Thermodynamic study of proton transfer reactions of Re(V)trans-dioxocomplexes in aqueous solution

Dublin Core

Título

Thermodynamic study of proton transfer reactions of Re(V)trans-dioxocomplexes in aqueous solution

Tema

RENIO
PROTONES
TERMODINAMICA
BIBLIOGRAFIA NACIONAL QUÍMICA
2009

Abstract

The thermodynamics of protonation of trans-[ReVO2L2]+ (L = aliphatic di and polyamines) complexes in aqueous solution was studied by using experimental and theoretical approaches. The complexes containing diamines undergo protonation on the oxo ligands, whereas those containing polydentate amines protonate on uncoordinated amino groups. The protonation reactions were studied experimentally by microcalorimetric techniques, in all cases exothermic with |DH◦| ranging from 7 to 50 kJ/mol. For complexes containing diamines, the exothermicity was in concordance with the basicities in some cases, while in others no systematic behaviour was found. For complexes with polydentate amines, the enthalpy dominates with a modest influence on the entropy. Theoretically, Density Functional Theory (DFT) methods were employed in the gas phase, and bulk solvent effects were treated by means of the Polarizable Continuum Model. Direct solute–solvent effects were considered adding explicit water molecules. The enthalpy change calculated in the gas phase was in marked disagreement with the experimental results due to the relevancy of solvation/desolvation processes. The explicit inclusion of water molecules led to a good improvement. A discrete-continuum model was also employed, for which DG◦ was overestimated in all cases. Further investigations, both experimental and theoretical are necessary to get a more complete picture of the proton transfer reactions of these complexes. The experimental values herein determined constitute the first step to construct a set of data to which it is possible to benchmark new theoretical approaches to compute the thermodynamics of proton transfer reactions of metal complexes in aqueous solution

Autor

Giorgi, Claudia
Bianchi, Antonio

Fuente

Dalton Transactions no.39, 2009. -- p.8257-8268

Editor

RSC

Fecha

2009

Formato

PDF

Tipo

Artículo

Identificador

DOI: 10.1039/B911121B
Fecha de agregación
March 17, 2014
Colección
Bibliografía Nacional Química
Tipo de Elemento
Document
Etiquetas
, ,
Citación
Gancheff, Jorge S., “Thermodynamic study of proton transfer reactions of Re(V)trans-dioxocomplexes in aqueous solution,” RIQUIM - Repositorio Institucional de la Facultad de Química - UdelaR, accessed April 18, 2024, https://riquim.fq.edu.uy/items/show/1315.
Archivos