Table 2. Overview of Anions Used in HIL Synthesis Divided by Reaction Types.

anion	type of reaction	yield (%)	refs
MCPA	metathesis	86–99	(16,25,43,45,50,55,56,58,59,63,73,79)
	quaternary ammonium hydroxide resulting from KOH in methanol	86–99	(37,47,55,60,67,68)
2,4-D	metathesis	82–99	(25,45,46,48,59,63,73)
	quaternary ammonium hydroxide resulting from KOH in methanol	89–99	(47,67)
	quaternary ammonium hydroxide resulting from KOH in ethanol	90–92	(41)
	quaternary ammonium hydroxide with the use of ion-exchange resin	82–99	(46)
	from commercially available choline hydroxide	97	(44)
dicamba	metathesis	90–99	(26,39,45,51,58,63,73)
	quaternary ammonium hydroxide resulting from KOH in methanol	90–98	(47,67,68)
	quaternary ammonium hydroxide with the use of ion-exchange resin	74–99	(26,51)
fomesafen	metathesis	81–98	(32)
MCPP	metathesis	90–98	(25,45,51,63,73)
	quaternary ammonium hydroxide resulting from KOH in methanol	92–97	(47,67)
	quaternary ammonium hydroxide with the use of ion-exchange resin	>92	(51,66)
metsulfuron-methyl (MSM)	metathesis	91–98	(29)
	quaternary ammonium hydroxide resulting from KOH in methanol	90–99	(29)
diclofop	metathesis		(8)
clodinafop	metathesis		(8)
bentazone	metathesis	83–97	(24)
clopyralid	metathesis		(27)
4-CPA	metathesis	85–91	(25)
bromoxynil	metathesis	94–99	(23)
pelargonate	metathesis	93–99	(33,62)
	quaternary ammonium hydroxide resulting from KOH in methanol	96–99	(34)
	from commercially available choline hydroxide	98	(77)
iodosulfuron-methyl (ISM)	metathesis	88–98	(62)
glyphosate	quaternary ammonium hydroxide resulting from KOH in methanol	90–98	(31,42)
2,4-DP	quaternary ammonium hydroxide resulting from KOH in methanol	89–95	(57)
	quaternary ammonium hydroxide with the use of ion-exchange resin	91–98	(65)
nicosulfuron	quaternary ammonium hydroxide resulting from KOH in methanol	86–93	(30)
MCPB	quaternary ammonium hydroxide with the use of ion-exchange resin	91–96	(64)
mesotrione	quaternary ammonium hydroxide resulting from KOH in methanol	87–95	(38)