Palladium nanoparticles in ionic liquids stabilized by mono-phosphines. Catalytic applications

Abstract

Palladium nanoparticles generated from organometallic complexes in the presence of functionalized mono-phosphines (L1-L3), in both THF and imidazolium-based ionic liquids (ImILs), were successfully synthesized. Depending on the phosphine and solvent nature, PdNPs with different extent of aggregation were observed. Actually, the ligand L1, P(CH2CH2CH2Ph)3, led to small and well-dispersed nanoparticles in both ILs, [BMI][PF6] and [EMI][HP(O)2OMe], in contrast to more agglomerated PdNPs obtained in THF. PdNPs in ILs were catalytically active and chemoselective in C-C cross-coupling (Suzuki-Miyaura and Heck-Mizoroki) and hydrogenation reactions. Well-defined Pd(0) and Pd(II) organometallic complexes containing L1, [PdCl2(L1)2] and [Pd(ma)(L1)2], were also prepared for comparative purposes.