verdazyl radicals

https://doi.org/10.1351/goldbook.V06609
Relatively @S05900@ delocalized @R05066@, derived from hydrazyl, H2NN.H, of the types shown, in particular the six-membered ring:
V06609.png
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1374 [Terms] [Paper]