Calculations of optical rotation: Influence of molecular structure

Abstract

The ab initio Hartree-Fock (HF) method and the Density Functional Theory (DFT) were used to calculate the optical rotation of 26 chiral compounds. The effects of the theory and basis sets used for the calculation, the influence of the solvent on the geometry and the values of the calculated optical rotation are all discussed. The polarizable continuum model, included in the calculation, did not improve the accuracy effectively, but was superior to ãs. The optical rotation of five-and six-membered cyclic compounds was calculated and 17 pyrrolidine or piperidine derivatives, which were calculated by the HF and DFT methods, gave acceptable predictions. The nitrogen atom dramatically affected the calculation results and it is necessary in the molecular structure in order to obtain an accurate computation result. Namely, when the nitrogen atom was substituted by an oxygen atom in the ring, the calculation result deteriorated.