Crystal and molecular structure of 1-picryl-2-phenyl-2-(4-picrylamidophenyl)-diazenium betaine: analogy between a picramido group and an oxygen atom

International audienceThe title compound is formed by a non-trivial reaction involving two molecules of the stable free radical 2,2-diphenyl-1-picryl-hydrazyl and one molecule of N-methoxy-picramide. We could now perform an X-ray diffraction experiment on a single crystal and can fully confirm the betaine structure which has a central quino-noid ring with alternating long and short bonds

Reaction of 2,2-Diphenyl-1-picrylhydrazyl with HO•, O2•–, HO– ,and HOO– Radicals and Anions

Using electronic absorption spectra and thin layer chromatography, the reactionof 2,2-diphenyl-1-picrylhydrazyl (DPPH) with O2•–, HO•, HO–, and HOO– anions and freeradicals revealed the formation of the para-nitro- and para-hydroxy-derivatives of 2,2-diphenyl-1-picrylhydrazine (DPPH-H) and of DPPH fragmentation products(diphenylamine, tetraphenylhydrazine). The reaction of DPPH with the O2•– anion-radical(from KO2 in benzene solution at room temperature in the presence of 18-crown-6 ether) ispseudo-first-order during the first 25 minutes