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101.
Hannah Bürckstümmer Elena V. Tulyakova Manuela Deppisch Martin R. Lenze Nils M. Kronenberg Marcel Gsnger Matthias Stolte Klaus Meerholz Frank Würthner 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2011,123(49):11832-11836
A series of dipolar donor–acceptor (D –A) chromophores with aminothiophene donor and different heterocyclic acceptor units is reported. By modulation of the acceptor strength, absorption bands over the whole visible spectrum are accessible as well as adjustment of the frontier molecular orbital levels. The performance of the chromophores in blends with fullerene acceptors in solution‐processed bulk heterojunction solar cells was studied and related to the molecular properties of the dyes. In particular, the effect of the large ground‐state dipole moments of these dyes was investigated by single crystal X‐ray analysis, which revealed antiparallel dimers, resulting in an annihilation of the dipole moments. This specific feature of supramolecular organization explains the excellent performance of merocyanine dyes in organic solar cells. With blends of HB366 :PC71BM, the most efficient solar cell with a VOC of 1.0 V, a JSC of 10.2 mA cm−2, and a power‐conversion efficiency of 4.5 % was achieved under standard AM1.5, 100 mW cm−2 conditions. Under reduced lighting conditions, even higher efficiencies up to 5.1 % was obtained. 相似文献
102.
We show that two partial latin squares of order mk are simultaneously avoidable if m > 4 and ${k>\frac{m^3(m^2-1)}{2}}$ . If m = 4, we show the same conclusion when k > 56. 相似文献
103.
Luke C. Henderson Megan T. Thornton Nolene Byrne Bronwyn L. Fox Kelsey D. Waugh Jennifer S. Squire Linden Servinis Joshua P. Delaney Hannah L. Brozinski Luke M. Andrighetto Jarrad M. Altimari 《Comptes Rendus Chimie》2013,16(7):634-639
The acid catalysed formation of diphenylmethyl (DPM) thioethers was successfully achieved using the protic ionic liquid (pIL) triethylamine:methanesulfonic acid (TeaMs) as the reaction solvent under microwave irradiation. A slight excess of methanesulfonic acid (10% v/v) was required to facilitate the reaction, which was applied to a variety of thiols. Aliphatic, aromatic and heterocyclic aromatic thiols were converted to their corresponding DPM thioethers in high yields (63–99%), in short reaction times (5–20 min) and using mild temperatures (80–100 °C). Finally, the pIL (TeaMS) was recycled five times without loss of yield. 相似文献
104.
Fok MP Deming H Nahmias M Rafidi N Rosenbluth D Tait A Tian Y Prucnal PR 《Optics letters》2011,36(1):19-21
We developed a hybrid analog/digital lightwave neuromorphic processing device that effectively performs signal feature recognition. The approach, which mimics the neurons in a crayfish responsible for the escape response mechanism, provides a fast and accurate reaction to its inputs. The analog processing portion of the device uses the integration characteristic of an electro-absorption modulator, while the digital processing portion employ optical thresholding in a highly Ge-doped nonlinear loop mirror. The device can be configured to respond to different sets of input patterns by simply varying the weights and delays of the inputs. We experimentally demonstrated the use of the proposed lightwave neuromorphic signal processing device for recognizing specific input patterns. 相似文献
105.
McAlexander Harley R. Giles Stephen A. Crouch Rebecca A. Peel Hannah R. Jones Stacy Bednar Anthony J. Shukla Manoj K. 《Structural chemistry》2020,31(3):975-982
Structural Chemistry - Alternatives to legacy munitions and explosives, materials that feature increased stability against external stimuli without compromising their energetic yields are currently... 相似文献
106.
Journal of Fluorescence - A benzothiazolium-based hemicyanine dye (probe 3) has been synthesized by attaching a morpholine group into a phenyl benzothiazolium skeleton. Probe 3 exhibited... 相似文献
107.
