Solvent-Regulated Chiral Exciton Coupling and CPL Sign Inversion of an Amphiphilic Glutamide-Cyanostilbene

2021 ◽  
Author(s):  
Lukang Ji ◽  
Yiran Liu ◽  
Zujian Li ◽  
Guanghui Ouyang ◽  
Minghua Liu
Keyword(s):  
Circular Dichroism ◽  
Solvent Polarity ◽  
Exciton Coupling ◽  
Hydration Effect ◽  
Sign Inversion ◽  
Circular Dichroïsm

The chiral exciton couplings within a Y-shaped amphiphilic glutamide-cyanostilbene (GCS) could be significantly biased by solvent polarity and hydration effect, which led to sign inversion of both circular dichroism and...

Sign inversion of circularly polarized luminescence by geometry manipulation of four naphthalene units introduced into a tartaric acid scaffold

2014 ◽  
Vol 50 (85) ◽  
pp. 12836-12839 ◽  
Author(s):  
Tomoyuki Amako ◽  
Kazuki Nakabayashi ◽  
Tadashi Mori ◽  
Yoshihisa Inoue ◽  
Michiya Fujiki ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Tartaric Acid ◽  
Circularly Polarized ◽  
Sign Inversion ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Circular Dichroïsm

Tethering four 1- vs. 2-naphthyls to the same chiral scaffold derived from tartaric acid led to oppositely signed circularly polarized luminescence and circular dichroism.

Unique ultraviolet-visible and circular dichroism behavior due to exciton coupling in a biscyanine dye

1991 ◽  
Vol 113 (18) ◽  
pp. 7046-7047 ◽  
Author(s):  
Dario Gargiulo ◽  
Fadila Derguini ◽  
Nikolina Berova ◽  
Koji Nakanishi ◽  
Nobuyuki Harada
Keyword(s):  
Circular Dichroism ◽  
Exciton Coupling ◽  
Circular Dichroïsm

Transmission of Point Chirality to Axial Chirality for Strong Circular Dichroism in Triarylmethylium-o,o-dimers

Synlett ◽  
2018 ◽  
Vol 29 (16) ◽  
pp. 2147-2154 ◽  
Author(s):  
Takanori Suzuki ◽  
Yusuke Ishigaki ◽  
Tomohiro Iwai ◽  
Yuki Hayashi ◽  
Aiichiro Nagaki ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Solvent Effects ◽  
Chiral Auxiliaries ◽  
Response Properties ◽  
Axial Chirality ◽  
Exciton Coupling ◽  
Π Stacking ◽  
Circular Dichroïsm

Triarylmethylium-o,o-dimers adopt a twisted geometry so that two diarylmethyliums are stacked in a slipped manner. Thus, chiral auxiliaries on the aryl groups induce a preference in the axial chirality of the central biphenyl unit. Strong circular dichroism is attained through exciton coupling, which can be used for additional spectral output in their electrochromic behavior. Diastereoselectivity based on π–π stacking exhibits unique solvent effects, thus endowing multifunctional response properties.

scholarly journals Vibrational Circular Dichroism: Recent Advances for the Assignment of the Absolute Configuration of Natural Products

2015 ◽  
Vol 10 (10) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Eleuterio Burgueño-Tapia ◽  
Pedro Joseph-Nathan
Keyword(s):  
Natural Products ◽  
Circular Dichroism ◽  
Absolute Configuration ◽  
Aromatic Compounds ◽  
Vibrational Circular Dichroism ◽  
Exciton Coupling ◽  
Coupling Approach ◽  
The Absolute ◽  
Circular Dichroïsm

Vibrational circular dichroism (VCD) emerged during the last decade as a reliable tool for the absolute configuration (AC) determination of organic compounds. The principles, instrumentation, and methodology applied prior to early 2013 were recently reviewed by us. Since VCD is a very dynamic field, the aim of this review is to update VCD advances for the AC assignment of terpenoids, aromatic compounds, alkaloids, and other natural products for the 2013-2014 period, when VCD was applied to the AC assignment of some 70 natural products. In addition, although discovered in 2012, a brief introduction to the VCD exciton coupling approach and its applications in natural products AC assignment is presented.

Circular Dichroism of Nitrate Esters: A Planar Symmetry Rule for the Nitrato Chromophore

1972 ◽  
Vol 50 (11) ◽  
pp. 1719-1728 ◽  
Author(s):  
R. E. Barton ◽  
L. D. Hayward
Keyword(s):  
Circular Dichroism ◽  
Carbon Atom ◽  
Point Group ◽  
Symmetry Plane ◽  
Solvent Polarity ◽  
Molecular Geometry ◽  
Absorption Bands ◽  
Nitrate Esters ◽  
Planar Symmetry ◽  
Circular Dichroïsm

Conformational analysis of nitrate esters based on X-ray and spectroscopic data showed the nitrato group to be coplanar with the α carbon atom and, in the preferred rotamer, the nitro moiety to be antiperiplanar to the β carbon atom. Three optically active absorption bands not apparent in the isotropic electronic spectra were resolved in the circular dichroism spectra. Band I (270 nm) reflected nitrato group libration changing sign and magnitude with changes in temperature and solvent polarity. Differences in rotatory strength of band III (210 nm) for cis- and trans-dinitrates indicated transition moment coupling. A planar symmetry rule for chromophores in the Cs point group correlated the molecular geometry and sign of band II for 42 nitrate esters: when the lowest-energy rotamer of the nitrate ester is viewed down the O—C bond with the nitro group uppermost rotatory contributions to band II (230 nm) are positive for perturbing atoms to the right and negative for those to the left of the nitrato symmetry plane.

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