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991.
Heterobimetallic complexes of the type R2Si(HL)Cl2 and R2SiL2 (where R = Me, Et, Ph; L = ferrocenyl aroylhydrazone) have been synthesized at 40 °C to 50 °C and at room temperature (25
°C), respectively, and characterized by elemental analysis, molar conductance, infrared and NMR (1H, 13C and 29Si) spectral data. The ligands behave as bidentate, coordinating through the azomethine nitrogen and the oxygen in the amidic
and the imidic acid forms of the ligand at low temperature and at room temperature, respectively. The ligands and their organosilicon
complexes have been evaluated for the antifungal activity against Alternaria alternata, Fusarium oxysporum and Rhizoctonia solani, as well as antibacterial activity against gram negative, Escherichia coli and gram positive, Bacillus subtilis, at 28 °C. Organosilicon complexes of ferrocenyl aroylhydrazone were found to be more potent than the parent ligands.
相似文献
992.
In this Letter, we report the confinement of a uniform beam of light (lambda(1) = 400 nm) at the nodes of a standing wave (lambda(2) = 532 nm) via absorbance modulation. In the present implementation of absorbance modulation, a thin polymer film containing a photochromic azobenzene side chain is exposed to a standing wave at lambda(2) and a uniform beam at lambda(1), resulting in alternate regions of high and low absorbance. Light at lambda(1) is localized around the low-absorbance regions. Using photoresist exposures, we mapped out the localized light intensity distribution, which agrees well with our theoretical model. Since the width of this distribution is primarily determined by the ratio of the intensities at the two wavelengths, this technique opens up the possibility of localizing light fields below the diffraction limit using far-field optics. 相似文献
993.
Andhariya N Chudasama B Patel R Upadhyay RV Mehta RV 《Journal of colloid and interface science》2008,323(1):153-157
In the present investigation we report the effect of capillary diameter and the direction of applied magnetic field on the rotational viscosity of water and kerosene based ferrofluids. We found that changes in the field induced rotational viscosity are larger in the case of water based magnetic fluid than that of kerosene based fluid. The field induced rotational viscosity is found to be inversely proportional to the capillary diameter and it falls exponentially as a function of the angle between the direction of field and vorticity of flow. Magnetophoretic mobility and hydrodynamic volume fraction of nanomagnetic particles are determined for above cases. 相似文献
994.
Pandey RK Wang L Wallock NJ Lindeman S Donaldson WA 《The Journal of organic chemistry》2008,73(18):7236-7245
The reactivity of (2-alkenyl-3-pentene-1,5-diyl)iron complexes toward olefin metathesis, cycloaddition, and mild oxidations (MnO 2 or mCPBA) was examined. Cycloaddition reactions were observed to occur with modest diastereoselectivity (33-63% de). Decomplexation of the (3-pentenediyl) ligand may be accomplished by oxidation with either CAN or alkaline hydrogen peroxide to afford vinylcyclopropanecarboxylates or divinylcyclopropanecarboxylates. Reduction of the latter, followed by Cope rearrangement generates cycloheptadienylmethanols. These studies demonstrate that (2-alkenyl-3-pentene-1,5-diyl)iron complexes can serve as organometallic scaffolds for the preparation of a wide variety of structural motifs containing up to 5 contiguous stereocenters. 相似文献
995.
This tutorial review provides an overview of bio-directed synthesis of nanomaterials, starting with the foundation of biomineralization research--how organisms are able to biomineralize materials in vivo--and progressing to studies of biomineralization in vitro. This research is of interest to biologists, chemists and materials scientists alike, especially in light of efforts to find 'greener' methods of inorganic material synthesis. Examples of applications of nanomaterials synthesized by these methods are provided to demonstrate the end goals of biomineralization research. 相似文献
996.
