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51.
Sargunam Caleb Noble Chandar Kannappan Santhakumar Mahadevimangalam Narayanasamy Arumugham 《Transition Metal Chemistry》2009,34(8):841-848
Twelve surfactant Schiff base ligands were synthesized from salicylaldehyde and its chloro-, bromo- and methoxy- derivatives
by condensation with long-chain aliphatic primary amines, and a number of mixed ligand cobalt(III) surfactant Schiff base
coordination complexes of the type [Co(trien)A]2+ were synthesized from the corresponding dihalogeno complexes by ligand substitution. The Schiff bases and their complexes
were characterized by physico-chemical and spectroscopic methods. The complexes form foams in aqueous solution upon shaking.
The critical micelle concentration (CMC) values of the complexes in aqueous solution were obtained from conductance measurements.
Specific conductivity data (at 303–323 K) served for the evaluation of the thermodynamics of micellization (
\Updelta G\textm0 \Updelta G_{\text{m}}^{0} ,
\Updelta H\textm0 \Updelta H_{\text{m}}^{0} ,
\Updelta S\textm0 \Updelta S_{\text{m}}^{0} ). The complexes were tested for its antimicrobial activity. 相似文献
52.
Mathew A. Johnson Pascal Noble L. Miguel Rodrigues Kevin Zumbrun 《Archive for Rational Mechanics and Analysis》2013,207(2):669-692
In a companion paper, we established nonlinear stability with detailed diffusive rates of decay of spectrally stable periodic traveling-wave solutions of reaction diffusion systems under small perturbations consisting of a nonlocalized modulation plus a localized (L 1) perturbation. Here, we determine time-asymptotic behavior under such perturbations, showing that solutions consist of a leading order of a modulation whose parameter evolution is governed by an associated Whitham averaged equation. 相似文献
53.
Blake Barker Mathew A. Johnson Pascal Noble L. Miguel Rodrigues Kevin Zumbrun 《Applied Mathematics Letters》2012,25(5):824-829
In this note, we announce a general result resolving the long-standing question of nonlinear modulational stability, or stability with respect to localized perturbations, of periodic traveling-wave solutions of the generalized Kuramoto–Sivashinsky equation, establishing that spectral modulational stability, defined in the standard way, implies nonlinear modulational stability with sharp rates of decay. The approach extends readily to other second- and higher-order parabolic equations, for example, the Cahn Hilliard equation or more general thin film models. 相似文献
54.
Prof. Dr. Peter Comba Dr. Nina Dovalil Prof. Dr. Lawrence R. Gahan Prof. Dr. Gebhard Haberhauer Prof. Dr. Graeme R. Hanson Dr. Christopher J. Noble Dr. Björn Seibold Dr. Prabha Vadivelu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(9):2578-2590
Two synthetic derivatives of the naturally occurring cyclic pseudooctapeptides patellamide A–F and ascidiacyclamide, that is, H4pat2, H4pat3, as well as their CuII complexes are described. These cyclic peptide derivatives differ from the naturally occurring macrocycles by the variation of the incorporated heterocyclic donor groups and the configuration of the amino acids connecting the heterocycles. The exchange of the oxazoline and thiazole groups by dimethylimidazoles or methyloxazoles leads to more rigid macrocycles, and the changes in the configuration of the side chains leads to significant differences in the folding of the cyclic peptides. These variations allow a detailed study of the various possible structural changes on the chemistry of the CuII complexes formed. The coordination of CuII with these macrocyclic species was monitored by high‐resolution electrospray mass spectrometry (ESI‐MS), spectrophotometric (UV/Vis) and circular dichroic (CD) titrations, and electron paramagnetic resonance (EPR) spectroscopy. Density functional theory (DFT) calculations and molecular mechanics (MM) simulations have been used to model the structures of the CuII complexes and provide a detailed understanding of their geometric preferences and conformational flexibility. This is related to the CuII coordination chemistry and the reactivity of the dinuclear CuII complexes towards CO2 fixation. The variation observed between the natural and various synthetic peptide systems enables conclusions about structure–reactivity correlations, and our results also provide information on why nature might have chosen oxazolines and thiazoles as incorporated heterocycles. 相似文献
55.
Lee J. Silverberg Carlos Pacheco Debashish Sahu Peter Scholl Hany F. Sobhi Joshua T. Bachert Kaitlyn Bandholz Ryan V. Bendinsky Heather G. Bradley Baylee K. Colburn David J. Coyle Jonathon R. Dahl Megan Felty Ryan F. Fox Kyanna M. Gonzalez Jasra M. Islam Stacy E. Koperna Quentin J. Moyer Duncan J. Noble Melissa E. Ramirez Ziwei Yang 《Journal of heterocyclic chemistry》2020,57(4):1797-1805
A series of 11 novel 3-aryl-2-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-ones was prepared at room temperature by T3P-mediated cyclization of N-aryl-C-phenyl imines with thiosalicylic acid. This provides simple and ready access to N-aryl compounds in this family, which have been generally difficult to prepare. 相似文献
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A NaOH-poisoned γ-alumina membrane with 4-nm diameter pores was used to separate CH3OH from a H2/CH3OH mixture. Between 373 and 473 K, CH3OH condensed in the pores for certain pressure ranges, and was preferentially removed through the pores. Separation factors as high as 600 for CH3OH over H2 were obtained. Capillary condensation was observed at CH3OH pressures (0.60 ± 0.05 Psat) much lower than those predicted by the Kelvin equation. Causes for the deviations are indicated. 相似文献