Impact of the Ligand Flexibility and Solvent on the O–O Bond Formation Step in a Highly Active Ruthenium Water Oxidation Catalyst

Govindarajan, Nitish; Tiwari, Ambuj; Ensing, Bernd; Meijer, Evert Jan

doi:10.1021/acs.inorgchem.8b00619

Cited by 48 publications

(49 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This approach has generic applicability, and it is extensively used in earlier studies to calculate free-energy barrier reactions in solution. 20 , 59 − 62 …”

Section: Simulation Methodsmentioning

confidence: 99%

Elucidating the Role of Tetraethylammonium in the Silicate Condensation Reaction from Ab Initio Molecular Dynamics Simulations

Lan

Hoang

et al. 2020

J. Phys. Chem. B

Self Cite

View full text Add to dashboard Cite

The understanding of the formation of silicate oligomers in the initial stage of zeolite synthesis is important. The use of organic structure-directing agents (OSDAs) is known to be a key factor in the formation of different silicate species and the final zeolite structure. For example, tetraethylammonium ion (TEA + ) is a commonly used organic template for zeolite synthesis. In this study, ab initio molecular dynamics (AIMD) simulation is used to provide an understanding of the role of TEA + in the formation of various silicate oligomers, ranging from dimer to 4-ring. Calculated free-energy profiles of the reaction pathways show that the formation of a 4-ring structure has the highest energy barrier (97 kJ/mol). The formation of smaller oligomers such as dimer, trimer, and 3-ring has lower activation barriers. The TEA + ion plays an important role in regulating the predominant species in solution via its coordination with silicate structures during the condensation process. The kinetics and thermodynamics of the oligomerization reaction indicate a more favorable formation of the 3-ring over the 4-ring structure. The results from AIMD simulations are in line with the experimental observation that TEA + favors the 3-ring and double 3-ring in solution. The results of this study imply that the role of OSDAs is not only important for the host–guest interaction but also crucial for controlling the reactivity of different silicate oligomers during the initial stage of zeolite formation.

show abstract

“…This approach has generic applicability, and it is extensively used in earlier studies to calculate free-energy barrier reactions in solution. 20 , 59 − 62 …”

Section: Simulation Methodsmentioning

confidence: 99%

Elucidating the Role of Tetraethylammonium in the Silicate Condensation Reaction from Ab Initio Molecular Dynamics Simulations

Lan

Hoang

et al. 2020

J. Phys. Chem. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…These observations indicated the need for an in‐depth investigation of solvent effects on the mechanism of hydrogen production from aqueous methanol promoted by complex 2′ . The importance of an explicit description of the solvent had also been demonstrated for aqueous methanol dehydrogenation catalysed by the [Ru(PNP)] complex, in addition to a number of other catalytic systems including water oxidation and transfer hydrogenation of ketones …”

Section: Introductionmentioning

confidence: 99%

An In‐Depth Mechanistic Study of Ru‐Catalysed Aqueous Methanol Dehydrogenation and Prospects for Future Catalyst Design

Govindarajan

Sinha²,

Trincado

et al. 2020

ChemCatChem

Self Cite

View full text Add to dashboard Cite

Herein we provide mechanistic insights into the dehydrogenation of aqueous methanol catalysed by the [Ru(trop2dae)] complex (which is in‐situ generated from [Ru(trop2dad)], trop2dad=1,4‐bis(5H‐dibenzo[a,d]cyclohepten‐5‐yl)‐1,4‐diazabuta‐1,3‐diene), established by density functional theory based molecular dynamics (DFT‐MD) and static DFT calculations incorporating explicit solvent molecules. The aqueous solvent proved to participate actively in various stages of the catalytic cycle including the catalyst activation process, and the key reaction steps involving C−H activation and hydrogen production. The aqueous solvent forms an integral part of the reactive system for the C−H activation steps in the [Ru(trop2dae)] system, with strong hydrogen bond interactions with the anionic oxygen (RO−, R=CH3, CH2OH, HCO) and hydride moieties formed along the reaction pathway. In contrast to the [Ru(trop2dad)] catalyst, C−H activation and hydrogen production does not proceed via a metal‐ligand cooperative pathway for the [Ru(trop2dae)] system. The pKa of the coordinated amine donors in these complexes provides a rationale for the divergent reactivity, and the obtained mechanistic information provides new guidelines for the rational design of active and additive free catalytic systems for aqueous methanol dehydrogenation.

show abstract

“…While computational studies about the above‐mentioned systems (see e.g., refs. [23–38]) on structural stability and reaction pathways have been published, mostly only a general picture of reaction related species, for example, reactants, transition states, intermediates, and products, based on energy criteria has been reported using Kohn–Sham DFT. [ 39 ] While DFT calculations often provide accurate nuclear structures, they can produce an incorrect description of the electronic structure, leading to difficulties in for example, dealing with near‐degeneracy in bond breaking/formation processes [ 40,41 ] or low‐energy spin states of transition metal complexes, [ 42–44 ] which can be of significance when one would like to have a deeper view into chemical reactions.…”

Section: Introductionmentioning

confidence: 99%

Complete active space analysis of a reaction pathway: Investigation of the oxygen–oxygen bond formation

Han

Luber

2020

J Comput Chem

View full text Add to dashboard Cite

Water nucleophilic attack is an important step in water oxidation reactions, which have been widely studied using density functional theory (DFT). Nevertheless, a single-determinant DFT picture may be insufficient for a deeper insight into the process, in particular during the oxygen-oxygen bond formation. In this work, we use complete active space self-consistent field calculations and describe an approach for a complete active space analysis along a reaction pathway. This is applied to the water nucleophilic attack at a Ru-based catalyst, which has successfully been used for efficient water oxidation and in silico design of new water oxidation catalysts recently. K E Y W O R D Scomplete active space, multiconfigurational method, reaction pathway, water nucleophilic attack, water oxidation

show abstract

Impact of the Ligand Flexibility and Solvent on the O–O Bond Formation Step in a Highly Active Ruthenium Water Oxidation Catalyst

Cited by 48 publications

References 37 publications

Elucidating the Role of Tetraethylammonium in the Silicate Condensation Reaction from Ab Initio Molecular Dynamics Simulations

Elucidating the Role of Tetraethylammonium in the Silicate Condensation Reaction from Ab Initio Molecular Dynamics Simulations

An In‐Depth Mechanistic Study of Ru‐Catalysed Aqueous Methanol Dehydrogenation and Prospects for Future Catalyst Design

Complete active space analysis of a reaction pathway: Investigation of the oxygen–oxygen bond formation

Contact Info

Product

Resources

About