Solvent Effect in NMR Parameters by ab initio Molecular Dynamics

• Grant number: 17/17750-3
• Support type: Regular Research Grants
• Duration: February 01, 2018 - January 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Lucas Colucci Ducati
• Grantee: Lucas Colucci Ducati
• Home Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The study of the solvation effect of water and, specially the contribution of the hydrogen bond between solvent and solute to the chemical shift (delta) of 14N of acyclic and cyclic nitrogen compounds is proposed. Some theoretical studies using models of implicit solvation in the literature suggest the use of explicit solvation and the description of the solute-solvent system in a dynamic way, to obtain a more realistic description of the experimental conditions and improve the precision of the estimated values. In addition, T1 relaxation values for some nitrogen compounds will also be calculated and compared with the experimental values. The influence of solvent (water) coordination on the shielding tensor (sigma)/chemical shift (delta) and on the indirect spin-spin (J) coupling constants of the Pt-Pt complexes, precursors of the Magnum salts, will also be studied. These salts are in equilibrium in aqueous medium, requiring the use of explicit solvation and a description of the solute-solvent system dynamically. The estimated theoretical values of the magnetic parameters with static geometries at the DFT level, including an implicit solvent effect and Hamiltonian with relativistic correction, overestimate the experimental values by about 100% for the diaquo compounds. For this, the Kohn-Sham (KS) Car-Parrinello (CPMD) molecular dynamics and hybrid KS calculations of magnetic properties, with and without solvent effect, will be used. This new computational technique, combining KS-CPMD and hybrid KS-DFT calculations for determination of magnetic properties, was proposed and developed in the last 2 years during this researcher's fellowship abroad, and has been successfully applied for Tl-Pt transition metal compounds. This project proposes a new application of this type of study, in order to establish and consolidate a new line of research, unprecedented in Brazil (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BATISTA, PATRICK R.; KARAS, LUCAS J.; VIESSER, RENAN V.; DE OLIVEIRA, CYNTHIA C.; GONCALVES, MARCOS B.; TORMENA, CLAUDIO F.; RITTNER, ROBERTO; DUCATI, LUCAS C.; DE OLIVEIRA, PAULO R. Dealing with Hydrogen Bonding on the Conformational Preference of 1,3-Aminopropanols: Experimental and Molecular Dynamics Approaches. Journal of Physical Chemistry A, v. 123, n. 40, p. 8583-8594, OCT 10 2019. Web of Science Citations: 0.

CHAUDHURI, PUSPITAPALLAB; DUCATI, LUCAS C.; GHOSH, ANGSULA. Spin-spin coupling constants in linear substituted HCN clusters. Molecular Physics, v. 117, n. 6, p. 693-704, MAR 19 2019. Web of Science Citations: 0.

PHILIPS, ADAM; MARCHENKO, ALEX; DUCATI, LUCAS C.; AUTSCHBACH, JOCHEN. Quadrupolar N-14 NMR Relaxation from Force-Field and Ab Initio Molecular Dynamics in Different Solvents. JOURNAL OF CHEMICAL THEORY AND COMPUTATION, v. 15, n. 1, p. 509-519, JAN 2019. Web of Science Citations: 1.

VIESSER, RENAN V.; DUCATI, LUCAS C.; TORMENA, CLAUDIO F.; AUTSCHBACH, JOCHEN. The halogen effect on the C-13 NMR chemical shift in substituted benzenes. Physical Chemistry Chemical Physics, v. 20, n. 16, p. 11247-11259, APR 28 2018. Web of Science Citations: 9.