Acyl intermediates include acyl anions, acyl radicals and acyl cations (synonym acylium ions) which are formally derived from oxoacids
RkE(=O)l(OH)m (
l ≠ 0) by removal of a hydroxyl cation
HO+, a hydroxyl radical
HO. or a hydroxyl anion
HO−, respectively, and replacement analogues of such intermediates. Acyl anions, radicals and cations can formally be represented by canonical forms having a negative charge, an unpaired electron or a positive charge on the acid-generating element of the oxoacid. Acyl anions. E.g.
A00129-1.png
Acyl radicals. E.g.
A00129-2.png
Acyl cations. E.g.
A00129-3.png
See also: acyl groups
Sources:
PAC, 1993, 65, 1357. 'Revised nomenclature for radicals, ions, radical ions and related species (IUPAC Recommendations 1993)' on page 1357 (https://doi.org/10.1351/pac199365061357)
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1312 (https://doi.org/10.1351/pac199567081307)