KCS

Radicals play important roles in chemical and biological reactions. However, certain radical species are unstable and highly reactive due to the unpaired electron. One of the general methods for stabilizing the radicals is to delocalize the unpaired electron by N-heterocyclic carbenes (NHCs). For instances, the Bertrand group has demonstrated successfully a phosphinyl radical stabilized by imidazolin-2-iminato. However, a triazenyl radical, an analogue of the phosphinyl radical, has not been demonstrated to date. Herein, we report synthesis of the triazenyl radical stabilized by 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr). The radical, IPr₂N₃, was fully characterized by single-crystal X-ray analysis and electron paramagnetic resonance (EPR) spectroscopy in addition to hydrogen-atom abstraction reactivity.