Human pangenome analysis of sequences missing from the reference genome reveals their widespread evolutionary, phenotypic, and functional roles.

Nonreference sequences (NRSs) are DNA sequences present in global populations but absent in the current human reference genome. However, the extent and functional significance of NRSs in the human genomes and populations remains unclear. Here, we de novo assembled 539 genomes from five genetically divergent human populations using long-read sequencing technology, resulting in the identification of 5.1 million NRSs. These were merged into 45284 unique NRSs, with 29.7% being novel discoveries. Among these NRSs, 38.7% were common across the five populations, and 35.6% were population specific. The use of a graph-based pangenome approach allowed for the detection of 565 transcript expression quantitative trait loci on NRSs, with 426 of these being novel findings. Moreover, 26 NRS candidates displayed evidence of adaptive selection within human populations. Genes situated in close proximity to or intersecting with these candidates may be associated with metabolism and type 2 diabetes. Genome-wide association studies revealed 14 NRSs to be significantly associated with eight phenotypes. Additionally, 154 NRSs were found to be in strong linkage disequilibrium with 258 phenotype-associated SNPs in the GWAS catalogue. Our work expands the understanding of human NRSs and provides novel insights into their functions, facilitating evolutionary and biomedical researches.

Controlled Sequential Doping of Metal Nanocluster.

Atomically precise doping of metal nanoclusters provides excellent opportunities not only for subtly tailoring their properties but also for in-depth understanding of composition (structure)-property correlation of metal nanoclusters and has attracted increasing interest partly due to its significance for fundamental research and practical applications. Although single and multiple metal atom doping of metal nanoclusters (NCs) has been achieved, sequential single-to-multiple metal atom doping is still a big challenge and has not yet been reported. Herein, by introducing a second ligand, a novel multistep synthesis method was developed, controlled sequential single-to-multiple metal atom doping was successfully achieved for the first time, and three doped NCs Au25Cd1(p-MBT)17(PPh3)2, Au18Cd2(p-MBT)14(PPh3)2, and [Au19Cd3(p-MBT)18]- (p-MBTH: para-methylbenzenethiol) were obtained, including two novel NCs that were precisely characterized via mass spectrometry, single-crystal X-ray crystallography, and so forth. Furthermore, sequential doping-induced evolutions in the atomic and crystallographic structures and optical and catalytic properties of NCs were revealed.

Bottom-Up Construction of Metal-Organic Framework Loricae on Metal Nanoclusters with Consecutive Single Nonmetal Atom Tuning for Tailored Catalysis.

The introduction of single or multiple heterometal atoms into metal nanoparticles is a well-known strategy for altering their structures (compositions) and properties. However, surface single nonmetal atom doping is challenging and rarely reported. For the first time, we have developed synthetic methods, realizing "surgery"-like, successive surface single nonmetal atom doping, replacement, and addition for ultrasmall metal nanoparticles (metal nanoclusters, NCs), and successfully synthesized and characterized three novel bcc metal NCs Au38I(S-Adm)19, Au38S(S-Adm)20, and Au38IS(S-Adm)19 (S-Adm: 1-adamantanethiolate). The influences of single nonmetal atom replacement and addition on the NC structure and optical properties (including absorption and photoluminescence) were carefully investigated, providing insights into the structure (composition)-property correlation. Furthermore, a bottom-up method was employed to construct a metal-organic framework (MOF) on the NC surface, which did not essentially alter the metal NC structure but led to the partial release of surface ligands and stimulated metal NC activity for catalyzing p-nitrophenol reduction. Furthermore, surface MOF construction enhanced NC stability and water solubility, providing another dimension for tunning NC catalytic activity by modifying MOF functional groups.

Building Block Metal Nanocluster-Based Growth in 1D Direction.

