Mild Solvothermal Syntheses and Characterization of Layered Copper Thioantimonates(III) and Thioarsenate(III)

The new copper thioantimonates­(III) and thioarsenate­(III) Rb₂Cu₂Sb₂S₅ (<b>1</b>), Cs₂Cu₂Sb₂S₅ (<b>2</b>), and Rb₈Cu₆As₈S₁₉ (<b>3</b>) have been synthesized solvothermally. Compound <b>1</b> contains a [Cu₂SbS₃] net to which [Sb₂S₄] chains adhere through Cu–S bonds and Sb–Cu interactions to give a layered structure. In compound <b>2</b>, the layer is formed by edge-sharing tetrahedral CuS₄ chains linked by dimeric [Sb₂S₅] units. The layered structure in compound <b>3</b> is constructed by helical chains built from [Cu₃S₇] moieties and dimeric [As₂S₅] units which are further connected by tetrameric [As₄S₉] groups. Their optical and thermal properties have been investigated

Mild Solvothermal Syntheses of Thioargentates A–Ag–S (A = K, Rb, Cs) and A–Ag–Ge–S (A = Na, Rb): Crucial Role of Excess Sulfur

A series sulfides of A–Ag–S (<b>1</b>–<b>3</b>; A = K, Rb, Cs), Na₅AgGe₂S₇ (<b>4</b>), and Rb₂Ag₂GeS₄ (<b>5</b>) have been prepared solvothermally in the presence of excess sulfur. Among these compounds, <b>4</b> is a new compound that has a novel layered structure; the others were obtained under mild conditions. The results showed that excess sulfur could increase the solubility of silver sulfide and lower the synthetic temperature effectively. The mineralizer effect of excess sulfur is discussed in detail

Mild Solvothermal Syntheses of Thioargentates A–Ag–S (A = K, Rb, Cs) and A–Ag–Ge–S (A = Na, Rb): Crucial Role of Excess Sulfur

A series sulfides of A–Ag–S (<b>1</b>–<b>3</b>; A = K, Rb, Cs), Na₅AgGe₂S₇ (<b>4</b>), and Rb₂Ag₂GeS₄ (<b>5</b>) have been prepared solvothermally in the presence of excess sulfur. Among these compounds, <b>4</b> is a new compound that has a novel layered structure; the others were obtained under mild conditions. The results showed that excess sulfur could increase the solubility of silver sulfide and lower the synthetic temperature effectively. The mineralizer effect of excess sulfur is discussed in detail

Formation of Brominated Disinfection Byproducts during Chloramination of Drinking Water: New Polar Species and Overall Kinetics

The formation of brominated disinfection byproducts (Br-DBPs), which are generally significantly more cytotoxic and genotoxic than their chlorinated analogues, in chloramination has not been fully examined. In this work, the formation of new polar Br-DBPs in simulated drinking waters was examined using state-of-the-art ultraperformance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry. As many as 29 aliphatic, aromatic, or nitrogenous polar Br-DBPs were detected in chloramination, and five of them (including 2,4,6-tribromoresorcinol, 2,6-dibromo-4-nitrophenol, 2,2,4-tribromo-5-hydroxy-4-cyclopentene-1,3-dione, 2,2,4-dibromochloro-5-hydroxy-4-cyclopentene-1,3-dione, and 2,2,4-bromodichloro-5-hydroxy-4-cyclopentene-1,3-dione) were tentatively identified. Unlike chlorination, chloramination favored the formation of aromatic and nitrogenous polar Br-DBPs and was mild enough to allow polar intermediate Br-DBPs to accumulate. To further explore the formation mechanism of Br-DBPs in chloramination, a quantitative empirical model involving 33 major reactions was developed to describe the overall kinetics. According to the modeling results, bromochloramine and monobromamine were the major species responsible for 54.2–58.1% and 41.7–45.7%, respectively, of the formed Br-DBPs, while hypobromous acid accounted for only 0.2% of the formed Br-DBPs; direct reactions between monochloramine and natural organic matter accounted for the majority of the formed chlorinated DBPs (93.7–95.1%); hypochlorous acid and hypobromous acid in the chloramination were at ng/L or subng/L levels, which were not enough to cause polar intermediate Br-DBPs to decompose

