Thermodynamic and Extrathermodynamic Studies of Enantioseparation of Imidazolinone Herbicides on Chiralcel OJ Column

Table 2

Thermodynamic parameters ΔΔ𝐻^∘, ΔΔ𝑆^∘, and ΔΔ𝐺^∘_(303K) of chiral separation.

Compound	Mobile phase	ΔΔ𝐻^∘	ΔΔ𝑆^∘	ΔΔ𝐺^∘(303K)	𝑄^∗(303K)
		kJ mol^−1	J mol^−1 K^−1	kJ mol^−1
Imazapyr	85/15	−4.47	−9.80	−1.50	1.50
	80/20	−4.54	−10.25	−1.44	1.46
	75/25	−4.42	−10.03	−1.38	1.45
	70/30	−4.46	−10.32	−1.33	1.43
	60/40	−3.78	−8.43	−1.23	1.48
Imazapic	85/15	−3.51	−7.20	−1.32	1.61
	80/20	−3.47	−7.24	−1.27	1.58
	75/25	−3.46	−7.36	−1.23	1.55
	70/30	−3.66	−8.11	−1.20	1.49
	60/40	−3.07	−6.46	−1.11	1.57
Imazethapyr	85/15	−1.77	−2.54	−1.00	2.30
	80/20	−1.78	−2.71	−0.95	2.16
	75/25	−1.85	−3.11	−0.91	1.97
	70/30	−1.85	−3.23	−0.88	1.90
	60/40	−1.60	−2.63	−0.80	2.01
Imazamox	85/15	−1.45	−1.23	−1.08	3.89
	80/20	−1.51	−1.58	−1.03	3.15
	75/25	−1.58	−1.95	−0.99	2.68
	70/30	−1.68	−2.38	−0.96	2.33
	60/40	−1.53	−2.12	−0.89	2.38
Imazaquin	85/15	−0.14	1.22	−0.51
	80/20	−0.13	1.19	−0.49
	75/25	−0.11	1.20	−0.48
	70/30	−0.11	1.18	−0.46
	60/40	−0.02	1.37	−0.44

∗Enthalpy-entropy ratios 𝑄, relative contribution of enthalpy and entropy to the enantioseparation at 303 K.