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Isomerization is highly important in all aspects of science, yet it is rarely observed in nanoscience. Here, we synthesized a unique triple core-shell Ag 84 nanocluster displaying isomerism, which is controlled by different carboxylic acids and a one-way transformation ( SD/Ag84a → SD/Ag84b ). The innermost core is a rare Ag 10 nanocluster which comprises an Ag 6 octahedral unit as seen in face-centred cubic (fcc) silver metal and four capped Ag atoms. It templates two crescent-shaped polyoxometalate (W 7 O 26 ) 10- shells which are then enclosed in a shell of silver shaped as rugby balls. The organic ligands ( i PrS - , n PrCOO - and PhCOO - ) finally shield the metallic clusters. Due to slight differences in structure at two poles and the steric hindrance of n PrCOO - and PhCOO - , SD/Ag84a and SD/Ag84b adopt the shapes of flat-headed and cuspidal prolate spheres, respectively. Interestingly, PhCOOH is dominant over n PrCOOH whereby crystals of SD/Ag84b were isolated if PhCOOH is added during the synthesis of SD/Ag84a . This demonstrates that PhCOOH not only alters the organic coats but also induces metal shell re-organization. This work reveals carboxylate-controlled skeletal isomerism in silver nanoclusters for the first time, thus deepening the understanding of silver nanocluster assembly, flexibility and reactivity.

A diphosphine-protected 18-gold-atom nanocluster was isolated via a facile reduction of an AuI precursor by NaBH4. Its composition was identified as {[Au18(dppm)6Cl4]·C6H6·3Cl·PF6} (SD/Au18, SD = SunDi; dppm = bis-(diphenylphosphino)methane) by X-ray single crystal structural analysis. This nanocluster possesses a prolate shape and is built from an Au10 kernel (bi-octahedral Au6 units sharing one edge) fused with two Au7 caps via sharing six gold atoms. The identity of the Au18 cluster is further demonstrated by ESI-MS. The number of valence electrons of [Au18(dppm)6Cl4]4+ is 10 (n* = 18-4-4), which does not match with the known magic numbers according to the spherical jellium model, and elongated models must be considered. The special stability of the Au18 cluster likely arises from geometrical factors in the metallic core. Two charge states are reported for this system. This work not only presents the structure elucidation of a diphosphine-protected Au18 nanocluster, but also provides an important insight into the growth pattern of gold nanoclusters and the charge states they can achieve.

Controlled trapping atom-precise ultrasmall silver nanoparticles into silver nanoclusters is challenging; thus only limited progress has been made in this area. We are therefore inspired to isolate two novel silver nanoclusters, Ag 10 @Ag 70 ( SD/Ag80a and SD/Ag80b ; SD = SunDi), where a novel fcc-structured Ag 10 kernel built from two single-edge opened Ag 6 octahedra by sharing one edge is trapped. The bioctahedral Ag 10 kernel is locked by a pair of Mo 7 O 26 10- anions to form an inner Ag 10 @(Mo 7 O 26 ) 2 core which is further encapsulated by an outer Ag 70 shell to form three-shell Ag 10 @(Mo 7 O 26 ) 2 @Ag 70 nanoclusters. Notably, the bioctahedral Ag 10 kernel has not been observed in silver nanoclusters ever before, thus representing a new embryo state of silver nanoparticles. SD/Ag80a emits in the near infrared (NIR) region ( λ em = 730 nm) at low temperature. This work will deepen our understanding on the atomic-level growth of silver nanoparticles and complicated three-shell self-assembly involving polyoxometalate (POM) and two different silver nanoclusters.

A visible light-driven photocatalytic generation of sulfonamidyl radicals, and application to intramolecular alkene hydroamination, has been accomplished, providing a mild and efficient approach to various functionalized isoxazolidines. The success of this protocol is based on the strategy of oxidative deprotonation electron transfer by merging the base and the photocatalyst under visible light irradiation, obviating installation of a photolabile handle or stoichiometric external oxidants.