Metal nanoclusters with precisely modulated structures at the nanoscale give us the opportunity to synthesize and investigate 1D nanomaterials at the atomic level. Herein, it realizes selective 1D growth of building block nanocluster "Au13 Cd2 " into three structurally different nanoclusters: "hand-in-hand" (Au13 Cd2 )2 O, "head-to-head" Au25 , and "shoulder-to-shoulder" Au33 . Detailed studies further reveals the growth mechanism and the growth-related tunable properties. This work provides new hints for the predictable structural transformation of nanoclusters and atomically precise construction of 1D nanomaterials.

Parallel evolution of morphological and genomic selfing syndromes accompany the breakdown of heterostyly.

Evolutionary transitions from outcrossing to selfing in flowering plants have convergent morphological and genomic signatures and can involve parallel evolution within related lineages. Adaptive evolution of morphological traits is often assumed to evolve faster than nonadaptive features of the genomic selfing syndrome. We investigated phenotypic and genomic changes associated with transitions from distyly to homostyly in the Primula oreodoxa complex. We determined whether the transition to selfing occurred more than once and investigated stages in the evolution of morphological and genomic selfing syndromes using 22 floral traits and both nuclear and plastid genomic data from 25 populations. Two independent transitions were detected representing an earlier and a more recently derived selfing lineage. The older lineage exhibited classic features of the morphological and genomic selfing syndrome. Although features of both selfing syndromes were less developed in the younger selfing lineage, they exhibited parallel development with the older selfing lineage. This finding contrasts with the prediction that some genomic changes should lag behind adaptive changes to morphological traits. Our findings highlight the value of comparative studies on the timing and extent of transitions from outcrossing to selfing between related lineages for investigating the tempo of morphological and molecular evolution.

First report of Botrytis cinerea causing grey mold on Corydalis yanhusuo in Panan, China.

Yanhusuo (Corydalis yanhusuo (Y. H. Chou & Chun C. Hsu) W. T. Wang ex Z.Y. Su & C.Y. Wu), a perennial herbaceous plant of the Papaveraceae family and genus Corydalis, is also known as Yuanhu and used as medicine by its tuberous roots. It is mainly planted in Zhejiang, Jiangsu and Anhui provinces of China, with the best quality produced in Panan County of Zhejiang province. Yanhusuo has the effects of promoting blood circulation, invigorating the flow of qi and relieving pain, and is widely used in Chinese traditional medicines. In surveys carried out in summer of 2020-2023, grey mold disease was found occurred on C. yanhusuo in Panan County. This disease begins at April, and lasts to July, with incidence of 20% to 70%. The diseased plants showed a large number of gray mold layers adhere to the leaves. When the disease infects from the leaf tips, it form V-shaped lesions; when the leaves are severely infected, the entire leaves die, shrink, curl, and have a large number of gray mold layers on the surface. To identify the causal agent of this leaf disease, diseased leaves were collected from Yanhusuo field at Panan County of Zhejiang province in China since 2020, and tissues at the junction of the healthy and diseased areas were cut off, disinfected with 75% ethanol for 30 seconds, rinsed with sterile water for 3 times for 1 minute each time, air-dried under sterile conditions, and then were inoculated in PDA medium and cultured in a 25℃ incubator. After 2-3 days, picked the edge hyphae of the fungi that grew on the PDA plate and cultured them on a new PDA plate. After 5 days, picked the single spore and inoculated on a new PDA plate for continuous cultivation until pure culture strains were obtained. Thirty strains were isolated from 30 samples that collected from 3 Yanhusuo fields in Panan County. One of the thirty purified strains was named "YH8" for further identification. When cultured on PDA medium, mycelia were initially whitish and turned gray with age. The hyphae accumulate into clusters, and no sclerotia are produced during the cultivation. The conidiophores are slender, septate. The base of the conidiophore is enlarged or slightly enlarged. The conidiophore often has branches and produces a large number of conidia, which are similar to grape clusters. The conidia are monosporous, ovoid, and colorless, 6.08 µm-12.76 µm×8.42 µm-19.34 µm, with an average size of 9.55 µm×14.50 µm. To further identify the species, YH8 genomic DNA was extracted, and the internal transcribed spacer (ITS), heat shock protein (HSP60), and glyceraldehyde-3-phosphate dehydrogenase (G3PDH) genes were amplified with the primers ITS1/4 (White et al. 1990), HSP60-F/HSP60-R, and G3PDH-F/G3PDH-R (Staats et al. 2005), respectively. A multilocus phylogenetic tree was constructed with the ITS, HSP60, and G3PDH reference sequences, and the sequences of PCR amplicons (Genbank number: PP388281, PP376066 and PP376067) were 100% (518 bp out of 518 bp), 99% (994 bp out of 995 bp) and 100% (880 bp out of 880 bp) identical to the Botrytis cinerea strain 5-3, respectively, and the grouping of strain YH8 was supported by 99% bootstrap value. To fulfill the Koch's postulates, spore suspension (approximately 103 CFU/mL) of YH8 was sprayed onto leaves of 3-week Yanhusuo seedlings, and sterile water was sprayed as negative control, 15 seedlings for each treatment, and the experiments was repeated for times. The seedlings were incubated in a growth chamber under 28℃ and 80% humidity. Seven days after inoculation, leaves of noninoculated controls were green and healthy, while the seedlings inoculated with spore suspension of YH8 showed lesions and molds, which were same with field symptoms. The causal pathogen was then reisolated from the lesions, and the gained pathogen showed same colony and spore morphology with YH8, which suggested the confirmation of Koch's postulates. Based on the morphological characteristics and molecular identification, the strain YH8 was identified as B. cinerea. To our knowledge, this is the first report of B. cinerea causing gray mold on the Corydalis yanhusuo in China. This report will provide guide to growers and local technicians for diagnostic and controlling grey mold disease of Yanhusuo.

