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 D_2d(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: D_3d, D_6h, C_s(IV), and either C_s(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 D_3d/C_s(IV) < D₂(III)/D_6h. The IR spectrum of [84]fullerene does not correlate well with theoretical predictions.