- Hydrogen production on a hybrid photocatalytic system composed of ultrathin CdS nanosheets and a molecular nickel complex
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The production of clean and renewable hydrogen through water splitting by using solar energy has received much attention due to the increasing global energy demand. We report an economic and artificial photosynthetic system free of noble metals, consisting of ultrathin CdS nanosheets as a photosensitizer and nickelbased complex as a molecular catalyst. Emission quenching and flash photolysis studies reveal that this hybrid system allows for effective electron transfer from the excited CdS nanosheets to the nickel-based complex to generate reduced intermediate species for efficient hydrogen evolution. Notably, the unique morphological and structural features of the ultrathin CdS nanosheets contribute to the highly efficient photocatalytic performance. As a consequence, the resulting system shows exceptional activity and stability for photocatalytic hydrogen evolution in aqueous solution with a turnover number (TON) of about 28 000 versus catalyst and a lifetime of over 90 h under visible light irradiation.
- Xu, You,Yin, Xuguang,Huang, Yi,Du, Pingwu,Zhang, Bin
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- Fe3O4@SiO2@Im[Cl]Mn(III)-complex as a highly efficient magnetically recoverable nanocatalyst for selective oxidation of alcohol to imine and oxime
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An efficient and environmentally friendly oxidation process for the one-pot preparation of oxime, imine and carbonyl compounds through alcohol oxidation in the presence of H2O2 and/or O2 have been developed by a melamine-Mn(III) Schiff base complex supported on Fe3O4@SiO2–Cl nanoparticles, named as Fe3O4@SiO2@Im[Cl]Mn(III)-complex nanocomposite, at room temperature. Direct oxidation of alcohol to carboxylic acid was performed using the catalyst in the presence of molecular O2 at room temperature in a different approach. The oxidation products were obtained with excellent yields and high TOFs. The properties of the catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis (C, H, N), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), inductive coupled plasma (ICP), cyclic voltammetry (CV), nuclear magnetic resonance (1H & 13C NMR), vibration sample magnetometer (VSM), Brunauer– Emmett–Teller (BET) and differential pulse voltammetry (DPV) analyses. The mechanism of the oxidation processes was investigated for the both H2O2 and O2 oxidants. The role of the imidazolium moiety in the catalyst as a secondary functionality was investigated. Chemoselectivity behavior of the catalyst was studied by some combinations. The catalyst could be recycled from the reaction mixture by a simple external magnet and reused for several times without any considerable reactivity loss.
- Kazemnejadi, Milad,Alavi, Seyyedeh Ameneh,Rezazadeh, Zinat,Nasseri, Mohammad Ali,Allahresani, Ali,Esmaeilpour, Mohsen
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p. 230 - 249
(2019/03/28)
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- Calculation and experimental measurement of paramagnetic NMR parameters of phenolic oximate Cu(II) complexes
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We present a strategy for predicting the unusual 1H and 13C shifts in NMR spectra of paramagnetic bisoximato copper(ii) complexes using DFT. We demonstrate good agreement with experimental measurements, although 1H-13C correlation spectra show that a combined experimental and theoretical approach remains necessary for full assignment.
- Dawson, Daniel M.,Ke, Zhipeng,Mack, Frederick M.,Doyle, Rachel A.,Bignami, Giulia P. M.,Smellie, Iain A.,Bühl, Michael,Ashbrook, Sharon E.
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supporting information
p. 10512 - 10515
(2017/09/29)
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- Synthesis, Crystal Structure, and Catalytic Property of a Copper(II) Complex Derived from 2-Hydroxy-5-Methoxybenzaldehyde Oxime
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With a bidentate Schiff base ligand 2-hydroxy-5-methoxybenzaldehyde oxime (HL) and copper acetate, a polynuclear copper(II) complex was prepared and characterized by elemental analysis, IR spectroscopy, and X-ray structure determination. The complex cryst
- Shen, Xi-Hai,Zhang, Zhi-Wei,Shao, Li-Jun,Lian, Qi,Liu, Chun
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p. 343 - 346
(2015/11/02)
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- HCV PROTEASE INHIBITORS
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The present invention discloses a compound of general formula (I); A is O, S, CH, NH or NR', when O links with Z3, Z1 is N or CRZ1, Z2 is CRZ2, when Z1 links with O, Z2 is CH, Z3 is C-Ar; Ra, Rb, Rc and Rd independently is H, OH, halogen or -Y1-Rm; A1 is NH or CH2; R1' is alkyl, aryl, cycloalkyl, heterocycloalkyl or heteroaryl; A2 is N, O or linking bond; R1 is hydrogen, or, R1 linking covalently with R3 forms C5-C9 saturated or unsaturated hydrocarbon chain substituted by O or N; R3 is alkyl, cycloalkyl, heterocycloalkyl, alkyl substituted by cycloalky etc; R4 is alkoxy-CO, alkyl-NHCO, (alkyl)2NCO, or formyl substituted by aryl, cycloalkyl, heterocycloalkyl.
