The exchange coupling between the valence electrons of the fullerene cage and the electrons of the N atoms in N@C60^{-1,3}

TL;DR

This study uses MCSCF calculations to analyze the exchange coupling between nitrogen electrons and fullerene cage electrons in N@C60 anions, explaining the absence of EPR signals due to strong coupling.

Contribution

It provides the first detailed computational analysis of exchange coupling in N@C60 anions, highlighting its magnitude and implications.

Findings

Exchange coupling is large compared to hyperfine interaction.

Strong coupling explains missing EPR signals.

Results support understanding of electronic interactions in fullerene complexes.

Abstract

MCSCF calculations are performed in order to determine the exchange coupling between the 2p electrons of the N atom and the LUMOs of the fullerene cage in the case of mono- and tri-anions of N@C60. The exchange coupling resulted by our calculations is large compared to the hyperfine interaction. The strong coupling can explain the missing EPR signal of the nitrogen in paramagnetic anions.