Understanding the interaction mechanisms of active compounds extracted from Tabernaemontana penduliflora on the surface of magnetite (111) nanoparticles in aqueous medium by DFT and MD approaches.

Computational techniques have been used to analyze the molecules of 10-hydroxycoronahydine (HC) and voacangine hydroxyindolenine (VH) molecules with the aim of studying the effect of base and temperature on their interaction mechanisms during synthesis green magnetite nanoparticles. Density functional theory (DFT) descriptors such as: energy gap, overall reactivity descriptors, dipole moment and adsorption energy have all been explored in depth to understand the nature of the interaction. The DFT results showed that the molecules studied (HC and VH) are interactive and stable in an aqueous medium, due to the fact that these molecules have free electronic doublets on the nitrogen atom and the bond of the aromatic ring. It was observed that each molecule effectively increased the stabilization energy of magnetite nanoparticles through electron transfer. According to the Fukui function reactivity results, HC and VH compounds both have high oxidizing powers. Thus, showing that they are good agents for functionalizing magnetite nanoparticles. The adsorption energy and interaction force of HC and VH with the magnetite (111) nanoparticle surface were shown to increase with temperature and depend on the base used. The results of molecular dynamic (MD) simulation demonstrated that the adsorption of molecules on the adsorbate is chemical in nature and that chemical bonds predominate over electrostatic interactions. The molecular dynamics simulation parameters show that the adsorption of 10-hydroxycoronahydine and voacangine hydroxyindolenine molecules is chemisorption, exothermic and spontaneous.