Nearest-Neighbor Interactions and Their Influence on the Structural Aspects of Dipeptides

Table 1

Gas and aqueous phase data on total energies^a (kcal/mol), rotational constants (GHZ), and dipole moments (Debye) of the dipeptides calculated using B3LYP/6-311++G(d,p) level of theory.

Dipeptides	Phases	Total energies	Rotational constants			Dipole moments
			A	B	C
Sec-Val	Aqueous	−1914673.58	0.89777	0.21696	0.20165	8.217
	Gas	−1914661.51	0.88925	0.21786	0.20379	5.408
Sec-Leu	Aqueous	−1939331.27	0.69533	0.19564	0.17033	8.749
	Gas	−1939318.66	0.66357	0.19800	0.17511	5.443
Sec-Asp	Aqueous	−1983716.72	0.63845	0.21115	0.18677	5.615
	Gas	−1983701.12	0.65542	0.22214	0.19679	2.910
Sec-Ser	Aqueous	−1912566.68	1.14681	0.21622	0.20891	10.530
	Gas	−1912551.23	1.13530	0.21713	0.20946	6.968
Sec-Gln	Aqueous	−1995899.84	0.90448	0.13379	0.12285	5.423
	Gas	−1995881.71	0.82585	0.13320	0.12498	3.165
Sec-His	Aqueous	−2006567.87	0.80904	0.12584	0.12281	12.542
	Gas	−2006548.27	0.70813	0.12993	0.12457	9.218
Sec-Pyl	Aqueous	−2201743.59	0.31784	0.04734	0.04349	8.428
	Gas	−2201725.10	0.24766	0.05474	0.04856	5.134

aZPVE corrected; scaled with a correction factor 0.9877.