DppfCuBH 4 : new reducing agents for the synthesis of ferrocene-functionalized metal nanoclusters.

A facile synthesis of atomically precise metal nanoclusters, especially those decorated with functional groups, is the prerequisite for finding applications in special fields and studying structure-and-property relationships. The exploration of simple and efficient synthetic prototypes for introducing functional ligands (such as ferrocene) into cluster moieties is thus of high interest. In this work, a type of reducing agent of dppfCuBH 4 (dppf is 1,1'-bis(diphenyphosphino)ferrocene) is introduced for the first time to prepare ferrocene-functionalized metal nanoclusters. Two new clusters of [Ag 25 Cu 4 (dppf) 6 (3-F-PhCC) 12 Cl 6 ] 3+ (1) and [Ag 4 (dppf) 5 Cl 2 ] 2+ (2) have been obtained from the simple synthetic method. The two compounds have been fully characterized by advanced techniques of electrospray ionization mass spectroscopy (ESI-MS), nuclear magnetic resonance (NMR), and ultraviolet-visible spectroscopy (UV-Vis). The total structure of the clusters, as determined by X-ray single-crystal diffraction, describes the Ag 13 @Ag 12 Cu 4 (dppf) 6 (3-F-PhCC) 12 Cl 6 core-shell structure of 1 and [Ag 2 Cl(dppf) 2 ] + -dppf-[Ag 2 Cl(dppf) 2 ] + polymeric structure of 2. This work opens the door to employing dppfCuBH 4 as a functional reducing agent to discover many underlying metal nanoclusters and even other nanomaterials which feature ferrocene-groups.