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11.
Narula Suraj P. Soni Sajeev Malhotra Rajesh Meenu Puri Jugal K. 《Transition Metal Chemistry》2002,27(7):795-798
Si(NHC6H4F-o)4 · 3TiCl4
(1) has been obtained from the disproportionation of (CF3CH2O)3SiNHC6H4F-o and TiCl4 in petroleum ether (40–60 °C) at –10 °C. The analytical (elemental analysis, molar conductance) and spectral (i.r., 1H- and 19F-n.m.r.) data suggested that (1) behaves as [Si(NHC6H4F-o)4 · Ti2Cl7]+ [TiCl5]–. The presence of these ions has been confirmed by characterising the products of metathetical reactions of (1) with R4NX (R = Bu and Et; X = I and Br) and with AgNO3. The data suggest the presence of a new titanium cation [Ti2Cl7]+. 相似文献
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Pragati R Sharma Shubham Pandey Vineet K Soni Ganpat Choudhary Rakesh K Sharma 《Supramolecular chemistry》2013,25(9):634-644
ABSTRACTThe current study reveals the synthesis of polymer appended Calix[4]amidocrown-5 with specific binding affinity for iodide at ppm-level. The low detection limits are observed via UV-vis and fluorescence spectroscopy. The time-dependent solution and solid-state 127I NMR studies with 18.8 and 19 ppm shifts, indicate a strong sensing nature of resin towards iodide ion. A significant reduction in surface area and pore volume with higher thermostability of resin after iodide uptake indicated iodide inclusion in the amidocrown cavity. The mechanism of iodide sensing may be governed by noncovalent interactions of NH and OH protons present in amidocrown and phenyl ring as observed in terms of emission enhancement in fluorescence spectroscopy. The binding affinity and stoichiometric determinations are determined by Benesi-Hildebrand and Jobs plots, respectively. 相似文献
16.
Nonlinear Dynamics - Based on a non-classical plate theory, a nonlinear analytical model is proposed to analyze transverse vibration of thin partially cracked and submerged orthotropic plate in the... 相似文献
17.
Oximes of ketones and aldehydes are efficiently deprotected with glyoxylic acid in an aqueous medium at room temperature. Oximes can be cleaved selectively in the presence of a TBDMS group. This method is high yielding, fast, clean, safe, cost effective, and therefore very suitable for practical organic synthesis. 相似文献
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The spectral characteristics of different drugs i.e. sulfanilamide, sulfanilic acid, sulfosalicylic acid dihydrate (SSAD) and sulfamethoxazole in aqueous α-cyclodextrin (CD) have been investigated at neutral pH. The formation of inclusion complexes of sulfa drugs with α-CD leads to the changes in fluorescence and absorption spectra which further enable the calculation of association constant of the bind processes by implementing the non-linear regression on the experimental data. The standard Gibbs energy ΔG was also calculated for the systems in which complex formation was observed. The α-CD study indicates that the sulpha drugs form 1:1 inclusion complex with α-CD. 相似文献
20.
In view of an excellent agreement between the recently determinedv
μ-hadron couplings and predictions of the standard model, the basic question discussed is how far its neutral current predictions
can be mimiced in going either from the isodoublet to an isotriplet (or an even higher isospin) left-handed representation
or from SU
L
(2) × U(1) toG × U(1), whereG is a simple group of rank two. This question is addressed with reference to a sufficiently broad class of schemes. Their
most distinctive properties are: in the higher isospin scheme, neutrino couplings are precisely in the form obtainable with
standard l.h. representation; the higher g.g. scheme isL+R type in which, to each light fermion of evenRU parity, a superheavy fermion of the same charge and oddRU parity is associated, parity conservation forbidding their mixing. Reasons for excluding theL-type andG
2 higher g.g. schemes are given. Their neutral current predictions are compared with those of the standard model. A higher
isospin representation can mimic the predictions of the standard model in inclusive and semi-inclusivev
μ-hadron reactions but is conclusively discriminated from the isodoublet representation by elasticv
μ
(−
p scattering. TheG × U(1) scheme can mimic standard model neutrino sector but is conclusively discriminated from minimal scheme by parity violating
effects. 相似文献