The delocalized radicals derived formally by @A00045@ of one hydrogen from the CH2 group of cyclohepta-1,3,5-triene and substitution derivatives thereof.
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1373 [Terms] [Paper]