Attempted Generation of the 2,4-Didehydro-5-oxyquinolinium Cation Leads to an Oxygen-Peribridged Quinolinium Monoradical

摘要

A new class of protonated mono- and biradicals with an oxygen-peribridged quinolinium skeleton was generated. Oxy-radical formation occurs via rearrangement upon elimination of NO· group adjacent to a radical site. Favorable radical-radical recombination follows. The reactivity of oxygen-peribridged quinolinium cation is very low toward DMDS which indicates that a phenyl radical site is more reactive than the oxygen-peribridged linkage. The oxygen-peribridged biradical is less reactive than its monoradical counterpart toward all the reagents tested, which may be explained by coupling of the biradical electrons Computational studies are underway to better understand the obsreved reactivity.