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排序方式: 共有153条查询结果,搜索用时 46 毫秒
31.
Rahul Bhowmick Abu Saleh Musha Islam Mihir Sasmal Atul Katarkar 《Journal of Coordination Chemistry》2018,71(11-13):2065-2081
A new, highly sensitive probe L2 for the selective detection of Hg2+ in organo-aqueous (H2O:CH3CN, 1:1, v/v, HEPES buffer, pH 7.2) medium has been synthesized from rhodamine 6G-hydrazide and 4-nitroindole-3-carboxaldehyde. It was thoroughly characterized by physicochemical techniques including single crystal X-ray diffraction studies. The reaction of L2 with Hg2+ gives a 1:1 stoichiometry resulting in a 146 fold fluorescence enhancement and a binding constant (Kf) of 3?×?104 M?1. The spirolactam form of the probe is non-fluorescent; however, it shows dual channel (absorbance and fluorescence) recognition of Hg2+ via CHEF effect through the opening of the spirolactam ring. The quantum yields of L2 (0.00045) and L2-Hg2+ (0.29) show the higher stability of complex in the excited state over the free ligand. The 44.5?nM LOD value demonstrates the detection of Hg2+ at a very low concentration range. Cell imaging studies show the cytoplasmic recognition of Hg2+ by L2. Experimental results are comparable with theoretical values obtained by DFT studies. The fluorescence emission of the complex was completely quenched by I- and from the reversibility studies an advance level INHIBIT logic gate and memory device can be framed. 相似文献
32.
Detection and incorporation of amino endgroups in free-radical polymerization of methyl methacrylate
Sukumar Maiti Mihir K. Saha 《Journal of polymer science. Part A, Polymer chemistry》1967,5(1):151-159
Amino endgroups have been incorporated in poly(methyl methacrylate) by two methods: (a) initiation with systems producing amine radicals and (b) chain transfer with amines. A new dye-partition technique with the use of disulfine blue was developed for qualitative and in some cases quantitative estimation of amino endgroups in the polymer. 相似文献
33.
The CERN Intersecting Storage Ring data on the inclusive reaction p + p → π° + X has been fitted with a phenomenological form where Wc(a,b,z) is the generalized confluent function defined by . M(a, b, z) being the well known Kummer's function. Using this form and primary proton spectrum of Goddard Space Flight Center Group the secondary neutral pion-nucleon flux ratio at the top of the atmosphere has been estimated. The derived result has been compared with those expected from p + p → π± + X data, via different models. 相似文献
34.
Summary Light pink-white microcrystalline ammonium and potassium fluoromonooxalatomanganates(II), A[MnF(C2O4)] (A = NH4 or K), and sodium fluoromonooxalatomanganate(II) dihydrate, Na[MnF(C2O4)] · 2H2O, have been synthesized by two different methods. Either KMnO4 is reduced in the presence of 40% HF and alkali metal oxalate, A2C2O4 (A = NH4, Na or K), or MnO(OH) in 40% HF reacts with A2C2O4. Characterisation was made by elemental analyses, determination of oxidation states, magnetic susceptibility measurements and infrared spectral studies. 相似文献
35.
Guchhait N Banerjee S Chakraborty A Nath D Patwari Naresh G Chowdhury M 《The Journal of chemical physics》2004,120(20):9514-9523
The hydrated clusters of tetrahydroisoquinoline have been investigated by laser-induced fluorescence (LIF), UV-UV hole burning, and IR-UV double-resonance spectroscopy in a seeded supersonic jet. Clusters of different sizes and isomeric structures have different 0-0 transitions (origins) in the LIF spectrum. UV-UV hole burning spectroscopy has been used to identify different cluster species and their vibrational modes. The structures of the clusters have been predicted by comparing the observed OH and NH frequencies in the IR-UV double-resonance spectra with the results calculated at different levels of sophistication. It is found that the water molecules form linear and six- and eight-membered cyclic H-bonded structures at the nitrogen center of 1:1, 1:2, and 1:3 clusters, respectively. 相似文献
36.
A scheme for studyingq deformed quasi exactly solvable problem has been applied to the Schrödinger Hulthen problem (l=0). It is found that for the confined Hulthen problem, the confining parameter can be related to the deformation parameterq. 相似文献
37.
Mihir K. Chaudhurp Shiv K. Chettri Gagan C. Mandal Pradip C. Paul Satya B. Paul Pendyala Srinivas 《Journal of Chemical Sciences》1995,107(4):305-316
An interpretative account of the results of reactions in aqueous medium of a highly peroxygenated vanadium(V) complex, K [V(O2
3]·3H2O, with different organic and inorganic substrates is presented. The reactions were monitored by solution EPR spectroscopy
and isolation of products at different stages of the reactions. Redox reactions between diperoxide, K[VO(O2)2(H2O)] and VOSO4 were conducted. The results of the investigation suggest that secondary oxygen exchange-reaction occurs which not only depends
on but also utilises the intermediates in the primary reaction during diperoxovanadate-dependent oxidation of VOSO4.
In an interesting reactiontris(acetylacetonato)-manganese(III), Mn(acac)3, on being reacted with a hydrogen peroxide adduct, KF·H2O2, and bpy and phen afforded crystalline [Mn(acac)2(bpy)] and [Mn(acac)2(phen)], respectively. The X-ray structural analysis of [Mn(acac)2(phen)] showed that the compound crystallised in orthorhombic space groupPbcn. The structure consists of a pseudooctahedral Mn(II) ion being bound to two acac−(C5H5O
2
−
) and a phen ligand with the molecule lying on two-fold axis.
Reactivity profiles of two new chromium(VI) reagents viz., pyridinium fluorochromate, C5H5NH[CrO3F] (PFC), and quinolinium fluorochromate C9H7NH [CrO3F] (QFC), have been presented. The compounds are capable of acting as both electron-transfer and oxygen-atom-transfer agents.
The X-ray analysis of PFC crystals reveals that the compound crystallises in the orthorhombic space group CmcZ1. The structure consists of discrete pyridinium cations and CrO3 F anions with no significant hydrogen bonding. This results in total disorder of the pyridinium cation. The tetrahedral [CrO3 F]− ion lies on a crystallographic mirror plane. 相似文献
38.
Sarit Maitra Rajkumar Roychoudhury Kalyan Kr. Mondal 《Czechoslovak Journal of Physics》2005,55(8):943-955
The effect of higher-order nonlinearity on dust acoustic solitary waves is studied taking into account the dust-charge variation.
The model of charge fluctuation, taken here, is of the formI
e+I
i=0,I
e andI
i being the electronic and ionic currents. The dust charge is determined self consistently from the current-balance equation.
It is found that the higher-order correction modifies the amplitude and width of the dust acoustic solitary waves. The effect
of dust-charge streaming is also discussed. 相似文献
39.
40.
The polarised optical spectra of single crystal of K3Mn(CN)6 is reported at liquid nitrogen temperature. A new system of transition is located along with its hot components which is verified by temperature variation studies. The crystal field parameters to reproduce the bands are given. 相似文献