Definition of acyl species

1. 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 not equal to 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. See under acyl groups.

   Acyl anions. E.g. RC-(=O), RS-(=O)2 , RC-(=S), RC-(=NH).

   Acyl radicals, RNRI Rule RC-81.2.2. E.g. RC.(=O), RS.(=O)2 .

   Acyl cations, RNRI Rule RC-82.2.3.2. E.g. RC+(=O) RCO+ .