Polymers I-X with functionalized main chain were synthesized from commercial polymers containing reactive groups, anhydride (for Gantrez), or carboxylate (for polyacrylates) moieties, to be used as stabilizers of metallic nanoparticles. H-1 HRMAS, C-13 MAS NMR, IR, and GPC techniques were applied to characterize the new polymers. Metal transition nanoparticles stabilized with these polymers were prepared in organic solvents (Pd and Pt) and also in water/ethanol medium (Rh), under hydrogen atmosphere. TEM analysis revealed the formation of small nanoparticles, in the range similar to 3-20 mn, depending on the solvent, metal precursor, metal concentration, and polymer nature. Preliminary catalytic applications, C-C couplings using palladium and hydrogenations using platinum and rhodium systems in organic and also aqueous medium, were tested. (C) 2007 Wiley Periodicals, Inc.