Microkinetic Assessment of Ligand-Exchanging Catalytic Cycles

Area of Science:

• Computational chemistry
• Chemical kinetics
• Catalysis

Background:

• Computational chemistry is vital for understanding and optimizing catalytic processes, particularly homogeneous organometallic catalysts.
• Microkinetic studies link computational Gibbs free energies to experimental data like conversion and selectivity.

Purpose of the Study:

• To develop an automated framework (MicroKatc) for microkinetic analysis.
• To investigate the impact of *in situ* ligand exchange on catalytic scaffolds.
• To apply the framework to rhodium-catalyzed ethylene hydroformylation.

Main Methods:

• Development of the automated MicroKatc framework for microkinetic analysis.
• Simulation of rhodium-catalyzed ethylene hydroformylation under varying trimethylphosphine (PMe3) concentrations.
• Determination of degree of rate control (DRC) and apparent activation energies.

Main Results:

• The MicroKatc framework successfully modeled *in situ* ligand exchange effects.
• Simulations confirmed that trimethylphosphine (PMe3) ligand exchange accelerates rhodium-catalyzed ethylene hydroformylation.
• The study determined the degree of rate control and apparent activation energies during the catalytic process.

Conclusions:

• The automated MicroKatc framework is effective for microkinetic analysis of catalytic systems with ligand exchange.
• Ligand exchange, specifically PMe3 displacing carbonyls, significantly enhances the rate of ethylene hydroformylation.
• This work provides a computational tool for deeper understanding and optimization of homogeneous catalysis.