Activation and Functionalization of [60]Fullerene: (Amine)[60]Fullerene as Precursors of Amine-[60]Fullerides

Activation and Functionalization of [60]fullerene: (Amine)[60]fullerene as precursors of amine-[60]fullerides José E. Cortés-Figueroa1* and Shirley M. Alvarado-Rodríguez2 1Organometallic Chemistry Research Laboratory, Department of Chemistry, University of Puerto Rico, Mayaguez , PR 00681-9019 2Department of Chemical Engineering, University of Puerto Rico, Mayaguez, PR 00681 Piperidine reacts with [60]fullerene in aromatic solvents to produce (C60)3(H)3(piperidine)3 (eq 1). The progress of the reactions were followed under conditions where [piperidine] >> [C60] by monitoring the growth of the absorbance at 407 nm. The reactions are first order with respect to [C60] and the order with respect to [piperidine] is complex and dependent on the nature of the solvent. The reactions are biphasic, where the plots of absorbance vs. time consist of two consecutive segments. This behavior suggests two step-wise 1, 4-additions, followed by a 1, 2-addition of piperidine to the spherical surface of [60]fulerene. The [(C60)(H)3(piperidine)3] adduct for the reaction where [piperidine] ? 1 M was characterized by 13C NMR spectrometry, elemental analysis, and infrared spectroscopy in the C=C region. Interestingly when [60]fullerene is coordinated to a transition metal (for example in (?2-C60)M(CO)5, M = Cr, Mo, W), formation of (C60)(piperidine) adducts is not observed. Adduct formation takes place only after [60]fullerene dissociates from the complex. For example, the reactions of (?2-C60)M(CO)5 with piperidine are triphasic. The first segment of the triphasic plot was ascribed to piperidine/[60]fullerene exchange and the second and third segments were assigned to (C60)(piperidine)adduct formation as depicted in equation 2. Keywords: [60]fullerene, Activation, Functionalization (*) Corresponding author E-mail: jose.cortes.figueroa@usa.net