quinomethanes

Also contains definition of: xylylenes
https://doi.org/10.1351/goldbook.Q05012
Methylidenecyclohexadienones and dimethylidenecyclohexadienes, formally derived from @Q05015@ by replacement of one or both of the quinone oxygens by methylidene groups. (The diradical, @T06503@ of quinodimethanes can also be called o- or p-xylylenes).
Q05012.png
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]