Circularly polarized luminescence in chiral silver nanoclusters

2017 ◽  
Vol 53 (7) ◽  
pp. 1269-1272 ◽  
Author(s):  
Jatish Kumar ◽  
Tsuyoshi Kawai ◽  
Takuya Nakashima
Keyword(s):  
Circular Dichroism ◽  
Mirror Image ◽  
Silver Nanoclusters ◽  
Dihydrolipoic Acid ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
First Time ◽  
Circular Dichroïsm

Sets of mirror image circular dichroism (CD) and circularly polarized luminescence (CPL) spectra are for the first time demonstrated using enantiomeric dihydrolipoic acid (DHLA)-capped silver nanoclusters.

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.

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 2: Perylenes, BODIPYs, Molecular Scintillators, Coumarins, Rhodamine B, and DCM

Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 363
Author(s):  
Michiya Fujiki ◽  
Julian R. Koe ◽  
Seiko Amazumi
Keyword(s):  
Circular Dichroism ◽  
Rhodamine B ◽  
Mirror Symmetry ◽  
Visible Region ◽  
Cd Spectroscopy ◽  
Mirror Image ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Circular Dichroïsm

We investigated whether semi-rigid and non-rigid π-conjugated fluorophores in the photoexcited (S1) and ground (S0) states exhibited mirror symmetry by circularly polarized luminescence (CPL) and circular dichroism (CD) spectroscopy using a range of compounds dissolved in achiral liquids. The fluorophores tested were six perylenes, six scintillators, 11 coumarins, two pyrromethene difluoroborates (BODIPYs), rhodamine B (RhB), and 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM). All the fluorophores showed negative-sign CPL signals in the ultraviolet (UV)–visible region, suggesting energetically non-equivalent and non-mirror image structures in the S1 state. The dissymmetry ratio of the CPL (glum) increased discontinuously from approximately −0.2 × 10−3 to −2.0 × 10−3, as the viscosity of the liquids increased. Among these liquids, C2-symmetrical stilbene 420 showed glum ≈ −0.5 × 10−3 at 408 nm in H2O and D2O, while, in a viscous alkanediol, the signal was amplified to glum ≈ −2.0 × 10−3. Moreover, BODIPYs, RhB, and DCM in the S0 states revealed weak (−)-sign CD signals with dissymmetry ratios (gabs) ≈ −1.4 × 10−5 at λmax/λext. The origin of the (−)-sign CPL and the (−)-sign CD signals may arise from an electroweak charge at the polyatomic level. Our CPL and CD spectral analysis could be a possible answer to the molecular parity violation hypothesis based on a weak neutral current of Z0 boson origin that could connect to the origin of biomolecular handedness.

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.

scholarly journals Ligand Induced Circular Dichroism and Circularly Polarized Luminescence in CdSe Quantum Dots

ACS Nano ◽  
2013 ◽  
Vol 7 (12) ◽  
pp. 11094-11102 ◽  
Author(s):  
Urice Tohgha ◽  
Kirandeep K. Deol ◽  
Ashlin G. Porter ◽  
Samuel G. Bartko ◽  
Jung Kyu Choi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Circular Dichroism ◽  
Cdse Quantum Dots ◽  
Induced Circular Dichroism ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Circular Dichroïsm

The synthesis of chiral triphenylpyrrole derivatives and their aggregation-induced emission enhancement, aggregation-induced circular dichroism and helical self-assembly

RSC Advances ◽  
2016 ◽  
Vol 6 (28) ◽  
pp. 23420-23427 ◽  
Author(s):  
Kaichang Liang ◽  
Lichao Dong ◽  
Na Jin ◽  
Didi Chen ◽  
Xiao Feng ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Self Assembly ◽  
Induced Circular Dichroism ◽  
Circularly Polarized ◽  
Aggregation Induced Emission ◽  
Self Assembling ◽  
Emission Enhancement ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Circular Dichroïsm

AIEE-active chiral triphenylpyrrole derivatives possess aggregation-induced circular dichroism and circularly polarized luminescence features with self-assembling helical nanofibers.

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