Computational Studies on Bimetallic Catalysis and X-ray Absorption Spectroscopy
type: CreativeWork
description: Computational studies are very important to gain an insight into reaction mechanisms and in interpreting and understanding complicated experimental observations. This report contains a discussion on computational studies performed on bimetallic catalysis and on X-ray absorption spectroscopy of insulators. The viability of a bimetallic rhodium and cobalt catalysts for industrially important hydroformylation and aldehyde-water shift catalysis (AWS) is discussed. Density functional theory (DFT) studies were used for bimetallic catalysis and time-dependent DFT studies were used for excited state dynamics. These studies were performed using Gaussian 09 package and NWChem. Hydroformylation is experimentally performed in acetone and 30% water/acetone systems and results in dicationic dirhodium complexes and monocationic dirhodium complexes respectively. DFT studies were used to determine the active catalyst and possible intermediates. Computational studies support the mechanism proposed by Prof. Stanley for hydrofomylation in acetone, but DFT studies demonstrate a different mechanism for hydroformylation in water/acetone which contains mono-bridging complexes. A detailed discussion on this is given in chapter 2. DFT studies were used to study the AWS catalysis with the bimetallic [rac-Rh2(μ-CO)2(CO)2(et,ph-P4)]2+ complex. These studies were performed in both vacuum and using explicit water molecules, and lower energies were obtained when explicit water molecules were used. The computations support an alternate mechanism with protonated acid intermediates different from the originally proposed mechanism. This mechanism is discussed in great detail in chapter 3. DFT studies are also performed to study the suitability of dicobalt analogs for hydroformylation and AWS catalysis. The most suitable active catalyst and possible mechanism for hydroformylation using Co2(μ-H)(μ-CO)(CO)3(H)(et,ph-P4)]2+ (Co_2), [rac- and [rac-Co2(μ-H)2(CO)4(et,ph-P4)]2+ (Co_2*) and [rac-Co2(μ-CO)2(CO)…
abstract: Computational studies are very important to gain an insight into reaction mechanisms and in interpreting and understanding complicated experimental observations. This report contains a discussion on computational studies performed on bimetallic catalysis and on X-ray absorption spectroscopy of insulators. The viability of a bimetallic rhodium and cobalt catalysts for industrially important hydroformylation and aldehyde-water shift catalysis (AWS) is discussed. Density functional theory (DFT) studies were used for bimetallic catalysis and time-dependent DFT studies were used for excited state dynamics. These studies were performed using Gaussian 09 package and NWChem. Hydroformylation is experimentally performed in acetone and 30% water/acetone systems and results in dicationic dirhodium complexes and monocationic dirhodium complexes respectively. DFT studies were used to determine the active catalyst and possible intermediates. Computational studies support the mechanism proposed by Prof. Stanley for hydrofomylation in acetone, but DFT studies demonstrate a different mechanism for hydroformylation in water/acetone which contains mono-bridging complexes. A detailed discussion on this is given in chapter 2. DFT studies were used to study the AWS catalysis with the bimetallic [rac-Rh2(μ-CO)2(CO)2(et,ph-P4)]2+ complex. These studies were performed in both vacuum and using explicit water molecules, and lower energies were obtained when explicit water molecules were used. The computations support an alternate mechanism with protonated acid intermediates different from the originally proposed mechanism. This mechanism is discussed in great detail in chapter 3. DFT studies are also performed to study the suitability of dicobalt analogs for hydroformylation and AWS catalysis. The most suitable active catalyst and possible mechanism for hydroformylation using Co2(μ-H)(μ-CO)(CO)3(H)(et,ph-P4)]2+ (Co_2), [rac- and [rac-Co2(μ-H)2(CO)4(et,ph-P4)]2+ (Co_2*) and [rac-Co2(μ-CO)2(CO)…
author: Fernando, Sayakkarage R. G.
keywords: molecular orbital, DFT, Time-dependent DFT, Hydroformylation, Aldehyde-water shift, organometallic
date published: 2015-01-01T08:00:00Z
date modified: 2026-07-24T02:57:39Z
provider: Lousiana State University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Chemistry

PropertyValue
property ID: DOI
value: 10.31390/gradschool_dissertations.423