Asymmetric hydroamination with far fewer chiral species than copper centers achieved by tuning the structure of supramolecular helical catalysts

2022 ◽  
Author(s):  
Paméla Aoun ◽  
Ahmad Hammoud ◽  
Mayte A. Martínez-Aguirre ◽  
Laurent Bouteiller ◽  
Matthieu Raynal
Keyword(s):  
Chiral Species

The incorporation of a few chiral monomers (the “sergeants”) in a backbone composed of a majority of achiral monomers (the “soldiers”) is a well-established strategy to control the handedness of...

Photophysical Characterisation, Metal Ion Binding and Enantiomeric Recognition of Chiral Ligands Containing Phenazine Fluorophore

2004 ◽  
Vol 69 (4) ◽  
pp. 885-896 ◽  
Author(s):  
Luisa Stella Dolci ◽  
Péter Huszthy ◽  
Erika Samu ◽  
Marco Montalti ◽  
Luca Prodi ◽  
...  
Keyword(s):  
Metal Ion ◽  
Photophysical Properties ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Ammonium Ions ◽  
Enantiomerically Pure ◽  
Binding Process ◽  
High Affinity ◽  
Enantiomeric Recognition ◽  
Chiral Species

Enantiomerically pure dimethyl- and diisobutyl-substituted phenazino-18-crown-6 ligands bind metal and ammonium ions and also primary aralkylammonium perchlorates in acetonitrile with high affinity, causing pronounced changes in their luminescence properties. In addition, they show enantioselectivity towards chiral primary aralkylammonium perchlorates. The possibility to monitor the binding process by photoluminescence spectroscopy can gain ground for the design of very efficient enantioselective chemosensors for chiral species. The observed changes in the photophysical properties are also an important tool for understanding the interactions present in the adduct.

scholarly journals Electronic Currents and Anapolar Response Induced in Molecules by Monochromatic Light

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 1022-1036
Author(s):  
Francesco Ferdinando Summa ◽  
Paolo Lazzeretti
Keyword(s):  
Numerical Integration ◽  
Electric Dipole ◽  
Monochromatic Light ◽  
Electric Quadrupole ◽  
Computational Techniques ◽  
Optical Fields ◽  
Electronic Current ◽  
Chiral Species ◽  
Preliminary Computation ◽  
Preliminary Application

It is shown that the electric dipole- and electric quadrupole–anapole polarizabilities, denoted respectively by fαβ′ and gα,βγ′, and the anapole magnetizability aαβ, are intrinsic properties of the electron cloud of molecules responding to optical fields. fαβ′ is a nonvanishing property of chiral and achiral compounds, whereas aαβ is suitable for enantiomer discrimination of chiral species. They can conveniently be evaluated by numerical integration, employing a formulation complementary to that provided by perturbation theory and relying on the preliminary computation of electronic current density tensors all over the molecular domain. The origin dependence of the dynamic anapolar response is rationalized via related computational techniques employing numerical integration, as well as definitions of molecular property tensors, for example, electric dipole and electric quadrupole polarizabilties and magnetizability. A preliminary application of the theory is reported for the Ra enantiomer of the hydrogen peroxide molecule, evaluating tensor components of electric dipole-anapole polarizability and anapole magnetizability as functions of the dihedral angle ϕ≡∠ H-O-O-H in the range 0∘≤ϕ≤180∘.

scholarly journals A Potentially Limitless Chiral Pool via Conglomerate Crystallisation: Unidentified Spontaneous Resolution in the CSD.

2022 ◽  
Author(s):  
Mark Walsh ◽  
James Barclay ◽  
Callum Begg ◽  
Jinyi Xuan ◽  
Matthew Kitching
Keyword(s):  
Organic Molecules ◽  
Biological Systems ◽  
Spontaneous Resolution ◽  
Cambridge Structural Database ◽  
Crystalline Materials ◽  
Molecular Chirality ◽  
Manual Search ◽  
Structural Database ◽  
Synthetic Routes ◽  
Chiral Species