Supercritical Deposition Route of Preparing Pt/Graphene Composites and Their Catalytic Performance toward Methanol Electrooxidation

The production of effective loading and direct deposition of Pt nanoparticles on graphene is difficult because this intriguing carbon material has highly hydrophobic surface properties. In this work, Pt/graphene sheet (GS) composites were successfully synthesized via a simple, effective, and environmentally benign one-pot supercritical carbon dioxide deposition route using dimethyl (1,5-cyclooctadiene) platinum­(II) (PtMe₂COD) as a soluble organometallic precursor. The preparation process obviates the need for solvents, which are often volatile and toxic. No post-treatment processes such as washing and drying are needed. Transmission electron microscopy shows that ultrafine metal nanoparticles with an average size as small as ∼2 nm are densely and evenly decorated on the hydrophobic surfaces of GS at Pt loadings up to 80 wt %. Electrochemical studies reveal that the prepared Pt/GS composites possess notably higher catalytic activity and better stability toward methanol electrooxidation in comparison with Pt/multiwalled carbon nanotube and Pt/carbon black composites. The supercritical carbon dioxide deposition method could be easily extended to the fabrication of other graphene-based metal composites with desirable properties by selecting suitable organometallic precursors

Synthesis of Pyrrolo[2,1,5-<i>cd</i>]indolizines through Dehydrogenative Heck Annelation of Indolizines with Diaryl Acetylenes Using Dioxygen as an Oxidant

A dehydrogenative Heck annelation reaction of indolizine with diaryl acetylene via dual C–H bond cleavage was developed. Oxygen gas was employed as a clean oxidant in this catalysis under base-free conditions. Diarylpyrrolo­[2,1,5-<i>cd</i>]­indolizines were synthesized with high atom economy. In addition, kinetic isotope experiments provided evidence for C–H bond metalation of the 5-position of the indolizine as the rate-limiting step

The expression of PPARγ in rat retina after ONC.

<p>A. The expression of PPARγ mRNA was increased after ONC. The highest expression was found on day 3, then returned to basal values on day 14 and remained unchanged until the end of the observation period of 28 days(n = 6 in each group). *p<0.05. B. Western blot analysis of PPARγ protein in the retina. C. The expression of PPARγ protein relative to GAPDH was determined by measuring the optical density using ImageJ software(n = 6 in each group). *p<0.05. D. Immunohistochemical staining of PPARγ in rat retina. High PPARγ immunoreactivity was observed in the nerve fiber layer (NFL), ganglion cell layer (GCL), inner neuclear layer (INL) and outer plexiform layer (OPL) 3 days after ONC. Bar = 100 µm.</p

Double immunofluorescence staining for PPARγ (green)/GS (red) and PPARγ (green)/NeuN (red) on the normal retina and the retina 7 days after ONC.

<p>Most of PPARγ positive cells are colocalized with GS positive Müller cells, not within NeuN positive RGCs. Bar = 100 µm.</p

Effect of Pio on Müller cell activation in retina.

<p>Immunoreactivity for PPARγ (green) and GFAP (red) in rat retinal sections of each group at 7days after ONC. Bar = 100 µm.</p

The anti-apoptotic effect of Pio on RGCs after ONC.

<p>(A) Representative of the terminal dUTP nick end labeling (TUNEL) staining in retinal sections of each group at 7 days after ONC. Hochest dye was used for nuclear staining. (B) TUNEL-positive cells in the RGCs layer at 7 days after ONC(n = 6 in each group). *p<0.05. Bar = 100 µm.</p