A route to new colorimetric pH sensors

2017 ◽  
Vol 72 (3) ◽  
pp. 199-206
Author(s):  
Sebastian Wandtke ◽  
Dietmar Stalke
Keyword(s):  
Large Range ◽  
Ph Sensors ◽  
Radiative Relaxation ◽  
Anthracene Derivatives ◽  
Target Molecules ◽  
Synthetic Routes ◽  
The One ◽  
Zinc Cations ◽  
New Sensors ◽  
Nitrogen Double Bond

Abstract The detection of target molecules via luminescence changes of appropriate sensors is a powerful tool to determine the presence of analytes qualitatively and quantitatively. Therefore, the exploration of synthetic routes to new sensors is important to facilitate the recognition of a large range of analytes. In this report we describe such a new route to sensors and discuss the behavior of the synthesized sensors in the presence of different analytes. The prepared anthracene derivatives belong to two classes of substances. On the one hand imines were synthesized wherein the isomerization of their inherent carbon nitrogen double bond provides an effective non-radiative relaxation pathway. On the other hand amines were received by reduction of the mentioned imines. Their intramolecular charge transfer (ICT) based sensing mechanism allows the detection of protons in a reversible colorimetric fashion. Furthermore, the addition of zinc cations in the aprotic solvent DCM provides the first example showing that the detection of these colorimetric pH sensors is not limited to protons.

TINDAK PENGANCAMAN DAN PENYELAMATAN WAJAH ANIES BASWEDAN DAN BASUKI “AHOK” TJAHAJA PURNAMA

Jurnal KATA ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 356
Author(s):  
Saiko Rudi Kasenda
Keyword(s):  
Qualitative Method ◽  
Common Ground ◽  
Large Range ◽  
Politeness Theory ◽  
Crucial Point ◽  
Passive Voice ◽  
Positive Image ◽  
The Face ◽  
Face Saving ◽  
The One

<p><em>This article is aimed to investigate face threathening acts and face saving acts demonstrated by Anies Baswedan dan Basuki Tjahaja Purnama as the candidates of DKI Jakarta governor during the debate held in April 2017. Face threatening act and face saving act are analyzed because they are able to show not only their positive image but also the negatve one in front of not only to each candidate but also to the audience watching the debate. Politeness theory from Brown and Levinson (1987.) are employed to analyze both candidates’ face threatening acts and saving acts since this theory provides detailed descriptions of a large range of strategies that can be used to deeply understand both face threatening acts and face saving act performed by the candidates. The context surrounding the debate becomes a crucial point to analyze how politeness strategy is applied to show face thratening act and face saving act. Through qualitative method, this study found that 1) Bald on-record is the strategy used by the candidates to show face threatening and they are intended to show contradictions, to disagree, to insult, to interrupt, to speak out-of-topic, to challenge, and to exaggerate. 2) Both candidates use positive and negative strategies to show face saving act intended to show contradictions, to assert common ground, to show agreement, to joke, to apologize, and to avoid disagreement. 3) The face threatening act and saving acts can be considered as the efforts to defend their argumentations and to preserve their positive faces, 4.) The use of the word “kita” and passive voice can be seen as markers in both candidates’ utterances to minimize the imposed face threatening act and to signal solidarity to each candidate and to audience, 5) While Anies is revealed to be the one who more frequently uses face threatening act, Basuki is the candidate who uses face saving act more often during the debate. The study is expected to enrich the study in the field of pragmatics focusing on the use of politeness strategy. </em></p><p> </p><p>Artikel ini bertujuan untuk menginvestigasi tindak pengancaman muka wajah dan tindak penyelamatan wajah yang ditunjukkan oleh Anies Baswedan dan Basuki Tjahaja Purnama pada Debat Pilkada gubernur provinsi DKI Jakarta 2017.<strong> </strong>Tindak pengancaman wajah dan penyelamatan wajah diteliti pada makalah ini karena dapat merepresentasikan citra positif maupun citra negatif kandidat pilkada Gubernur DKI tidak hanya dihadapan masing-masing kandidat tetapi juga kepada masyarakat umum yang menyaksikan. Teori kesantunan dari Brown dan Levinson digunakan untuk menganalisis tindak pengancaman muka dan tindak penyelamatan muka kedua kandidat karena teori ini memiliki penjelasan yang komprehensif tentang berbagai strategi yang dapat dipergunakan untuk memahami secara mendalam bagaimana tindak pengancaman dan penyelamatan wajah ditunjukkan oleh kedua kandidiat. Konteks topik debat yang diangkat dipahami untuk dapat menganalisis tindak pengancaman dan penyelamatan wajah oleh Anies dan Basuki.  Melalui metode kualitatif, studi ini menemukan bahwa 1) Bald on-record adalah strategi yang sering digunakan untuk menunjukkan tindak pengancaman muka dan ditujukan untuk menyatakan kontradiksi, menyatakan ketidaksetujuan, menyinggung, menginterupsi, berbicara di luar topik pembicaraan, menantang kandidat lain, dan memberikan pernyataan yang berlebihan. 2) Tindak penyelamatan muka dilakukan dengan strategi kesantunan positif dan negatif seperti menyatakan kontradiksi, menegaskan common ground, memberikan persetujuan, membuat lelucon, meminta maaf, dan menghindari ketidaksetujuan. 3) Tindak pengancaman muka dan penyelamatan muka dapat dianggap sebagai cara untuk mempertahankan argumentasi kedua kandidat dan untuk melindungi wajah positif masing-masing.4) Penggunaan kata “kita” dan kalimat pasif dimaksudkan untuk meminmalisiri ancaman sekaligus sebagai sinya solidaritas.5) Anies ditunjukkan sebagai kandidat yang lebih sering menggunakan tindak pengancaman muka, sedangkan Basuki adalah kandidat yang lebih sering menunjukkan penyelamatan muka selama debat berlangsung. Studi ini diharapkan dapat memperkaya pemahaman di bidang pragmatik khususnya tentang penggunaan strategi kesantunan</p>