Conglomerate crystallisation is the behaviour responsible for spontaneous resolution and the discovery of molecular chirality by Pasteur. The phenomenon of conglomerate crystallisation of chiral organic molecules has been left largely undocumented and offers synthetic chemists a potential new chiral pool not reliant on biological systems to supply stereochemical information. While other crystallographic behaviours can be interrogated by automated searching, conglomerate crystallisations are not identified within the Cambridge Structural Database (CSD) and are therefore not accessible by conventional means. By conducting a manual search of the CSD, a list of over 1,700 chiral species capable of conglomerate crystallisation was curated by inspection of the synthetic routes described in each publication. The majority of these are produced by synthetic chemists who seldom note and rarely exploit the implications this phenomenon can have on the enantioenrichment of their crystalline materials. We propose that this list represents a limitless chiral pool which will continually grow in size as more conglomerate crystals are synthesised and recorded.

scholarly journals Orientation of Chiral Schiff Base Metal Complexes Involving Azo-Groups for Induced CD on Gold Nanoparticles by Polarized UV Light Irradiation

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1094
Author(s):  
Nobumitsu Sunaga ◽  
Tomoyuki Haraguchi ◽  
Takashiro Akitsu
Keyword(s):  
Gold Nanoparticles ◽  
Schiff Base ◽  
Uv Light ◽  
Light Irradiation ◽  
Spatial Features ◽  
Dipole Interactions ◽  
Uv Light Irradiation ◽  
Linearly Polarized ◽  
Chiral Species ◽  
Schiff Base Metal Complexes

In this study, we report the synthesis, characterization, and chiroptical properties of azo-group-containing chiral salen type Schiff base Ni(II), Cu(II), and Zn(II) complexes absorbed on gold nanoparticles (AuNPs) of 10 nm diameters. Induced circular dichroism (CD) around the plasmon region from the chiral species weakly adsorbed on the surface of AuNP were observed when there were appropriate dipole–dipole interactions at the initial states. Spectral changes were also observed by not only cis-trans photoisomerization of azo-groups but also changes of orientation due to Weigert effect of azo-dyes after linearly polarized UV light irradiation. Spatial features were discussed based on dipole-dipole interactions mainly within an exciton framework.

scholarly journals Enantioselective fragmentation of an achiral molecule in a strong laser field

2019 ◽  
Vol 5 (3) ◽  
pp. eaau7923 ◽  
Author(s):  
K. Fehre ◽  
S. Eckart ◽  
M. Kunitski ◽  
M. Pitzer ◽  
S. Zeller ◽  
...  
Keyword(s):  
Single Molecule ◽  
Light Propagation ◽  
Polarized Light ◽  
Strong Laser Field ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Single Molecule Level ◽  
The Difference ◽  
Living Nature ◽  
Chiral Species

Chirality is omnipresent in living nature. On the single molecule level, the response of a chiral species to a chiral probe depends on their respective handedness. A prominent example is the difference in the interaction of a chiral molecule with left or right circularly polarized light. In the present study, we show by Coulomb explosion imaging that circularly polarized light can also induce a chiral fragmentation of a planar and thus achiral molecule. The observed enantiomer strongly depends on the orientation of the molecule with respect to the light propagation direction and the helicity of the ionizing light. This finding might trigger new approaches to improve laser-driven enantioselective chemical synthesis.

Phosphorus Metal Double Bond Complexes: Functional and Chiral Species Cp(L)(L′)M=PR2(M = Mo, W) and the Iron Derivative Cp (CO) Fe = PMes2

1990 ◽  
Vol 49-50 (1-4) ◽  
pp. 441-444 ◽  
Author(s):  
Wolfgang Malisch ◽  
Martin Märkl ◽  
Sandro Amann ◽  
Ulrich Hirth ◽  
Martin Schmeußer
Keyword(s):  
Double Bond ◽  
Chiral Species

Electrochemical Recognition of Chiral Species Using Quaternary Ammonium Binaphthyl Salts

2002 ◽  
Vol 74 (16) ◽  
pp. 4002-4006 ◽  
Author(s):  
Andrew P. Abbott ◽  
George W. Barker ◽  
David L. Davies ◽  
Gerald A. Griffiths ◽  
Andrew J. Walter ◽  
...  
Keyword(s):  
Quaternary Ammonium ◽  
Electrochemical Recognition ◽  
Chiral Species
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