Probing the properties of C 60 through fulleroids ABC 61

Abstract

We show that the fulleroid synthesis opens the opportunity to investigate the response of the fulleroid ‘π’ electrons to external magnetic fields. The response is expressed as a general deshielding of protons which are near the surface of the sphere. A more subtle effect is the ‘shielding’ effect experienced by protons which are over certain junctures of the fulleroid. A remarkable consequence of the various deshielding strengths of the spheroid is observable as a quasi shift reagent effect. We also show that the discovery of control over the electron acceptor and donor strength of fulleroids through periconjugation by the use of 9-fluorenyl-derived fulleroids opens further the already large arsenal for fullerene modification into the preparation of more electropositive (electron-donating) and more electronegative (electron-withdrawing) fulleroids by suitable substitution into fluorene and fluorene-like moieties.