N@C₆₀–Porphyrin: A Dyad of Two Radical Centers

Abstract

Dyads of endohedral nitrogen fullerene and porphyrin have been synthesized. In the two-radical-center dyad, the copper­(II) tetraphenylporphyrin suppressed the electron spin resonance (ESR) signal of N@C₆₀ through intramolecular dipolar coupling with a strength of 27.0 MHz. Demetalation of the metalloporphyrin moiety of the dyad, which effectively turned the two-radical-center dyad into a single-radical-center dyad, recovered 82% of the ESR signal of N@C₆₀. Such mechanism of switching a spin state on and off could find use in molecular spintronics applications