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991.
Arpita Banerjee Averi Guha Pali Maiti Somen Goswami Tanmay Chattopadhyay Tapan Kumar Mondal Santanu Bhattacharya Ennio Zangrando Debasis Das 《Transition Metal Chemistry》2011,36(8):829-839
Three Ni(II) complexes of cresol-based Schiff-base ligands, namely [Ni2(L1)(NCS)3(H2O)2], (1) [Ni2(L2)(CH3COO)(NCS)2(H2O)] (2) and [Ni2(L3)(NCS)3] (3), (where L1 = 2,6-bis(N-ethylpyrrolidineiminomethyl)-4-methylphenolato, L2 = 2,6-bis(N-ethylpiperidineiminomethyl)-4-methylphenolato and L3 = 2,6-bis{N-ethyl-N-(3-hydroxypropyl iminomethyl)}-4-methylphenolato), have been synthesized and structurally characterized by X-ray single-crystal diffraction in addition to routine physicochemical techniques. Density functional theory calculations have been performed to understand the nature of the electronic spectra of the complexes. Complexes 1?C3 when reacted with 4-nitrophenyl phosphate in 50:50 acetonitrile?Cwater medium promote the cleavage of the O?CP bond to form p-nitrophenol and smoothly convert 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ) either in MeOH or in MeCN medium. Phosphatase- and catecholase-like activities were monitored by UV?Cvis spectrophotometry and the Michaelis?CMenten equation was applied to rationalize all the kinetic parameters. Upon treatment with urea, complexes 1 and 2 give rise to [Ni2(L1)(NCS)2(NCO)(H2O)2] (1??) and [Ni2(L2)(CH3COO)(NCO)(NCS)(H2O)] (2??) derivatives, respectively, whereas 3 remains unaltered under same reaction conditions. 相似文献
992.
Mondal S Roy N Laskar RA Sk I Basu S Mandal D Begum NA 《Colloids and surfaces. B, Biointerfaces》2011,82(2):497-504
In this paper, we have demonstrated for the first time, the superb efficiency of aqueous extract of dried leaves of mahogany (Swietenia mahogani JACQ.) in the rapid synthesis of stable monometallic Au and Ag nanoparticles and also Au/Ag bimetallic alloy nanoparticles having spectacular morphologies. Our method was clean, nontoxic and environment friendly. When exposed to aqueous mahogany leaf extract, competitive reduction of Au(III) and Ag(I) ions present simultaneously in same solution leads to the production of bimetallic Au/Ag alloy nanoparticles. UV-visible spectroscopy was used to monitor the kinetics of nanoparticles formation. UV-visible spectroscopic data and TEM images revealed the formation of bimetallic Au/Ag alloy nanoparticles. Mahogany leaf extract contains various polyhydroxy limonoids which are responsible for the reduction of Au(III) and Ag(I) ions leading to the formation and stabilization of Au and Ag nanopaticles. 相似文献
993.
Biplab Das Shekhar Kumar P. Mondal 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(2):503-505
Flash point of a chemical characterizes its operating safety envelope. Tri-isoamyl phosphate (TiAP) is being proposed as an
alternate to conventional nuclear solvent tri-n-butyl phosphate but flash point of TiAP containing organic solutions are not available in literature. Flash points of C8–C16
n-alkanes and 36% TiAP/C8–C16
n-alkane solutions were experimentally measured and correlated by means of empirical correlations. This paper is probably the
first reported work in the literature on flash points of TiAP containing solutions. 相似文献
994.
An efficient stereoselective approach to the construction of a hydrindane derivative having a bridged lactone is described toward the synthesis of the sesquiterpenes of the seco-prezizaane family. The key step involves RO-RCM of a norbornene derivative. 相似文献
995.
Charan S Chien FC Singh N Kuo CW Chen P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(18):5165-5170
A simple, sensitive, and highly specific lipid targeting Raman probe (Nile red coated silver nanoparticles) has been developed to image living nematode Caenorhabditis elegans (C. elegans). Our idea of imaging lipids in C. elegans is to combine the specificity of the fluorescent dye, Nile red, and the highly enhanced Raman scattering on the silver nanoparticles. Our strategy involves the fabrication of a lipid targeting probe, which is incorporated into the intracellular intestinal granules of C. elegans by incubating these worms in the solution containing Raman probes, resulting in an uptake and subsequent incorporation of these Raman probes into the intestinal granule, thus allowing fast visualization of lipid droplets through a conventional confocal imaging technique. 相似文献
996.
Recently, Li and Liu have studied global monopole of tachyon in a four dimensional static space–time. We analyze the motion
of massless and massive particles around tachyon monopole. Interestingly, for the bending of light rays due to tachyon monopole
instead of getting angle of deficit we find angle of surplus. Also we find that the tachyon monopole exerts an attractive
gravitational force towards matter. 相似文献
997.
Monoclinic single crystals of Ho2GeO5 were grown by a flux technique. The molar principal susceptibilities (χ1 and χ3) have been measured in the temperature range 300–13.5 K. The principal magnetic anisotropies (χ1–χ2,χ2–χ3 and χ1–χ3) are obtained from the measured anisotropies in different modes of suspensions (b-axis vertical, c-axis vertical and (1 0 0) plane horizontal) of the crystal. The molar principal susceptibility (χ2) is obtained from the observed values of the principal anisotropies. The observed principal susceptibilities together with their anisotropies are explained by invoking the crystal field interaction of the Ho3+ ion with its diamagnetic neighbors in non-axial symmetry. The molar susceptibilities are correlated to the ionic values by finding out the proper orientation of the principal molar susceptibilities, i.e., crystal susceptibilities with respect to that of the ionic susceptibilities (Kx, Ky and Kz). The electronic heat capacities are calculated from the crystal field analysis showing Schottky type anomalies. 相似文献
998.