Pd8 Nanocluster with Nonmetal-to-Metal- Ring Coordination and Promising Photothermal Conversion Efficiency.

Constructing ambient-stable, single-atom-layered metal-based materials with atomic precision and understanding their underlying stability mechanisms are challenging. Here, stable single-atom-layered nanoclusters of Pd were synthesized and precisely characterized through electrospray ionization mass spectrometry and single-crystal X-ray crystallography. A pseudo-pentalene-like Pd8 unit was found in the nanocluster, interacting with two syn PPh units through nonmetal-to-metal -ring coordination. The unexpected coordination, which is distinctly different from the typical organoring-to-metal coordination in half-sandwich-type organometallic compounds, contributes to the ambient stability of the as-obtained single-atom-layered nanocluster as revealed through theoretical and experimental analyses. Furthermore, quantum chemical calculations revealed dominant electron transition along the horizontal x-direction of the Pd8 plane, indicating high photothermal conversion efficiency (PCE) of the nanocluster, which was verified by the experimental PCE of 73.3 %. Therefore, this study unveils the birth of a novel type of compound and the finding of the unusual nonmetal-to-metal -ring coordination and has important implications for future syntheses, structures, properties, and structure-property correlations of single-atom-layered metal-based materials.

Concomitant Near-Infrared Photothermy and Photoluminescence of Rod-Shaped Au52(PET)32 and Au66(PET)38 Synthesized Concurrently.

Gold nanoclusters exhibiting concomitant photothermy (PT) and photoluminescence (PL) under near-infrared (NIR) light irradiation are rarely reported, and some fundamental issues remain unresolved for such materials. Herein, we concurrently synthesized two novel rod-shaped Au nanoclusters, Au52(PET)32 and Au66(PET)38 (PET = 2-phenylethanethiolate), and precisely revealed that their kernels were 4 × 4 × 6 and 5 × 4 × 6 face-centered cubic (fcc) structures, respectively, based on the numbers of Au layers in the [100], [010], and [001] directions. Following the structural growth mode from Au52(PET)32 to Au66(PET)38, we predicted six more novel nanoclusters. The concurrent synthesis provides rational comparison of the two nanoclusters on the stability, absorption, emission and photothermy, and reveals the aspect ratio-related properties. An interesting finding is that the two nanoclusters exhibit concomitant PT and PL under 785 nm light irradiation, and the PT and PL are in balance, which was explained by the qualitative evaluation of the radiative and non-radiative rates. The ligand effects on PT and PL were also investigated.

