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941.
The better selectivity of Am3+ over Eu3+ ion with N‐based CyMe4‐BTPhen compared to CyMe4‐BTBP for experimentally observed [ML2(NO3)]2+ complexes was demonstrated using scalar relativistic DFT in conjunction with Born‐Haber thermodynamic cycle and COSMO solvation model. The calculated free energy of extraction, ΔGext reveals strong dependence on the hydration free energies of Am3+ and Eu3+ ions and week dependence to the difference in Gibbs free energy of solvation of the ligand or metal‐ligand complexes. Further, for the first time, we have computed the effect of co‐anion species ([M(NO3)5]2–) on ΔGext of Am3+ and Eu3+ ions with CyMe4‐BTPhen and CyMe4‐BTBP, which adds a positive contribution and thus reduces the ΔGext. The calculated values of ΔΔΔGext (= ΔΔGext,L1 – ΔΔGext,L2, ΔΔGext = ΔGext,M1 – ΔGext,M2) can be used to avoid the very sensitive metal ion solvation energy, effect of co‐anionic species and thus provides a robust approach to determine the selectivity between two metal ions towards different competitive ligands. The natural population analysis (NPA), molecular orbital analysis, Mayer bond order analysis, and bond character analysis using Bader's quantum theory of atoms in molecules indicates slightly more covalency for complexes of Am3+ ion that are correlated to the experiental selectvity of Am3+ ion over Eu3+ ion and hence might be useful in the design and development of next generation extractants. 相似文献
942.
The work demonstrated the microstructure and the relaxation behavior of flexible electroactive blends of poly(vinylidene fluoride) (PVDF)/hydrogenated nitrile rubber (HNBR) by small‐angle X‐ray scattering and dielectric relaxation spectroscopy. Very few studies have been done so far on this topic for crystalline/rubbery blends. Lamellar morphology was observed for both the PVDF and its blends. HNBR suppressed the mobility of PVDF above its melting temperature, as evident from lowering of crystallization temperature, due to physical interaction. The interaction was increased with HNBR content. However, after complete crystallization, HNBR segments were expelled out from the lamella, and crystal long period remained intact in all the blends. Interestingly, some HNBR segments remained in the amorphous part of PVDF which reduced the electron density contrast of its crystalline and amorphous region. When HNBR was crosslinked, the interaction was reduced, and consequently, the crystallization became faster and electron density contrast increased. From the microscopic study, polydispersed particles were observed within the crystalline lamella. Interfacial polarization (IP) relaxation of PVDF was absent in the blends due to physical interaction, whereas IP relaxation of HNBR shifted to a higher frequency. The shift was higher at higher HNBR content and decreased when HNBR was crosslinked. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 851–866 相似文献
943.
Dr. Aleksandr M. Agafontsev Dr. Anil Ravi Dr. Tatiana A. Shumilova Dr. Aleksandr S. Oshchepkov Prof. Dr. Evgeny A. Kataev 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(11):2684-2694
Nucleotides are constituents of nucleic acids and they have a variety of functions in cellular metabolism. Synthetic receptors and sensors are required to reveal the role of nucleotides in living organisms and mechanisms of signal transduction events. In recent years, a large number of nucleotide-selective synthetic receptors have been devised, which utilize different molecular designs and sensing mechanisms. This Minireview presents recent progress in the design of synthetic molecular receptors for selective recognition of nucleotides in aqueous solution. The binding properties of receptors and the origins of their selectivity for a particular nucleotide are discussed. 相似文献
944.
Rajnish Kaur Anil Kumar Mateusz Czyzycki Alessandro Migliori Andreas G. Karydas Sanjiv Puri 《X射线光谱测定》2019,48(2):126-137
In the present work, the X-ray intensity ratios, ILk/ILα (k = l, β, γ1,5, γ2,3, γ4), have been measured for different compounds of 66Dy, namely, Dy2O3, Dy2(CO3)3, Dy2(SO4)3.8H2O, DyI2, and the 66Dy metallic foil by tuning the incident photon energies across its Li (i = 1–3) absorption-edge energies covering the region 7.8–10 keV in order to investigate the influence of chemical effects on these intensity ratios in the presence of the many-body effects, which become significant at photon energies in proximity to the Li absorption-edge energies. The present measured intensity ratios ILk/ILα have been compared with two sets of values calculated using the nonrelativistic Hartree–Fock–Slater model-based Li (i = 1–3) subshell photoionization cross sections, the Dirac–Fock model-based X-ray emission rates, and two sets of the fluorescence and Coster–Kronig yields. The L3 absorption-edge energy of 66Dy in its different compounds and metallic foil has been deduced from the XANES spectra recorded in the present work. The L3 absorption-edge energy shifts obtained from these absorption-edge energies are found to increase linearly with the partial charge on the metal atom (66Dy). 相似文献
945.
