Bis adducts of the Prato reaction with gadolinium-fullerenes

The structures of two bis-ethylpyrrolidinoadducts of Gd3N@Ih-C80, obtained by regioselective 1,3-dipolar cycloadditions, were elucidated by single crystal X-ray, visible-near infrared (vis-NIR) spectra, studies on their thermal isomerization, and theoretical calculations. The structure of the minor-bis-adduct reveals a C2-symmetric carbon cage with [6,6][6,6]-addition sites and with an endohedral Gd3N cluster that is completely flattened. This is the first example of a crystal structure of Gd3N@Ih-C80 derivatives. The structure of the major-bis-adduct was inferred by the vis-NIR spectrum being corresponded to the structure of a previously reported major-bis-adduct of Y3N@Ih-C80 known to have an asymmetric [6,6][6,6]-structure. Based on experimental results showing that the minor-bis-adduct of Gd3N@Ih-C80isomerized to the major-adduct, a possible second addition site was elucidated with support from density functional theory calculations. It was published recently in Journal of the American Chemical Society.

O. Semivrazhskaya, A. Romero-Rivera, S. Aroua, S.I. Troyanov, M. Garcia-Borràs, S. Stevenson, S. Osuna, and Y. Yamakoshi
“Structures of Gd3 N@C80 Prato Bis-Adducts: Crystal Structure, Thermal Isomerization, and Computational Study”
J. Am. Chem. Soc. 2019, 141, 10988-10993 [abstract]
DOI: 10.1021/jacs.9b05603