Quantum chemical computational insights into interaction of Gold (III) complex nanoparticles with piperazine derivative compound - prediction of biological sensing activities

This study examines how a 1-boc-4-(4-hydroxy-phenyl)-piperazine (1B4HPP) interacts with Gold (III) complex nanoparticles (AuCl₃) in order to determine how well they work for drug delivery and sensing purposes. Through adsorption procedures, the usage of Gold (III) complex nanoparticles modifies the energy levels of frontier molecular orbitals (FMO), which eventually improves drug delivery systems. Theoretical UV–vis. studies show that absorption peak of 1B4HPP@AuCl₃ is seen at 807 nm with the oscillator strength of 0.008, where major orbital contributions come from H-3- > LUMO (66 %) in gas phase whereas in water phase observed at 859 nm with the oscillator strength of 0.375, where major orbital contributions come from HOMO- > LUMO (89 %). In the complex form the range of molecular electrostatic potential (MEP) values are in the range of −6.039 x 10^-2 (a.u.) to 6.039 x 10^-2 (a.u.) and – 0.114 (a.u.) to 0.114 (a.u.) in gas and water phase respectively. Non-linear optical (NLO) studies have been carried out on the molecule and its complex, and noticed that first order hyper polarizability value of complex is 2.13 × 10⁻²⁸ esu in gas phase whereas 2.28 × 10⁻²⁸ esu in water phases, respectively. Different kinds of intermolecular interactions, including H (hydrogen) bonds, van-der Waals forces, and repulsive steric effects, have been identified through the non-covalent interaction (NCI) inquiry. The investigation of the compound's bioactivity and drug-likeness properties is another important component of the study. In the future, it is expected that the application of molecular docking techniques would be essential for assessing the interaction energies related to drug delivery procedures.