Anil Kumar Shivali Jamwal Shahaba Khan Nasseb Singh Vijai K. Rai 《Phosphorus, sulfur, and silicon and the related elements》2017,192(3):381-385
The Bi(NO3)3.5H2O mediated synthesis of α-hydroxyphosphonates via phosphonylation of aldehydes is reported herein. Both conventional and microwave technology was efficiently applied to range of aromatic, heteroaromatic, α,β-unsaturated aldehydes under solvent-free conditions. The solvent free conditions, avoidance of toxic reagents and excellent yield are some of the remarkable features of this protocol to access the medicinally privileged structure, α-hydroxyphosphonates. 相似文献
946.
Anil Kanwat Natalia Yantara Priyanka Kajal Nripan Mathews 《Advanced Optical Materials》2024,12(8):2301342
The flexibility and adaptability of halide perovskites position them as a promising material for a variety of cutting-edge technologies. In addition to their primary applications in photovoltaics and light-emitting diodes, they have recently garnered interest for potential use in switchable technologies, such as smart windows, switchable photovoltaics, memory devices, neuromorphic computing, and sensors. This interest stems from these switchable properties, which allow them to alter color or other physical properties in response to external stimuli like heat, electric fields, light, pressure, and moisture. This review investigates their switching properties and examines their practical applications across a range of emerging chromic technologies. An in-depth analysis of the mechanisms of reversibility, switchable optical and electrical properties, as well as the chemical and structural transformations these materials undergo is also presented. Furthermore, they are categorized based on their unique switching mechanisms. To assist the research community in developing new multichromic halide perovskite designs, several essential criteria are outlined for effective switchable materials. Lastly, the current challenges faced by these emerging materials are discussed, and a perspective on future developments and potential breakthroughs in this promising research area is offered. 相似文献
947.
Anil Kanwat Natalia Yantara Priyanka Kajal Nripan Mathews 《Advanced Optical Materials》2024,12(8):2470026
948.
Tomoki Furuhashi Anil Kanwat Sankaran Ramesh Nripan Mathews Tze Chien Sum 《Advanced Optical Materials》2024,12(8):2301230
A library of large organic cation spacers is available for engineering the performance of layered two-dimensional (2D) halide perovskite devices. Despite extensive photophysics studies, there remains a research gap over the structure-function relations in 2D perovskites, especially the underlying factors influencing the Auger recombination (AR) process. Herein, the contributions of exciton binding energy, exciton-phonon coupling, and defects/film morphology to the AR process in 2D perovskites are examined. Phenyl-alkyl-ammonium cations with different lengths of attached alkyl groups, commonly used in blue light-emitting diodes, are investigated. The findings reveal an order of magnitude higher threshold carrier density for the AR onset as well as a reduced AR in cations with longer alkyl chain length. Although possessing similar exciton binding energies, the exciton-phonon coupling strength is found to play a major role in reducing the AR rate, with a smaller contribution from the defect states/film morphology. The findings can help provide further guidance on organic spacer cation engineering for highly efficient 2D perovskite light emitters. 相似文献
949.
A series of chiral 2-hydroxy ethyl/benzyl benzimidazole based aryl triazole tweezers have been prepared using click chemistry in high yields. Chiral pool strategy has been used to obtain the benzimidazole-based tweezers in very high enantiomerically enriched form. The aryl triazole tweezers, S -(−)- 5a and S -(+)- 8a displayed a high degree of selectivity for iodide anion over other anions, including other halides. The aryl triazole tweezers, S -(−)- 5a and S -( + )- 8a display significant enantio-discrimination for chiral amines. The chiral recognition studies were carried out using UV and circular dichroism (CD) spectroscopy. NMR analysis has been used for establishing the sites for ligation of the iodide anion. 相似文献
950.