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., radikaal, mis tekib oksohapetest hüdroksüülradikaali HO· eemaldamisel