P. Mahanandia P.N. Vishwakarma K.K. Nanda V. Prasad K. Barai A.K. Mondal S. Sarangi G.K. Dey S.V. Subramanyam 《Solid State Communications》2008,145(3):143-148
A new pyrolysis technique has been developed for the synthesis of multi-walled carbon nanotubes (MWCNTs). In this simple method diethyl ether and nickelocene is pyrolysized in a reaction quartz tube without using carrier gas. The samples are prepared at pyrolysis temperatures of 650 and 950 °C and the effect of temperature on the tube morphology investigated. Purification has been done following the standard oxidation and acid bath treatment. The as-synthesized and purified nanotubes have been characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and micro-Raman spectroscopy. The technique has great advantages such as low cost and easy operation for the production of CNTs. 相似文献
999.
S. B. Ghosh M. Mondal A. Mondal D. Ghosh A. Deb 《Physics of Particles and Nuclei Letters》2018,15(5):499-505
Two different classes of events exist in case of 16O–AgBr interactions at 60 AGeV, namely, ring-like and jet-like structured events. We have performed a rigorous study on the erratic behaviour of produced particles in ring-like and jet-like events in 16O–AgBr interactions at 60 AGeV with the help of entropy index μq. We have analysed the data in two dimensional phase space. The data reveal different pionisation for ring-like and jet-like events. 相似文献
1000.
De P Maji S Chowdhury AD Mobin SM Mondal TK Paretzki A Lahiri GK 《Dalton transactions (Cambridge, England : 2003)》2011,40(46):12527-12539
The present article describes ruthenium nitrosyl complexes with the {RuNO}(6) and {RuNO}(7) notations in the selective molecular frameworks of [Ru(II)([9]aneS(3))(bpy)(NO(+))](3+) (4(3+)), [Ru(II)([9]aneS(3))(pap) (NO(+))](3+) (8(3+)) and [Ru(II)([9]aneS(3))(bpy)(NO˙)](2+) (4(2+)), [Ru(II)([9]aneS(3))(pap)(NO˙)](2+) (8(2+)) ([9]aneS(3) = 1,4,7-trithiacyclononane, bpy = 2,2'-bipyridine, pap = 2-phenylazopyridine), respectively. The nitrosyl complexes have been synthesized by following a stepwise synthetic procedure: {Ru(II)-Cl} → {Ru(II)-CH(3)CN} → {Ru(II)-NO(2)} → {Ru(II)-NO(+)} → {Ru(II)-NO˙}. The single-crystal X-ray structure of 4(3+) and DFT optimised structures of 4(3+), 8(3+) and 4(2+), 8(2+) establish the localised linear and bent geometries for {Ru-NO(+)} and {Ru-NO˙} complexes, respectively. The crystal structures and (1)H/(13)C NMR suggest the [333] conformation of the coordinated macrocyclic ligand ([9]aneS(3)) in the complexes. The difference in π-accepting strength of the co-ligands, bpy in 4(3+) and pap in 8(3+) (bpy < pap) has been reflected in the ν(NO) frequencies of 1945 cm(-1) (DFT: 1943 cm(-1)) and 1964 cm(-1) (DFT: 1966 cm(-1)) and E°({Ru(II)-NO(+)}/{Ru(II)-NO˙}) of 0.49 and 0.67 V versus SCE, respectively. The ν(NO) frequency of the reduced {Ru-NO˙} state in 4(2+) or 8(2+) however decreases to 1632 cm(-1) (DFT: 1637 cm(-1)) or 1634 cm(-1) (DFT: 1632 cm(-1)), respectively, with the change of the linear {Ru(II)-NO(+)} geometry in 4(3+), 8(3+) to bent {Ru(II)-NO˙} geometry in 4(2+), 8(2+). The preferential stabilisation of the eclipsed conformation of the bent NO in 4(2+) and 8(2+) has been supported by the DFT calculations. The reduced {Ru(II)-NO˙} exhibits free-radical EPR with partial metal contribution revealing the resonance formulation of {Ru(II)-NO˙}(major)?{Ru(I)-NO(+)}(minor). The electronic transitions of the complexes have been assigned based on the TD-DFT calculations on their DFT optimised structures. The estimated second-order rate constant (k, M(-1) s(-1)) of the reaction of the nucleophile, OH(-) with the electrophilic {Ru(II)-NO(+)} for the bpy derivative (4(3+)) of 1.39 × 10(-1) is half of that determined for the pap derivative (8(3+)), 2.84 × 10(-1) in CH(3)CN at 298 K. The Ru-NO bond in 4(3+) or 8(3+) undergoes facile photolytic cleavage to form the corresponding solvent species {Ru(II)-CH(3)CN}, 2(2+) or 6(2+) with widely varying rate constant values, (k(NO), s(-1)) of 1.12 × 10(-1) (t(1/2) = 6.2 s) and 7.67 × 10(-3) (t(1/2) = 90.3 s), respectively. The photo-released NO can bind to the reduced myoglobin to yield the Mb-NO adduct. 相似文献