectrum suggested a C2-symmetrical structure. DFT calculations reveal that a 1,4-adduct is more favorable than a 1,2-adduct by >10 kcal/mol. The 1,4-structure on 566 ring junctions was unambiguously confirmed by X-ray crystallographic analysis UV-vis spectra revealed that the removal of two p orbitals from the n system of the cage together with the benzylic substituents change the electronic properties of the metallofullerene in a manner similar to those reported for disilirane and trifluoromethyl moieties.