Long-term stable 3 nm gold nanoparticles are prepared by a simple reaction between HAuCl4 and sodium borohydride in water under ambient conditions which very efficiently catalyze 4-nitrophenol reduction to 4-nitroaniline.

The stereoelectronic properties of the stabilizing ligands of gold nanoparticles (AuNPs) are shown to play a considerable role in their catalytic efficiency for 4-nitrophenol reduction by NaBH4, consistent with a mechanism involving restructuration of the AuNP surface that behaves as an "electron reservoir".

[{Ir(Cod)Cl}2] (Cod = 1,5-cyclooctadiene) reacts with o-(diphenylphosphino)benzaldehyde (PPh2(o-C6H4CHO)) (Ir:P = 1:2) in methanol to give the hydridoirida-β-diketone complex [IrH{(PPh2(o-C6H4CO))2H}Cl] (1). The reactivity of 1 to afford neutral and cationic hydridoirida-β-diketones is also discussed