scholarly journals Lanthanide ion-doped silica nanohelices: helical inorganic network acts as chiral source for metal ions

2021 ◽  
Author(s):  
Tomoyuki Harada ◽  
Hiroshi Yanagita ◽  
Naoya Ryu ◽  
Yutaka Okazaki ◽  
Yutaka Kuwahara ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Metal Ions ◽  
Lanthanide Ions ◽  
Lanthanide Ion ◽  
Chiroptical Properties ◽  
Circularly Polarized ◽  
Circular Dichroïsm ◽  
Inorganic Network

We demonstrate that lanthanide ions doped in nanometrical silica helices with chirally arranged siloxane network without any organic mediates show induced chiroptical properties such as circular dichroism and circularly polarized...

scholarly journals Questions of Mirror Symmetry at the Photoexcited and Ground States of Non-Rigid Luminophores Raised by Circularly Polarized Luminescence and Circular Dichroism Spectroscopy: Part 1. Oligofluorenes, Oligophenylenes, Binaphthyls and Fused Aromatics

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2606 ◽  
Author(s):  
Michiya Fujiki ◽  
Julian Koe ◽  
Takashi Mori ◽  
Yoshihiro Kimura
Keyword(s):  
Circular Dichroism ◽  
Mirror Symmetry ◽  
Neutral Current ◽  
Visible Region ◽  
Cd Spectroscopy ◽  
Mirror Image ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Circular Dichroïsm

We report experimental tests of whether non-rigid, π-conjugated luminophores in the photoexcited (S1) and ground (S0) states dissolved in achiral liquids are mirror symmetrical by means of circularly polarized luminescence (CPL) and circular dichroism (CD) spectroscopy. Herein, we chose ten oligofluorenes, eleven linear/cyclic oligo-p-arylenes, three binaphthyls and five fused aromatics, substituted with alkyl, alkoxy, phenyl and phenylethynyl groups and also with no substituents. Without exception, all these non-rigid luminophores showed negative-sign CPL signals in the UV-visible region, suggesting temporal generation of energetically non-equivalent non-mirror image structures as far-from equilibrium open-flow systems at the S1 state. For comparison, unsubstituted naphthalene, anthracene, tetracene and pyrene, which are achiral, rigid, planar luminophores, did not obviously show CPL/CD signals. However, camphor, which is a rigid chiral luminophore, showed mirror-image CPL/CD signals. The dissymmetry ratio of CPL (glum) for the oligofluorenes increased discontinuously, ranging from ≈ −(0.2 to 2.0) × 10−3, when the viscosity of the liquids increased. When the fluorene ring number increased, the glum value extrapolated at [η] = 0 reached −0.8 × 10−3 at 420 nm, leading to (–)-CPL signals predicted in the vacuum state. Our comprehensive CPL and CD study should provide a possible answer to the molecular parity violation hypothesis arising due to the weak neutral current mediated by the Z0-boson.

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.

The near infra red (NIR) chiroptical properties of nickel dithiolene complexes

2015 ◽  
Vol 39 (1) ◽  
pp. 122-129 ◽  
Author(s):  
Yann Le Gal ◽  
Antoine Vacher ◽  
Vincent Dorcet ◽  
Marc Fourmigué ◽  
Jeanne Crassous ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Thin Layer ◽  
Chiroptical Properties ◽  
Infra Red ◽  
Redox Switching ◽  
Circular Dichroïsm

Circular dichroism (CD) thin layer spectro-electrochemical experiments reveal a redox switching of CD-active bands in the NIR region.

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