Abstrakt
Relative populations of three energy-lowest IPR (isolated-pentagon-rule) isomers of Eu@C-88 are computed using the Gibbs energy based on characteristics from density functional theory and MP2 calculations (M06-2X/3-21GTILDE OPERATOR+D91SDD entropy term, and the MP2=FU/6-31G*TILDE OPERATOR+D91SDD or B2PLYPD=FU/6-31 + G*TILDE OPERATOR+D91SDD energetics). The calculations predict coexistence of three isomers, in agreement with extraction using a polar solvent, and offer a possible explanation why the Eu@C (2)(27)-C(88) species should prevail with a non-polar solvent.
Role of extraction solvents and catalysis is thus pointed out.