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1.
Subbarayan Velusamy 《Tetrahedron letters》2005,46(22):3819-3822
Copper(II) complex 1 catalyzes the oxidation of sulfides to sulfoxides with 30% H2O2 in high yields. Addition of a catalytic amount of TEMPO to the reaction mixture enhances the conversion and selectivity. Complex 1 can be recycled without loss of activity. 相似文献
2.
[reaction: see text] Oxidation of alcohols to aldehydes and ketones has been studied in high yields using atmospheric oxygen and a catalytic amount of V2O5 in toluene under heating (ca. 100 degrees C). Secondary alcohols can be chemoselectively converted into ketones in the presence of primary hydroxy groups. 相似文献
3.
Four new iron(III) complexes of the bis(phenolate) ligands N,N-dimethyl-N',N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine [H2(L1)], N,N-dimethyl-N',N'-bis(2-hydroxy-4-nitrobenzyl)ethylenediamine [H2(L2)], N,N'-dimethyl-N,N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine [H2(L3)], and N,N'-dimethyl-N,N'-bis(2-hydroxy-4-nitrobenzyl)ethylenediamine [H2(L4)] have been isolated and studied as structural and functional models for the intradiol-cleaving catechol 1,2-dioxygenases (CTD). The complexes [Fe(L1)Cl] (1), [Fe(L2)(H2O)Cl] (2), [Fe(L3)Cl] (3), and [Fe(L4)(H2O)Cl] (4) have been characterized using absorption spectral and electrochemical techniques. The single-crystal X-ray structures of the ligand H2(L1) and the complexes 1 and 2 have been successfully determined. The tripodal ligand H2(L1) containing a N2O2 donor set represents the metal-binding region of the iron proteins. Complex 1 contains an FeN2O2Cl chromophore with a novel trigonal bipyramidal coordination geometry. While two phenolate oxygens and an amine nitrogen constitute the trigonal plane, the other amine nitrogen and chloride ion are located in the axial positions. In contrast, 2 exhibits a rhombically distorted octahedral coordination geometry for the FeN2O3Cl chromophore. Two phenolate oxygen atoms, an amine nitrogen atom, and a water molecule are located on the corners of a square plane with the axial positions being occupied by the other nitrogen atom and chloride ion. The interaction of the complexes with a few monodentate bases and phenolates and differently substituted catechols have been investigated using absorption spectral and electrochemical methods. The effect of substituents on the phenolate rings on the electronic spectral features and FeIII/FeII redox potentials of the complexes are discussed. The interaction of the complexes with catecholate anions reveals changes in the phenolate to iron(III) charge-transfer band and also the appearance of a low-energy catecholate to iron(III) charge-transfer band similar to catechol dioxygenase-substrate complexes. The redox behavior of the 1:1 adducts of the complexes with 3,5-di-tert-butylcatechol (H2DBC) has been also studied. The reactivities of the present complexes with H2DBC have been studied and illustrated. Interestingly, only 2 and 4 catalyze the intradiol-cleavage of H2DBC, the rate of oxygenation being much faster for 4. Also 2, but not 4, yields an extradiol cleavage product. The reactivity of the complexes could be illustrated not on the basis of the Lewis acidity of the complexes alone but by assuming that the product release is the rate-determining phase of the catalytic reaction. 相似文献
4.
Kathiravan Velusamy Kishore Kumar Krishnani 《Applied biochemistry and biotechnology》2013,169(6):1978-1992
In this work, herbivorous fish Mugil cephalus has been cultured to secrete protein rich green slime, which helps nitrifying and oxygen tolerant denitrifying bacteria to grow and colonize. Four strains representing Alcaligenaceae family have been isolated from greenwater system and characterized using biochemical test, fatty acid methyl ester (GC-FAME) analysis, 16S rRNA and functional gene approaches. They were tested for an ability to nitrify ammonia and nitrite aerobically. Two strains showed notable nitrification activity, when grown in a mineral salts medium containing ammonium sulfate and potassium nitrite. Functional gene analysis confirmed the presence of nitrous oxide reductase (nosZ) gene showing that they have an oxygen-tolerant denitrification system. It has been proposed that Alcaligenes faecalis strains heterotrophically nitrify ammonia into nitrite via formation of hydroxyl amine, which is oxidized to nitrous oxide using oxygen or nitrite as electron acceptor. These results provide a possible advantage of having nitrification and denitrification capabilities in the same organism, which plays an important role in biological wastewater system. 相似文献
5.
High‐performance alternating current electroluminescent layers solution blended with mechanically and electrically robust nonradiating polymers 下载免费PDF全文
6.
Velusamy B. Subramanian Naresh Kumar Katari Thirupathi Dongala Sreekantha B. Jonnalagadda 《Biomedical chromatography : BMC》2020,34(1):e4719
A quality by design (QbD) based high-resolution HPLC method is described for determination of impurities in apixaban (APX) in the tablet dosage form. Employing a simple and stability-indicating HPLC method, nine known impurities were quantified with good peak resolution. Mobile phase A (MP-A) was prepared with buffer and acetonitrile 90:10 v/v, while mobile phase B (MP-B) contained water and acetonitrile 10:90 v/v. The gradient program was 0 min, MP-A 75%, B 25%; 20 min, MP-A 65%, B 35%; 30 min, MP-A 40%, B 60%; 40min, MP-A 40%, B 60%; 42 min, MP-A 75%, B 25%; and 50 min, MP-A 75%, B 25%. The chromatographic separation was achieved using a Zorbax RX C18 250 × 4.6 mm column, 5 μm (1.0 ml min−1, 280 nm, 50 μl) and a column temperature of 40°C. Several separation studies were carried out using design of experiments to optimize the method. Validation results confirm the applicability of the developed method for quality analysis and stability studies of the regular product on the manufacturing stream. 相似文献
7.
Anna Liguori Tommaso Gallingani Dilli Babu Padmanaban Romolo Laurita Tamilselvan Velusamy Gunisha Jain Manuel Macias-Montero Davide Mariotti Matteo Gherardi 《Plasma Chemistry and Plasma Processing》2018,38(6):1209-1222
The influence of the liquid composition on the chemical and morphological properties of copper-based nanostructures synthesized by a non-equilibrium atmospheric plasma treatment is investigated and discussed. The synthesis approach is simple and environmentally friendly, employs a non-equilibrium nanopulsed atmospheric pressure plasma jet as a contactless cathode and a Cu foil as immersed anode. The process was studied using four distinct electrolyte solutions composed of distilled water and either NaCl?+?NaOH, NaCl only or NaOH only at two different concentrations, without the addition of any copper salts. CuO crystalline structures with limited impurities (e.g. Cu and Cu(OH)2 phases) were produced from NaCl?+?NaOH containing solutions, mainly CuO and CuCl2 structures were synthesized in the electrolyte solution containing only NaCl and no synthesis occurred in solutions containing only NaOH. Both aggregated and dispersed nanostructures were produced in the NaCl?+?NaOH and NaCl containing solutions. Reaction pathways leading to the formation of the nanostructures are proposed and discussed. 相似文献
8.
Chinh Tam Le Daniel J. Clark Farman Ullah Velusamy Senthilkumar Joon I. Jang Yumin Sim Maeng‐Je Seong Koo‐Hyun Chung Hyoyeol Park Yong Soo Kim 《Annalen der Physik》2016,528(7-8):551-559
In this study, we utilized picosecond pulses from an Nd:YAG laser to investigate the nonlinear optical characteristics of monolayer MoSe2. Two‐step growth involving the selenization of pulsed‐laser‐deposited MoO3 film was employed to yield the MoSe2 monolayer on a SiO2/Si substrate. Raman scattering, photoluminescence (PL) spectroscopy, and atomic force microscopy verified the high optical quality of the monolayer. The second‐order susceptibility χ(2) was calculated to be ~50 pm V?1 at the second harmonic wavelength ~810 nm, which is near the optical gap of the monolayer. Interestingly, our wavelength‐dependent second harmonic scan can identify the bound excitonic states including negatively charged excitons much more efficiently, compared with the PL method at room temperature. Additionally, the MoSe2 monolayer exhibits a strong laser‐induced damage threshold ~16 GW cm?2 under picosecond‐pulse excitation. Our findings suggest that monolayer MoSe2 can be considered as a promising candidate for high‐power, thin‐film‐based nonlinear optical devices and applications. 相似文献
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10.
Subbarayan Velusamy 《Tetrahedron letters》2006,47(6):923-926
Copper(II) complex 1 selectively catalyzes the oxidation of primary alcohols to aldehydes in high yields by atmospheric oxygen in the presence of TEMPO. This procedure does not require an additive and the catalyst 1 is recyclable without loss of activity. 相似文献