In Situ Observation of the Growth of ZnO Nanostructures Using Liquid Cell Electron Microscopy

Understanding the growth mechanisms and associated kinetics is a fundamental issue toward the specific function-oriented controlled synthesis of nanostructures. In this work, the growth of zinc oxide nanostructures with different sizes and morphologies are directly observed by in situ liquid-cell transmission electron microscopy (TEM). Real-time observation and quantitative analysis reveal that the concentration ratios of the precursors are responsible for the different growth kinetics, resulting in different morphology and size of the synthesized ZnO nanostructures

Facile Method toward Hierarchical Fullerene Architectures with Enhanced Hydrophobicity and Photoluminescence

A two-step self-assembly strategy has been developed for the preparation of fullerene hierarchical architectures. Typically, the precipitation method is utilized to synthesize the initial fullerene microstructures, and subsequently a drop-drying process is employed to facilitate the fullerene microstructures to self-assemble into the final hierarchical structures. Overall, this methodology is quite simple and feasible, which can be applied to prepare fullerene hierarchical structures with different morphological features, simply by choosing proper solvent. Moreover, the as-obtained C₇₀ hierarchical structures have many superior properties over the original C₇₀ microrods such as superhydrophobicity and unique photoluminescence behaviors, promising their applications as waterproof optoelectronics

Anion Templated Synthesis of Silver(I)-Ethynide Dithiophosphate Clusters

Reaction of AgCC^<i>t</i>Bu with (EtO)₂PS₂Na at room temperature leads to the isolation of two new silver­(I)-ethynide compounds incorporating the dithiophosphate ligand, namely, {CO₃@(Ag₃)₄(CC^<i>t</i>Bu)₄(EtO)₂PS₂]₆}·0.5H₂O (<b>1</b>) and {(CO₃)₂@Ag₂₆(CC^<i>t</i>Bu)₁₆[(EtO)₂PS₂]₄}·2­(OH)·4MeOH·6H₂O (<b>2</b>). Besides, we obtain another three silver­(I)-ethynide clusters S@Ag₁₁(CC^<i>t</i>Bu)₂[(EtO)₂PS₂]₇ (<b>3</b>), {S@Ag₁₄(CCPh)₈[(EtO)₂PS₂]₄(TMEDA)₂}·5MeOH (<b>4</b>), and {S@Ag₁₄(CCPh)₈[(^<i>i</i>PrO)₂PS₂]₄(TMEDA)₂}·7CH₃OH (<b>5</b>), with AgCCR (R= ^<i>t</i>Bu, Ph) and (RO)₂PS₂Na (R= Et, ^<i>i</i>Pr) as the starting materials. Complexes <b>1</b>–<b>2</b> are templated by a carbonate anion in situ generated from the fixation of atmospheric CO₂ in a basic TMEDA-containing solution, and TMEDA can also lead to the disassembly of dithiophosphate to give a sulfide ion as the template for the generation of <b>3</b>–<b>5</b>

Lu₂@C₈₂ Nanorods with Enhanced Photoluminescence and Photoelectrochemical Properties

One-dimensional (1D) single-crystalline hexagonal nanorods of Lu₂@<i>C</i>_3<i>v</i>(8)–C₈₂ were prepared for the first time using the liquid–liquid interface precipitation (LLIP) method from the interfaces between carbon disulfide (CS₂) and isopropyl alcohol (IPA). The length of the nanorods can be readily controlled by varying the concentration of the Lu₂@C₈₂ solution in addition to the volume ratio of CS₂ to IPA. The latter factor also exhibits a significant influence on the morphology of the crystals. The crystalline structure of the nanorods has been investigated by XRD and selected area electron diffraction (SAED), suggesting a face-centered cubic structure. Photoluminescence of the Lu₂@C₈₂ nanorods shows a remarkable enhancement as compared to that of pristine Lu₂@C₈₂ powder because of the high crystallinity. Furthermore, we have investigated the photoelectrochemical properties of Lu₂@C₈₂ nanorods, proving their potential applications as photodetectors

Isolation and Crystallographic Characterization of La₂C₂@C_s(574)‑C₁₀₂ and La₂C₂@C₂(816)‑C₁₀₄: Evidence for the Top-Down Formation Mechanism of Fullerenes

Tubular higher fullerenes are prototypes of finite-length end-capped carbon nanotubes (CNTs) whose structures can be accurately characterized by single-crystal X-ray diffraction crystallography. We present here the isolation and crystallographic characterization of two unprecedented higher fullerenes stabilized by the encapsulation of a La₂C₂ cluster, namely, La₂C₂@C_s(574)-C₁₀₂, which has a perfect tubular cage corresponding to a short (10, 0) zigzag carbon nanotube, and La₂C₂@C₂(816)-C₁₀₄ which has a defective cage with a pyracylene motif inserting into the cage waist. Both cages provide sufficient spaces for the large La₂C₂ cluster to adopt a stretched and nearly planar configuration, departing from the common butterfly-like configuration which has been frequently observed in midsized carbide metallofullerenes (e.g., Sc₂C₂@C_80–84), to achieve strong metal–cage interactions. More meaningfully, our crystallographic results demonstrate that the defective cage of C₂(816)-C₁₀₄ is a starting point to form the other three tubular cages known so far, i.e., D₅(450)-C₁₀₀, C_s(574)-C₁₀₂, and D_3d(822)-C₁₀₄, presenting evidence for the top-down formation mechanism of fullerenes. The fact that only the large La₂C₂ cluster has been found in giant fullerene cages (C_>100) and the small clusters M₂C₂ (M = Sc, Y, Er, etc.) are present in midsized fullerenes (C₈₀–C₈₆) indicates that geometrical matching between the cluster and the cage, which ensures strong metal–cage interactions, is an important factor controlling the stability of the resultant metallofullerenes, in addition to charge transfer

