Synthesis of β-cyclodextrin-calix[4]arene coupling product and its adsorption of basic fuchsin and methylene blue from water

Two new β-CD-calix[4]arene coupling products 3,4 which contained one or two β-CD units in molecules were synthesized by ammonolysis of p-tert-butyl-25,27-dihydroxyl-26,28-di (ethoxy carbonyl methoxyl) calix[4]arene 1 and mono-6-ethylenediamino-6-deoxy-β-CD 2, and their structures were confirmed by ¹H NMR, IR and MS (Maldi-Tof). The probable mechanism for forming 3 was discussed also. Using water-insoluble coupling product 3 as an adsorbent, the influences of the adsorption capacities of 3 including initial concentration, temperature and pH onto basic fuchsin (BF) and methylene blue (MB) from aqueous solution were investigated. Results showed that the adsorption capability of 3 to BF was obviously higher than that to MB at similar adsorption conditions. The values of %sorption to BF were over 90 % in range of initial concentrations from 20 to 140 mg L^?1 whenas those to MB dropped rapidly from 92 to 58 %. The adsorptions of 3 to both BF and MB obeyed Freundlich adsorption isotherm well.     

Validity of Inorganic Nanosheets as an Efficient Planar Substituent To Enhance the Enantioselectivity of Transition‐Metal‐Catalyzed Asymmetric Synthesis

Effectively enhancing the enantioselectivity is a persistent challenge in heterogeneous asymmetric catalysis. Here, the validity of a layered double hydroxides (LDH) nanosheet as an efficient planar substituent to enhance the enantioselectivity has been investigated theoretically; first in vanadium‐catalyzed asymmetric epoxidation of allylic alcohols, and then in zinc‐catalyzed direct asymmetric aldol addition. The computational predication is further confirmed experimentally in zinc‐catalyzed direct asymmetric aldol addition by controlling the location of catalytic sites.     

Palladium‐Catalyzed C(sp3)?H Activation: A Facile Method for the Synthesis of 3,4‐Dihydroquinolinone Derivatives

3,4‐Dihydroquinolinones were synthesized by the palladium‐catalyzed, oxidative‐addition‐initiated activation and arylation of inert C(sp³) H bonds. Pd(OAc)₂ and P(o‐tol)₃ were used as the catalyst and ligand, respectively, to improve the efficiency of the reaction. A further advantage of this reaction is that it could be performed in air. A relatively rare seven‐membered palladacycle was proposed as a key intermediate of the catalytic cycle.     

A New Lactam from Cannabis sativa

Chemistry of Natural Compounds - A new lactam, 5-hydroxy-1-[(4-hydroxyphenyl)methyl]-2-pyrrolidinone (1), was isolated from the ethyl acetate extract of Cannabis sativa L. The structure was...     

Slow-light fourier transform interferometer

We describe a new type of Fourier transform (FT) interferometer in which the tunable optical delay between the two arms is realized by using a continuously variable slow-light medium instead of a moving arm as in a conventional setup. The spectral resolution of such a FT interferometer exceeds that of a conventional setup of comparable size by a factor equal to the maximum group index of the slow-light medium. The scheme is experimentally demonstrated by using a rubidium atomic vapor cell as the tunable slow-light medium, and the spectral resolution is enhanced by a factor of approximately 100.     

Controlled synthesis of dendritic ruthenium nanostructures under microwave irradiation and their catalytic properties for p-chloronitrobenzene hydrogenation

Transition Metal Chemistry - In this study, the shape-controlled synthesis of ruthenium (Ru) nanostructures was examined using microwave irradiation. Dendritic Ru nanostructures, with an average...     

Electrospinning synthesis and photocatalytic property of CaFe2O4/MgFe2O4 heterostructure for degradation of tetracycline

CaFe₂O₄/MgFe₂O₄ nanowires with heterostructure had been successfully synthesized by electrospinning method. The obtained samples were systematically characterized by scanning electron microscopy (SEM), X‐Ray diffraction (XRD), UV–Vis diffuse reflectance spectra (UV‐Vis DR) and Environment scanning electron microscopy (ESEM). The novel CaFe₂O₄/MgFe₂O₄ nanowires exhibit an enhanced photocatalytic activity for degrading of tetracycline (TC) under visible light. Compared with bare CaFe₂O₄ or MgFe₂O₄ samples, the prepared CaFe₂O₄/MgFe₂O₄ (Ca:Mg:Fe = 3:2:10) composited nanowires show the best photocatalytic performance with a degradation efficiency of 40% after 150 min reaction time. This enhancement is attributed to the heterostructure of CaFe₂O₄/MgFe₂O₄ nanowires, which effectively repress the recombination of photo‐generated electrons and holes. Based on heterostructure and energy band positions, the enhancement of mechanism under visible‐light enhances the photocatalytic activity.