Competitive Retro-Cycloaddition Reaction in Fullerene Dimers Connected through Pyrrolidinopyrazolino Rings

• Published in: Journal of organic chemistry 2009-11, Vol.74 (21), p.8174-8180
• Main Authors: Delgado, Juan Luis, Osuna, Sílvia, Bouit, Pierre-Antoine, Martínez-Alvarez, Roberto, Espíldora, Eva, Solà, Miquel, Martín, Nazario
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Materials science; Organic chemistry; Other chromatographic methods; Physics; Preparations and properties; Specific materials
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo901644b

Competitive retro-cycloaddition in [60]- and [70]fullerene homodimers (1a,1c) as well as [60]/[70]heterodimer (1b), linked through 2-pyrazolinopyrrolidino bridges, has been studied by means of HPLC, mass spectrometry, and theoretical calculations at the density functional theory (DFT) level by using the two-layered ONIOM approach. The results of these investigations indicate that the retro-cycloaddition reaction of pyrrolidinofullerenes is favored compared to the retro-cycloaddition reaction of 2-pyrazolinofullerenes in compounds 1a−c. Evidence of the occurrence of this process have been observed both by HPLC and MS-MALDI, these findings being in good agreement with those predicted by theoretical calculations.