Cations Controlling the Chiral Assembly of Luminescent Atomically Precise Copper(I) Clusters

Abstract

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH3OH)2(18‐crown‐6)]+[Cu5(StBu)6]− (1⋅CH3OH) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu5(StBu)6]− cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH3OH of the cationic units turned the chiral 1⋅CH3OH crystal into a mesomeric crystal [K(18‐crown‐6)]+[Cu5(StBu)6]− (1), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu5(StBu)6]− units. The switchable chiral/achiral rearrangement of [Cu5(StBu)6]− clusters along with the capture/release of CH3OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d/l‐valinol(18‐crown‐6)]+[Cu5(StBu)6]− (d/l‐Cu5V), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1⋅CH3OH and mesomeric 1.

Atom-precise fluorescent copper cluster for tumor microenvironment targeting and transient chemodynamic cancer therapy

“…Our previous work also explored photothermic behavior from coordinated-metal centers for cancer therapy [31]. By far, our group have designed and synthesized dozens of metal NCs with atomically precise assembly [32][33][34][35][36][37][38]. Benefiting from the precise formulas, both the structure and the physicochemical properties of atomically precise metal NCs are controllable [39,40].…”

Revealing the chirality origin and homochirality crystallization of Ag14 nanocluster at the molecular level

“…The majority of chirality typically belongs to the second type in nanoclusters because inter-ligand non-covalent interactions such as π···π stacking, C–H···π, hydrogen bond interactions etc. can effectively drive the asymmetric arrangement of surface structures 25 . While the last type is rather difficult to access in experiments due to the more subtle influencing factors.…”