Organic–Inorganic Hybrid Glasses of Atomically Precise Nanoclusters

Abstract

High Resolution Image Download MS PowerPoint Slide Organic–inorganic atomically precise nanoclusters provide indispensable building blocks for establishing structure–property links in hybrid condensed matter. However, robust glasses of ligand-protected nanocluster solids have yet to be demonstrated. Herein, we show [Cu 4 I 4 (PR 3 ) 4 ] cubane nanoclusters coordinated by phosphine ligands (PR 3 ) form robust melt-quenched glasses in air with reversible crystal–liquid–glass transitions. Protective phosphine ligands critically influence the glass formation mechanism, modulating the glasses’ physical properties. A hybrid glass utilizing ethyldiphenylphosphine-based nanoclusters, [Cu 4 I 4 (PPh 2 Et) 4 ], exhibits superb optical properties, including >90% transmission in both visible and near-infrared wavelengths, negligible self-absorption, near-unity quantum yield, and high light yield. Experimental and theoretical analyses demonstrate the structural integrity of the [Cu 4 I 4 (PPh 2 Et) 4 ] nanocluster, i.e., iodine-bridged tetranuclear cubane, has been fully preserved in the glass state. The strong internanocluster CH−π interactions found in the [Cu 4 I 4 (PPh 2 Et) 4 ] glass and subsequently reduced structural vibration account for its enhanced luminescence properties. Moreover, this highly transparent glass enables performant X-ray imaging and low-loss waveguiding in fibers drawn above the glass transition. The discovery of “nanocluster glass” opens avenues for unraveling glass formation mechanisms and designing novel luminescent glasses of well-defined building blocks for advanced photonics.