Persistent Hydrogen‐Bonded and Non‐Hydrogen‐Bonded Phenoxyl Radicals

摘要: The production of stable phenoxyl radicals is undoubtedly a synthetic chemical challenge. Yet it useful way to gain information on the properties biological tyrosyl radicals. Recently, several persistent have been reported, but only limited variations could be achieved. Herein, we show that amide-o-substituted radical (i.e. with salicylamide backbone) can synthesised in manner, thereby permitting easy modifications made through amide bond. To study effect H-bonding phenolate/phenoxyl redox couple, simple H-bonded and non-H-bonded o,p-tBu-protected salicylamidate compounds prepared. Their were examined by cyclic voltammetry showed fully reversible one-electron oxidation process corresponding species. Remarkably, potential appears correlated, at least partially, H-bond strength, as relatively large differences (ca. 300 mV) between phenolate salts are observed. produced electrochemically room temperature for an hour; their UV/Vis EPR characterisation consistent radicals, which makes them excellent models analyses experimental data coupled theoretical calculations indicate both deviation from planarity function intramolecular influence phenolate. latter predominantly exerted not (or little) radical. Thus, these systems energy involved small.