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61.
Nagi Reddy Vanga Anudeep Kota Ramakrishna Sistla Mallavadhani Uppuluri 《Molecular diversity》2017,21(2):273-282
62.
H.S.S. Ramakrishna Matte A.K. Cheetham C.N.R. Rao 《Solid State Communications》2009,149(23-24):908-910
Hybrid organic–inorganic framework compounds constitute an important class of materials whose properties, especially paired ones, have not been adequately investigated hitherto. In this communication, we report the non-linear optical properties of hybrid compounds exhibiting interesting magnetic properties. 相似文献
63.
B. N. Lakshminarayana C. R. Gnanendra T. N. Mahadeva Prasad M. A. Sridhar Nagaraja Naik D. Chenne Gowda J. Shashidhara Prasad 《Journal of chemical crystallography》2010,40(8):686-690
Abstract
The novel 3-methyl-2,6-dip-toylpiperidine-4-one was acylated by 3-chloropropanoychloride and subjected for dehydrohalogenation. The synthesized compound was characterized by spectroscopic techniques and finally confirmed by X-ray diffraction studies. The molecule crystallizes in the monoclinic crystal class in the space group C 2/c with cell parameters a = 18.538(2) ?, b = 9.9050(1) ?, c = 22.954(2) ?, β = 94.486(8)° and Z = 8. The piperidine ring adopts a twist boat conformation. 相似文献64.
The catalytic role of various inert solid supports on acceleration of alcohol fermentation by Saccharomyces cerevisiae was investigated. The enhanced rate of alcohol production was dependent on the nature of the support as well as on the amount
used. Among all the tested supports, chitosan flakes showed the maximum yield of alcohol (93% of theoretical yield). This
higher rate of alcohol production was associated with the twofold increase in the activity of alcohol dehydrogenase over control.
Our results suggest that the addition of a small fraction of solids in submerged fermentations to facilitate cell anchorage
for enhanced metabolic activity is easier and more economical compared to cell immobilization processes.
IICT Communication No. 4266. Some of the results in this article are covered under a patent. 相似文献
65.
Given a continuous P0-function F : Rn Rn, we describe a method of constructing trajectories associated with the P0-equation F(x) = 0. Various well known equation-based reformulations of the nonlinear complementarity problem and the box variational inequality problem corresponding to a continuous P0-function lead to P0-equations. In particular, reformulations via (a) the Fischer function for the NCP, (b) the min function for the NCP, (c) the fixed point map for a BVI, and (d) the normal map for a BVI give raise to P0-equations when the underlying function is P0. To generate the trajectories, we perturb the given P0-function F to a P-function F(x, ); unique solutions of F(x, ) = 0 as varies over an interval in (0, ) then define the trajectory. We prove general results on the existence and limiting behavior of such trajectories. As special cases we study the interior point trajectory, trajectories based on the fixed point map of a BVI, trajectories based on the normal map of a BVI, and a trajectory based on the aggregate function of a vertical nonlinear complementarity problem. 相似文献
66.
M. C. Reddy B. P. Nagi Reddy K. R. Sridharan J. Ramakrishna 《Magnetic resonance in chemistry : MRC》1984,22(7):464-467
From consideration of 1H–1H vicinal coupling constants and 13C? 1H long-range coupling constants in a series of amino acid derivatives, the precise values of 13C component vicinal coupling constants have been calculated for the three minimum energy staggered rotamers for the C(α)H? C(β)H2 side-chains of amino acids. 相似文献
67.
A sensitive spectrophotometric method for the determination of carbon monoxide is described, based on the reduction of palladium(II) by carbon monoxide. The resulting elemental palladium is reacted with iodate in acidic medium in the presence of chloride, to produce an ICl(-)(n) species that is readily extracted as an ion-pair with Pyronine-G into benzene. Measurement of the absorbance of the extract at 535 nm permits the determination of carbon monoxide down to 1 mul/l. in air. The effect of interfering gases is discussed. The method is suitable for determination of carbon monoxide in motor vehicle exhaust gases and ambient air. 相似文献
68.
The kinetics of oxidation of arginine, histidine, and threonine by chloramine-T (CAT) have been investigated in alkaline medium at 35°C. The rates are first order in both [CAT] and [amino acid] and inverse fractional order in [OH?] for arginine and histidine. The rate is independent of [OH?] for threonine. Variation of ionic strength and addition of the reaction product, p-toluenesulfonamide, or Cl? ions had no effect on the rate. A decrease of the dielectric constant of the medium by adding methanol decreased the rate with arginine, while the rates increased with histidine and threonine. The solvent isotope effect was studied using D2O. (kobs)/(kobs) was found to be 0.55 and 0.79 for arginine and histidine, respectively. The reactions were studied at different temperatures, and activation parameters have been computed. The oxidation process in alkaline medium, under conditions employed in the present investigations, has been shown to proceed via two paths, one involving the interaction of RNHCl (formed rapidly from RNCl?), with the amino acid in a slow step to form monochloroamino acid, which subsequently interacts with another molecule of RNHCl in a fast step to give the products, p-toluenesulfonamide (RNH2), and the corresponding nitrile of the amino acid (R'CN). The other path involves the interaction of RNCl? with the amino acid in a similar way to give RNH2 and R'CN. Mechanisms proposed and the derived rate laws are consistent with the observed kinetics. The rate constants predicted using the derived rate laws, as [OH?] varies, are in excellent agreement with the observed rate constants, thus justifying these rate laws and hence the proposed mechanistic schemes. 相似文献
69.
70.
Singh AK Mondal JA Ramakrishna G Ghosh HN Bandyopadhyay T Palit DK 《The journal of physical chemistry. B》2005,109(9):4014-4023
The dynamics of ultrafast photoinduced intermolecular electron transfer (ET) from the excited singlet (S1) state of perylene (Pe) to an electron-accepting cationic surfactant molecule, N-cetylpyridinium chloride (CPC), in aqueous micellar solutions has been investigated using the femtosecond transient absorption spectroscopic technique with temporal resolution of 120 fs. The Pe molecule is localized at or near the micellar surface, where it coexists with the pyridinium moieties (headgroups of the micelle) of the surfactant molecule. Following photoexcitation of Pe, an electron is transferred to the neat and geometrically restricted headgroup of the micelle. Dynamics of the forward ET process as well as the geminate recombination or back ET (BET) process have been followed by monitoring the temporal evolution of the S1 state of Pe and the cation radical of Pe (Pe*+), respectively. The multiexponential forward ET process indicates that the ET dynamics is highly correlated with the spatial distributions of the micellar headgroups around a donor Pe molecule and thus dependent on the donor-acceptor distance. The distance-dependent ET and BET rates have been calculated following the method of Weidemaier and Fayer (J. Chem. Phys. 1995, 102, 3820) to get the best fit parameters for the multiexponetial temporal profiles for the S1 state of Pe as well as Pe*+. Because the acceptor is a constituent of the neat micellar medium, their confinement on the surface of the microheterogeneous medium provides a very large concentration such that, even though the forward transfer rate is 0.06 ps(-1) at the distance of closest approach, the ET process is complete within a 200-ps time domain. If the concepts of distribution of ET distances are utilized, the possible role of material diffusion on the kinetics of forward ET is ruled out. This is an experimental study to show, for the first time, the ultrafast distance-dependent light-induced ET dynamics following both the excited state of the donor and the cation radical formed in an ET process using the transient absorption spectroscopic technique in a self-reactive restrictive environment. 相似文献