scholarly journals Stepwise radial complexation from the outer layer to the inner layer of a dendritic ligand: a phenylazomethine dendrimer with an inverted coordination sequence

2014 ◽  
Vol 50 (81) ◽  
pp. 12177-12180 ◽  
Author(s):  
Ken Albrecht ◽  
Noriko Sakane ◽  
Kimihisa Yamamoto
Keyword(s):  
Outer Layer ◽  
Lewis Acids ◽  
Coordination Sequence ◽  
Dendritic Ligand

A meta-substituted phenylazomethine dendrimer was discovered as a dendritic ligand that sequentially coordinates to Lewis acids from the outer layer to the inner layer in a stepwise radial fashion.

Extraverts Have Larger Social Network Layers

2011 ◽  
Vol 32 (3) ◽  
pp. 161-169 ◽  
Author(s):  
Thomas V. Pollet ◽  
Sam G. B. Roberts ◽  
Robin I. M. Dunbar
Keyword(s):  
Social Network ◽  
Social Relationships ◽  
Outer Layer ◽  
Network Size ◽  
Emotional Intensity ◽  
Emotional Closeness ◽  
Network Layer ◽  
Network Layers ◽  
Social Network Size

Previous studies showed that extraversion influences social network size. However, it is unclear how extraversion affects the size of different layers of the network, and how extraversion relates to the emotional intensity of social relationships. We examined the relationships between extraversion, network size, and emotional closeness for 117 individuals. The results demonstrated that extraverts had larger networks at every layer (support clique, sympathy group, outer layer). The results were robust and were not attributable to potential confounds such as sex, though they were modest in size (raw correlations between extraversion and size of network layer, .20 < r < .23). However, extraverts were not emotionally closer to individuals in their network, even after controlling for network size. These results highlight the importance of considering not just social network size in relation to personality, but also the quality of relationships with network members.

DESIGN OF FLEXIBLE ELECTRICAL CAPACITANCE TOMOGRAPHY SENSOR

2015 ◽  
Vol 77 (28) ◽  
Author(s):  
MT Masturah ◽  
MHF Rahiman ◽  
Zulkarnay Zakaria ◽  
AR Rahim ◽  
NM Ayob
Keyword(s):  
Outer Layer ◽  
Electrical Capacitance Tomography ◽  
Electrical Capacitance ◽  
Capacitance Tomography ◽  
Fluid Imaging

This paper discussed the design–functionality and application of Flexible Electrical Capacitance Tomography sensor (FlexiECT). The sensors consist of 12 electrodes allocated surrounding the outer layer of the pipeline. The sensor is designed in such that the flexibility features suit the applications in the pipeline of multiple size. This paper also discussed the preliminary result of FlexiECT applications in fluid imaging by identifying the percentage of two mixing fluids.

scholarly journals Theoretical Insight into the Reversal of Chemoselectivity in Diels-Alder Reactions of α,β-Unsaturated Aldehydes and Ketones Catalyzed by Brønsted and Lewis Acids

Organics ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 38-49
Author(s):  
Lakhdar Benhamed ◽  
Sidi Mohamed Mekelleche ◽  
Wafaa Benchouk
Keyword(s):  
Lewis Acids ◽  
Major Product ◽  
Diels Alder ◽  
Unsaturated Ketone ◽  
Unsaturated Aldehydes ◽  
Aldehydes And Ketones ◽  
Theoretical Insight ◽  
Insight Into ◽  
Good Agreement

