We introduce here a new subclass of copper(I) hybrid emitters simultaneously containing [Cu_xI_y]^z− anions and Cu⁺ cations, separated in space by a Janus head ligand. When UV-irradiated at 298 K, these unique “Two-In-One” hybrids exhibit a short-lived green TADF with near-unity quantum yield and a strong solvatochromic effect. Moreover, they manifest a strong radioluminescence upon X-ray irradiation. These findings open up new possibilities for the design of highly performing TADF materials.

A family of brightly luminescent dinuclear complexes of [Cu(μ₂-X)(N^N)]₂ type (X = I or SCN) has been synthesized in 76–90% yields by the reaction of bis(2-pyridyl)phosphine oxides (N^N) with the corresponding Cu(I) salts. The X-ray diffraction study reveals that the Cu₂I₂ core of the [Cu(μ₂-I)(N^N)]₂ complexes has either a butterfly- or rhomboid-shaped structure, while the eighth-membered [Cu(^SCN _NCS)Cu] ring in the [Cu₂(SCN)₂(N^N)]₂ complexes is nearly planar. In the solid state, these compounds exhibit a strong green-to-yellow emission (λ^em _max = 536–592 nm) with high PLQYs (up to 63%) and short lifetimes (1.9–10.0 μs). The combined photophysical and DFT study indicates that the ambient-temperature emission of the complexes obtained can be assigned to the thermally activated-delayed fluorescence (TADF) from the ¹(M + X)LCT excited state, while at 77 K, phosphorescence from the ³(M + X)LCT state is likely observed.

The first observation of luminescence from Ag(I) complexes with a square-planar geometry of the metal is reported. [Ag(Py₃PO)₂]ClO₄ and [Ag(Py₃PO)₂]OTf – first examples of the emissive square-planar Ag(I) complexes – have been synthesized by the reaction of tris(2-pyridyl)phosphine oxide (Py₃PO) with Ag(I) salts. Both complexes exhibit pronounced photoluminescence in the solid state at ambient temperature with nano- and microsecond lifetime components. Remarkably, the luminescence of the complexes has a reversible thermochromic behavior, changing their emission color from yellow (λ^em _max ≈ 585 nm) at room temperature to red-orange (λ^em _max = 620 nm) at 77 K. The spectroscopic and computational results reveal that the emission of the title compounds can be assigned to the ³MLCT phosphorescence with admixture of the ¹MLCT fluorescence.