Geometry, Tautomerism, and Noncovalent Interaction of Bentiromide with a Carbon-Nanotube and γ-Fe2O3 Nanoparticles: A Quantum Mechanical Study

Abstract

A doctor can find out how pancreas is working using bentiromide. This drug can exist as six possible tautomers. Herein, by density functional theory (DFT) and handling the solvent effects with the polarizable continuum model (PCM), the mechanism of its tautomerization, energies, and structural parameters of the tautomers are investigated. Also, the natural bond orbital analysis (NBO) is used for exploring the frontier molecular orbitals. The most stable tautomer of bentiromide has three carbonyl groups in its structure. The amount of other tautomers is negligible in the aqueous solution. The non-covalent interactions of the most stable tautomer of bentiromide with an armchair (5,5) single-wall carbon nanotube and a γ-Fe₂O₃ nanoparticle are explored. In each case, three possible forms are optimized. Their most stable form is determined. The intermolecular H bonds have a critical role in the energy behavior of the interaction between bentiromide and the γ-Fe₂O₃ nanoparticle.