Sulfonated Polystyrene Ionomers Neutralized with Mixtures of Various Cations Studied by Dynamic Mechanical and Small-Angle X-Ray Scattering Techniques

2003 ◽  
Vol 778 ◽  
Author(s):  
Ho Seung Jeon ◽  
Ju-Myung Song ◽  
Joon-Seop Kim
Keyword(s):  
Glass Transition ◽  
Dynamic Mechanical Properties ◽  
The Other ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
Cluster Phase ◽  
The One ◽  
Zinc Cations

AbstractThe effects of the addition of mixed cations, i.e. Na+/Cs+, Ba2+/Cs+, and Ba2+/Zn2+, to the acid form sulfonated styrene copolymers on their dynamic mechanical properties and morphology were investigated. It was found that the matrix glass transition temperatures did not change with the ratio of the one cation to the other. As expected, however, the ratio of one cation to the other in the mixed cations affected cluster glass transition temperatures significantly. It was also found that the activation energies for the glass transitions for the matrix phase remained constant, while those for the cluster phase changed with the ratio of the two cations. In addition, the position of the SAXS peak was found to be affected by the type of cations. From the results obtained above, the decrease in the cluster Tg with increasing the amount of cesium and zinc cations in Na/Cs, Ba/ Cs, and Ba/Zn mixtures, were explained on the basis of the considerations of the size, charge, and type of cations, which alter the degree of clustering as well as ion-hopping mechanism.

Niobium and zirconium telluride thin films prepared by sputtering

1999 ◽  
Vol 14 (5) ◽  
pp. 2070-2079 ◽  
Author(s):  
Daniel Pailharey ◽  
Yves Mathey ◽  
Mohamad Kassem
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Substrate Temperature ◽  
Large Range ◽  
Sputter Deposition ◽  
The Other ◽  
Striking Feature ◽  
Structural Types ◽  
The One ◽  
Film Form

A versatile procedure of sputter deposition, well-adapted for getting a large range of Te/M ratios (with M = Zr or Nb), has led to the synthesis of several highly anisotropic zirconium and niobium polytellurides in thin film form. Upon tuning the two key parameters of the process, i.e., the Te percentage in the target and the substrate temperature during the deposition, preparation of systems ranging from ZrTe0.72 to ZrTe6.7, on the one hand, and from NbTe1.28 to NbTe7.84, on the other, has been achieved. Besides their amorphous or crystalline (with or without preferential orientations) behavior and their relationship to known structural types, the most striking feature of these films is their large departure from the stoichiometry of the bulk MTex reference compounds. This peculiarity, together with the possible changes of composition under annealing, are described and interpreted in terms of variable amounts of Te and M atoms trapped or intercalated within the parent structures.

scholarly journals An Efficient and Recycling Catalyst for the One-Pot Three-Component Synthesis of Substituted 3,4-Dihydropyrimidin-2(1H)-ones

2008 ◽  
Vol 5 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Taoues Boumoud ◽  
Boudjemaa Boumoud ◽  
Salah Rhouati ◽  
Ali Belfaitah ◽  
Abdelmadjid Debache ◽  
...  
Keyword(s):  
Reaction Times ◽  
Aromatic Aldehydes ◽  
One Pot ◽  
First Derivative ◽  
Target Molecules ◽  
The One ◽  
High Yields

