. Author manuscript; available in PMC: 2018 Sep 28.

Published in final edited form as: Fluid Phase Equilib. 2017 May 3;448:15–21. doi: 10.1016/j.fluid.2017.04.020

Table 1.

Kamlet-Taft parameters of water, organic acids and DES composed of ammonium-based salts (HBAs) and carboxylic acids (HBDs), in different mole ratios, using the following set of probes: N,N-diethyl-4-nitroaniline, 4-nitroaniline and pyridine-N-oxide.

HBA	HBD	Mole ratio (salt:carboxylic acid)	α	β	π*
–	Water [32]	–	1.23	0.49	1.14

–	Butanoic Acid	–	1.06	0.22	0.47

–	Hexanoic Acid	–	1.05	0.21	0.43

–	Octanoic Acid	–	0.94	0.23	0.38

[N₂₂₂₂]Cl	Butanoic Acid	1:2	0.99	0.76	0.92
	Hexanoic Acid	1:2	0.97	0.85	0.86
	Octanoic Acid	1:2	0.96	0.87	0.81

[N₃₃₃₃]Cl	Butanoic Acid	1:2	0.94	0.84	0.93
	Hexanoic Acid	1:2	0.91	0.92	0.85
	Octanoic Acid	1:2	0.90	0.96	0.80

[N₄₄₄₄]Cl	Butanoic Acid	1:2	0.92	0.99	0.86
	Hexanoic Acid	1:2	0.90	1.02	0.81
	Octanoic Acid	1:2	0.84	1.19	0.80
	Decanoic Acid	1:2	0.85	1.28	0.69
		1:1	0.91	1.21	0.86

[N₃₃₃₃]Br	Butanoic Acid	1:2	1.07	0.80	0.93
[N₃₃₃₃]Br	Hexanoic Acid	1:2	1.02	0.86	0.87

[N₄₄₄₄]Br	Butanoic Acid	1:2	1.02	0.81	0.93
		1:1	1.09	0.84	0.90
		2:1	0.94	0.82	0.95
	Hexanoic Acid	1:2	1.02	0.93	0.92
	Octanoic Acid	1:2	0.98	1.09	0.84
	Decanoic Acid	1:2	0.95	1.05	0.71