A 90-nucleus silver cluster (SD/Ag38) cocapped by tBuC6H4S- and PhCOO- ligands was synthesized using hetero-anion template method. Single-crystal X-ray diffraction (SCXRD) revealed a 90-nucleus metallic dumbbell-like core constructed by two large W5O19@Ag38 heads sandwiching one slender (SO4)2@Ag14 waist. Both W5O198- and SO42- templates were in situ generated and synergistically induced the formation of the largest known anion-templated silver cluster. Although SD/Ag38 is emission-silent at room temperature, increasingly brighter near-infrared (NIR) emission at ca. 742 nm was detected on cooling from 293 to 93 K.

Due to distinctive quantum confinement effects, ultrasmall gold nanoparticles usually exhibit interesting electronic structure and molecular-like properties. However, the lack of atomically-precise structural information makes the understanding of them almost impossible, such as understanding the relationships between their compositions and unique properties. Herein, by reducing a diphosphine Au I precursor (Au 2 (dppm) 2 Cl 2 ; dppm = Ph 2 PCH 2 PPh 2 ) with or without a S 2- releasing reagent, we enriched our knowledge of the members in the families of Au 13 and Au 8 by the structural determinations of two new dppm-protected gold nanoclusters, [Au 13 (dppm) 6 ] 5+ ( SD/Au1 ) and [Au 8 (dppm) 4 S 2 ] 2+ ( SD/Au2 ), respectively. Within SD/Au1 , the Au 13 kernel significantly deviates from the ideal I h icosahedron by the elongation of three surface Au-Au bonds to ∼3.5 Å, giving it C 3 symmetry, whereas SD/Au2 has a novel heart-shaped C 2 symmetric Au 8 S 2 core (central Au 4 tetrahedron + two Au 2 S units) protected by four μ 2 -dppm ligands in the outer shell. Of note, SD/Au1 represents a rare Au 13 nanocluster with an opened icosahedral geometry, and SD/Au2 shows a new edge-shared "core + 4 exo " structure type that has never been observed before. The electronic structures and optical absorption spectra of these systems are correlated with time-dependent density functional theory (TDDFT) calculations. Based on the spherical jellium model, the stability of the Au 13 and Au 8 nanoclusters can be ascribed to 8- and 2-electron superatoms with 1S 2 1P 6 and 1S 2 configurations, respectively. Interestingly, the cluster SD/Au2 exhibits bright yellow luminescence with an emission maximum at 591 nm that slightly hypsochromically shifts to 581 nm upon cooling to 93 K. Our findings not only enrich the family of diphosphine-protected ultrasmall gold nanoclusters, but also demonstrate the rich variations of gold kernels during the transformation from a simple Au I precursor to Au nanoclusters.

An efficient visible light photocatalytic and external oxidant-free N-radical 5-exo cyclization/addition/aromatization cascade of β,γ-unsaturated hydrazones is described, which provides a practical route to various biologically interesting dihydropyrazole-fused benzosultams in satisfactory yields.

A PhI(OAc)2-promoted radical cyclization of β,γ-unsaturated hydrazones and oximes has been developed for an efficient synthesis of various valuable pyrazoline and isoxazoline derivatives with satisfactory yields (up to 96%) under mild conditions.

A visible-light-induced photocatalytic oxytrifluoromethylation reaction of N-allylamides has been developed for the efficient synthesis of CF3-containing oxazolines and benzoxazines under mild reaction conditions.

Eleven new triterpenoids, schinchinenins A–H (1–8) and schinchinenlactones A–C (9–11) together with three known triterpenoids, henrischinins A–C (12–14), were isolated from the leaves and stems of Schisandra chinensis by bioassay-guided fractionation. Schinchinenin A (1) is the first example of a highly oxygenated triterpenoid characterized by a 5/5/7/6/5-fused pentacyclic ring and a 3-one-2-oxabicyclo[3.2.1]-octane moiety. Schinchinenins E and F (5 and 6) are highly oxygenated triterpenoids that contain a hydroperoxyl moiety, which is rare in compounds from the Schisandra genus. The structures and stereochemistry of 1–11 were elucidated using spectroscopic analysis, single-crystal X-ray diffraction, computational optical rotation, chemical transformation, and CD exciton chirality methods. The activities of compounds 1, 2, 7, and 12–14 against HSV-2 and adenovirus were evaluated for the first time, and of these compounds, 13 was the most active inhibitor of HSV-2, with a selectivity index value as high as 29.95.