Spin dynamics of tri-addition endohedral nitrogen fullerene with transversal chemical functionalization

Abstract

Endohedral nitrogen fullerenes are ideal spin-carrier molecules, possessing both internal spin inertia for ultra-long coherence times and external chemical activity for facile modifications. Using the multifunctionality of the fullerene [6,6] bonds, we synthesized two trans-3 tris-addition endohedral nitrogen fullerene cyclopropane derivatives via well-controlled Bingel reactions. Compared to previous axial additions, the transversal modification of the fullerene provides an extensible approach for constructing two-dimensional spin assemblies in the future. Their molecular structure and spin properties were characterized using nuclear magnetic resonance and electron paramagnetic resonance, respectively. The tris-adducts in the D₃ point group showed well-resolved zero-field splitting effects of the ⁴S_3/2 spin system. Spin relaxation time measurements and nutation experiments proved the microsecond coherence time and energy level addressability of these derivatives.