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41.
Thiruneelakandan Chockalingam Manohar Muthuraman Rajkumar Seenivasan Rajagopal 《Transition Metal Chemistry》2006,31(4):549-555
The electron transfer reaction of Cr(VI) with organic sulfides is facilitated by added pyridine bases 2,2′-bipyridine, 1,10-phenanthroline,
picolinic acid and pyridine 2,6-dicarboxylic acid. The added base forms a Cr(VI)-base adduct carrying positive charge which
acts as a more reactive oxidant compared to Cr(VI). UV–Visible spectrophotometric study provides evidence for the formation
of Cr(V) as the intermediate. The reactions in the absence and presence of pyridine bases follow the reactivity–selectivity
principle. 相似文献
42.
Rhodium(II) acetate catalyzed reactions of various substituted 3-diazopiperidin-2-ones with a range of aromatic amines, indoles, and benzotriazole yield exclusively the corresponding N-H insertion products despite competing C-H or O-H insertions. This strategy provides an example of a facile chemoselective N-H insertion reaction delivering a library of 3-arylamino and 3-heteroarylpiperidin-2-one derivatives in high yields. 相似文献
43.
The mesoporous Si-MCM-41 was synthesized by hydrothermal method and various wt.% (20 and 30 wt.%) of HPW were loaded on Si-MCM-41 by wet impregnation method. The synthesized Si-MCM-41 and HPW-loaded catalysts were characterized by XRD, BET surface area, FT-IR, TEM and TGA–DTG techniques. The catalytic activity of the catalyst was tested over the condensation reaction of aniline with various aromatic aldehydes at refluxing temperature under liquid-phase condition, which yields highly commercial product namely diamino triphenyl methanes (DATPMs). The effects of various parameters like catalyst, mole ratio, solvents and substituent effect on the formation of DATPMs were optimized. The catalytic activity of the catalysts showed the following order: H3PW12O40·nH2O > H3PMo12O40·nH2O > H4SiW12O40·nH2O > 20 wt.% HPW/MCM-41 > 30 wt.% HPW/MCM-41 > HM (12) > Hβ (8) > HY (4) > HZSM-5 (15) > Al-MCM-41 (25). The results showed that mole ratio of 4:1 (aniline:aldehyde) gave higher yield than the other mole ratios. Acetonitrile and ethyl acetate shows better activity especially in the supported materials than toluene was used as a solvent. The product thus obtained was analyzed by 1H NMR, FT-IR techniques. 相似文献
44.
Two acrylate monomers – 4‐(2′‐methoxycinnamoyl)phenyl acrylate, and 4‐(2′,5′‐dimethoxycinnamoyl)phenyl acrylate – comprising photocrosslinkable pendant chalcone moiety and a free radical polymerizable group were synthesized. The monomers were polymerized in the presence of ethyl methyl ketone at 70°C using benzoyl peroxide as the initiator. The polymers were characterized by UV, FT‐IR, 1H‐NMR, and 13C‐NMR spectra. The weight and number average molecular weights of the polymers were determined by gel permeation chromatography. The thermal stability of the polymers was studied by TGA under a nitrogen atmosphere. Glass transition temperatures of the polymers were studied by differential scanning calorimetry. The photoreactivity of the polymers was investigated for potential applications as photoresists in solution using various solvents. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
45.
Ghedeir M. Alshammari Abu ElGasim A. Yagoub Pandurangan Subash-Babu Amro B. Hassan Doha M. Al-Nouri Mohammed A. Mohammed Mohammed A. Yahya Rasha Elsayim 《Molecules (Basel, Switzerland)》2021,26(23)
The present study reports a cost-effective, environmentally friendly method to increase the bioavailability and bio-efficacy of B. rufescens stem bark extract in the biological system via functional modification as B. rufescens stem bark nanoparticles (BR-TO2-NPs). The biosynthesis of BR- -NPs was confirmed by UV-visible (UV-vis) and Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction analyses. The shifts in FT-IR stretching vibrations of carboxylic and nitro groups (1615 cm−1), the O–H of phenolics or carboxylic acids (3405 cm−1), alkanes, and alkyne groups (2925 and 2224 cm−1) of the plant extract and lattice (455) indicated successful biosynthesis of BR- -NPs. Compared with the stem bark extract, 40 ng/dL dose of BR- -NPs led to a reduction in adipogenesis and an increase in mitochondrial biogenesis-related gene expressions, adiponectin-R1, PPARγC1α, UCP-1, and PRDM16, in maturing-adipocytes. This confirmed the intracellular uptake, bioavailability, and bio-efficiency of BR-TiO2-NPs. The lipid-lowering capacity of BR-TiO2-NPs effectively inhibited the metabolic inflammation-related gene markers, IL-6, TNF-α, LTB4-R, and Nf-κb. Further, BR-TiO2-NPs stimulating mitochondrial thermogenesis capacity was proven by the significantly enhanced CREB-1 and AMPK protein levels in adipocytes. In conclusion, BR-TiO2-NPs effectively inhibited lipid accumulation and proinflammatory adipokine levels in maturing adipocytes; it may help to overcome obesity-associated comorbidities. 相似文献
46.
