scholarly journals Role of Exchange Interactions in the Magnetic Response and Intermolecular Recognition of Chiral Molecules

Nano Letters ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 7077-7086 ◽  
Author(s):  
Arezoo Dianat ◽  
Rafael Gutierrez ◽  
Hen Alpern ◽  
Vladimiro Mujica ◽  
Amir Ziv ◽  
...  
Keyword(s):  
Exchange Interactions ◽  
Magnetic Response ◽  
Chiral Molecules ◽  
Intermolecular Recognition

scholarly journals Chiral Magneto-Electrochemistry

2018 ◽  
Vol 4 (3) ◽  
pp. 36 ◽  
Author(s):  
Anup Kumar ◽  
Prakash Mondal ◽  
Claudio Fontanesi
Keyword(s):  
Magnetic Field ◽  
Experimental Studies ◽  
Spin Accumulation ◽  
Chiral Molecules ◽  
Electrochemical System ◽  
Ferromagnetic Electrodes ◽  
Spin Polarized ◽  
The Magnetic Field ◽  
Research Domain

Magneto-electrochemistry (MEC) is a unique paradigm in science, where electrochemical experiments are carried out as a function of an applied magnetic field, creating a new horizon of potential scientific interest and technological applications. Over time, detailed understanding of this research domain was developed to identify and rationalize the possible effects exerted by a magnetic field on the various microscopic processes occurring in an electrochemical system. Notably, until a few years ago, the role of spin was not taken into account in the field of magneto-electrochemistry. Remarkably, recent experimental studies reveal that electron transmission through chiral molecules is spin selective and this effect has been referred to as the chiral-induced spin selectivity (CISS) effect. Spin-dependent electrochemistry originates from the implementation of the CISS effect in electrochemistry, where the magnetic field is used to obtain spin-polarized currents (using ferromagnetic electrodes) or, conversely, a magnetic field is obtained as the result of spin accumulation.

scholarly journals A hidden catalysis: metal-, and organocatalyst-free one-pot assembly of chiral aza-tricyclic molecules containing six contiguous stereocenters

2020 ◽  
Author(s):  
Dung Do
Keyword(s):  
Chemical Space ◽  
Structural Diversity ◽  
Therapeutic Agents ◽  
Chiral Molecules ◽  
One Pot ◽  
Complex Molecules ◽  
Chiral Complex ◽  
Enamine Catalysis ◽  
Daunting Challenge

<p></p><p>Chiral molecules with their defined 3-D structures are of paramount importance for the study of chemical biology and drug discovery. Having rich structural diversity and unique stereoisomerism, chiral molecules offer a large chemical space that can be explored for the design of new therapeutic agents.<sup>1</sup> In practice, chiral architectures are usually prepared from organometallic and organocatalytic processes where a transition metal or an organocatalyst is tailor-made for a desired reaction. As a result, developing a method that enables rapid assembly of chiral complex molecules under a metal- and organocatalyst-free condition represents a daunting challenge. Here we developed a straightforward one-pot procedure to create a chiral 3-D structure from 2-D structures and an amino acid without any chiral catalyst. The center of this research is the design of a <a>special chiral spiroimidazolidinone cyclohexadienone intermediate</a>, a merger of a chiral reactive substrate with multiple nucleophillic/electrophillic sites and a transient organocatalyst. <a>This unique substrate-catalyst (“sub-catalyst”) dual role of the intermediate was displayed in its aza-Michael/Michael cascade reaction with an </a>α,β-unsaturated aldehyde under an iminium/enamine catalysis. <a>The enhanced co-ordinational proximity of the chiral substrate and catalyst</a> in the transition state resulted in a substantial steric discrimination and an excellent overall diastereoselectivity. Aza-tricylic molecules with six contiguous stereocenters were assembled from <i>N</i>-alkylated aminophenols, α,β-unsaturated aldehydes and chiral α-amino acids under a hidden “sub-catalysis” where the strategically produced “sub-catalyst” does not present in initial components of the reaction. The success of this methodology will pave the way for many efficient preparations of chiral complex molecules.</p><br><p></p>

scholarly journals Электронные состояния атомов в монослоях, адсорбированных на карбиде кремния

2022 ◽  
Vol 56 (2) ◽  
pp. 221
Author(s):  
С.Ю. Давыдов ◽  
О.В. Посредник
Keyword(s):  
Charge Transfer ◽  
Experimental Verification ◽  
Exchange Interactions

Estimates of charge transfer between adsorbate monolayer and SiC substrate based on account of the dipole-dipole repulsion and exchange interactions are presented. It is demonstrated that all the interaction channels lead to adlayer depolarization. Role of the band and local adatoms states are analyzed. Methods of experimental verification of the obtained results are proposed.

Magnetic response of polycrystalline YBaCo 4 O 7+δ synthesized through the physical and chemical route: The role of phase inhomogeneities

2014 ◽  
Vol 360 ◽  
pp. 59-66
Author(s):  
E. Vallejos ◽  
V. Galeano ◽  
L. Gómez ◽  
J.L. Izquierdo ◽  
J.F. Montoya ◽  
...  
Keyword(s):  
Magnetic Response ◽  
Chemical Route ◽  
Physical And Chemical

Colloidal magnetic nanocrystal clusters: variable length-scale interaction mechanisms, synergetic functionalities and technological advantages

2015 ◽  
Vol 4 (6) ◽  
Author(s):  
Athanasia Kostopoulou ◽  
Alexandros Lappas
Keyword(s):  
Magnetic Particles ◽  
Critical Role ◽  
Exchange Interactions ◽  
Magnetic Behavior ◽  
Building Blocks ◽  
Spatial Arrangement ◽  
Magnetic Characteristics ◽  
Surface Functionality ◽  
Magnetic Nanocrystal

AbstractMagnetic particles of optimized nanoscale dimensions can be utilized as building blocks to generate colloidal nanocrystal assemblies with controlled size, well-defined morphology, and tailored properties. Recent advances in the state-of-the-art surfactant-assisted approaches for the directed aggregation of inorganic nanocrystals into cluster-like entities are discussed, and the synthesis parameters that determine their geometrical arrangement are highlighted. This review pays attention to the enhanced physical properties of iron oxide nanoclusters, while it also points to their emerging collective magnetic response. The current progress in experiment and theory for evaluating the strength and the role of intra- and inter-cluster interactions is analyzed in view of the spatial arrangement of the component nanocrystals. Numerous approaches have been proposed for the critical role of dipole-dipole and exchange interactions in establishing the nature of the nanoclusters’ cooperative magnetic behavior (be it ferromagnetic or spin-glass like). Finally, we point out why the purposeful engineering of the nanoclusters’ magnetic characteristics, including their surface functionality, may facilitate their use in diverse technological sectors ranging from nanomedicine and photonics to catalysis.

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