HIGH-RESOLUTION ELECTRON-MICROSCOPY OBSERVATIONS OF LARGE PD CLUSTERS

Giant cationic palladium clusters approximated as Pd561L60(OAc)180 (L = Dipy, Phen) have been characterized by electron diffraction and high resolution microscopy. Most of the Pd clusters showed a cuboctahedral structure with an observed size obeying a normal distribution centred around 2.2 +/- 0.4 nm. The electron diffraction patterns confirmed th at the structure of the observed Pd particles is FCC with lattice para meter very close to those of metallic palladium. Most of the larger pa rticles (8 nm) exhibit multiple twinning. High resolution images confi rmed that some of these particles have a distorted icosahedron structu re.