COMPUTATIONAL EVIDENCE FOR A NEW C-84 ISOMER

Endohedral chemical shifts of all isolated pentagon isomers of C-76 an d C-78, as well as those of the most stable isolated pentagon isomers of C-84, have been computed at the GIAO-SCF/DZP level using DFT optimi zed geometries (Becke88-Perdew86/3-21G). The theoretical data support tentative assignments of recent experimental delta(He-3) NMR data to t he major components in a partly separated, He-3 labeled mixture. The i dentification of at least one new fullerene isomer, C-84-D-2d(4), is s uggested, based on the endohedral chemical shift of - 25.0 ppm (calc.) versus - 24.4 ppm (erp.).