title: Covalently Bound Nitroxyl Radicals in an Organic Framework.
abstract: A series of covalent organic framework (COF) structures is synthesized that possesses a tunable density of covalently bound nitroxyl radicals within the COF pores. The highest density of organic radicals produces an electron paramagnetic resonance (EPR) signal that suggests the majority of radicals strongly interact with other radicals, whereas for smaller loadings the EPR signals indicate the radicals are primarily isolated but with restricted motion. The dielectric loss as determined from microwave absorption of the framework structures compared with an amorphous control suggests that free motion of the radicals is inhibited when more than 25% of available sites are occupied. The ability to tune the mode of radical interactions and the subsequent effect on redox, electrical, and optical characteristics in a porous framework may lead to a class of structures with properties ideal for photoelectrochemistry or energy storage.
authors: National Renewable Energy Laboratory , 15013 Denver West Pkwy, Golden, Colorado 80401, United States.
authors: Barbara K
authors: BK
authors: Hughes
authors: National Renewable Energy Laboratory , 15013 Denver West Pkwy, Golden, Colorado 80401, United States.
authors: Wade A
authors: WA
authors: Braunecker
authors: National Renewable Energy Laboratory , 15013 Denver West Pkwy, Golden, Colorado 80401, United States.
authors: David C
authors: DC
authors: Bobela
authors: National Renewable Energy Laboratory , 15013 Denver West Pkwy, Golden, Colorado 80401, United States.
authors: Sanjini U
authors: SU
authors: Nanayakkara
authors: National Renewable Energy Laboratory , 15013 Denver West Pkwy, Golden, Colorado 80401, United States.|Renewable and Sustainable Energy Institute, University of Colorado , Boulder, Colorado 80309, United States.
authors: Obadiah G
authors: OG
authors: Reid
authors: National Renewable Energy Laboratory , 15013 Denver West Pkwy, Golden, Colorado 80401, United States.
authors: Justin C
authors: JC
authors: Johnson