Synthesis of the first completely spin-compatible N@C60 cyclopropane derivatives by carefully tuning the DBU base catalyst†
Abstract
Two cyclopropane derivatives of N@C60 were synthesised by well-controlled Bingel reactions, in which 94% of the spin centres were retained, as confirmed by a series of quantitative electron spin paramagnetic resonance (EPR) measurements. Further study on the influence of the DBU catalyst base revealed a spin loss mechanism through a fullerene–DBU diradical.