47.
David G. Harris Ehab Morsy Gopal Pandurangan Peter Robinson Aravind Srinivasan 《Random Structures and Algorithms》2016,49(2):322-344
Basic graph structures such as maximal independent sets (MIS's) have spurred much theoretical research in randomized and distributed algorithms, and have several applications in networking and distributed computing as well. However, the extant (distributed) algorithms for these problems do not necessarily guarantee fault‐tolerance or load‐balance properties. We propose and study “low‐average degree” or “sparse” versions of such structures. Interestingly, in sharp contrast to, say, MIS's, it can be shown that checking whether a structure is sparse, will take substantial time. Nevertheless, we are able to develop good sequential/distributed (randomized) algorithms for such sparse versions. We also complement our algorithms with several lower bounds. Randomization plays a key role in our upper and lower bound results. © 2016 Wiley Periodicals, Inc. Random Struct. Alg., 49, 322–344, 2016 相似文献
48.
Sreekanth T. V. M. Pandurangan Muthuraman Jung Min-Ji Lee Yong Rok Eom In-Yong 《Research on Chemical Intermediates》2016,42(6):5665-5676
Research on Chemical Intermediates - The aim of the present study was to focus on the green synthesis of silver nanoparticles (AgNPs) using the aqueous extract of dried jujube fruit and the... 相似文献
49.
Narendran Rajendran Shankar Subramaniam Lowrence Rene Christena Meenakshi Sundaram Muthuraman Nagarajan Sai Subramanian Brindha Pemiah 《Natural product research》2016,30(17):2002-2006
Scutellaria oblonga Benth., a hitherto phytochemically unexplored Indian medicinal folklore plant was extracted with acetone and subjected to chromatography to yield nine flavonoids, for the first time from this plant. Antimicrobial assays were performed against 11 foodborne pathogens, and three molecules (Techtochrysin, Negletein and Quercitin-3-glucoside) depicted significant activity. These molecules were assessed for their rate of antibacterial action using time–kill curves which depicted complete inhibition of most of the bacteria within 12–16 h. The significant biofilm-reducing capability exhibited by these three molecules formed a significant finding of the current study. In most of the experiments, a 90–95% reduction in biofilms was observed. Thus, flavonoids as natural molecules from S. oblonga could be further researched to be used as potent antimicrobial and antibiofilm agents. 相似文献
50.
Monometallic and bimetallic diimine complexes of rhenium(I) and osmium(II), [(CO)3(bpy)Re(4,4′-bpy)](PF6) I, [(CO)3(bpy)Re(4,4′-bpy)Re(bpy)(CO)3](PF6)2II, [Cl(bpy)2Os(4,4′-bpy)](PF6) III and [Cl(bpy)2Os(4,4′-bpy)Os(bpy)2Cl](PF6)2IV, and a new heterobimetallic complex of rhenium(I) and osmium(II) [(CO)3(bpy)Re(4,4′-bpy)Os(bpy)Cl](PF6)2V (bpy = 2,2′-bipyridine; 4,4′-bpy = 4,4′-bipyridine) have been synthesized and characterized by various spectral techniques. The photophysical properties of all the complexes have been studied and a comparison is made between the heterobimetallic and corresponding monometallic and homobimetallic complexes. Emission and transient absorption spectral studies reveal that excited state energy transfer from the rhenium(I) chromophore (∗Re) to osmium(II) takes place. The energy transfer rate constant is found to be 8.7 × 107 s−1. 相似文献