DETECTION BY INFRARED SPECTROSCOPY OF BENZYNE FORMED BY FLASH VACUUM PYROLYSIS AND TRAPPED IN AN ARGON MATRIX

Article abstract of DOI:10.1016/S0040-4039(86)80052-1

Benzyne has been detected in the argon matrices obtained from pyrolyses of isobenzofuran-1,3-dione (1), 2,3-benzodioxin-1,4-dione (2), benzocyclobutenedione (3), 2,2-dimethyl-5-(octahydro-1',2',4'-methano-3'H-cyclobutapentalen-3'-ylidene)-1,3-dioxan-4,6-dione (8) and 5,5'-(pentacyclo<5.3.0^2,6.0^4,10.0^5,8>decane-3'',9''-diylidene)bis(2,2-dimethyl-1,3-dioxan-4,6-dione) (9).At both 650 deg C and 700 deg C compound (3) yields only benzyne while (8) yields ketenes and benzyne.It is suggested that compounds (1), (2) and (3) undergo concerted fragmentation to benzyne while (8) and (9) give ketene intermediates which fragment to benzyne.