用于苯与分子氧羟基化制苯酚的长链脂肪胺修饰的杂多酸催化剂

 将十二胺或十八胺与磷钼钒杂多酸结合, 制备了有机-无机杂化催化剂, 并在高压釜中考察了它们在苯与分子氧羟基化制苯酚反应中的催化性能. 结果表明, 当十二胺与杂多酸的摩尔比为 4:1 时, 所制备的杂化催化剂上苯酚产率为 11.5%, 大大高于纯杂多酸催化剂上的 3.9%. 结合长链脂肪胺与杂多酸之间的相互作用, 以及杂多酸的“假液相”特性, 初步讨论了长链脂肪胺的促进作用.     

Ab initio studies of the characteristics of hydrogen bonds involving aromatically bound hydroxyl and amino groups and the effects of aromatic fluorine substitution on these interactions

In this work, we study the hydrogen bonds (H‐bonds) involving hydroxyl and amino groups bonded to phenyl and pyrimidine rings (as H‐bond donors). These types of interactions play important roles in the recognition of ligands by proteins and are also important in the design of materials. The effects of aromatic fluorine substitutions on aromatic rings are also investigated, and it is found that these substitutions can have large effects on the hydrogen bonding interactions that occur in our model systems, making them substantially stronger. This finding offers a new mechanism for the modification of these types of interactions, potentially opening new paths in the design of novel pharmaceuticals and materials. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Zeolite-Y enslaved manganese(III) complexes as heterogeneous catalysts

Traditional catalytic procedures for oxidation of phenol produce environmentally undesirable wastes. As a consequence, there is a clear demand for development of an environmentally benign catalytic route for the selective oxidation of phenol. A series of zeolite-Y enslaved Mn(III) complexes with Schiff bases derived from vanillin furoic-2-carboxylic acid hydrazone (VFCH), vanillin thiophene-2-carboxylic acid hydrazone (VTCH), ethylvanillin thiophene-2-carboxylic acid hydrazone (EVTCH), and/or ethylvanillin furoic-2-carboxylic acid hydrazone have been synthesized and characterized by physico-chemical techniques. Catalytic oxidations of phenol using 30% H₂O₂ as an oxidant over [Mn(VTCH)₂·2H₂O]⁺-Y, [Mn(VFCH)₂·2H₂O]⁺-Y, and [Mn(EVTCH)₂·2H₂O]⁺-Y under mild conditions were studied. These zeolite-Y enslaved Mn(III) complexes are stable and recyclable under current reaction conditions.     

Copper(II) complex of monobasic tridentate ONN donor ligand: synthesis,encapsulation in zeolite-Y,characterization, and catalytic activity

Reaction between CuCl₂ and (Z)-2-(1-(2-(1H-benzo[d]imidazol-2-yl)ethylimino)ethyl)phenol (Hhap-aebmz) derived from o-hydroxyacetophenone (Hhap) and 2-aminoethylbenzimidazole (aebmz) gives [Cu^II(hap-aebmz)Cl]. Elemental analysis, magnetic susceptibility, spectral (IR and electronic) data, and single crystal X-ray studies confirm the distorted square planar structure of the complex. [Cu^II(hap-aebmz)Cl] has been encapsulated in the nano-cavity of zeolite-Y and its encapsulation is ensured by various physico-chemical techniques. The encapsulated complex has been used as a catalyst for oxidation of cyclohexene and phenol in the presence of H₂O₂. With nearly quantitative oxidation of cyclohexene, the selectivity of the oxidation products follows the order, 2-cyclohexene-1-ol (44%)?>?2-cyclohexene-1-one (40%)?>?cyclohexeneoxide (12%)?>?cyclohexane-1,2-diol (4%). Oxidation of phenol (65.7%) gives catechol (66.1%)?>?hydroquinone (32.9%).     

Current Response of Cytochrome C Promoted by Dodecyl Benzene Sodium Sulfonate

Abstract

A simple TLC separation and semi-quantitative visual determination method was used to analyse the volatile phenols in the waste water of the petroleum industry and the grain irrigated by the waste water. The phenol in the rice irrigated by the water that contained phenol for artificial preparation was also studied. A preliminary conclusion was obtained, that the grain could absorb volatile phenols from irrigation water.     

