@article{8b02817846b942aba75e4c0eaadfe95b,
title = "Persistent, highly localized, and tunable [4]helicene radicals",
abstract = "Persistent organic radicals have gained considerable attention in the fields of catalysis and materials science. In particular, helical molecules are of great interest for the development and application of novel organic radicals in optoelectronic and spintronic materials. Here we report the syntheses of easily tunable and stable neutral quinolinoacridine radicals under anaerobic conditions by chemical reduction of their quinolinoacridinium cation analogs. The structures of these [4]helicene radicals were determined by X-ray crystallography. Density functional theory (DFT) calculations, supported by electron paramagnetic resonance (EPR) measurements, indicate that over 40% of spin density is located at the central carbon of our [4]helicene radicals regardless of their structural modifications. The localization of the charge promotes a reversible oxidation to the cation upon exposure to air. This unusual reactivity toward molecular oxygen was monitored via UV-Vis spectroscopy.",
author = "Shaikh, {Aslam C.} and Jules Moutet and Veleta, {Jos{\'e} M.} and Hossain, {Md Mubarak} and Jan Bloch and Astashkin, {Andrei V.} and Gianetti, {Thomas L.}",
note = "Funding Information: We are grateful for nancial support from the University of Arizona for this work. We thank Professor Rebecca Page and Dr Michael Clarkson from the University of Arizona for Single crystal X-ray diffractions data collection. We thank Professors Elisa Tomat and Jon Njardarson from the University of Arizona, and Prof. Robert G. Bergman from UC Berkeley for helpful discussions. J. M. V. would like to acknowledge the effort of individuals, groups, and institutions working towards a more diverse and inclusive environment in academia. Funding Information: We are grateful for financial support from the University of Arizona for this work. We thank Professor Rebecca Page and Dr Michael Clarkson from the University of Arizona for Single crystal X-ray diffractions data collection. We thank Professors Elisa Tomat and Jon Njardarson from the University of Arizona, and Prof. Robert G. Bergman from UC Berkeley for helpful discussions. J. M. V. would like to acknowledge the effort of individuals, groups, and institutions working towards a more diverse and inclusive environment in academia. Publisher Copyright: {\textcopyright} The Royal Society of Chemistry.",
year = "2020",
month = oct,
day = "28",
doi = "10.1039/d0sc04850j",
language = "English (US)",
volume = "11",
pages = "11060--11067",
journal = "Chemical Science",
issn = "2041-6520",
publisher = "Royal Society of Chemistry",
number = "40",
}