An Air-Stable, Neutral Phenothiazinyl Radical with Substantial Radical Stabilization Energy.

ABSTRACT: The vital effect of radical states on the pharmacological activity of phenothiazine-based drugs has long been speculated. Whereas cationic radicals of N-substituted phenothiazines show high stability, the respective neutral radicals of N-unsubstituted phenothiazines have never been isolated. Herein, the 1,9-diamino-3,7-di-tert-butyl-N¹ ,N⁹ -bis(2,6-diisopropylphenyl)-10H-phenothiazin-10-yl radical (SQH₂ ^. ) is described as the first air-stable, neutral phenothiazinyl free radical. The crystalline dark-blue species is characterized by means of EPR and UV/Vis/near-IR spectroscopy, as well as cyclic voltammetry, spectro-electrochemical analysis, single-crystal XRD, and computational studies. The SQH₂ ^. radical stands out from o

SUBMITTER: Sigmund LM 

PROVIDER: S-EPMC7079145 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature