Mirror-image magnetic circularly polarized luminescence (MCPL) from optically inactive EuIII and TbIIItris(β-diketonate)

2020 ◽  
Vol 49 (28) ◽  
pp. 9588-9594 ◽  
Author(s):  
Hiroki Yoshikawa ◽  
Gaku Nakajima ◽  
Yuki Mimura ◽  
Takahiro Kimoto ◽  
Yoshiro Kondo ◽  
...  

Five optically inactive EuIII and TbIII complexes with achiral organic ligands revealed north-up/south-up magnet geometry dependent mirror-image magnetic circularly polarized luminescence in solutions, in films and bulk powder under 1.6 Tesla.

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2606 ◽  
Author(s):  
Michiya Fujiki ◽  
Julian Koe ◽  
Takashi Mori ◽  
Yoshihiro Kimura

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.


2017 ◽  
Vol 53 (7) ◽  
pp. 1269-1272 ◽  
Author(s):  
Jatish Kumar ◽  
Tsuyoshi Kawai ◽  
Takuya Nakashima

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.


2020 ◽  
Author(s):  
Haruka Kano ◽  
Hironobu Hayashi ◽  
Kyohei Matsuo ◽  
Michiya Fujiki ◽  
Hiroko Yamada ◽  
...  

Abstract Optically active fullerenes (C76, C82, C84), including C60 and C70 derivatives carrying organic substituents, possess various potent applications because of unique spectroscopic, catalytic, and chiral recognition properties. However, their inherent photoexcited chirality has not yet been elucidated because of a very poor quantum yield of fluorescence (FL). With this background in mind, we synthesized new chiral C70 derivatives, X70A, solely by reacting bis-borylated xanthene with C70 in a one-step double addition reaction with 20% yield, followed by a successful optical resolution using a recyclable chiral-HPLC technique. The isolated X70A enantiomers were confirmed by their mirror-image circular dichroism spectra in the range of 300 nm and 700 nm. The enantiomeric pair of X70A in toluene revealed clearly mirror-image circularly polarized luminescence (CPL) spectra with a high |glum| value of 7.0 × 10–3 at 690 nm associated with FL lifetime of 0.99 ns. The deep-red CPL of X70A should provide new photofunctionality as chiral nanocarbon materials.


2015 ◽  
Vol 51 (43) ◽  
pp. 9014-9017 ◽  
Author(s):  
Shuwei Zhang ◽  
Yuxiang Wang ◽  
Fandian Meng ◽  
Chunhui Dai ◽  
Yixiang Cheng ◽  
...  

Two AIE-active chiral BINOL-based O-BODIPY enantiomers (R/S-5) were synthesized and showed mirror-image red-colour CPL induced via intramolecular energy transfer.


2016 ◽  
Vol 45 (48) ◽  
pp. 19234-19237 ◽  
Author(s):  
Tian-Yi Li ◽  
You-Xuan Zheng ◽  
Yong-Hui Zhou

Two iridium complexes with a chiral metal center and chiral carbons were separated as four isomers termed Λ/Δ-(dfppy)2Ir(chty-R) and Λ/Δ-(dfppy)2Ir(chty-S). Each enantiomeric couple shows mirror-image crystal structures, and ECD/CPL spectra highlight both the chiral sources.


Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 363
Author(s):  
Michiya Fujiki ◽  
Julian R. Koe ◽  
Seiko Amazumi

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.


1977 ◽  
Vol 77 (6) ◽  
pp. 773-792 ◽  
Author(s):  
Frederick S. Richardson ◽  
James P. Riehl

2021 ◽  
Author(s):  
Zhaoming Zhang ◽  
Takunori Harada ◽  
Adriana Pietropaolo ◽  
Yuting Wang ◽  
Yue Wang ◽  
...  

Preferred-handed propeller conformation was induced by circularly polarized light irradiation to three amorphous molecules with trigonal symmetry, and the molecules with induced chirality efficiently exhibited blue circularly polarized luminescence. In...


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