Rh/DNA Nanoparticles, Synthesis, Characterization and Catalytic Activity in On Water Asymmetric Hydroformylation Reaction

DNA-stabilized Rh NPs were synthesized by the chemical reduction of Rh(acac)(CO)(2) (acac=acetylacetonate) in water at 80 degrees C. The obtained nanoparticles, Rh/DNA, were characterized by various spectroscopic and microscopic methods, such as IR, UV-Vis, XRD (X-ray diffraction), ICP-AES (Inductively coupled plasma atomic emission spectroscopy), EDX (Energy-dispersive X-ray spectroscopy analysis), TEM (Transmission electron microscopy), and SEM (Scanning electron microscopy) analyses. Their catalytic activity was successfully investigated in the ''on water'' hydroformylation of styrene. The conversion of styrene and chemoselectivity towards aldehydes were 100%. A high iso/n ratio was also obtained, up to 6.1 and 16.7 with PPh3 (triphenylphosphine) and (R)-BINAP (2,2'-bis(diphenylphosphino)-1,1'-binaphthyl) ligands respectively. In the hydroformylation of vinyl acetate with Rh/DNA, performed in the presence of a chiral BINAP ligand ''on water'', high enantioselectivity was obtained, up to 49% ee. These results were significantly better than when utilizing Rh(acac)(CO)(2) as a catalyst under the same conditions.