On the Formation of Palladium (II) Iodide Nanoparticles: An In Situ SAXS/XAS Study and Catalytic Evaluation on an Aryl Alkenylation Reaction in Water Medium

Abstract

The synthesis of small spherical palladium(II) iodide nanoparticles is reported for the first time. The formation of the particles by ligand exchange, in the presence of poly(vinyl pyrrolidone) in aqueous medium at room temperature, was investigated by in situ time‐resolved synchrotron‐based SAXS and XANES/EXAFS analysis. These new nanomaterials exhibit a double catalytic role in an aryl alkenylation chemical reaction, working without a base or ligand, in aqueous milieu. There is strong experimental evidence to suggest that the mechanism follows a single‐electron transfer (SET) pathway with the participation of iodide as a radical promoter and the palladium atoms as activator of the alkene moiety. This new protocol could evolve into a broadly applicable radical reaction for the functionalization of alkenes.

In Situ Synchrotron X‐ray Characterization Shining Light on the Nucleation and Growth Kinetics of Colloidal Nanoparticles

“…The number of NPs slightly decreased at ~200 s due to Ostwald ripening, which led to a size focusing of the NPs. The in situ SAXS has been successfully applied to study the synthesis of CNPs of a wide range of materials including Ag [27] , Au [28] , Pd [29] , Pt [30] , PdI2 [31] , CdS [32] , ZnO [33] , Iron oxide [34] , SiO2 [35] , CaCO3 [36] , metal-organic frameworks (MOFs) [37] , and zeolitic imidazolate frameworks (ZIFs) [38] .…”

An Imidazole‐Rich Pd(II)‐Polymer Pre‐catalyst for the Suzuki‐Miyaura Coupling: Stability Influenced by Dissolved Oxygen and Reactants Concentration

“…The decrease in Pd(0) contribution might be associated with the increase of these particles size, resulting in a reduction of the surface area available for XPS analysis, resulting in an apparent increase of the Pd(II) portion. Therefore, akin to Latocheski et al, [66] who reported the formation of PdI 2 nanoparticles, the particles shown in Figure S8 are mainly composed of Pd(II) ions.…”

Understanding Synthesis and Structural Variation of Nanomaterials Through In Situ/Operando XAS and SAXS

“…evaluated the kinetics of the formation of PdI 2 colloids prepared by ligand exchange in an aqueous medium at room temperature. [ 36 ] In situ SAXS data indicated that the diameter of PdI 2 NPs increases and dispersity decreases as the reaction time advances. The higher KI concentration leads to faster kinetics and the formation of smaller NPs.…”