Study of nitrate compounds - 195Pt (IV) in solution by ab initio molecular dynamics and relativistic NMR calculations

• Grant number: 22/04799-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2022
• End date: May 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Lucas Colucci Ducati
• Grantee: Felipe Scalise Gaspar
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This study has as its main focus understanding the solvent effect in the chemical shift of aqua-hydroxy-nitrate-platinum complexes. Given that isolated and implicit solvation simulations are incapable of achieving results with less than a 20% margin of error, we aim, through this project, to verify how explicit solvation affects the accuracy of theoretical calculations of nuclear properties of the many platinum-nitrate complexes. The poor description of the electronic structure of the molecules through static models necessitates the development of dynamic ones for a better description of magnetic properties and the clarification of the electronic density in platinum and the bonding between the metal and its ligands. To this end, Car-Parrinello (CP) Kohn-Sham (KS) molecular dynamics and hybrid KS calculations of magnetic properties, with and without solvent effects, will be used. Furthermore, we aim to understand to which degree of precision it is relevant to simulate the solvent species to obtain accurate results and the effect of this in chemical exchange, seen as NMR measurements are done in a variety of chemical conditions. To achieve this, we will simulate molecular dynamics both in approximate experimental conditions (15.8M HNO3) as well as in pure water. Through this, we also expect to comprehend better the characteristics of the bond between Pt(IV) and its ligands with a joint analysis of orbitals and magnetic properties. This new computational technique, joining KS-CPMD and hybrid KS-DFT calculations to determine magnetic properties was proposed and has been developing in the past few years, having been applied successively to transition metal dinuclear compounds Tl Pt and Pt Pt.(AU)