Synergistic coordination of diphosphine with primary and tertiary phosphorus centers: Ultrastable icosidodecahedral Ag nanoclusters with metallic aromaticity.

As versatile ligands with extraordinary coordination capabilities, RPH (R = alkyl or aryl) are rarely used in constructing metal nanoclusters due to their volatility, toxicity, spontaneous flammability, and susceptibility to oxidation. In this work, we designed a primary and tertiary phosphorus-bound diphosphine chelator (2-PhPCHPH) to create ultrastable silver nanoclusters with metallic aromaticity. By controlling the deprotonation rate of 2-PhPCHPH and adjusting the templates, we successfully synthesized two near-infrared emissive nanoclusters, and , which have analogous icosidodecahedral Ag shells with an symmetry. Deprotonated ligand (2-PhPCHP) exhibits a coordination mode of μ-η(P),η(P,P), which endows a unique metallic aromaticity to and . The solution-processed organic light-emitting diodes based on achieve an external quantum efficiency of 15.1%, representing the breakthrough in application of silver nanoclusters to near-infrared-emitting devices. This work represents a special ligand system for synthesizing ligand-protected coinage metal nanoclusters and opens up horizons of creating nanoclusters with distinct geometries and metal aromaticity.