Novel super-structures resulting from the coordination of chiral oxazolines on platinum nanoparticles

The reaction of Pt-2(dba)(3) with CO in toluene leads rapidly to the formation of platinum nanoparticles which can be further stabilized by addition of aminoalcohol or oxazoline ligands. The coordination of the oxazoline ligands at the surface of the particles is demonstrated by IR after purification of the colloids. The fcc structure of the particles is evidenced by WAXS investigations, a statistical method which also gives information about the degree of crystallinity of the particles. TEM and HREM micrographs reveal surprising organisations of the particles into super-structures depending on the nature and/or position of the substituents present on the ligands. In addition, these particles are catalytically active in the hydrogenation of ethyl pyruvate, even if the preliminary results are modest.