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- Characterization of scavengers of γ-ketoaldehydes that do not inhibit prostaglandin biosynthesis
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Expression of cyclooxygenase-2 (COX-2) is associated with the development of many pathologic conditions. The product of COX-2, prostaglandin H2 (PGH2), can spontaneously rearrange to form reactive γ-ketoaldehydes called levuglandins (LGs). This γ-ketoaldehyde structure confers a high degree of reactivity on the LGs, which rapidly form covalent adducts with primary amines of protein residues. Formation of LG adducts of proteins has been demonstrated in pathologic conditions (e.g., increased levels in the hippocampus in Alzheimer's disease) and during physiologic function (platelet activation). On the basis of knowledge that lipid modification of proteins is known to cause their translocation and to alter their function, we hypothesize that modification of proteins by LG could have functional consequences. Testing this hypothesis requires an experimental approach that discriminates between the effects of protein modification by LG and the effects of cyclooxygenase-derived prostanoids acting through their G-protein coupled receptors. To achieve this goal, we have synthesized and evaluated a series of scavengers that react with LG with a potency more than 2 orders of magnitude greater than that with the ε-amine of lysine. A subset of these scavengers are shown to block the formation of LG adducts of proteins in cells without inhibiting the catalytic activity of the cyclooxygenases. Ten of these selective scavengers did not produce cytotoxicity. These results demonstrate that small molecules can scavenge LGs in cells without interfering with the formation of prostaglandins. They also provide a working hypothesis for the development of pharmacologic agents that could be used in experimental animals in vivo to assess the pathophysiological contribution of levuglandins in diseases associated with cyclooxygenase up-regulation.
- Zagol-Ikapitte, Irene,Amarnath, Venkataraman,Bala, Manju,Roberts II, L. Jackson,Oates, John A.,Boutaud, Olivier
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scheme or table
p. 240 - 250
(2011/02/22)
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- SUBSTITUTED PYRIMIDINES
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The invention relates to novel substituted pyrimidines of formula (I), in which R1, R2, R3, R4, Q, X and n have the meanings as cited in the description. The invention also relates to a method and intermediate products for producing these pyrimidines, and to the use thereof as plant control agents, particularly as herbicides.
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Page/Page column 25-26
(2008/06/13)
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- NMR spectral assignment of substituted salicylaldoximes by inverse pulse techniques with z-gradient selection: Correlation of NMR parameters with substituent constants
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1H and 13C and also 1H,13C HMQC and 1H,X HMBC (X = 13C and 15N) correlation maps with z-gradient selection of seven salicylaldoximes were recorded and assigned and their paramete
- Kolehmainen, Erkki,Gawinecki, Ryszard,O?mia?owski, Borys,Trzebiatowska, Katarzyna
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p. 778 - 784
(2007/10/03)
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- Magnesium-mediated ortho-Specific Formylation and Formaldoximation of Phenols
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Deprotonation of phenols using magnesium methoxide, followed by distillative removal of free methanol and addition of paraformaldehyde results in ortho-specific magnesium mediated formylation to give the corresponding salicyladehyde magnesium salts, from which the salicylaldehydes can be isolated by acidic work-up.Addition of aq. hydroxylamine sulfate to the salicylaldehyde magnesium salt, in place of the acid work-up, gives the corresponding salicylaldoximes.
- Aldred, Robert,Johnston, Robert,Levin, Daniel,Neilan, James
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p. 1823 - 1832
(2007/10/02)
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