Highly Effective Hybrid Copper(I) Iodide Cluster Emitter with Negative Thermal Quenched Phosphorescence for X-Ray Imaging

The low efficiency triplet emission of hybrid copper(I) iodide clusters is a critical obstacle to their further practical optoelectronic application. Herein, we present an efficient hybrid copper(I) iodide cluster emitter (DBA)₄ Cu₄ I₄ , where the cooperation of excited state structure reorganization and the metallophilicity interaction enables ultra-bright triplet yellow-orange emission with a photoluminescence quantum yield over 94.9 %, and the phonon-assisted de-trapping process of exciton induces the negative thermal quenching effect at 80-300 K. We also investigate the potential of this emitter for X-ray imaging. The (DBA)₄ Cu₄ I₄ wafer demonstrates a light yield higher than 10⁴  photons MeV^-1 and a high spatial resolution of ≈5.0 lp mm^-1 , showing great potential in practical X-ray imaging applications. Our new copper(I) iodide cluster emitter can serve as a model for investigating the thermodynamic mechanism of photoluminescence in hybrid copper(I) halide phosphorescence materials.

Superatomic Three-Center Bond in a Tri-Icosahedral Au36Ag2(SR)18 Cluster: Analogue of 3c-2e Bond in Molecules

Probing the nature of electronic stability for ligand-protected gold clusters is important in gold chemistry. A thermally stable Au₃₆Ag₂(SR)₁₈ nanocluster was synthesized recently. It has a D_3h tri-icosahedral [Au₃₀Ag₂]¹²⁺ core with 20 valence electrons, which does not follow the magic number of gold superatoms. Herein, we propose a superatomic three-center bond to unveil its electronic stability. The [Au₃₀Ag₂]¹²⁺ core is viewed as a union of three face-fused superatoms, and chemical bonding analysis suggests a three-superatom-center two-electron (3sc-2e) bond for the octet rule of each superatom, which mimics the bonding framework of the D_3h O₃^2- molecule. Moreover, a liganded tri-icosahedral [Au₂₇Pt₃Ag₂]¹¹⁺ core with 18 valence electrons is predicted, and three 2sc-2e bonds are formed between each of two superatoms to satisfy the octet rule (analogue of D_3h O₃), indicating the flexibility of superatomic bonding. Such a superatomic three-center bond extends the community of superatomic bonding and gives a new perspective for superatom assembling.

Making copper, silver and gold fullerene cages breathe

We show that optical properties change when the fullerene structures of Au₃₂, Cu₃₂and Ag₃₂inflate and deflate. We first observe significant differences in the extinction spectra employing a classical approach based on the Green's dyadic method. By means of real-time time-dependent density functional theory. We continue to calculate the optical spectrum (OP) via aδ-kick simulation, comparing results with the ground-state energetic property the HOMO-LUMO (HL) gap. Red-shift of the OP is expected as the fullerenes inflate, with only ±10% change in the size. As the fullerene breathes, a 0.8 eV shift in the first peak position could be observed in the gold nanoparticle. Ag has a smoother behaviour than both Au and Cu. We have also found changes in the optical spectra can not be directly interpreted as a result of changes in the HL gap.