Dinâmica molecular de Car-Parrinello : Fulereno C 70 como um nanofrasco para o estudo da reatividade química do nitrogênio atômico e a solvatação aquosa do ácido indolacético

Abstract

In recent years, research on fullerenes that encapsulate different chemical species has grown significantly. Morinaka and collaborators investigated the chemical reactivity of the nitrogen atom using a C 70 fullerene as a nanoflask (endohedral fullerene). In this work we present the analysis of these results using Car-Parrinello molecular dynamics (DMCP). It was possible to confirm through DMCP, RDG and QTAIM, that the nitrogen atom (N) in the ground state does not react with the hydrogen molecule (H 2 ), nor with the deuterium molecule (D 2 ) at a temperature of 300K, inside the C 70 fullerene. For the nitrogen atom in the first excited state, it is possible to observe the formation of the radical NH 2 and ND 2. The usefulness of fullerenes as nanobottles is then demonstrated. Another theoretical study also using DMCP was developed in parallel to the main work on the C 70 fullerene, we investigated the effect of solvation on the geometric parameters of indoleacetic acid. Indoleacetic acid is a natural hormone responsible for promoting plant growth. It is the main and strongest auxin found due to its potential to induce the expansion of plant cells. Due to the biological importance of IAA as a plant hormone, we investigated its solvation in aqueous media using ab initio calculations. We seek to understand the mechanism of interaction between the molecules of the system. We compared the geometric results obtained in vacuum with DMCP and density functional theory with the PBE functional, to experimental results and verified the solvation behavior of this molecule. In these works, we use DMCP in very different systems to also demonstrate its versatility.