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51.
Iwona E. Głowacka Dorota G. Piotrowska Andrzej E. Wróblewski Aleksandra Trocha 《Tetrahedron: Asymmetry》2017,28(11):1602-1607
A simple and efficient synthetic strategy to all four enantiomerically pure diethyl 1,2-di(N-Boc-amino)propylphosphonates has been elaborated starting from the corresponding N-[(R)-(1-phenylethyl)]aziridine-(2S)- and N-[(S)-(1-phenylethyl)]aziridine-(2R)-carboxaldehydes, employing a one-pot three-components Kabachnik-Fields reaction followed by the hydrogenolytic removal of the chiral auxiliary and aziridine ring opening with simultaneous protection of the amino groups as the N-Boc derivatives. 相似文献
52.
Dr. Pritam Ghosh Dr. Natalia Fridman Prof. Dr. Galia Maayan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(2):634-640
The construction of synthetic protein mimics is a central goal in chemistry. A known approach for achieving this goal is the self-assembly of synthetic biomimetic sequences into supramolecular structures. Obtaining different 3D structures via a simple sequence modification, however, is still challenging. Herein we present the design and synthesis of biomimetic architectures, via the self-assembly of distinct copper-peptoid duplexes. We demonstrate that changing only one non-coordinating side-chain within the peptoids—sequence-specific N-substituted glycine oligomers—leads to different supramolecular structures. Four peptoid trimers incorporating 2,2’-bipyridine and pyridine ligands, and a non-coordinating but rather a structure-directed bulky group were synthesized, and their solutions were treated with Cu2+ in a 1:1 ratio. Single-crystal X-ray analysis of the products revealed the self-assembly of each peptoid into a metallopeptoid duplex, followed by the self-assembly of multiple duplexes and their packing into a three-dimensional supramolecular architecture via hydrogen bonding and π–π interactions. Tuning the non-coordinating side-chain enables to regulate both the final structure being either a tightly packed helical rod or a nano-channel, and the pore width of the nano-channels. Importantly, all the metallopeptoids structures are stable in aqueous solution as verified by cryo-TEM measurements and supported by UV/Vis and EPR spectroscopies and by ESI-MS analysis. Thus, we could also demonstrate the selective recognition abilities of the nano-channels towards glycerol. 相似文献
53.
Dr. Lina M. Aguirre-Díaz Marcelo Echeverri Dr. Katherine Paredes-Gil Dr. Natalia Snejko Dr. Berta Gómez-Lor Prof. Dr. Enrique Gutiérrez-Puebla Prof. Dr. M. Ángeles Monge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(16):5298-5306
Three new cadmium-based coordination polymers, denoted [Cd(hfipbb)(4,4’-bipy)] ( CdPF-1 ), [Cd(hfipbb)(2,2’-bipy)] ( CdPF-2 ), and [Cd(hfipbb)(1,10-phen)] ( CdPF-3 ), have been hydrothermally synthesized by using the well-known V-shaped organic linker 4,4’-(hexafluoroisopropylidene)bis(benzoic acid) (H2hfipbb), together with different nitrogenated auxiliary linkers. Considering the d10 configuration of the transition metal selected, the luminescent properties for these CdPF-n materials were explored, finding that materials CdPF-2 and CdPF-3 act as excellent sensors in the detection of explosive nitro aromatic compounds. The photoluminescence properties of CdPF-2 and CdPF-3 revealed that significant and sensitive fluorescence quenching was observed toward NP (nitrophenol) for CdPF-2 and PA (picric acid) for CdPF-3 in MeOH suspensions. 相似文献
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Jon E. Carlé Martin Helgesen Natalia K. Zawacka Morten V. Madsen Eva Bundgaard Frederik C. Krebs 《Journal of Polymer Science.Polymer Physics》2014,52(13):893-899
Two low‐band gap polymer series based on benzo[1,2‐b:4,5‐b′]dithiophene (BDT) and dithienylbenzothiadiazole, with different numbers of fluorine substituents on the 2,3,1‐benzothiadiazole unit, have been synthesized and explored in a comparative study of the photochemical stability and operational lifetime in flexible large area roll‐coated bulk heterojunction solar cells. The two polymer series have different side chains on the BDT unit, namely 2‐hexyldecyloxy (BDTHDO) ( P1–P3 ) or 2‐hexyldecylthiophene (BDTTHD) ( P4–P6 ). The photochemical stability clearly shows that the stability enhances along with the number of fluorine atoms incorporated on the polymer backbone. Fabrication of the polymer solar cells based on the materials was carried out in ambient atmosphere on a roll coating/printing machine employing flexible and indium‐tin‐oxide‐free plastic substrates. Solar cells based on the P4–P6 series showed the best performance, reaching efficiencies up to 3.8% for an active area of 1 cm2, due to an enhanced current compared to P1–P3 . Lifetime measurements, carried out according to international summit on OPV stability (ISOS), of encapsulated devices reveals an initial fast decay for P1–P6 in the performance followed by a much slower decay rate, still retaining 40–55% of their initial performance after 250 h of testing under ISOS‐L‐1 conditions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 893–899 相似文献
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Enhanced Responsivity of ZnSe‐Based Metal–Semiconductor–Metal Near‐Ultraviolet Photodetector via Impact Ionization (Phys. Status Solidi RRL 2/2018) 下载免费PDF全文
58.
Nonexistence of global solutions to new ordinary differential inequality and applications to nonlineardispersive equations 下载免费PDF全文
Nikolay Kutev Natalia Kolkovska Milena Dimova 《Mathematical Methods in the Applied Sciences》2016,39(9):2287-2297
A new ordinary differential inequality without global solutions is proposed. Comparison with similar differential inequalities in the well‐known concavity method is performed. As an application, finite time blow up of the solutions to nonlinear Klein–Gordon equation and generalized Boussinesq equation is proven. The initial energy is arbitrary high positive. The structural conditions on the initial data generalize the assumptions used in the literature for the time being. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
59.
Theo Steininger Jait Dixit Philipp Frank Maksim Greiner Sebastian Hutschenreuter Jakob Knollmüller Reimar Leike Natalia Porqueres Daniel Pumpe Martin Reinecke Matev raml Csongor Varady Torsten Enßlin 《Annalen der Physik》2019,531(3)
NIFTy , “Numerical Information Field Theory,” is a software framework designed to ease the development and implementation of field inference algorithms. Field equations are formulated independently of the underlying spatial geometry allowing the user to focus on the algorithmic design. Under the hood, NIFTy ensures that the discretization of the implemented equations is consistent. This enables the user to prototype an algorithm rapidly in 1D and then apply it to high‐dimensional real‐world problems. This paper introduces NIFTy 3, a major upgrade to the original NIFTy framework. NIFTy 3 allows the user to run inference algorithms on massively parallel high performance computing clusters without changing the implementation of the field equations. It supports n‐dimensional Cartesian spaces, spherical spaces, power spaces, and product spaces as well as transforms to their harmonic counterparts. Furthermore, NIFTy 3 is able to handle non‐scalar fields, such as vector or tensor fields. The functionality and performance of the software package is demonstrated with example code, which implements a mock inference inspired by a real‐world algorithm from the realm of information field theory. NIFTy 3 is open‐source software available under the GNU General Public License v3 (GPL‐3) at https://gitlab.mpcdf.mpg.de/ift/NIFTy/tree/NIFTy_3 . 相似文献
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