CHIRAL NON-RACEMIC C-60 DERIVATIVES - A PROPOSED SECTOR RULE FOR FULLERENE ABSOLUTE-CONFIGURATION

A number of higher fullerenes as well as carbon nanotubes hare been pr edicted to be chiral. Our lab has recently reported the resolution and CD spectra of several enantiomeric C-60 derivatives. It appears that chromatographic resolutions using Whelk-O columns are rather general. Using optically active enones and dienes, non-racemic C-60 adducts cal l also be formed. Recently we have discovered that fullerene CD spectr a appear to arise from a UV band diagnostic For reaction at the C-C bo nd between two six membered rings, the most common site for mono-addit ion. A Cotton effect is observed in tile CD associated with this chrom ophore and allows proposal of a sector rule for fullerene chirality. P reparation of chiral (non-racemic) fullerene adducts of known absolute configuration allows assignment of the sign to each of the sectors. T hese CD bands are due to asymmetric perturbation of an intrinsically s ymmetric chromophore and provide a new tool for a prior determination of absolute configuration. (C) 1996 Elsevier Science Ltd