The minor isomers and IR spectrum of [84]fullerene

Abstract

One hundred and fifty four lines have been detected in 120 000 and 50 000 scan 13C NMR spectra of main and tail HPLC fractions, respectively, of [84]fullerene. Five minor isomers are deduced to be present (in ca. 25% and 40% overall yields in the main and tail cuts, respectively), as well as the two main isomers [D2(IV) and D2d(II), which are present in a ratio of ca. 2.25∶1]. A second D2 isomer, which calculations predict to be D2(III), is firmly established as one of the components, and the other isomers are indicated to be: D3d, D6h, Cs(IV), and either Cs(V) or C2(IV). The relative proportions of the isomers differ according to the HPLC fraction, and a partial elution order (Cosmosil Buckyprep/toluene) is D3d/Cs(IV) < D2(III)/D6h. The IR spectrum of [84]fullerene does not correlate well with theoretical predictions.