Absolute configuration through the DFT simulation of the optical rotation. importance of the correct selection of the input geometry: a caveat.
In ab initio calculation of ORs of flexible molecules, the input geometries and conformer populations obtained at different levels of theory can yield opposite OR values. Therefore, when at the commonly used DFT/B3LYP/6-31G* level several conformers result, even showing the same sign of OR, additional geometry optimization at a higher level of theory will be absolutely required.
Dipartimento di Chimica, Università della Basilicata, via N. Sauro 85, 85100, Potenza, Italy.
Giuseppe
G
Mazzeo
Egidio
E
Giorgio
Riccardo
R
Zanasi
Nina
N
Berova
Carlo
C
Rosini