quinomethanes

Also contains definition of: xylylenes
https://doi.org/10.1351/goldbook.Q05012
Methylidenecyclohexadienones and dimethylidenecyclohexadienes, formally derived from
quinones
by replacement of one or both of the quinone oxygens by methylidene groups. (The diradical,
triplet state
of quinodimethanes can also be called o- or p-xylylenes).
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1362 [Terms] [Paper]