An isoindoline EPR label: 5-acetamido-1,1,3,3-tetramethylisoindolin-2-yloxyl
Abstract
The crystal structure of the isoindoline nitroxide amide 5-acetamido-1,1,3,3-tetramethylisoindolin-2-yloxyl, C14H19N2O2, which has utility as an EPR label, shows a characteristically stable tetramethyl-substituted nitroxide ring system which is essentially coplanar with the amide side-chain substituent. A single intermolecular hydrogen bond between the amide H atom and the nitroxide O atom links the molecules head-to-tail into an infinite polymeric chain.