Modeling the Conformational Preference, Spectral Analysis and Other Quantum Mechanical Studies on Three Bioactive Aminobenzoate Derivatives and Their SERS Active Graphene Complexes

Abstract

Three aminobenzoate derivatives, benzocaine (B1), butamben (B2) and n-pentyl 4-aminobenzoate (B3) were analyzed for the structural, nonlinear optical, electronic and biological properties. The functional nature of the compounds were analyzed using vibrational spectra and was compared with the scaled, simulated spectra obtained using density functional theory (DFT) with diffused orbitals. Relaxed potential energy scan predicts the stable conformers. Frontier molecular orbital was found and used to generate some important data pertaining to the reactivity and stability of the molecule. Time dependent DFT was used to model the excitation and de-excitation dynamics of these molecules and to predict the use of these molecules as effective photo sensitizer in DSSC. This work further discusses in detail, Natural Bond Orbital (NBO) study for intra molecular interactions, molecular electrostatic potential (MEP) for reactivity preferences and hyperpolarizability calculations for predicting the optical properties. Further molecular docking studies were conducted for the compounds with eye irritation inactive inhibitor (PDBID: 1AUE), prolylaminopeptidase inhibitor (2EEP), 5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase inhibitor (5BST), arginine 2-monooxygenase inhibitor (6DA8) to predict their utility as potential. Surface enhanced Raman spectrum (SERS) is an important tool in analytical chemistry as it can be used for the assay of various compounds. It is found that all the three compounds interact very well with graphene monolayer and behaves uniquely with the scattering of light by providing a measurable enhancement in the Raman activity of the adsorbed systems, making the assay easy for this commonly used class of compounds.B2-graphene complex is found to be more stable with adsorption energy −4.2043 kcal/mol among the three followed by the complexes of B3 (−2.1963) and B1 (−0.8158).

Keywords:

• DFT
• aminobenozate
• SERS
• NLO
• docking
• graphene

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Program.