Shaifali Mishra Rajesh K. Yadav Satyam Singh Surabhi Chaubey Pooja Singh Chandani Singh Sarvesh Kumar Gupta Shivani Gupta Dhanesh Tiwary Tae Wu Kim 《Photochemistry and photobiology》2023,99(4):1080-1091
Photocatalysis is a defendable manner for production of several organic chemicals, energy and its storage from solar energy. For the evolution of metal free, cost-effective catalyst a 2D composite has been appear as a photocatalyst. Here, we had reported the synthesis of a light harvesting composite as a photocatalyst which was assembled by a poly-condensation mechanism between graphitic carbon nitride and tetrakis(4-nitrophenyl) porphyrin and the resulting composite manifest the excellent light harvesting properties, suitable energy band and low charge recombination. The photocatalyst [(NO2)4TPP@g-C3N4] enables the efficient photocatalytic production of nicotinamide adenine dinucleotide (NADH) from consumed NAD+ also the production of organic chemicals like 4-methoxybenzylimines from 4-methoxybenzylamines. The photocatalytic efficiency of the photocatalyst was estimated by the percentage of NADH regeneration and the percentage yield of organic transformations. It shows the tetrakis(4-nitrophenyl) porphyrin could enhance the charge transfer capacity of graphitic carbon nitride which shows excellent photocatalysis activities and organic transformations. 相似文献
997.
Sen R Bera R Bhattacharjee A Gütlich P Ghosh S Mukherjee AK Koner S 《Langmuir : the ACS journal of surfaces and colloids》2008,24(11):5970-5975
A layered oxo-vanadium(IV) dihydrogen phosphate, {VO(H2PO 4)2} n has been synthesized hydrothermally and characterized by several physicochemical methods. Single-crystal X-ray analysis (crystal system, tetragonal; space group, P4/ ncc; unit cell dimensions, a = b = 8.9632(4), c = 7.9768(32) A) of {VO(H2PO4) 2} n reveals that the compound has an extended two-dimensional structure. The VO2+ moieties are connected through bridging H 2PO4 (-) ions, and this type of connection propagates parallel to the crystallographic ab plane which gives rise to a layered structure. The layers are staked parallel to the crystallographic c axis with a separation between the layers of ca. 4.0 A. Magnetic susceptibility of {VO(H2PO4)2} n has been measured in the temperature range 2-300 K on a SQUID magnetometer. The magnetic property of {VO(H2PO4)2} n is explicable in the light of a two-dimensional quantum Heisenberg antiferromagnet model. Magnetic pathways are available through the dihydrogen-phosphato bridges within the layer and provide for weak antiferromagnetic interactions. Notably {VO(H2PO4)2} n catalyzes the epoxidation reaction of alkenes with tert-BuOOH in acetonitrile medium under heterogeneous condition. 相似文献
998.
Viksit Kumar H. J. Bharathkumar Sangram D. Dongre Rajesh Gonnade Kothandam Krishnamoorthy Sukumaran Santhosh Babu 《Angewandte Chemie (International ed. in English)》2023,62(47):e202311657
Recently, chiral and nonplanar cutouts of graphene have been the favorites due to their unique optical, electronic, and redox properties and high solubility compared with their planar counterparts. Despite the remarkable progress in helicenes, π-extended heterohelicenes have not been widely explored. As an anode in a lithium-ion battery, the racemic mixture of π-extended double heterohelical nanographene containing thienothiophene core exhibited a high lithium storage capability, attaining a specific capacity of 424 mAh g−1 at 0.1 A g−1 with excellent rate capability and superior long-term cycling performance over 6000 cycles with negligible fade. As a first report, the π-extended helicene isomer (PP and MM), with the more interlayer distance that helps faster diffusion of ions, has exhibited a high capacity of 300 mAh g−1 at 2 A g−1 with long-term cycling performance over 1500 cycles compared to the less performing MP and PM isomer and racemic mixture (150 mAh g−1 at 2 A g−1). As supported by single-crystal X-ray analysis, a unique molecular design of nanographenes with a fixed (helical) molecular geometry, avoiding restacking of the layers, renders better performance as an anode in lithium-ion batteries. Interestingly, the recycled nanographene anode material displayed comparable performance. 相似文献
999.
A series of novel pyrazolyl isoxazolines were synthesized by 1,3‐dipolar cycloaddition of pyrazolyl nitrile oxide with various activated alkene, such as acrylonitrile, methyl acrylate, and vinyl acetate, in the presence of iodobenzene diacetate in methanol containing a catalytic amount of TFA at room temperature (13 compounds upto 92% yield were isolated). 相似文献
1000.