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Palladium monophosphine Pd(PPh3): is it really accessible in solution?
Pietro Vidossich1, Gregori Ujaque, Agustí Lledós
1Departament de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallés, Spain. vido@klingon.uab.es gregori@klingon.uab.es agusti@klingon.uab.es.
Chemical Communications (Cambridge, England)
|November 28, 2013
Summary
This study reveals that bare palladium monophosphine species are not found in solution. Realistic simulations show solvent molecules coordinate to palladium, forming accessible solvated species like (Sol)Pd(PPh3).
Area of Science:
- Homogeneous catalysis
- Organometallic chemistry
- Computational chemistry
Background:
- Catalyst speciation is crucial for understanding reaction mechanisms in homogeneous catalysis.
- Previous models often simplified solvent interactions, potentially misrepresenting active catalytic species.
Purpose of the Study:
- To investigate solvent coordination in palladium-triphenylphosphine (Pd-PPh3) systems using advanced computational methods.
- To determine the accessibility of various palladium species in solution, including the commonly depicted bare monophosphine species.
Main Methods:
- Utilizing ab initio molecular dynamics (AIMD) simulations.
- Employing realistic models with explicit solvent representation.
Main Results:
- Demonstrated the accessibility of solvated palladium species: (Sol)Pd(PPh3), (Sol)Pd(PPh3)2, and (Sol)2Pd(PPh3).
- Conclusively showed that the bare Pd(PPh3) species is not accessible in solution under the studied conditions.
Conclusions:
- Solvent coordination significantly influences palladium speciation in solution.
- The commonly assumed bare Pd(PPh3) active species is likely an inaccurate representation in solution-phase homogeneous catalysis.