Atomically Precise Nanometer-Sized Pt Catalysts with an Additional Photothermy Functionality.

Atomically precise ~1-nm Pt nanoparticles (nanoclusters, NCs) with ambient stability are important in fundamental research and exhibit diverse practical applications (catalysis, biomedicine, etc.). However, synthesizing such materials is challenging. Herein, by employing the mixture ligand protecting strategy, we successfully synthesized the largest organic-ligand-protected (~1-nm) Pt23 NCs precisely characterized with mass spectrometry and single-crystal X-ray diffraction analyses. Interestingly, natural population analysis and Bader charge calculation indicate an alternate, varying charge -layer distribution in the sandwich-like Pt23 NC kernel. Pt23 NCs can catalyze the oxygen reduction reaction under acidic conditions without requiring calcination and other treatments, and the resulting specific and mass activities without further treatment are sevenfold and eightfold higher than those observed for commercial Pt/C catalysts, respectively. Density functional theory and d-band center calculations interpret the high activity. Furthermore, Pt23 NCs exhibit a photothermal conversion efficiency of 68.4 % under 532-nm laser irradiation and can be used at least for six cycles, thus demonstrating great potential for practical applications.

Coexistent, Competing Tunnelling, and Hopping Charge Transport in Compressed Metal Nanocluster Crystals.

Understanding charge transport among metal particles with sizes of approximately 1 nm poses a great challenge due to the ultrasmall nanosize, yet it holds great significance in the development of innovative materials as substitutes for traditional semiconductors, which are insulative and unstable in less than ∼10 nm thickness. Herein, atomically precise gold nanoclusters with well-defined compositions and structures were investigated to establish a mathematical relation between conductivity and interparticle distance. This was accomplished using high-pressure in situ resistance characterizations, synchrotron X-ray diffraction (XRD), and the Murnaghan equation of state. Based on this precise correlation, it was predicted that the conductivity of Au25(SNap)18 (SNap: 1-naphthalenethiolate) solid is comparable to that of bulk silver when the interparticle distance is reduced to approximately 3.6 Å. Furthermore, the study revealed the coexisting, competing tunneling, and incoherent hopping charge transport mechanisms, which differed from those previously reported. The introduction of conjugation-structured ligands, tuning of the structures of metal nanoclusters, and use of high-pressure techniques contributed to enhanced conductivity, and thus, the charge carrier types were determined using Hall measurements. Overall, this study provides valuable insight into the charge transport in gold nanocluster solids and represents an important advancement in metal nanocluster semiconductor research.

Nanoclusterzyme for Dual Colorimetric Sensings: A Case Study on [Au14 (Dppp)5 I4 ]2.

The enzymatic activity of atomically precise metal nanoclusters has recently been recognized; however, the number of nanoclusterzymes is very small. Besides, the applications of nanoclusterzyme wait to be explored. Herein, a novel nanoclusterzyme is synthesized and its structure is majorly resolved by single-crystal X-ray diffraction and mass spectrometry, which reveal that the nanocluster consists of an Au13 icosahedron capped by an exterior shell including four I, three Dppp (1,3-bis(diphenylphosphino) propane) ligands, and a rarely reported Dppp-Au-Dppp handle staple, which contributes a lot to the enzyme activity of [Au14 (Dppp)5 I4 ]2+ nanocluster. The as-obtained nanocluster can catalyze oxygen to O2 •- under visible light irradiation with a specific activity up to 0.182 U·mg-1 and lead to the blue color of 3,3',5,5'-tetramethylbenzidine (TMB) in both solution and solid states. With the addition of acetylcholinesterase (AChE), the blue color of (Au14  + TMB) solution system disappears due to the nanoclusterzyme activity inhibition, but the further addition of organophosphorus pesticides (OPs) into the above mixture can restore the nanoclusterzyme and recover the blue color. Based on the color turn-off and on, the various nanoclusterzyme-containing systems are used to colorimetrically sense AChE and OPs with the detection limits reaching 0.04 mU·mL-1 and 0.02 ng·mL-1 , respectively.

