Synergistic coordination of diphosphine with primary and tertiary phosphorus centers: Ultrastable icosidodecahedral Ag30 nanoclusters with metallic aromaticity | Science Advances
Abstract
As versatile ligands with extraordinary coordination capabilities, RPH
2
(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-Ph
2
PC
6
H
4
PH
2
) to create ultrastable silver nanoclusters with metallic aromaticity. By controlling the deprotonation rate of 2-Ph
2
PC
6
H
4
PH
2
and adjusting the templates, we successfully synthesized two near-infrared emissive nanoclusters,
Ag30
and
Ag32
, which have analogous icosidodecahedral Ag
30
shells with an
I
h
symmetry. Deprotonated ligand (2-Ph
2
P
α
C
6
H
4
P
β
2−
) exhibits a coordination mode of μ
5
-η
1
(P
β
),η
2
(P
α
,P
β
), which endows a unique metallic aromaticity to
Ag30
and
Ag32
. The solution-processed organic light-emitting diodes based on
Ag30
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.