ABSTRACT
Four group 10 metal nanoclusters, Ni10(4-MePhS)20, Ni11(PhS)22, Pd9(PhS)18 and Pd10(PhS)20 were synthesized from disulfides based on a photochemical reduction-oxidation cascade process, which proceeds via a different mechanism to that of the conventional two-step reduction process. The as-obtained nanoclusters possess oxidative resistance and structural robustness under different conditions. Their atomically precise structures are determined to be nickel or palladium rings in which the metal atoms are bridged by Ar-S groups. Their catalytic performance in oxygen reduction reaction was compared, and the ring size-dependent catalytic activity of the group 10 metal nanoclusters was revealed. This work provides an efficient route to atomically precise and structurally stable group 10 metal nanoclusters, and sheds light on their further applications in electrocatalysis.
ABSTRACT
A gold nanocluster Au17 Cd2 (PNP)2 (SR)12 (PNP=2,6-bis(diphenylphosphinomethyl)pyridine, SR=4-MeOPhS) consisting of an icosahedral Au13 kernel, two Au2 CdS6 staple motifs, and two PNP pincer ligands has been designed, synthesized and well characterized. This cadmium and PNP pincer ligand co-modified gold nanocluster showed high catalytic efficiency in the KA2 reaction, featuring high TON, mild reaction conditions, broad substrate scope as well as catalyst recyclability. Comparison of the catalytic performance between Au17 Cd2 (PNP)2 (SR)12 and the structurally similar single cadmium (or PNP) modified gold nanoclusters demonstrates that the co-existence of the cadmium and PNP on the surface is crucial for the high catalytic activity of the gold nanocluster. This work would be enlightening for developing efficient catalysts for cascade reactions and discovering the catalytic potential of metal nanoclusters in organic transformations.
ABSTRACT
An Au4Ni2 nanocluster containing a square-planar [-PPh2-Au-S-Au-]2 ring and two nickel-pincer arms is reported here. Abundant intra- and inter-cluster noncovalent interactions promote the assembly of the nanocluster into a porous framework material. The assembly-dependent unique solubility and photoluminescence were also investigated.