A near-complete assembly of asparagus bean provides insights into anthocyanin accumulation in pods.

Asparagus bean (Vigna unguiculata ssp. sesquipedialis), a subspecies of V. unguiculata, is a vital legume crop widely cultivated in Asia for its tender pods consumed as vegetables. However, the existing asparagus bean assemblies still contain numerous gaps and unanchored sequences, which presents challenges to functional genomics research. Here, we present an improved reference genome sequence of an elite asparagus bean variety, Fengchan 6, achieved through the integration of nanopore ultra-long reads, PacBio high-fidelity reads, and Hi-C technology. The improved assembly is 521.3 Mb in length and demonstrates several enhancements, including a higher N50 length (46.4 Mb), an anchor ratio of 99.8%, and the presence of only one gap. Furthermore, we successfully assembled 14 telomeres and all 11 centromeres, including four telomere-to-telomere chromosomes. Remarkably, the centromeric regions cover a total length of 38.1 Mb, providing valuable insights into the complex architecture of centromeres. Among the 30 594 predicted protein-coding genes, we identified 2356 genes that are tandemly duplicated in segmental duplication regions. These findings have implications for defence responses and may contribute to evolutionary processes. By utilizing the reference genome, we were able to effectively identify the presence of the gene VuMYB114, which regulates the accumulation of anthocyanins, thereby controlling the purple coloration of the pods. This discovery holds significant implications for understanding the underlying mechanisms of color determination and the breeding process. Overall, the highly improved reference genome serves as crucial resource and lays a solid foundation for asparagus bean genomic studies and genetic improvement efforts.

Comparison of Cerebrospinal Fluid Cellular Analysis by Optical Microscopy and Sysmex XN 9000.

BACKGROUND: This study was designed to compare the body fluid module of Sysmex XN9000 (XN-BF) with optical microscopy (OM) for cerebrospinal fluid (CSF) analysis after two-step cell slide centrifuge (TSCSC), defining the best procedure for CSF optical microscopy analysis. METHODS: Items of RBC, WBC enumeration and differentiation were observed. The cell count and morphologic evaluation of the cellular composition by OM was carried out both with and without two-step cell slide centrifuge (TSCSC) and were compared the data with XN-BF. RESULTS: There were 69.98 ± 4.94 RBC and 36.98 ± 3.39 WBC in one OSCSC microscopic field whereas there were 96.35 ± 5.41 RBC and 66.15 ± 4.85 WBC in one TSCSC microscopic field in the same sample (*200). There was a statistical difference between those two methods (p = 0.000). Excellent correlation was found between total cell count with both OM and XN-BF. The R2 value for RBC and WBC counts were 0.99 and 0.96, respectively. For WBC differential, the R2 values were 0.98 for PMN and 0.70 for MN. Correlation of MN was poorer than PMN. As far as the tumor cell, phagocyte, and plasma cell with high fluorescence were concerned, OM were not consistent with XN-BF. CONCLUSIONS: The TSCSC procedure contributes to the separation of cells and other ingredients. XN-BF displays excellent performance at RBC and WBC cell count except for mononuclear cells, tumor cells, phagocytes, and leukemia cells. which makes it just a practical alternative to total cell (WBC, RBC) count for CSF samples. Detailed morphologic workup of CSF samples is mandated in all cases with meningoencephalitis, elevated cell count, sub-arachnoid hemorrhage and meningeal carcinomatosis, the TSCSC procedure is recommended.

Single-Atom-Kernelled Nanocluster Catalyst.

