1,2-Didehydrobenzene (the aryne derived from benzene) and its derivatives formed by substitution; see arynes, dehydroarenes. The terms
m- and
p-benzyne are occasionally, but erroneously, used for 1,3- and 1,4-didehydrobenzene, respectively.
Sources:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1088 (https://doi.org/10.1351/pac199466051077)
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1322 (https://doi.org/10.1351/pac199567081307)