Hannah P. Ferguson Johns Emily E. Harrison Kyla J. Stingley Prof. Marcey L. Waters 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(22):6620-6644
Selective molecular recognition of hydrophilic guests in water plays a fundamental role in a vast number of biological processes, but synthetic mimicry of biomolecular recognition in water still proves challenging both in terms of achieving comparable affinities and selectivities. This Review highlights strategies that have been developed in the field of supramolecular chemistry to selectively and non-covalently bind three classes of biologically relevant molecules: nucleotides, carbohydrates, and amino acids. As several groups have systematically modified receptors for a specific guest, an evolutionary perspective is also provided in some cases. Trends in the most effective binding forces for each class are described, providing insight into selectivity and potential directions for future work. 相似文献
108.
Paola Rubiano-Buitrago Shrikant Pradhan Christian Paetz Hannah M. Rowland 《Molecules (Basel, Switzerland)》2023,28(1)
Cardiac glycosides are a large class of secondary metabolites found in plants. In the genus Asclepias, cardenolides in milkweed plants have an established role in plant–herbivore and predator–prey interactions, based on their ability to inhibit the membrane-bound Na+/K+-ATPase enzyme. Milkweed seeds are eaten by specialist lygaeid bugs, which are the most cardenolide-tolerant insects known. These insects likely impose natural selection for the repeated derivatisation of cardenolides. A first step in investigating this hypothesis is to conduct a phytochemical profiling of the cardenolides in the seeds. Here, we report the concentrations of 10 purified cardenolides from the seeds of Asclepias curassavica. We report the structures of new compounds: 3-O-β-allopyranosyl coroglaucigenin (1), 3-[4′-O-β-glucopyranosyl-β-allopyranosyl] coroglaucigenin (2), 3′-O-β-glucopyranosyl-15-β-hydroxycalotropin (3), and 3-O-β-glucopyranosyl-12-β-hydroxyl coroglaucigenin (4), as well as six previously reported cardenolides (5–10). We test the in vitro inhibition of these compounds on the sensitive porcine Na+/K+-ATPase. The least inhibitory compound was also the most abundant in the seeds—4′-O-β-glucopyranosyl frugoside (5). Gofruside (9) was the most inhibitory. We found no direct correlation between the number of glycosides/sugar moieties in a cardenolide and its inhibitory effect. Our results enhance the literature on cardenolide diversity and concentration among tissues eaten by insects and provide an opportunity to uncover potential evolutionary relationships between tissue-specific defense expression and insect adaptations in plant–herbivore interactions. 相似文献
109.
Dr. Hannah Lingard Jeongmin T. Han Dr. Amber L. Thompson Dr. Ivanhoe K. H. Leung Dr. Richard T. W. Scott Dr. Sam Thompson Prof. Andrew D. Hamilton 《Angewandte Chemie (International ed. in English)》2014,53(14):3650-3653
In the search for synthetic mimics of protein secondary structures relevant to the mediation of protein–protein interactions, we have synthesized a series of tetrasubstituted diphenylacetylenes that display β‐sheet structures in two directions. Extensive X‐ray crystallographic and NMR solution phase studies are consistent with these proteomimetics adopting sheet structures, displaying both hydrophobic and hydrophilic amino acid side chains. 相似文献
110.
Tuning Phenols with Intra‐Molecular Bond Shifted HYdrogens (IM‐SHY) as diaCEST MRI Contrast Agents 下载免费PDF全文
Xing Yang Nirbhay N. Yadav Xiaolei Song Prof. Sangeeta Ray Banerjee Hannah Edelman Il Minn Prof. Peter C. M. van Zijl Prof. Martin G. Pomper Prof. Michael T. McMahon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(48):15824-15832
The optimal exchange properties for chemical exchange saturation transfer (CEST) contrast agents on 3 T clinical scanners were characterized using continuous wave saturation transfer, and it was demonstrated that the exchangeable protons in phenols can be tuned to reach these criteria through proper ring substitution. Systematic modification allows the chemical shift of the exchangeable protons to be positioned between 4.8 to 12 ppm from water and enables adjustment of the proton exchange rate to maximize CEST contrast at these shifts. In particular, 44 hydrogen‐bonded phenols are investigated for their potential as CEST MRI contrast agents and the stereoelectronic effects on their CEST properties are summarized. Furthermore, a pair of compounds, 2,5‐dihydroxyterephthalic acid and 4,6‐dihydroxyisophthalic acid, were identified which produce the highest sensitivity through incorporating two exchangeable protons per ring. 相似文献