The Biginelli one-pot three-component cyclocondensation was applied in this work to prepare 3,4-dihydropyrimidinone and its analogues using the first derivative of lead, Pb(NO3)2, as a recycling catalyst, from a diversity of aromatic aldehydes, β-ketoesters and urea. The reaction was carried out in refluxing acetonitrile and afforded the target molecules in good to excellent yields. The method offers several advantages including high yields of the products, short reaction times and easy experimental workup procedure

scholarly journals Processing and Analysis of Long-Range Scans with an Atomic Force Microscope (AFM) in Combination with Nanopositioning and Nanomeasuring Technology for Defect Detection and Quality Control

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5862
Author(s):  
Ingo Ortlepp ◽  
Jaqueline Stauffenberg ◽  
Eberhard Manske
Keyword(s):  
Quality Control ◽  
High Resolution ◽  
Atomic Force Microscope ◽  
Range Of Motion ◽  
Defect Detection ◽  
Large Range ◽  
The Other ◽  
Atomic Force ◽  
Measuring Machine ◽  
The One

This paper deals with a planar nanopositioning and -measuring machine, the so-called nanofabrication machine (NFM-100), in combination with a mounted atomic force microscope (AFM). This planar machine has a circular moving range of 100 mm. Due to the possibility of detecting structures in the nanometre range with an atomic force microscope and the large range of motion of the NFM-100, structures can be analysed with high resolution and precision over large areas by combining the two systems, which was not possible before. On the basis of a grating sample, line scans over lengths in the millimetre range are demonstrated on the one hand; on the other hand, the accuracy as well as various evaluation methods are discussed and analysed.

scholarly journals Interpretable Retrosynthesis Prediction in Two Steps

2020 ◽  
Author(s):  
Chaochao Yan ◽  
Qianggang Ding ◽  
Shuangjia Zheng ◽  
Jinyu Yang ◽  
Yang Yu ◽  
...  
Keyword(s):  
State Of The Art ◽  
Building Blocks ◽  
Computer Aided ◽  
Free Model ◽  
Benchmark Datasets ◽  
Previous State ◽  
Target Molecules ◽  
Template Free ◽  
Synthetic Routes ◽  
High Diversity

Retrosynthesis is the process of recursively decomposing target molecules into available building blocks. Computer-aided retrosynthesis can potentially assist chemists in designing synthetic routes; however, at present, it is cumbersome and lacks interpretability behind their predictions. In this study, we devise a novel template-free model for retrosynthetic expansion by automating the procedure that chemistsusedtodo. Our method plans synthesis in two steps, by first identifying the potential disconnection bonds of the molecule graph with a graph neural network and thereafter generating synthons according to the identified disconnection bonds of the target molecule graph, and then predicting the associated reactants SMILES based on the obtained synthons with a reactant prediction model. While outperforming previous state-of-the-art baselines by a significant margin on the benchmark datasets, our model also provides predictions with high diversity and chemically reasonable interpretation.

scholarly journals Interpretable Retrosynthesis Prediction in Two Steps

2020 ◽  
Author(s):  
Chaochao Yan ◽  
Qianggang Ding ◽  
Peilin Zhao ◽  
Shuangjia Zheng ◽  
Jinyu Yang ◽  
...  
Keyword(s):  
State Of The Art ◽  
Building Blocks ◽  
Computer Aided ◽  
Free Model ◽  
Benchmark Datasets ◽  
Previous State ◽  
Target Molecules ◽  
Template Free ◽  
Synthetic Routes ◽  
High Diversity

Retrosynthesis is the process of recursively decomposing target molecules into available building blocks. Computer-aided retrosynthesis can potentially assist chemists in designing synthetic routes; however, at present, it is cumbersome and lacks interpretability behind their predictions. In this study, we devise a novel template-free model for retrosynthetic expansion by automating the procedure that chemistsusedtodo. Our method plans synthesis in two steps, by first identifying the potential disconnection bonds of the molecule graph with a graph neural network and thereafter generating synthons according to the identified disconnection bonds of the target molecule graph, and then predicting the associated reactants SMILES based on the obtained synthons with a reactant prediction model. While outperforming previous state-of-the-art baselines by a significant margin on the benchmark datasets, our model also provides predictions with high diversity and chemically reasonable interpretation.

scholarly journals Aerobically Stable and Substitutionally Labile α-Diimine Rhenium Dicarbonyl Complexes

2021 ◽  
Author(s):  
Kevin Schindler ◽  
Aurélien Crochet ◽  
Fabio Zobi
Keyword(s):  
Solid State ◽  
High Yield ◽  
Distorted Octahedral Geometry ◽  
The Core ◽  
Axial Ligands ◽  
Distorted Octahedral ◽  
Synthetic Routes ◽  
Monodentate Ligands ◽  
Electron Reduction ◽  
The One

