Condensation of bis(2-aminophenyl)disulphide with aromatic aldehydes yielded the corresponding dithiophenyldiimines. Dinuclear ruthenium complexes were obtained by reacting the diimines (3) [bis(3-nitrobenzaldehyde)-phenyldisulphide diimine], (5) [bis(2-chlorobenzaldehyde)-phenyldisulphide diimine], (8) [bis(2-methoxybenzaldehyde)-phenyldisulphide diimine] and (9) [bis(2-hydroxybenzaldehyde)-phenyldisulphide diimine], with RuCl3 in the presence of L (L=2,2-bipyridine, 1,10-phenanthroline, 3,4-diaminotoluene, pyridine and PPh3) in EtOH. The two metal centres, connected through bridging chlorides, are in octahedral environments with one metal centre coordinated to sulphur and water while the other is coordinated to L. 相似文献
The kinetics and mechanism of the oxidation of lactose by N-bromophthalimide in the absence and presence of cetyltrimethylammonium bromide and sodium dodecyl sulfate micelles was investigated in the presence of sulfuric acid medium. Under pseudo-first-order conditions reaction rate agreed with a first-, fractional- and negative fractional-order kinetics in N-bromophthalimide, lactose and sulfuric acid, respectively. In the presence of additives, the critical micellar concentration values were lower than those given in the literature. The catalytic role of cationic micelles was explained by the Berezin model. The anionic micelles showed slightly inhibitory effect. The influence of salts, phthalimide and mercuric acetate on the reaction rate was also studied. Using the kinetic data, the rate constant, binding constants, and corresponding activation parameters were evaluated. A possible reaction mechanism, which is based on the kinetic results and the product analysis, is proposed. 相似文献
In this paper we use the coupled mode analysis to study nonlinear phase shifts of the fundamental beam caused by cascaded second order nonlinear effects in the Quasi Phase Matched Cerenkov (QPMC) configuration in waveguides. Under the no-pump depletion approximation which is valid for low conversion efficiencies, we obtain the nonlinear phase shift as a function of length of interaction and grating period. It is observed that the nonlinear phase shift of the fundamental beam can be maximized by choosing a grating period for which the phase matched second harmonic radiation mode is radiated parallel to the film-substrate interface, i.e., for zero Cerenkov angle. Although the phase shifts are smaller than in the case of all guided geometry, QPM Cerenkov configuration is expected to have greater tolerance towards various waveguide parameters and the fundamental wavelength. 相似文献
Some anomalies are observed in the subinospheric VLF electromagnetic (EM) signals at 19.8 kHz transmitted from North West
Cape, Australia (lat: 21.82° S; long: 114.16° E) and 40 kHz from Fukushima, Japan (lat: 36.18° N, long: 139.85° E), recorded
by VLF receivers near Kolkata (lat: 22.56° N, long: 88.5° E) during the occurrence of the two earthquakes at Andaman Island
(lat:14.018° N, long: 92.92° E), India and other at South Coast of Honsu (lat: 34.78° N, long: 138.27° E), Japan. The analyses
of these seismo-ionospheric VLF EM anomalies at these two frequencies during some days before and after the occurrence of
earthquake on August 11, 2009 will be presented here. VLF-LF transient variations of significant magnitude in the form of
spikes are observed few days prior to the day of occurrence of the earthquakes that continued several days more, then decaying
gradually and finally ceased. Signals are examined to describe their connectivity with earthquakes. The enhancements of the
amplitude and frequency of the fourth mode of Schumann resonance spectra have been detected during the occurrence of the two
earthquakes, which will also be reported here. 相似文献
The hexadentate N2S2O2 donor ligand N,N’-bis(3,5-tert-butylsalicylidene) diphenyl disulfide-2,2’-diamine was synthesised by the condensation of 2-aminophenyl disulfide and 3,5-di-tert-butyl-2-hydroxybenzaldehyde and its molecular structure was confirmed by X-ray studies. One of the tert-butyl groups in the Schiff base has rotational disorder around the C–C bond with ratio 0.56:0.44. The palladium complexes were prepared by the direct reaction of PdCl2(CH3CN)2 and Schiff base ligands N,N’-bis (5-tert-butylsalicylidene) diphenyl disulfide-2,2’-diamine and N,N’-bis(3,5-tert-butylsalicylidene) diphenyl disulfide-2,2’-diamine, respectively. The structure of the metal complexes was characterized by physico-chemical and spectroscopic methods. Palladium is in square-planar geometry bonded to imine nitrogen and phenolic O in both the complexes. The catalytic efficiency of the palladium complexes was evaluated in the cross-coupling reactions; Heck-Mizoroki reaction of iodobenzene and methyl acrylate and the Suzuki-Miyaura reaction of phenylboronic acid and iodobenzene, which gave low to moderate yields. Higher conversions were obtained for 2a as catalyst due to the increase in the number of bulky tertiary butyl groups in the structure.
