Organic radicals are reactive and often short-lived species typically formed through either the addition of a chemical agent or photochemical means. On account of their open-shell electronic structure, they have attracted attention based upon their magnetic properties and desirable spectroscopic behavior. Redox-sensitive molecules, such as viologen (V), undergo one-electron reductions to form radical species. These species hold significant potential in myriad applications but are limited because they are rapidly quenched by oxygen in air. Using methyl viologen (MV) as an example, we show that the MV radical (MV^+⋅) can be formed through electrochemical, chemical, and photochemical stimuli as well as a novel thermal stimulus in various deep eutectic solvents (DESs) and was found to be exceptionally stable. The conductive properties of DESs allowed for the fabrication of an aerobic electrochromic device through a straightforward, economical approach. Our report represents a unique approach to extending reactive radical lifetimes in air without altering the parent structure.

有机自由基通常是通过添加化学试剂或光化学方法而形成的反应性且通常为短寿命的物种。由于其开壳式电子结构，基于其磁性能和理想的光谱行为，它们引起了人们的关注。氧化还原敏感分子，如紫精（V），经过单电子还原形成自由基。这些物质在多种应用中具有巨大的潜力，但由于它们被空气中的氧气迅速淬灭而受到限制。以甲基紫精（MV）为例，我们显示了MV自由基（MV ^{+ ⋅}）可通过电化学，化学和光化学刺激以及新型的热刺激在各种深共熔溶剂（DES）中形成，并且被发现异常稳定。DES的导电特性允许通过一种简单，经济的方法来制造好氧电致变色器件。我们的报告代表了一种独特的方法，可以在不改变母体结构的情况下延长空气中的反应性自由基寿命。