New synthetic routes to aerobically stable and substitutionally labile a-diimine rhenium(I) dicarbonyl complexes are described. The molecules are prepared in high yield from the <i>cis-cis-trans-</i>[Re(CO)<sub>2</sub>(<i><sup>t</sup></i>Bu<sub>2</sub>bpy)Br<sub>2</sub>]<sup>-</sup> anion (<b>2</b>, where<b> </b><i><sup>t</sup></i>Bu<sub>2</sub>bpy is 4,4'-di-<i>tert</i>-butyl-2,2'-bipyridine), which can be isolated from the one electron reduction of the corresponding 17-electron complex (<b>1</b>). Compound <b>2 </b>is stable in the solid state, but in solution it is oxidized by molecular oxygen back to <b>1</b>. Replacement of a single bromide of <b>2</b> by s-donor monodentate ligands (Ls) yields stable neutral 18-electron <i>cis-cis-trans-</i>[Re(CO)<sub>2</sub>(<i><sup>t</sup></i>Bu<sub>2</sub>bpy)Br(L)] species. In coordinating solvents like methanol the halide is replaced giving the corresponding solvated cations. [Re(CO)<sub>2</sub>(<i><sup>t</sup></i>Bu<sub>2</sub>bpy)Br(L)] species can be further reacted with Ls to prepare stable <i>cis-cis-trans-</i>[Re(CO)<sub>2</sub>(<i><sup>t</sup></i>Bu<sub>2</sub>bpy)(L)<sub>2</sub>]<sup>+</sup> complexes in good yield. Ligand substitution of Re(I) complexes proceeds via pentacoordinate intermediates capable of Berry pseudorotation. In addition to the <i>cis-cis-trans-</i>complexes, <i>cis-cis-cis-</i> (all cis) enantiomers are also formed. In particular, <i>cis-cis-trans-</i>[Re(CO)<sub>2</sub>(<i><sup>t</sup></i>Bu<sub>2</sub>bpy)(L)<sub>2</sub>]<sup>+</sup> complexes establish an equilibrium with all cis enantiomers in solution. The solid state crystal structure of nearly all molecules presented could be elucidated. The molecules adopt a slightly distorted octahedral geometry. In comparison to similar <i>fac</i>-[Re(CO)<sub>3</sub>]<sup>+</sup>complexes, Re(I) diacarbonyl species are characterized by a bend (ca. 7°) of the axial ligands towards the a-diimine unit. [Re(CO)<sub>2</sub>(<i><sup>t</sup></i>Bu<sub>2</sub>bpy)Br<sub>2</sub>]<sup>-</sup> and [Re(CO)<sub>2</sub>(<i><sup>t</sup></i>Bu<sub>2</sub>bpy)Br(L)] complexes may be considered as synthons for the preparation of a variety of new stable diamagnetic dicarbonyl rhenium <i>cis-</i>[Re(CO)<sub>2</sub>]<sup>+</sup> complexes, offering a convenient entry in the chemistry of the core.

scholarly journals A Halomanganates(II) with P,P’-Diprotonated Bis(2-Diphenylphosphinophenyl)ether: Wavelength-Excitation Dependence of the Quantum Yield and Role of the Non-Covalent Interactions

2021 ◽  
Vol 22 (13) ◽  
pp. 6873
Author(s):  
Alexey S. Berezin
Keyword(s):  
Quantum Yield ◽  
Excitation Energy ◽  
The Other ◽  
Green Luminescence ◽  
Radiative Relaxation ◽  
Bright Green ◽  
Non Covalent Interactions ◽  
The One ◽  
Covalent Interactions

A [H2DPEphos][MnX4] [X = Br, Cl] tetrahalomanganates(II) with P,P’-diprotonated bis[2-(diphenylphosphino)phenyl]ether cation has been designed and investigated in photophysics and EPR terms. The complexes exhibit a green luminescence resulted from the Mn(II) d–d transitions (4T1→6A1) with the wavelength-excitation dependence of the quantum yield. The solid [H2DPEphos][MnBr4] complex exhibits a bright green phosphorescence (λmax = 515 nm) with the high luminescence quantum yield depending on the excitation energy whereas the solid [H2DPEphos][MnCl4] complex exhibits a very weak phosphorescence (λmax = 523 nm). The unexpected shorter luminescence lifetime for the [H2DPEphos][MnCl4] than for the [H2DPEphos][MnBr4] at 300 K can be a result of the higher non-radiative relaxation contribution. On the one hand, the non-covalent PH…X(Mn) interactions quench the manganese(II) luminescence. On the other hand, the PH…X(Mn) interactions are a pathway of the excitation transfer from [H2DPEphos]2+ to [MnX4]2−.

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