Heterometallic Coinage Metal Acetylenediide Clusters Showing Tailored Thermochromic Luminescence

Abstract Acetelyenediide (C 2 2− ) species have been encapsulated in bimetallic and trimetallic clusters: [(AuL) 6 Ag 7 (C≡C) 3 ](BF 4 ) 7 ( 2 ) and [(AuL) 6 AgCu 6 (C≡C) 3 ](BF 4 ) 7 ( 3 ), L=phenylbis(2‐pyridyl)phosphine (PPhpy 2 ). Single‐crystal X‐ray diffraction analysis revealed that they are isostructural and six silver atoms in 2 are replaced with copper in 3 . Both clusters have a trefoil skeleton, which can be viewed as three trigonal bipyramidal (LAu‐C≡C‐AuL)M 2 Ag (M=Ag/Cu) motifs sharing a common silver atom. TDDFT calculations showed Cu‐doping significantly increases the energy level of (C 2 ‐Cu)‐involved occupied orbital, thus inducing interesting transition coupling of dual‐emission at low temperature. This work not only provides a strategy for constructing heterometallic clusters, but also shows the prospect for pursuing novel thermochromic luminescent materials by incorporating multi‐congeneric metal components.