Palladium Acetate Trimer: Understanding Its Ligand-Induced Dissociation Thermochemistry Using Isothermal Titration Calorimetry, X-ray Absorption Fine Structure, and 31P Nuclear Magnetic Resonance
| Autor: | Saeed Mozaffari, Sergei A. Ivanov, Wenhui Li, Ayman M. Karim, Narasimhamurthy Shanaiah |
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| Rok vydání: | 2018 |
| Předmět: |
010405 organic chemistry
Organic Chemistry Trioctylphosphine chemistry.chemical_element Isothermal titration calorimetry Trimer Homogeneous catalysis 010402 general chemistry 01 natural sciences Dissociation (chemistry) 0104 chemical sciences X-ray absorption fine structure Inorganic Chemistry chemistry.chemical_compound Nuclear magnetic resonance chemistry Thermochemistry Physical and Theoretical Chemistry Palladium |
| Zdroj: | Organometallics. 38:451-460 |
| ISSN: | 1520-6041 0276-7333 |
| Popis: | Palladium acetate trimer, Pd3(OAc)6, is a common precursor for Pd nanoparticle synthesis and an important precatalyst for homogeneous catalysis reactions. Added ligands (L, e.g., phosphines) are well-known to dissociate the Pd3(OAc)6 trimer into Pd(OAc)2 monomers and form Pd(OAc)2(L)2 complexes. Despite the importance of the trimer dissociation and ligand–monomer binding thermodynamics on the properties of the resulting Pd complex, little is known about either reaction. Using a combination of isothermal titration calorimetry (ITC), X-ray absorption fine structure (XAFS), and 31P nuclear magnetic resonance (31P NMR) on trimer samples containing monomer impurities, we developed a methodology and a trimer–monomer ITC model to obtain the Gibbs free energy, enthalpy, and entropy for both reactions in toluene and quantify the monomer content. The results provide the following, previously inaccessible, quantitative insights on the reactions. Trioctylphosphine (TOP)-monomer binding reaction is enthalpically drive... |
| Databáze: | OpenAIRE |
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