Exceptional Chemical Properties of Sc@<i>C</i>_2<i>v</i>(9)–C₈₂ Probed with Adamantylidene Carbene

It has been an interesting finding that reactions of M@<i>C</i>_2<i>v</i>(9)–C₈₂ (M = Y, La, Ce, Gd) with diazirine adamantylidene (AdN₂, <b>1</b>) gave rise to only two monoadduct isomers, indicating that the cage reactivity of monometallofullerenes is not dependent on the type of the internal metal. However, we found here that Sc@<i>C</i>_2<i>v</i>(9)–C₈₂ shows an exceptional chemical reactivity toward the electrophile <b>1</b>, affording four monoadduct isomers (<b>2a</b>–<b>d</b>). Single-crystal X-ray diffraction crystallographic results of the most abundant isomer (<b>2a</b>) confirm that the addition takes place at a [6,6]-bond junction which is very close to the internal metal ion. Theoretical calculations reveal that 2 out of the 24 nonequivalent cage carbons of Sc@<i>C</i>_2<i>v</i>(9)–C₈₂ are highly reactive toward <b>1</b>, but only one cage carbon of the other M@<i>C</i>_2<i>v</i>–C₈₂ (M = Y, La, Ce, Gd) is sufficiently reactive. The exceptional chemical property of Sc@<i>C</i>_2<i>v</i>(9)–C₈₂ is associated with the small ionic radius of Sc³⁺, which allows stronger metal–cage interactions and makes back-donation of charge from the cage to the metal more pronounced. Our results have provided new insights into the art of altering the chemical properties of fullerene molecules at the atomic level, which would be useful in the future in utilizing EMFs in quantum computing systems

Characterization of Zebrafish Abcc4 as an Efflux Transporter of Organochlorine Pesticides

<div><p>DDT and lindane are highly toxic organochlorine pesticides and posing adverse effects on the environment and public health due to their frequent usage in developing countries. ABCC4/MRP4 is an organic anion transporter that mediates cellular efflux of a wide range of exogenous and endogenous compounds such as cyclic nucleotides and anti-cancer drugs; however, it remains unclear whether ABCC4 and its orthologs function in the detoxification of organochlorine pesticides. Here, we demonstrated the roles of zebrafish Abcc4 in cellular efflux of DDT and lindane. Zebrafish <i>abcc4</i> was maternally expressed in the oocytes and its transcripts were detected in the lens, pancreas, gills, liver, intestine and bladder of developing embryos and in adult tissues examined. DDT and lindane were able to induce the expression of <i>abcc4</i> gene and overexpression of Abcc4 significantly decreased the cytotoxicity and accumulation of DDT and lindane in LLC-PK1 cells and developing embryos. In contrast, overexpression of an Abcc4-G1188D mutant abolished its transporter function without effects on its substrate binding activity, and sensitized LLC-PK1 cells and developing embryos to toxic pesticides. Moreover, glutathione (GSH) was involved in the efflux of cellular pesticides and ATPase activity in developing embryos can be induced by DDT or lindane. Thus, zebrafish Abcc4 plays crucial roles in cellular efflux of organochlorine pesticides and can be used a potential molecular marker for the monitor of DDT and lindane contamination in the aquatic environment.</p></div

Zebrafish Abcc4 is involved in the excretion of DDT and lindane in developing embryos.

<p>(<b>A and B</b>) Contents of DTT or lindane in embryos expressing GFP, Abcc4 and Abcc4-G1188D at the indicated exposure time points. (<b>C and D</b>) Contents of MCB in embryos expressing GFP, Abcc4 and Abcc4-G1188D after exposed to DTT or lindane at indicated concentrations. Values are expressed as means ± standard deviations (n = 3). Significant differences are indicated by ^*<i>p</i><0.05 and ^**<i>p</i><0.01.</p

DDT and lindane are potential efflux substrates of zebrafish Abcc4 in LLC-PK1 cells.

<p>(<b>A and B</b>) Effect of Abcc4 on the accumulation of MCB. Stable cell lines were exposed to 25 µM MCB and 0.1–5 µg/mL of DDT or 1–100 µg/mL of lindane for 24 hours. (<b>C and D</b>) Effect of Abcc4 on the excretion of DDT or lindane. Stable cell lines were exposed to 2.5 µg/mL of DDT or 10 µg/mL of lindane for 5 to 180 minutes. Values are expressed as means ± standard deviations (n = 3). Significant differences are indicated by ^*<i>p</i><0.05 and ^**<i>p</i><0.01.</p

Th-Based Endohedral Metallofullerenes: Anomalous Metal Position and Significant Metal-Cage Covalent Interactions with the Involvement of Th 5f Orbitals

Endohedral metallofullerenes (EMFs) containing actinides are rather intriguing due to potential 5f-orbital participation in the metal–metal or metal–cage bonding. In this work, density functional theory calculations first characterized the structure of recently synthesized ThC₇₄ as Th@<i>D</i>_3<i>h</i>(14246)-C₇₄. We found that the thorium atom adopts an unusual off-axis position inside cage due to small metal ion size and the requirement of large coordination number, which phenomenon was further extended to other Th-based EMFs. Significantly, besides the strong metal–cage electrostatic attractions, topological and orbital analysis revealed that all the investigated Th-based EMFs exhibit obvious covalent interactions between metal and cage with substantial contribution from the Th 5f orbitals. The encapsulation by fullerenes is thus proposed as a practical pathway toward the f-orbital covalency for thorium. Interestingly, the anomalous internal position of Th led to a novel three-dimensional metal trajectory at elevated temperatures in the <i>D</i>_3<i>h</i>-C₇₄ cavity, as elucidated by the static computations and molecular dynamic simulations