All-Calixarene-Protected Silver Nanocluster with All Silver Atoms in a Face-Centered Cubic Arrangement.

Tailoring the surface ligands of metal nanoclusters is important for engineering unique configurations of metal nanoclusters. Thiacalix[4]arene has found extensive applications in the construction of metal nanoclusters. In this investigation, we present the synthesis and characterization of the first all-calixarene-protected silver nanoclusters, [Ag(CHCN)][Ag(BTCA)] (, HBTCA = -butylthiacalix[4]arene).

Interplay of kernel shape and surface structure for NIR luminescence in atomically precise gold nanorods.

It is challenging to attain strong near-infrared (NIR) emissive gold nanoclusters. Here we show a rod-shaped cluster with the composition of [Au(p-MBT)(Hdppa)](SOCF) (1 for short, Hdppa is N,N-bis(diphenylphosphino)amine, p-MBT is 4-methylbenzenethiolate) has been synthesized. Single crystal X-ray structural analysis reveals that it has a rod-like face-centered cubic (fcc) Au kernel built from two interpenetrating bicapped cuboctahedral Au units.

Near-unity NIR phosphorescent quantum yield from a room-temperature solvated metal nanocluster.

Metal nanoclusters have emerged as promising near-infrared (NIR)-emissive materials, but their room-temperature photoluminescence quantum yield (PLQY), especially in solution, is often low (<10%). We studied the photophysics of Au(BuPhC≡C) (Au) and its alloy counterpart AuCu(BuPhC≡C) (AuCu) (where Bu is -butyl and Ph is phenyl) and found that copper (Cu) doping suppressed the nonradiative decay (~60-fold less) and promoted intersystem crossing rate (~300-fold higher). The AuCu nanocluster exhibited >99% PLQY in deaerated solution at room temperature with an emission maximum at 720 nanometers tailing to 950 nanometers and 61% PLQY in the oxygen-saturated solution.

Site-specific doping of silver atoms into a Au nanocluster as directed by ligand binding preferences.

For the first time site-specific doping of silver into a spherical Au nanocluster has been achieved in [AuAg(MeOPhS)(PPh)] (BF) (AuAg) through a dual-ligand coordination strategy. Single crystal X-ray structural analysis shows that the cluster has a distorted centered icosahedral Au@AuAg core of symmetry, in contrast to the Au@Au kernel in the well-known [Au(SR)] (R = CHCHPh). An interesting feature is the coexistence of [Au(SPhOMe)] dimeric staples and [P-Au-SPhOMe] semi-staples in the title cluster, due to the incorporation of PPh.

A 59-Electron Non-Magic-Number Gold Nanocluster Au(C≡CR) Showing Unexpectedly High Stability.

An atomically resolved gold nanocluster Au(C≡CCH-2,4-F) () with an unusual 59 valence electrons has been synthesized. Single-crystal X-ray diffraction reveals that its Au kernel is a Au Marks decahedron capped by two Au units. The surface structure of consists of 20 linear Au(C≡CR) staples.

Synthesis and antigastric ulcer activity of novel 5-isoproyl-3,8-dimethylazulene derivatives.

5-Isoproyl-3,8-dimethylazulene derivatives were synthesized and evaluated for antigastric ulcer activity in vivo. Some of them possess the best activity against gastric ulcer with ulcer index values lower than the drug reference (omeprazole). The structure-activity relationship (SAR) shows that the lipophilic flat structure contributes to quite potent antigastric ulcer activity.