Table 5. Inter-amide Interactions (cm–1) for Diamide 2l (−62°, – 41°) α-Helixa.
| method | nπ*1-nπ*2 | nπ*1-πnbπ*2 | πnbπ*1-nπ*2 | πnbπ*1-πnbπ*2 |
|---|---|---|---|---|
| ab initio | 31 | –7 | 16 | –971 |
| diabatic | –359 | –660 | –131 | –363 |
| nπ*2 | 359 | –660 | 131 | –363 |
| nπ*1 | 359 | 660 | –131 | –363 |
| nπ*2 and nπ*1 | –359 | 660 | 131 | –363 |
a
The first and second rows are from the DichroCalc ab initio and the standard diabatic approaches (as per Rogers et al.26), respectively. In the rows that follow, for the state(s) indicated, the monomer electric transition dipole moment has undergone a sign change before diabatization.