Table 2.

Relative free energy in the gas-phase (ΔG^gp; in kcal/mol) and in carbon tetrachloride, chloroform, methanol and aqueous solutions (ΔG^CCl4, ΔG^CHCl3, ΔG^CH3OH and ΔG^H2O, respectively; in kcal/mol) for the minimum energy conformations of Ac-βtAmp-NHMe, Ac-βcAmp-NHMe, Ac-γtAmp-NHMe and Ac-γcAmp-NHMe at the B3LYP/6-31+G(d,p) level.

# Conf.	ΔGgp	ΔGCCl4	ΔGCHCl3	ΔGCH3OH	ΔGH2O
Ac-βtAmp-NHMe
t-γL[d]	0.0a	0.0	1.3	5.8	6.4
c-εL[u]	2.7	1.0	0.8	3.2	3.5
c-αL[u]	4.7	3.0	2.5	4.1	4.2
c-εL[d]	3.9	1.6	0.0	0.0	0.0
Ac-βcAmp-NHMe
t-γL[d]	0.0b	1.0	0.0	2.7	3.3
t-αL[d]	2.7	0.0	0.2	1.1	1.4
c-αL[d]	3.3	0.6	1.3	2.5	2.3
c-εL[d]	4.4	3.3	0.3	0.0	0.0
c-αL[u]	4.4	1.6	2.6	3.9	3.7
t-αL[u]	7.6	6.4	2.9	1.5	1.2
Ac-γtAmp-NHMe
t-γL[u]	0.0c	0.0	0.5	4.4	5.1
c-αL[d]	1.7	4.2	0.4	2.9	2.9
c-εL[u]	4.4	5.4	0.0	0.0	0.0
Ac-γcAmp-NHMe
t-γL[d]	0.0d	0.4	2.3	7.0	7.9
t-γL[u]	1.3	0.8	1.7	5.4	6.3
c-αL[d]	2.2	0.0	0.0	2.7	3.4
c-αL[u]	3.9	2.3	2.2	4.4	4.3
t-αL[u]	3.7	1.2	1.5	2.9	3.2
c-εL[d]	4.6	2.3	1.3	1.8	2.1
c-εL[u]	6.0	2.8	0.8	0.0	0.0

^aG=-628.468989 a.u.

^bG= -628.469683 a.u.

^cG=-628.468329 a.u.

^dG= -628.470592 a.u.