Electrocatalytic Phenol Oxidation on Mixed Pt‐RuO2 Nanoparticle Modified Electrode

Abstract

Nanoscale Pt/RuO₂ colloid with carbon paste support was synthesized and used to prepare a modified electrode for phenol detection. The results showed that the Pt/RuO₂ catalyst has high activity for electrooxidation of phenol with reduced intermediate polymerization due to its significantly low potential for phenol oxidation. The detection limit was as low as 10^?9 mol L^?1 for the polishable Pt/RuO₂/C paste electrode with good reproducibility.     

Highly Selective and Sensitive Triiodide PVC‐Based Membrane Electrode Based on a New Charge Transfer Complex of 2‐(((2‐(((E)‐1‐(2‐Hydroxyphenyl) Methylidine) Amino) Phenyl) Imino) Methyl) Phenol for Nano‐Level Monitoring of Triiodide

Abstract

A highly selective and sensitive triiodide sensor based on a 2‐(((2‐(((E)‐1‐(2‐hydroxy phenyl) methylidine) amino) phenyl) imino) methyl) phenol with iodine (CTC) as membrane carrier was developed. The electrode revealed a Nernstian behavior over a very wide triiodide‐ion concentration range (5.0×10^?8–1.0×10^?2 M), and relatively low detection limit (3.0×10^?8 M). The potentiometric response is independent of the pH of solution in the pH range of 3.0–10.0. The electrodes manifest advantages of low resistance, very fast response (<12 s), and most importantly, good selectivities relative to a wide variety of inorganic and organic anions, including iodide, bromide, chloride, fluoride, sulfite, sulfate, cyanide, thiocyanate, and acetate. In fact, the selectivity behavior of the proposed triiodide ion‐selective electrode shows great improvements compared to the previously reported electrodes for the triiodide ion. The proposed membrane sensor can be used for at least 6 months without any significant divergences in the potential. The electrode was successfully applied as an indicator electrode in the titration of triiodide with thiosulfate ion.     

Synthesis and Crystal Structure of 2-(2,3,4-Trimethoxy-6-Methylbenzylideneamino)phenol

Abstract  The title compound 2-(2,3,4-trimethoxy-6-methylbenzylideneamino)phenol (C₁₇H₁₉NO₄, M _r = 301.33) was synthesised and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 10.4458(14), b = 8.3870(10), c = 17.780(2) ?, β = 91.102(2)^°, V = 1557.4(3) ?³, Z = 4, D _c = 1.285 g/cm³, λ = 0.71073 ?, μ(Mo Kα) = 0.092 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0452, wR(F ²) = 0.1065 for 2,743 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the molecule adopts an E configuration at the C=N functional bond. The dihedral angle between the two phenyl rings is 38.3(3)°. The crystal structure is stabilized by C–H···O, O–H···O and O–H···N hydrogen bonds and π–π stacking interactions. Graphical Abstract  The title compound 2-(2,3,4-trimethoxy-6-methylbenzylideneamino)phenol (C₁₇H₁₉NO₄, M _r = 301.33) was synthesised and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 10.4458(14), b = 8.387(1), c = 17.780(2) ?, β = 91.102(2)°, V = 1557.4(3) ?³, Z = 4, D _c = 1.285 g/cm³, λ = 0.71073 ?, μ(Mo Kα) = 0.092 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0452, wR(F ²) = 0.1065 for 2,743 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the molecule adopts an E configuration at the C=N functional bond. The dihedral angle between the two phenyl rings is 38.3(3)°. The crystal structure is stabilized by C–H···O and O–H···O hydrogen bonds and π–π stacking interactions.      

Selective hydrogenation of phenol in supercritical carbon dioxide

Liquid phase hydrogenation of phenol over Pt/C catalysts was investigated under conventional conditions and supercritical carbon dioxide (scCO2). The equivalent ration of hydrogen to phenol shows a significant effect on the product selectivity. Hydrogenation of phenol in different solvents was also studied, the experimental results show that polarity of solvents influences the yield of cyclohexanone remarkably, scCO2 has the highest one. Catalytic hydrogenation of phenol in scCO2 or sub-scCO2 was emphatically researched. The result is that near the critical point of CO2 phenol has higher reaction activity than that of normal organic solvents, cyclohexanone has 47% in yield and 87% in selectivity.     

Synthesis of a caryophyllene isoprenologue, a potential diterpene natural product

(−)-β-Caryophyllene has been converted into three stereoisomers of a new bicyclic compound that is structurally related to the known macrocyclic diterpene, flexibilene, in the same way β-caryophyllene is related to humulene. Key steps are selective cleavage of caryophyllene, addition of a five carbon component by a Wittig reaction and McMurry cyclization.