ABSTRACT
Before embarking on using the predicted chiroptical properties to interpret corresponding experimental data, it is necessary to ensure that the complete conformational space of a given molecule has been explored, and that all possible conformations have been evaluated for obtaining the predicted properties. The identification of predominant conformations and determination of Boltzmann population weights (see Appendix 5) for these conformers is a prerequisite for utilizing the predicted properties. A number of conformational search programs are commercially available (Conflex 2010; HyperChem 2014; MacroModel 2008; Spartan 2014) to facilitate the determination of predominant conformations. The main theme of conformational search programs is to rotate the rotatable groups around single bonds, pucker the rings (when present), and utilize built-in molecular mechanics force fields to determine the lowest energy conformers. However, it is necessary to be aware of limitations in using these programs, as discussed in Section 6.1.
