Time dependent density functional theory modeling of specific rotation and optical rotatory dispersion of the aromatic amino acids in solution

摘要

Time Dependent Density Functional Theory ( TDDFT) along with the COnductor-like Screening MOdel ( COSMO) has been applied to model the specific rotation at 589.3 nm and the optical rotatory dispersion ( ORD) of the aromatic amino acids phenylalanine, tyrosine, histidine, and tryptophan. Solution structures at low, neutral, and high pH were determined. Both the anomalous dispersion absorbing ( resonance) region and the lower energy ( transparent) region of the ORD of the compounds were modeled. Linear response calculation of the specific rotation and ORD as well as Kramers-Kronig transformations of calculated circular dichroism spectra to model resonant ORD were compared with experimental data from the literature.