Table 2.

Selected torsion angles (°) of local minima for Ac-l-Ala-[psi](Imz)⁺-4-Me (3) optimized at M06-2X/6–311++G(d,p) method, their relative energies (ΔE) and the relative energy difference between tautomers (ΔEτ/π) in kcal/mol, and population (p)

Ac-l-Ala-[psi](Imz)+-4-Me (3)
Conformer	φ	ψ	E [a.u.]	ΔE	p [%]
Gas Phase
C7eq	− 73.9	63.0	− 552.5016	0.00	49.71
αRτ	− 73.8	− 118.6	− 552.5012	0.19	35.84
C7ax	67.0	− 59.5	− 552.4998	1.09	8.00
αLτ	66.9	126.0	− 552.4995	1.23	6.27
αLπ	59.2	42.3	− 552.4950	4.08	0.05
αDτ	59.1	− 137.6	− 552.4950	4.13	0.05
β	− 64.2	140.9	− 552.4951	4.18	0.04
αRπ	− 64.1	− 40.2	− 552.4950	4.24	0.04
Chloroform
αRτ	− 74.7	− 118.6	− 552.5808	0.00	51.62
C7eq	− 74.8	64.2	− 552.5809	0.15	40.26
C7ax	67.1	− 61.4	− 552.5786	1.63	3.34
αLτ	66.9	125.8	− 552.5784	1.71	2.93
αLπ	59.5	38.2	− 552.5767	2.64	0.61
αRπ	− 64.9	− 37.2	− 552.5772	2.68	0.57
β	− 67.4	149.5	− 552.5771	2.83	0.45
αDτ	59.9	− 143.5	− 552.5765	3.25	0.22
Water
αRτ	− 75.6	− 115.5	− 552.5923	0.00	33.19
C7eq	− 75.9	64.2	− 552.5924	0.07	29.59
αRπ	− 62.4	− 38.4	− 552.5919	0.57	12.69
β	− 63.9	148.2	− 552.5918	0.64	11.33
αLπ	55.9	42.8	− 552.5906	1.09	5.28
C7ax	67.9	− 60.6	− 552.5902	1.42	3.07
αDτ	56.9	− 142.2	− 552.5904	1.61	2.23
αLτ	67.6	122.4	− 552.5901	1.51	2.63