Estimation of Absolute Spin Counts in Nitronyl Nitroxide-Bearing Graphene Nanoribbons

The degrees of spin labeling of a polyphenylene-based polymer and its graphitized derivative with a stable nitronyl nitroxide were evaluated by estimating the absolute numbers of spins in a set of samples using continuous wave (CW) electron spin resonance (ESR). For these particular systems, the degrees of spin labeling were found to be approximately 0.8% and 1.3%, respectively. The developed procedure complements the more advanced time-resolved/cryogenic ESR studies on these systems by focusing on the stable spin labels introduced in these magnetically intricate materials and providing an estimate of their absolute amount, which is indispensable in the development of synthetic approaches to prepare modified graphene systems and for evaluating the success of these systems. View Full-Tex