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81.
Kalyan K. Banerji 《Journal of Chemical Sciences》1988,100(5):397-403
The kinetics of the oxidation of twelve ortho-substituted benzaldehydes by N-bromobenzamide (NBB) to the corresponding benzoic
acids have been studied. The reaction is first order with respect to NBB, the aldehyde and hydrogen ions. The addition of
benzamide has no effect on the reaction rate. (PhCONH2Br)+ has been postulated as the reactive oxidising species. The correlation of rates with the single substituent-parameter equations
is poor. The correlation with Charton’s equation of inductive, resonance and steric parameters is satisfactory. However, excellent
correlations were obtained, when Charton’s steric parameter was used along with Taft’s σ1; andσ
R
+
substituent constants. The polar reaction constants have negative values. The reaction is subject to steric hindrance by
the ortho-substituents. 相似文献
82.
The kinetics of oxidation of some neutralized α‐hydroxy compounds such as glycolic (GA), lactic (LA), α‐hydroxyisobutyric(IB), mandelic (MA), atrolactic (AL), and benzilic (BA) acids by tetrachloroaurate(III) have been studied. The substrates are oxidized to give formaldehyde, acetaldehyde, acetone, benzaldehyde, acetophenone, and benzophenone for the respective reactions. The rate of the reaction increases with increasing [substrate] and pH but decreases with increase in [Cl−1]. Temperature influence is quite marked in all these reactions. A mechanism involving the formation of an unstable complex, which decomposes to give the respective reaction products, is proposed. The reactivity of the α‐hydroxy acids towards gold(III) are as follows: AL > MA > BA > IB > LA > GA. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 873–882, 1999 相似文献
83.
The oxidation of substituted benzyl alcohols by bis(2,2′-bipyridyl) copper(II) permanganate (BBCP), leading to the corresponding benzaldehydes is first-order with respect to BBCP. Michaelis-Menten type kinetics were observed with respect to the alcohols. The oxidation of a,a-dideuteriobenzyl alcohol indicated the presence of a substantial kinetic isotope effect. The rates of oxidation of meta- and para-substituted benzyl alcohols were correlated in terms of Charton's triparametric LDR equation whereas ortho- substituted benzyl alcohols were correlated with a four parametric LDRS equation. The results of correlation analyses point to an electron-deficient reaction center in the transition state. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 9–16, 1997. 相似文献
84.
The kinetics of the reaction between glycolaldehyde (GA) and tetrachloroaurate(III) in acetic acid-sodium acetate buffer has been studied. The reaction is first-order with respect to [AuIII] as well as [GA]. Both H+ and Cl− ions retard the rate of reaction. AuCl4−, AuCl3(OH2), and AuCl3(OH)− are the reactive species of gold(III) with gradually increasing reactivity. A reaction mechanism involving two-electron transfer rate determining steps has been proposed. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet: 30: 613–619, 1998 相似文献
85.
Hemlata Gangwani Pradeep K. Sharma Kalyan K. Banerji 《Reaction Kinetics and Catalysis Letters》2000,69(2):369-374
Oxidation of thioacids by hexamethylenetetramine-bromine proceeds through an intermediate complex in the pre-equilibrium and its subsequent decomposition in the slow step. 相似文献
86.
A general theory for constructing a weak Markov dilation of a uniformly continuous quantum dynamical semigroup T
t
on a von Neumann algebra ? with respect to the Fock filtration is developed with the aid of a coordinate-free quantum stochastic
calculus. Starting with the structure of the generator of T
t
, existence of canonical structure maps (in the sense of Evans and Hudson) is deduced and a quantum stochastic dilation of
T
t
is obtained through solving a canonical flow equation for maps on the right Fock module ?⊗Γ(L
2(ℝ+,k
0)), where k
0 is some Hilbert space arising from a representation of ?′. This gives rise to a *-homomorphism j
t
of ?. Moreover, it is shown that every such flow is implemented by a partial
isometry-valued process. This leads to a natural construction of a weak Markov process (in the sense of [B-P]) with respect
to Fock filtration.
Received: 15 June 1998/ Accepted: 4 March 1999 相似文献
87.
Lszl Ktai Gyula Argay Sndor Holly gnes Keszler Bla Puknszky Kalyan K. Banerji 《无机化学与普通化学杂志》2001,627(1):114-118
The crystal structures of ammonium permanganate and ammonium perchlorate at 293 K were determined and compared. X‐ray and vibrational spectroscopic data confirmed the existence of weak hydrogen bonds in NH4MnO4. These hydrogen bonds proved to be slightly stronger than H‐bonds in ammonium perchlorate. Difference between the results of diffuse reflectance and KBr matrix pellet IR spectra of NH4MnO4 has been explained. 相似文献
88.
Rapid urbanization has inevitably raised challenges by indirectly adding industry waste to the environment. This problem becomes even more severe when contamination of consumable water is considered. As a leading sector in semiconductor-related research to face such challenges, gallium oxide and its derivatives have shown remarkable performance by exhibiting controlled, recyclable photocatalytic activities. This work demonstrates the enhancement of the photocatalytic performance of β-Ga2O3, which is related to the structural and morphological variation induced by rGO wrapping. Firstly, the Ga2O3 nanostructures are obtained by calcinating gallium oxide hydroxide (GaOOH), which is synthesized via a simple chemical route. On the other hand, rGO wrapped β-Ga2O3 is synthesized using in-situ hydrothermal treatment. In addition to traditional characterizations such as X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, etc., the photocatalytic performance of both pristine and composite systems is studied by time-dependent UV–Vis absorption spectrum for the degradation of different organic toxic pollutants. It is observed that the composite sample exhibited a larger effective surface area and enhanced optical absorption in the UV–Vis range as compared to the pristine gallium oxide sample. Under UV light irradiation, the rGO wrapped β-Ga2O3 nanobars can degrade rhodamine B dye entirely within 25 min and exhibit a higher photodegradation rate of 0.1598 min−1 which became 3.5 times higher as compared to that of pure gallium oxide. 相似文献
89.
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
90.
Kalyan Sinha 《Reports on Mathematical Physics》1978,14(1):65-73
Relative scattering is studied in the presence of a uniform field. It is shown that as the field strength tends to zero, the time delay tends to the time delay of the system without the field. 相似文献