Solvent effect on the Pt-195 NMR properties in pyridonate-bridged Pt-III dinuclear complex derivatives investigated by ab initio molecular dynamics and localized orbital analysis

Autor(es)

Batista, Patrick R. ^[1] ; Ducati, Lucas C. ^[1] ; Autschbach, Jochen ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Av Prof Linea Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Buffalo State Univ New York, Dept Chem, Buffalo, NY 14260 - USA

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. 23, n. 22, p. 12864-12880, JUN 2 2021.
• Citações Web of Science: 0

Resumo

An ab initio molecular dynamics investigation of the solvent effect (water) on the structural parameters, Pt-195 NMR spin-spin coupling constants (SSCCs) and chemical shifts of a series of pyridonate-bridged Pt-III dinuclear complexes is performed using Kohn-Sham (KS) Car-Parrinello molecular dynamics (CPMD) and relativistic hybrid KS NMR calculations. The indirect solvent effect (via structural changes) has a dramatic effect on the (1)J(PtPt) SSCCs. The complexes exhibit a strong trans influence in solution, where the Pt-Pt bond lengthens with increasing axial ligand sigma-donor strength. In the diaqua complex, where the solvent effect is more pronounced, the SSCCs averaged for CPMD configurations with explicit plus implicit solvation agree much better with the experimental data, while the calculations for static geometry and CPMD unsolvated configurations show large deviations with respect to experiment. The combination of CPMD with hybrid KS NMR calculations provides a much more realistic computational model that reproduces the large magnitudes of (1)J(PtPt) and Pt-195 chemical shifts. An analysis of (1)J(PtPt) in terms of localized and canonical orbitals shows that the SSCCs are driven by changes in the s-character of the natural atomic orbitals of Pt atoms, which affect the `Fermi contact' mechanism. (AU)

• Processo FAPESP: 17/17750-3 - Efeito do Solvente em Parâmetros Espectroscópicos de RMN por Dinâmica Molecular ab initio
• Beneficiário: Lucas Colucci Ducati
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/07308-4 - Efeito do solvente em cálculos de tensor blindagem e constante de acoplamento de complexos dinucleares de platina (III) via dinâmica molecular ab initio
• Beneficiário: Patrick Rodrigues Batista
• Modalidade de apoio: Bolsas no Brasil - Doutorado