Water-soluble metal nanoparticles with PEG-tagged 15-membered azamacrocycles as stabilizers

The synthesis of palladium, platinum and ruthenium nanoparticles stabilized by azamacrocycles bearing polyoxyethylenated chains has been achieved by decomposition of the corresponding organometallic precursors (Pd(dba)(2), Pt(2)(dba)(3) and Ru(COD)(COT)) under dihydrogen atmosphere, whereas gold and rhodium nanoparticles have been obtained in the presence of these ligands by reduction of HAuCl(4) and RhCl(3), respectively. The metal nanoparticles were characterized by several techniques including IR, NMR, UV-vis, HRTEM, ED, and elemental analysis. The Pd nanoparticles have been used as recoverable catalyst in Suzuki cross-coupling in aqueous medium.