Evaluation of Poly(glycidyl methacrylate)-Coated Column for Enantioseparation with Azithromycin Lactobionate and Clindamycin Phosphate as Chiral Selectors in Capillary Electrophoresis

Chromatographia - In this study, a poly(glycidyl methacrylate) nanoparticle (PGMA NP)-coated column system with two antibiotics as selector was constructed for enantioseparation. The PGMA NP...     

Cationic and temperature-sensitive liposomes loaded with eugenol for the application to silk

Silk has been widely used in the clothing industry due to their soft and smooth features, good biocompatibility, good heat dissipation, warmth and ultraviolet resistance. The application of fragrance to silk can significantly improve the performance of silk. However, there are two key scientific problems that need to be solved: slowing down the release rate of fragrances and increasing the scent lasting time of silk. In this study, cationic and temperature-sensitive liposomes were designed and prepared to encapsulate eugenol. These fragrance-loaded liposomes significantly slowed down the release rate of the fragrance and controlled the release rate of the fragrance in a thermo-sensitive manner. The liposomes adhered to the silk through electrostatic adsorption interaction. The positive charge on the fragrance-loaded liposomes neutralized much negative charge on silk and thereby increasing the adhesion efficiency.     

Microwave-Assisted Synthesis,Crystal Structure and Magnetic Behavior of a Schiff Base Heptanuclear Cobalt Cluster

The reaction of Co(ClO₄)₂·6H₂O with 2-hydroxy-3-methoxy-benzaldehyde and an aqueous solution of methylamine in acetonitrile/MeOH under microwave irradiation and controlled temperature/pressure leads to formation of heptanuclear cobalt cluster [Co₇(mmp)₆(CH₃O)₆]·(ClO₄)₂ (1) (mmp is 2-methoxy-6-methyliminomethyl-phenol anion) in only 20 min and also results in higher yields in contrast to other synthesis methods. Complex 1 displays dominant ferromagnetic interactions through μ ₃-O and μ ₂-O (oxidophenyl) binding modes.     

Syntheses and Crystal Structures of Two New Pentaborates Templated by Transition-Metal Complexes

Two new pentaborates [M(dap)₃][B₅O₆(OH)₄]₂·H₂O (M = Co (1) and Ni (2); dap = 1,2-diaminopropane) have been hydrothermally synthesized. Both structures were determined by single crystal X-ray diffraction and further characterized by elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence spectroscopy. Two compounds are isostructural and consist of isolated pentaborate [B₅O₆(OH)₄]^? anions and [M(dap)₃]²⁺ complex cations. The anionic [B₅O₆(OH)₄]^? groups are linked by extensive hydrogen bonds to form a 3-D supramolecular framework with large channels, in which the transition-metal complex templates are located. The luminescent properties of 1 and 2 were studied, and blue luminescence occurs with an emission maximum at 405 and 408 nm upon excitation at 332 and 328 nm respectively. Crystal data: 1, monoclinic, space group P2₁/c (No. 14), a = 9.7159(5) Å, b = 29.3372(19) Å, c = 11.5121(6) Å, β = 103.286(5)°, V = 3193.6(3) ų, Z = 4; 2, monoclinic, space group P2₁/c, a = 9.7264(4) Å, b = 29.3810(16) Å, c = 11.5185(6) Å, β = 103.249(4)°, V = 3204.0(3) ų, Z = 4.     

Synergistic effect of methyl phenyl silicone resin and DOPO on the flame retardancy of epoxy resins

Polymers based on styrene (STY) and divinylbenzene (DVB) are widely used for water treatment. The chemical modification of these materials, with the introduction of chemical groups, increases their selectivity for certain types of contaminants. The incorporation of magnetic particles makes these systems useful for removing contaminants from aquifers, due to their magnetic attraction of certain residues. In this work, STY–DVB resins (unmodified, sulfonated, and impregnated with nickel and cobalt particles) were analyzed by thermogravimetry. The thermal stabilities of all the samples were compared, showing that sulfonation reduces the thermal stability of the resin, but the incorporation of metal particles restores that stability, with the extent of this recovery depending on the type of metal. This result shows that even when the incorporation of metal particles does not involve removal of contaminants by magnetic attraction, this inclusion is still justified because it increases the material’s thermal stability and also makes it more efficient for removing certain types of non-metallic contaminants, as observed in a previous study. Besides this, the thermogravimetric analysis was highly useful to ascertain the changes caused to the materials, including allowing inferences on the semi-quantitative results of the degree of sulfonation and confirming that metal compounds are not only physical mixtures.     

The Photo‐Nazarov Reaction: Scope and Application

The reaction conditions and scope of the photo‐Nazarov reaction of aryl vinyl ketones were investigated. In contrast to the conventional acid‐catalyzed methods, this photolytic electrocyclization proceeds in the neutral or basic conditions. Irradiating substrates bearing various aromatic rings, acid‐sensitive groups, cyclohexenyl, cycloheptenyl, and unsaturated pyran with UV‐light (254 nm) smoothly yielded hexahydrofluorenones and related structures. This photo‐Nazarov reaction could also be applicable to the substrates carrying β‐alkyl groups on the enone, which gave corresponding polycyclic rings containing quaternary centers. These photo‐electrocyclized products may prove useful for synthesizing a variety of natural products and their derivatives. Further application of this mild photo‐Nazarov reaction in the synthesis of taiwaniaquinol B was achieved.     

4‐Benzamido‐TEMPO Catalyzed Oxidation of a Broad Range of Alcohols to the Carbonyl Compounds with NaBrO3 under Mild Conditions

4‐Benzamido‐TEMPO catalyzed oxidation system for conversion of a wide range of alcohols to the aldehydes or ketones with NaBrO₃ under room temperature conditions has been developed. The credible, operationally convenient and economical, and condition mild oxidation protocol is particularly of interest in laboratory and in fine chemicals manufacture.     

One-pot synthesis–assembly–separation of cucurbit[6]uril via SO3H-functionalized ionic liquids

A novel microwave-assisted route to synthesize cucurbit[n]uril in SO₃H-functionalized ionic liquids was reported, which enabled the automatic separation of cucurbit[6]uril through anion assembly. For the first time, the route has realized synthesis–assembly–separation of cucurbit[6]uril in one pot. The reaction yield and separation efficiency can be tuned by choice of anionic groups in ionic liquids.