Experimentally, a reversal of chemoselectivity has been observed in catalyzed Diels–Alder reactions of α,β-unsaturated aldehydes (e.g., (2E)-but-2-enal) and ketones (e.g., 2-hexen-4-one) with cyclopentadiene. Indeed, using the triflimidic Brønsted acid Tf2NH as catalyst, the reaction gave a Diels–Alder adduct derived from α,β-unsaturated ketone as a major product. On the other hand, the use of tris(pentafluorophenyl)borane B(C6F5)3 bulky Lewis acid as catalyst gave mainly the cycloadduct of α,β-unsaturated aldehyde as a major product. Our aim in the present work is to put in evidence the role of the catalyst in the reversal of the chemoselectivity of the catalyzed Diels–Alder reactions of (2E)-but-2-enal and 2-Hexen-4-one with cyclopentadiene. The calculations were performed at the ωB97XD/6-311G(d,p) level of theory and the solvent effects of dichloromethane were taken into account using the PCM solvation model. The obtained results are in good agreement with experimental outcomes.

scholarly journals Understanding How Lewis Acids Dope Organic Semiconductors: A “Complex” Story

2021 ◽  
Author(s):  
Pablo Simon Marques ◽  
Giacomo Londi ◽  
Brett Yurash ◽  
Thuc-Quyen Nguyen ◽  
Stephen Barlow ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Lewis Acids ◽  
Computational Studies

We report on computational studies of the potential of three borane Lewis acids (LAs) (B(C6F5)3 (BCF), BF3, and BBr3) to form stable adducts and/or to generate positive polarons with three...

scholarly journals Bulky Polyfluorinated Terphenyldiphenylboranes. Water Tolerant Lewis Acids

2020 ◽  
Author(s):  
Corina Stoian ◽  
Marian Olaru ◽  
Theodor Cucuiet ◽  
Krisztina Kegyes ◽  
Alexandru Sava ◽  
...  
Keyword(s):  
Lewis Acids

Novel and Efficient Lewis Acids as Catalysts for Single-step Synthesis of Pyrano- and Furoquinolines

2004 ◽  
Vol 33 (11) ◽  
pp. 1526-1527 ◽  
Author(s):  
Biswanath Das ◽  
M. Ravinder Reddy ◽  
V. Saidi Reddy ◽  
R. Ramu
Keyword(s):  
Lewis Acids ◽  
Single Step

scholarly journals Analysis of the possibility and molecular mechanism of carbon dioxide consumption in the Diels-Alder processes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Karolina Kula ◽  
Agnieszka Kącka-Zych ◽  
Agnieszka Łapczuk-Krygier ◽  
Radomir Jasiński
Keyword(s):  
Carbon Dioxide ◽  
Molecular Mechanism ◽  
Lewis Acids ◽  
Chemical Reactivity ◽  
Carbon Dioxide Concentration ◽  
Diels Alder ◽  
Wide Range ◽  
Bet Analysis ◽  
Earth’S Climate ◽  
Step Mechanism

Abstract The large and significant increase in carbon dioxide concentration in the Earth’s atmosphere is a serious problem for humanity. The amount of CO2 is increasing steadily which causes a harmful greenhouse effect that damages the Earth’s climate. Therefore, one of the current trends in modern chemistry and chemical technology are issues related to its utilization. This work includes the analysis of the possibility of chemical consumption of CO2 in Diels-Alder processes under non-catalytic and catalytic conditions after prior activation of the C=O bond. In addition to the obvious benefits associated with CO2 utilization, such processes open up the possibility of universal synthesis of a wide range of internal carboxylates. These studies have been performed in the framework of Molecular Electron Density Theory as a modern view of the chemical reactivity. It has been found, that explored DA reactions catalyzed by Lewis acids with the boron core, proceeds via unique stepwise mechanism with the zwitterionic intermediate. Bonding Evolution Theory (BET) analysis of the molecular mechanism associated with the DA reaction between cyclopentadiene and carbon dioxide indicates that it takes place thorough a two-stage one-step mechanism, which is initialized by formation of C–C single bond. In turn, the DA reaction between cyclopentadiene and carbon dioxide catalysed by BH3 extends in the environment of DCM, indicates that it takes place through a two-step mechanism. First path of catalysed DA reaction is characterized by 10 different phases, while the second by eight topologically different phases.

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