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

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH3 OH)2 (18-crown-6)]+ [Cu5 (St Bu)6 ]- (1⋅CH3 OH) in the chiral space group was prepared, in which the chiral red-emissive anionic [Cu5 (St Bu)6 ]- cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH3 OH of the cationic units turned the chiral 1⋅CH3 OH crystal into a mesomeric crystal [K(18-crown-6)]+ [Cu5 (St Bu)6 ]- (1), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu5 (St Bu)6 ]- units. The switchable chiral/achiral rearrangement of [Cu5 (St Bu)6 ]- clusters along with the capture/release of CH3 OH 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 (St Bu)6 ]- (d/l-Cu5V ), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL-silent racemic mixture of 1⋅CH3 OH and mesomeric 1.

Self-Assembly of a Stable Silver Thiolate Nanocluster Encapsulating a Lacunary Keggin Phosphotungstate Anion.

A polyoxometalate-templated silver(I) thiolate nanocluster has been synthesized by a one-pot reaction in high yield. This novel and stable nanocluster exhibits a core-shell structure with a Ag67S36 shell and two lacunary Keggin [PW9O34]9- cores, which is fully characterized by X-ray crystallography, X-ray photoelectron spectroscopy, UV-vis, powder X-ray diffraction, and cyclic voltammetry.

Tandem Silver Cluster Isomerism and Mixed Linkers to Modulate the Photoluminescence of Cluster-Assembled Materials.

Silver chalcogenolate cluster assembled materials (SCAMs) are a category of promising light-emitting materials the luminescence of which can be modulated by variation of their building blocks (cluster nodes and organic linkers). The transformation of a singly emissive [Ag12 (SBut )8 (CF3 COO)4 (bpy)4 ]n (Ag12 bpy, bpy=4,4'-bipyridine) into a dual-emissive [(Ag12 (SBut )6 (CF3 COO)6 (bpy)3 )]n (Ag12 bpy-2) via cluster-node isomerization, the critical importance of which was highlighted in dictating the photoluminescence properties of SCAMs. Moreover, the newly obtained Ag12 bpy-2 served to construct visual thermochromic Ag12 bpy-2/NH2 by a mixed-linker synthesis, together with dichromatic core-shell Ag12 bpy-2@Ag12 bpy-NH2 -2 via solvent-assisted linker exchange. This work provides insight into the significance of metal arrangement on physical properties of nanoclusters.

Effects of treadmill exercise on anxiety-like behavior in association with changes in estrogen receptors ERα, ERß and oxytocin of C57BL/6J female mice.

Exercise can reduce the incidence of stress-related mental diseases, such as depression and anxiety. Control group was neither exposed to CVMS nor TRE (noCVMS/noTRE). Females were tested and levels of serum17-beta-oestradiol (E2), estrogen receptors α immunoreactive neurons (ERα-IRs), estrogen receptors ß immunoreactive neurons (ERß-IRs) and oxytocin immunoreactive neurons (OT-IRs) were measured. The results showed there's increased anxiety-like behaviors for mice from CVMS/noTRE, CVMS/higher speed TRE (CVMS/HTRE) and noCVMS/HTRE groups when they were put in open field and elevated maze tests. They had lower serum E2 levels than mice from CVMS/low-moderate speed TRE (CVMS/LMTRE), noCVMS/LMTRE and noCVMS/noTRE groups. The three groups of CVMS/noTRE, CVMS/HTRE and noCVMS/HTRE mice had more ERα-IRs and less ERß-IRs in the medial preoptic area (mPOA), bed nucleus of the stria terminalis (BNST) and medial amygdala (MeA), hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON). The number of OT-IRs in PVN and SON of CVMS/noTRE, CVMS/HTRE and noCVMS/HTRE mice was also lower than that of mice from CVMS/LMTRE, noCVMS/LMTRE and noCVMS/noTRE groups. Interestingly, CVMS/LMTRE and noCVMS/LMTRE mice were similar to noCVMS/noTRE mice in that they did not show anxiety, while CVMS/HTRE and noCVMS/HTRE mice did not, which were similar to the mice in CVMS/noTRE. We propose that LMTRE instead of HTRE changes the serum concentration of E2. ERß/ERα ratio and OT level in the brain may be responsible for the decrease in anxiety-like behavior in female mice exposed to anxiety-inducing stress conditions.

Layer-sliding-driven crystal size and photoluminescence change in a novel SCC-MOF.

A novel silver-chalcogenolate cluster-based framework Ag12TPPA·AA with long-lived afterglow was successfully synthesized. It transformed into more densely packed Ag12TPPA·AB and Ag12TPPA·ABC by layer sliding accompanied by macroscopic crystal contraction and changing luminescence.