Vibrational Spectral Simulation of 1-Benzyl-1H-Imidazole Using Scaled DFT Force Fields

Abstract

The Fourier Transform Raman and infrared spectra of the crystallized pharmaceutical molecule 1‐benzyl‐1H‐imidazole (BI) have been recorded and analyzed. The geometry, intermolecular hydrogen bond, and harmonic vibrational frequencies of BI have been predicted with the help of B3PW91 density functional theory (DFT) methods. The vibrational spectra have been simulated with the aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). The pronounced double‐bond derealization in the imidazole ring upon intermolecular H‐bonding becomes the cause for its enhanced aromaticity.