Pramana - This paper deals with the nonlinear generalised advection–diffusion–reaction (GADR) equation subject to some initial and boundary conditions (BCs). Some exact finite... 相似文献
Divergenceless expression for the energy-momentum tensor of scalar field is obtained using the momentum cut-off regularization
technique. We consider a scalar field with quartic self-coupling in a spatially flat (3+1)-dimensional Robertson-Walker space-time,
having arbitrary mass and coupled to gravity. As special cases, energy-momentum tensor for conformal and minimal coupling
are also obtained. The energy-momentum tensor is observed to exhibit trace anomaly in curved space-time 相似文献
Kinetic investigations of oxidation of dextrose by N-bromophthalimide (NBP) in acidic medium in the presence of mercuric(II) acetate as a scavenger have been studied. In both the absence and presence of surfactants, the oxidation kinetics of dextrose by NBP shows a first-order dependence on NBP, fractional order on dextrose, and negative fractional order dependence on sulfuric acid. The determined stoichiometric ratio was 1:1 (dextrose:NBP). The variation of Hg(OAC)2 and phthalimide (reaction product) have an insignificant effect on reaction rate. Effects of surfactants, added acrylonitrile, added salts, and solvent composition variation have been studied. Activation parameters for the reaction have been evaluated from Arrhenius plot by studying the reaction at different temperature. The rate law has been derived on the basis of obtained data. A plausible mechanism has been proposed from the results of kinetic studies, reaction stoichiometry and product analysis. The role of anionic and non-ionic micelle was best explained by the Berezin’s model. 相似文献
Slow diffusion reaction of 2,2′‐dithiodibenzoic acid (dtdb) with CuCl2 in the presence of N‐donor ligands results in the formation of different coordination polymers where both S–S and C–S scission and oxidation of S is observed. X‐ray diffraction analysis of [Cu(tdb)(phen)(H2O)]2 · 2H2O.2DMF] ( 1 ), [Cu(tdb)(py)2(H2O)]2 ( 3 ), and [Cu(tdb)(bipy)(H2O)]2 · 0.5H2O ( 4 ) (tdb = thiodibenzoic acid, phen = phenanthroline, py = pyridine, bipy = 2,2′‐bipyridine) show that the metal ions are coordinated to the carboxylate oxygen atoms of the in situ generated tdb ligand in a monodenate fashion. In [Cu(phen)(SO4)2(H2O)2]n ( 2 ) and [Cu(bipy)(SO4)2(H2O)2]n ( 5 ), the sulfur is oxidized to sulfate ions prior to coordination with the metal. Complex 1 has a dimeric structure with π–π interactions between the phen ligands, whereas 3 and 4 form 1D polymeric chains. 相似文献
Parametric amplification of signal wave in a four-layered leaky waveguide configuration in Z-cut LiNbO 3 , where the pump and signal waves are guided modes and the idler is radiated into the substrate has been studied using coupled mode approach. It is shown that in this configuration, the signal gain can be greatly enhanced as compared to the case of a three-layered QPM Cerenkov-idler configuration. The studies show that by appropriately choosing the waveguide parameters, one can have a trade-off between signal gain bandwidth and the peak signal gain achieved. These studies should find application in designing optical parametric amplifiers and oscillators. 相似文献