Structural parameters of amphetamine: A DFT approach

Abstract

The structural parameters of Amphetamine, a significant psychoactive drug, are investigated experimentally and computationally using spectroscopic and DFT methods. The molecule is subjected to optimization using the B3LYP functional with both 6-311+G (2d,p) and augmented cc-pVTZ basis sets. Resulting values are then compared against published crystal data for validation. Analysis of the Fourier Transform Infrared and Raman spectra is carried out with PED assignments and after scaling, the calculated spectral frequency values are verified with experimental spectra, revealing a favorable match between them. The NMR spectrum of the molecule is obtained using TD-DFT techniques. The quantum theory of atoms in molecules is employed to analyze the electron density distributions. The reactivity of the molecule is predicted using various tools including analysis of the molecular electrostatic potential surface, electron localized function, molecular graph, non-covalent interaction (NCI), Hirshfeld charge, frontier orbital as well as local and global reactivity descriptors. Natural bonding orbital analysis identifies the hybridization, charge transfer and correlation effects. The results of this study could be utilized for the development of novel chemical sensors for drug detection and to predict the correlation between the structure and pharmacological activity of various amphetamine derivatives.