Pyrrolidine derivatives of N@C-60 have been synthesized and characterized. The photochemical stability of the derivatives as well as pristine N@C-60 are studied and compared. While the attachment of a pyrrolidine group to C-60 cage significantly lowers the photolytic stability of N@C-60, the effect of a peripheral optically active pyrenyl group on photoinduced decay is negligible. A mechanism involving carbon-carbon bond dissociation and a subsequent inversion of the endohedral nitrogen atom is proposed to account for the observed spin loss. (C) 2011 Elsevier B. V. All rights reserved.