DppfCuBH: 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 (dppf is 1,1'-bis(diphenyphosphino)ferrocene) is introduced for the first time to prepare ferrocene-functionalized metal nanoclusters. Two new clusters of [AgCu(dppf)(3-F-PhCC)Cl] (1) and [Ag(dppf)Cl] (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@AgCu(dppf)(3-F-PhCC)Cl core-shell structure of 1 and [AgCl(dppf)]-dppf-[AgCl(dppf)] polymeric structure of 2. This work opens the door to employing dppfCuBH as a functional reducing agent to discover many underlying metal nanoclusters and even other nanomaterials which feature ferrocene-groups.