Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing

The study of the UV spectroscopic behaviour of alkali metal iodides dissolved in supercritical ammonia showed that two absorbing species contributed to the UV absorption of the solutions. The two species differed in the type of interaction of iodide with the cation, i.e. going from contact ion pairs...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Sciaini, Alberto Germán, Marceca, Ernesto Jose, Fernandez Prini, Roberto
Publicado:	2006
Materias:	ammonia ion potassium iodide solvent article chemical structure chemistry computer simulation pressure temperature volatilization Ammonia Computer Simulation Ions Models, Molecular Potassium Iodide Pressure Solvents Temperature Volatilization
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v8_n42_p4839_Sciaini http://hdl.handle.net/20.500.12110/paper_14639076_v8_n42_p4839_Sciaini
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_14639076_v8_n42_p4839_Sciaini
record_format	dspace
spelling	paper:paper_14639076_v8_n42_p4839_Sciaini2023-06-08T16:16:37Z Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing Sciaini, Alberto Germán Marceca, Ernesto Jose Fernandez Prini, Roberto ammonia ion potassium iodide solvent article chemical structure chemistry computer simulation pressure temperature volatilization Ammonia Computer Simulation Ions Models, Molecular Potassium Iodide Pressure Solvents Temperature Volatilization The study of the UV spectroscopic behaviour of alkali metal iodides dissolved in supercritical ammonia showed that two absorbing species contributed to the UV absorption of the solutions. The two species differed in the type of interaction of iodide with the cation, i.e. going from contact ion pairs to free iodide ion, the observed absorption band varied according to the species that prevailed as the solvent density (ρ1) changed. This experimental evidence was supplemented with molecular dynamics simulations and electronic structure calculations which showed that at very low ρ1 when the contact ion pair is the dominant species, a sudden change from the internal charge transfer photoexcitation route to a charge-transfer-to-solvent transition occurred. This finding emphasized the importance of solvation at very low ρ1 not only for the photoexcitation process, it also allows connecting the thermodynamic behaviour of the solutes in solution with that observed in their vapour phase. We have tried to draw a consistent picture of the available information of UV photoexcitation for iodides in vapour, in solution either forming contact ion pairs or present as free iodide ions, including their behaviour in small clusters of highly polar molecules. The importance of the cation has been clearly shown in this investigation. A relation between the photoexcited electron in contact ion pairs and the solvated electron of alkali metals in small NH3 clusters has been conjectured. © the Owner Societies 2006. Fil:Sciaini, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Marceca, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Fernández-Prini, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2006 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v8_n42_p4839_Sciaini http://hdl.handle.net/20.500.12110/paper_14639076_v8_n42_p4839_Sciaini
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	ammonia ion potassium iodide solvent article chemical structure chemistry computer simulation pressure temperature volatilization Ammonia Computer Simulation Ions Models, Molecular Potassium Iodide Pressure Solvents Temperature Volatilization
spellingShingle	ammonia ion potassium iodide solvent article chemical structure chemistry computer simulation pressure temperature volatilization Ammonia Computer Simulation Ions Models, Molecular Potassium Iodide Pressure Solvents Temperature Volatilization Sciaini, Alberto Germán Marceca, Ernesto Jose Fernandez Prini, Roberto Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing
topic_facet	ammonia ion potassium iodide solvent article chemical structure chemistry computer simulation pressure temperature volatilization Ammonia Computer Simulation Ions Models, Molecular Potassium Iodide Pressure Solvents Temperature Volatilization
description	The study of the UV spectroscopic behaviour of alkali metal iodides dissolved in supercritical ammonia showed that two absorbing species contributed to the UV absorption of the solutions. The two species differed in the type of interaction of iodide with the cation, i.e. going from contact ion pairs to free iodide ion, the observed absorption band varied according to the species that prevailed as the solvent density (ρ1) changed. This experimental evidence was supplemented with molecular dynamics simulations and electronic structure calculations which showed that at very low ρ1 when the contact ion pair is the dominant species, a sudden change from the internal charge transfer photoexcitation route to a charge-transfer-to-solvent transition occurred. This finding emphasized the importance of solvation at very low ρ1 not only for the photoexcitation process, it also allows connecting the thermodynamic behaviour of the solutes in solution with that observed in their vapour phase. We have tried to draw a consistent picture of the available information of UV photoexcitation for iodides in vapour, in solution either forming contact ion pairs or present as free iodide ions, including their behaviour in small clusters of highly polar molecules. The importance of the cation has been clearly shown in this investigation. A relation between the photoexcited electron in contact ion pairs and the solvated electron of alkali metals in small NH3 clusters has been conjectured. © the Owner Societies 2006.
author	Sciaini, Alberto Germán Marceca, Ernesto Jose Fernandez Prini, Roberto
author_facet	Sciaini, Alberto Germán Marceca, Ernesto Jose Fernandez Prini, Roberto
author_sort	Sciaini, Alberto Germán
title	Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing
title_short	Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing
title_full	Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing
title_fullStr	Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing
title_full_unstemmed	Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing
title_sort	development of the charge-transfer-to-solvent process with increasing solvent fluid density: the effect of ion pairing
publishDate	2006
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v8_n42_p4839_Sciaini http://hdl.handle.net/20.500.12110/paper_14639076_v8_n42_p4839_Sciaini
work_keys_str_mv	AT sciainialbertogerman developmentofthechargetransfertosolventprocesswithincreasingsolventfluiddensitytheeffectofionpairing AT marcecaernestojose developmentofthechargetransfertosolventprocesswithincreasingsolventfluiddensitytheeffectofionpairing AT fernandezpriniroberto developmentofthechargetransfertosolventprocesswithincreasingsolventfluiddensitytheeffectofionpairing
_version_	1768542332490088448

Development of the charge-transfer-to-solvent process with increasing solvent fluid density: The effect of ion pairing

Ejemplares similares