To propose the concept of single-atom-kernelled nanocluster, we synthesized a Pd-based trimetal nanocluster with a single-Ag atom-kernel for the first time by introducing some steric hindrance factors and employing a joint alloying strategy that combines the coreduction with an antigalvanic reduction (AGR). Although the AGR-derived Pd-based trimetal nanoclusters with single-silver atom kernels have low contents of gold, they show higher activity and selectivity than those of the bimetal precursor nanocluster in the electrocatalytical reduction of CO2 to CO. Furthermore, it is revealed that the kernel single atoms from both Au4Pd6(TBBT)12 and Au3AgPd6(TBBT)12 are not the active sites for catalysis, but greatly influence the catalytical performance by effecting the electronic configuration. Thus, it is demonstrated that the single-atom-kernelled nanocluster can not only improve the precious metal utilization (even to 100%) but also better the properties and provide insight into the structure-property correlation for metal nanoclusters.

Sandwich-Kernelled AgCu Nanoclusters with Golden Ratio Geometry and Promising Photothermal Efficiency.

Metal nanoclusters have recently attracted extensive interest from the scientific community. However, unlike carbon-based materials and metal nanocrystals, they rarely exhibit a sheet kernel structure, probably owing to the instability caused by the high exposure of metal atoms (particularly in the relatively less noble Ag or Cu nanoclusters) in such a structure. Herein, we synthesized a novel AgCu nanocluster with a sandwich-like kernel (diameter≈0.9 nm and length≈0.25 nm) by introducing the furfuryl mercaptan ligand (FUR) and the alloying strategy. Interestingly, the kernel consists of a centered silver atom and two planar Ag10 pentacle units with completely mirrored symmetry after a rotation of 36 degrees. The two Ag10 pentacles and some extended structures show an unreported golden ratio geometry, and the two inner five-membered rings and the centered Ag atom form an unanticipated full-metal ferrocene-like structure. The featured kernel structure causes the dominant radial direction transition of excitation electrons, as determined via time-dependent density functional theory calculations, which affords the protruding absorption at 612 nm and contributes to the promising photothermal conversion efficiency of 67.6 % of the as-obtained nanocluster, having important implications for structure-property correlation and the development of nanocluser-based photothermal materials.

Lattice Compression Revealed at the ≈1†nm Scale.

Lattice tuning at the ≈1 nm scale is fascinating and challenging; for instance, lattice compression at such a minuscule scale has not been observed. The lattice compression might also bring about some unusual properties, which waits to be verified. Through ligand induction, we herein achieve the lattice compression in a ≈1 nm gold nanocluster for the first time, as detected by the single-crystal X-ray crystallography. In a freshly synthesized Au52 (CHT)28 (CHT=S-c-C6 H11 ) nanocluster, the lattice distance of the (110) facet is found to be compressed from 4.51 to 3.58 Šat the near end. However, the lattice distances of the (111) and (100) facets show no change in different positions. The lattice-compressed nanocluster exhibits superior electrocatalytic activity for the CO2 reduction reaction (CO2 RR) compared to that exhibited by the same-sized Au52 (TBBT)32 (TBBT=4-tert-butyl-benzenethiolate) nanocluster and larger Au nanocrystals without lattice variation, indicating that lattice tuning is an efficient method for tailoring the properties of metal nanoclusters. Further theoretical calculations explain the high CO2 RR performance of the lattice-compressed Au52 (CHT)28 and provide a correlation between its structure and catalytic activity.

Surface-Clean Au25 Nanoclusters in Modulated Microenvironment Enabled by Metal-Organic Frameworks for Enhanced Catalysis.

Metal nanoclusters (NCs) with atomically precise structures have sparked interest in catalysis. Unfortunately, their high aggregation tendency and the spatial resistance of surface ligands pose significant challenges. Herein, Au25 NCs are encapsulated into isoreticular metal-organic frameworks (MOFs), namely UiO-66-X (X = H, NH2, OH, and NO2), followed by the removal of surface ligands on Au25 NCs. The resulting surface-clean Au25 NCs, protected by the MOF spatial confinement, exhibit much superior activity and stability with respect to pristine Au25 NCs in the oxidative esterification of furfural. Remarkably, experimental and theoretical results jointly demonstrate that diverse functional groups on UiO-66-X modulate the Au25 electronic state, giving rise to the discriminated substrate adsorption energy of Au25@UiO-66-X. As a result, the high electron density and suitable substrate adsorption ability dominate the activity trend: Au25@UiO-66-NH2 > Au25@UiO-66-OH > Au25@UiO-66 > Au25@UiO-66-NO2. This work develops a new strategy for the stabilization of surface-clean metal NCs in pore wall-engineered MOFs for enhanced catalysis.

