Хуудас 1 -аас 50 үр дүн
Free-base and zinc(II) porphyrins bearing either one, two, or four hydroquinone entities at the meso positions are shown to bind quinones in solutions via a quinhydrone pairing mechanism. Electrochemical studies reveal that the quinhydrone complexes are stabilized by charge-transfer interactions
Hybrid molecularly imprinted mesoporous silicas were synthesized by co-condensation of tetraethoxysilane and functional organosilica precursors of HQP and BPAP, in which hydroquinone (HQ) and bisphenol A (BPA) were linked as imprinting molecules. Owing to the existence of a thermally reversible
A range of pi-electron-rich macrocyclic polyethers incorporating dioxybenzene (hydroquinone) and/or dioxynaphthalene units have been synthesized in good yields by simple two-step procedures. These macrocycles are able to bind bipyridinium-based guests as a result of a series of cooperative
Molecular dynamics simulations are used to investigate the molecular interactions of hydrogen-loaded beta-hydroquinone clathrate. It is found that, at lower temperatures, higher loadings are more stable, whereas at higher temperatures, lower loadings are more stable. Attractive forces between the
The molecular interactions and structural behavior of a previously unexplored clathrate system, hydrogen-loaded β-hydroquinone (β-HQ+H2), were investigated under high pressure with synchrotron X-ray diffraction and Raman/infrared spectroscopies. The β-HQ+H2 system exhibits coupling of two
The crystal structure of the β-polymorph of hydroquinone (β-HQ), the apohost of a large family of clathrates, is reported with a specific focus on intermolecular interactions and the electrostatic nature of its cavity. Hirshfeld surface analysis reveals subtle close contacts between two
X-ray/neutron (X/N) diffraction data measured at very low temperature (15 K) in conjunction with ab initio theoretical calculations were used to model the crystal charge density (CD) of the host-guest complex of hydroquinone (HQ) and acetonitrile. Due to pseudosymmetry, information about the
Colloid milium (CM) is a rare condition characterized by the presence of multiple dome-shaped amber- or flesh-colored papules developing on sun-exposed skin. It is a degenerative condition linked to excessive sun exposure and possibly exposure to petroleum products and hydroquinone. The origin of
The energy landscape governing a new pressure-induced phase transition in the hydroquinone-formic acid clathrate is reported in which the host structure collapses, opening up the cavity channels within which the guest molecules migrate and order. The reversible isosymmetric phase transition causes
Clathrates have been proposed for use in a variety of applications including gas storage, mixture separation and catalysis due to the potential for controlled guest diffusion through their porous lattices. Here molecular dynamics simulations are employed to study guest transport in clathrates of
Magnetic cyclodextrin-chitosan/graphene oxide (CCGO) with high surface area was synthesized via a simple chemical bonding method. The characteristics results of FTIR, SEM, TEM and XRD showed that CCGO was prepared. The large saturation magnetization (22.35 emu/g) of the synthesized nanoparticles
We report a new synthesis method of fibrous carbon material with pores sizes that are precisely controlled at the Ångstrom level, by carbonization of two dimensional (2D) porous sheets of pillar[6]arenes. The 2D porous sheets were prepared by 2D supramolecular polymerization induced by oxidation of
A new method of analysis of the factor contributing to solvation of small molecules is described. Approximations of the energetic contributions to the entry of a molecule into water have been derived from partition coefficient data of solutes and selected derivatives from a multiplicity of solvents.
The lignins separated from angiosperm and gymnosperm trees, peat and xylitic brown coal were investigated by quantitative EPR. Observed free radicals in lignins are sensitive to alkaline environment. Gaseous ammonia interacting with solid lignins in resonance cavity shifts quinone-hydroquinone
Propylene is used as a starting material in the production of polypropylene plastics and various other chemicals, including acrylonitrile, isopropyl alcohol, propylene oxide, butyraldehyde, cumene, dodecane, nonene, and allyl chloride. The major derivatives are polypropylene (25%), acrylonitrile