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In an effort to study the scope of microwave radiation for organic bromination reactions, some reactions were studied using a domestic microwave oven. Results reveal that these radiation-induced reactions are unique in their high yields and that they require extremely short reaction times compared with conventional room-temperature reactions. In these reactions tetrabutyl ammonium tribromide was used as an alternative brominating reagent in order to avoid the chemical hazards associated with liquid bromine (Br2). As all the reactions were successfully carried out in solid state under microwave conditions, the use of solvent was not required. All these aspects make the bromination protocol quite environment friendly. 相似文献
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In this paper, we obtain reliable expressions to calculate the barrier and pocket positions of the real part of the effective
phenomenological optical potential having Woods-Saxon form factor, for different partial waves. The comparison of the results
obtained from these formulae, when compared with the numerical results obtained using Newton-Raphson iterative procedure are
found to be quite accurate, with error less than 1%. We also obtain algebraic expressions for estimatingl
poc, the angular momentum at which the potential pocket vanishes, the accuracy of which is tested with the exact calculations,
using self-consistent iterative procedures. These and other expressions deduced in this paper provide simple and useful methods
for calculating critical parameters of heavy ion effective potentials like barrier and pocket positions, curvatures at the
barrier and pocket positions,l
poc and the grazing angular momentuml
g to carry out the analysis of heavy ion scattering. 相似文献
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Madugula Sita Sirisha Nagamani Selvaraman Jamir Esther Priyadarsinee Lipsa Sastry G. Narahari 《Molecular diversity》2022,26(3):1675-1695
Molecular Diversity - Development of potential antitubercular molecules is a challenging task due to the rapidly emerging drug-resistant strains of Mycobacterium tuberculosis (M.tb).... 相似文献
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Dr. Heather F. Barton Jovenal D. Jamir Alexandra K. Davis Gregory W. Peterson Prof. Gregory N. Parsons 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(4):1465-1472
New materials and chemical knowledge for improved personal protection are among the most pressing needs in the international community. Reported attacks using chemical warfare agents (CWAs,) including organophosphate soman (GD) and thioether mustard gas (HD) are driving research in field-deployable catalytic composites for rapid toxin degradation. In this work, we report simple template-free low temperature synthesis that enables for the first time, a deployable-structured catalytic metal-organic framework/polymer textile composite “MOF-fabric” showing rapid hydrolysis and oxidation of multiple active chemical warfare agents, GD and HD, respectively, and their simulants. Our method yields new zirconium–porphyrin based nano-crystalline PCN-222 MOF-fabrics with adjustable MOF loading and robust mechanical adhesion on low-cost nonwoven polypropylene fibers. Importantly, we describe quantitative kinetic analysis confirming that our MOF-fabrics are as effective as or better than analogous MOF powders for agent degradation, especially for oxidation. Faster oxidation using the MOF-fabrics is ascribed to the composite geometry, where active MOF catalysts are uniformly displayed on the MOF-textile enabling better reactant transport and reactive oxidant generation. Furthermore, we note the discovery of visible photo-activation of GD hydrolysis by a MOF-fabric, which is ascribed to oxidation at the active metal node site, significantly increasing the rate over that observed without illumination. These results provide important new insights into the design of future materials and chemical systems to protect military, first-responders, and civilians upon exposure to complex chemical toxins. 相似文献
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Using several illustrative examples, the nature of resonance poles and the corresponding zeroes of the s-waveS matrix is examined for several potentials having an absorptive pocket followed by a barrier. It is shown that even though
the presence of absorption practically suppresses the manifestation of resonance in the elastic scattering cross section,
the effect of the resonances generated by the absorptive pocket is more clearly manifested in the absorption cross section
provided the barrier width is not too large. We further find that the signature of barrier top resonances are also more clearly
manifested in the absorption cross section rather than in the elastic scattering cross section. These results have been interpreted
in terms of complex resonance poles and corresponding zeroes of theS matrix. This implies that in complex potential scattering like heavy ion collisions, the reaction channel cross section peak
is a more reliable signature of resonance phenomenon than the variation of the elastic channel cross section with energy. 相似文献
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