The Genomic Selfing Syndrome Accompanies the Evolutionary Breakdown of Heterostyly.

The evolutionary transition from outcrossing to selfing can have important genomic consequences. Decreased effective population size and the reduced efficacy of selection are predicted to play an important role in the molecular evolution of the genomes of selfing species. We investigated evidence for molecular signatures of the genomic selfing syndrome using 66 species of Primula including distylous (outcrossing) and derived homostylous (selfing) taxa. We complemented our comparative analysis with a microevolutionary study of P. chungensis, which is polymorphic for mating system and consists of both distylous and homostylous populations. We generated chloroplast and nuclear genomic data sets for distylous, homostylous, and distylous-homostylous species and identified patterns of nonsynonymous to synonymous divergence (dN/dS) and polymorphism (πN/πS) in species or lineages with contrasting mating systems. Our analysis of coding sequence divergence and polymorphism detected strongly reduced genetic diversity and heterozygosity, decreased efficacy of purifying selection, purging of large-effect deleterious mutations, and lower rates of adaptive evolution in samples from homostylous compared with distylous populations, consistent with theoretical expectations of the genomic selfing syndrome. Our results demonstrate that self-fertilization is a major driver of molecular evolutionary processes with genomic signatures of selfing evident in both old and relatively young homostylous populations.

Partial Phosphorization: A Strategy to Improve Some Performance(s) of Thiolated Metal Nanoclusters Without Notable Reduction of Stability.

Thiolates endow metal nanoclusters with stability while sometimes inhibit the catalytic activity due to the strong M-S interaction (M: metal atom). To improve the catalytic activity and keep the stability to some extent, one strategy is the partial phosphorization of thiolated metal nanoclusters. This is demonstrated by successful partial phosphorization of Au23 (SC6 H11 )16 and by revealing that the products Au22 (SC6 H11 )14 (PPh3 )2 and Au22 (SC6 H11 )12 (PPh3 )4 , with varied degree of phosphorization, both show excellent activity in the photocatalytic oxidation of thioanisole without notable reduction of stability. Furthermore, Au22 (SC6 H11 )12 (PPh3 )4 exhibits better photoluminescence performance than the mother nanocluster Au23 (SC6 H11 )16 , indicating that partial phosphorization can also improve some other performance(s) except for the catalytic performance. The intermediates Au22-x Cux (SC6 H11 )12 (PPh3 )4 (x=1, 2) in the transformation from Au23 (SC6 H11 )16 (Au22 (SC6 H11 )14 (PPh3 )2 ) to Au22 (SC6 H11 )12 (PPh3 )4 were captured and identified by mass spectrometry and single crystal X-ray diffraction, which throws light on the understanding of the non-alloyed anti-galvanic reaction.

Thiolated, Reduced Palladium Nanoclusters with Resolved Structures for the Electrocatalytic Reduction of Oxygen.

Although thiolated, reduced Group 11 metal nanoclusters with atomic monodispersity have been repeatedly reported in the past decade, their Pd analogues have not been reported thus far. In this work, we provide a resolution for the challenging synthesis and obtain for the first time an atomically monodisperse thiolated, reduced Pd (q=+0.75) nanocluster with a di-tetrahedron Pd8 kernel and a +3 charged interstitial B atom, as revealed by ESI-MS, SCXRD, etc. µ-6 B is found for the first time in Group 10 and 11 metal nanoclusters. More importantly, the as-obtained Pd nanoclusters show better catalytic activity compared to 1.4 nm Pd nanoparticles, Pd2 complexes and even a commercial Pt/C catalyst for the oxygen reduction reaction (ORR), having significant implications for the influence of the metal charge state and space structure on the catalytic activity.