Fluorescent enantioselective receptor for S-mandelate anion based on cholic acid

A chiral fluorescent receptor 1 based on cholic acid was designed and synthesized. The enantioselective recognition ability of 1 to mandelate anion was studied by the fluorescence in CH₃CN and a ¹H NMR spectroscopic method. The results indicate that 1 exhibited a good enantioselectivity to the enantiomer of the mandelate anion in CH₃CN.     

Combustion chemistry of enols: possible ethenol precursors in flames

Before the recent discovery that enols are intermediates in many flames, they appeared in no combustion models. Furthermore, little is known about enols' flame chemistry. Enol formation in low-pressure flames takes place in the preheat zone, and its precursors are most likely fuel species or the early products of fuel decomposition. The OH + ethene reaction has been shown to dominate ethenol production in ethene flames although this reaction has appeared insufficient to describe ethenol formation in all hydrocarbon oxidation systems. In this work, the mole fraction profiles of ethenol in several representative low-pressure flames are correlated with those of possible precursor species as a means for judging likely formation pathways in flames. These correlations and modeling suggest that the reaction of OH with ethene is in fact the dominant source of ethenol in many hydrocarbon flames, and that addition-elimination reactions of OH with other alkenes are also likely to be responsible for enol formation in flames. On this basis, enols are predicted to be minor intermediates in most flames and should be most prevalent in olefinic flames where reactions of the fuel with OH can produce enols directly.     

Directional and Ultrafast Charge Transfer in Oxygen-Vacancy-Rich ZnO@Single-Atom Cobalt Core-Shell Junction for Photo-Fenton-Like Reaction

In photosynthesis, solar energy is harvested by photosensitizers, and then, the excited electrons transfer via a Z-Scheme mode to enzymatic catalytic centers to trigger redox reactions. Herein, we constructed a core–shell Z-scheme heterojunction of semiconductor@single-atom catalysts (SACs). The oxygen-vacancy-rich ZnO core and single-atom Co−N₄ sites supported on nitrogen-rich carbon shell (SA-Co-CN) act as the photosensitizer and the enzyme-mimicking active centers, respectively. Driven by built-in electric field across the heterojunction, photoexcited electrons could rapidly (2 ps) transfer from the n-type ZnO core to the p-type SA-Co-CN shell, finally boosting the catalytic performance of the surface-exposed single-atom Co−N₄ sites for peroxymonosulfate (PMS) activation under light irradiation. The synergies between photocatalysis and heterogeneous Fenton-like reaction lead to phenomenally enhanced production of various reactive oxygen species for rapid degradation of various microcontaminants in water. Experimental and theoretical results validate that the interfacial coupling of SA-Co-CN with ZnO greatly facilitates PMS adsorption and activation by reducing the adsorption energy and enhancing the cascade electron transfer processes for the photo-Fenton-like reaction.     

5. Applications of cellulose acetate 5.1 Cellulose acetate in textile application

The first cellulose acetate fiber, commonly referred to as acetate, was produced in Europe in 1918 and on a large scale in the United States of America in 1924 making acetate the second man-made fiber to be produced.¹ The usage of acetate worldwide peaked at a consumption of approximately 400 kilotons in the early 1970's.² In the past three decades the use of acetate fiber has declined as fabric manufacturers moved to lower costs manmade fibers such as polyester. Manufacturers of acetate have worked aggressively to reduce their cost while maintaining product quality. These efforts have had some reward, leading to acetate's categorization as a niche fiber. As such, cellulose acetate represents less than one percent of the world's total fiber consumption as compared to cotton at over a third³ of the world's consumption and polyester at around a fourth.⁴ Acetate has been used and continues to be used in many different textile applications because of its attributes and good textile processing performance. It is used in woven fabrics, knits and braids. It is found in multiple applications including medical gauze, ribbons, coffin linings, home furnishings, woven velvets, tricot knits, men's linings, circular knits, woven satins, woven fashion, women's linings. It is found in a variety of deniers, lusters, colors, finishes, compactions types and package sizes. It is often blended with other fibers to make combination yarns.     

Phosphine-based coordination cages and nanoporous coordination polymers

Recent findings in the use of multidentate phosphines to synthesise porous coordination polymers (metal-organic frameworks) and their possible precursor cages are reviewed. Additional recent investigations into using large adamantoid Age cages as polymer vertices in giant diamandoid structures are also presented. The results are discussed in terms of possible strategies for the controled synthesis of porous coordination polymers.