Smart Reversible Transformations between Chiral Superstructures of Copper Clusters for Optical and Chiroptical Switching

Abstract

Superstructures made from nanoscale clusters with new collective properties are promising in high-tech applications; however, chiral superstructures remain elusive, and the limited intercluster coupling effect at room temperature hampers the tailoring of collective properties. Here, we show that from chiral monomeric copper clusters to two enantiomeric pairs of supercrystals with distinct phases, the absorption band edge red-shifts by over 1.3 eV, with photoluminescence and circularly polarized phosphorescence from visible (572 nm) to near-infrared (NIR, 858 nm). These supercrystals with high NIR quantum yields of up to 45% at room temperature are prototyped for night-vision imaging. In response to solvent and temperature stimuli, chiral supercrystal-to-supercrystal transformations occurred, concomitant with high-contrast optical/chiroptical switching. In situ single-crystal Xray diffraction (SCXRD), steady-state and time-resolved optical spectroscopy, and response experiments combined with theoretical calculations demonstrate that distance-sensitive intercluster orbital interactions contribute to the exceptional collective optical responses. Such chiral supercrystals built from subnanoscale metal clusters with novel collective chiroptical responses would be useful in the fields of information storage and NIR optical devices.

Heterometallic Au(I)–Cu(I) Clusters: Luminescence Studies and1O2Production

“…A red shift of the emission is recorded in almost all cases (except for Cu2a ) when the powders are cooled (Figure ). The observed red shift at low temperatures has been observed in other heterometallic Au­(I)/Cu­(I) complexes reported in the literature. − …”

The effect of conjugation degree of aromatic carboxylic acids on electronic and photo-responsive behaviors of naphthalenediimide-based coordination polymers

“…Organic–inorganic hybrid photochromic systems composed of electron donors (EDs) and electron acceptors (EAs) have attracted a great degree of scientific attention due to their exceptional photo-responsive characteristics (instantaneous photo-responsive rate, wide photo-responsive range and intense coloration contrast) and wide range of application prospects in data storage, optical switches, sensors, protection, inkless printing and so forth. 1–17 Some extraordinary achievements have been made in organic–inorganic hybrid photochromic materials through ingenious structural design. 18–21 Especially, the photochromic performances in terms of photo-responsive rate, photo-response range and coloration contrast of these hybrids have been optimized by rational selection and masterly integration of EDs and EAs as well as effectively modulating intermolecular electronic behaviors.…”

High-Efficiency Pure Blue Circularly Polarized Phosphorescence from Chiral N-Heterocyclic-Carbene-Stabilized Copper(I) Clusters

“…30−32 They exhibit a wide range of tunable luminescence properties 33−35 and diverse chirality. 36−49 Green, 38,48 yellow, 36,46 red, 39,40,49 and near-infrared (NIR) 37,41,44 CPP with higher efficiency has been achieved in metal clusters through the fine-tuning of the inorganic metal skeleton and/or organic protecting ligands. For example, the Tang group pioneered the yellow CPL with a PLQY of 3.6% in the Au 3 cluster based on the chiral phosphine ligand.…”