scholarly journals Iridium(iii) phosphorescent complexes with dual stereogenic centers: single crystal, electronic circular dichroism evidence and circularly polarized luminescence properties

2016 ◽  
Vol 45 (48) ◽  
pp. 19234-19237 ◽  
Author(s):  
Tian-Yi Li ◽  
You-Xuan Zheng ◽  
Yong-Hui Zhou
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Mirror Image ◽  
Luminescence Properties ◽  
Iridium Complexes ◽  
Electronic Circular Dichroism ◽  
Circularly Polarized ◽  
Stereogenic Centers ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence

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.

scholarly journals Synthesis and circularly polarized luminescence properties of BINOL-derived bisbenzofuro[2,3-b:3’,2’-e]pyridines (BBZFPys)

2020 ◽  
Vol 16 ◽  
pp. 325-336 ◽  
Author(s):  
Ryo Takishima ◽  
Yuji Nishii ◽  
Tomoaki Hinoue ◽  
Yoshitane Imai ◽  
Masahiro Miura
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Crystal Structures ◽  
Optically Active ◽  
Ring Closure ◽  
Circularly Polarized ◽  
X Ray ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Palladium Catalyzed

A series of optically active bisbenzofuro[2,3-b:3’,2’-e]pyridine (BBZFPy) derivatives was synthesized starting with the readily available (S)- and (R)-1,1’-bi-2-naphthols through a palladium-catalyzed multiple intramolecular C–H/C–H coupling as the key ring-closure step. The effect of terminal tert-butyl substituents on the BBZFPy skeleton was systematically investigated to uncover a unique aggregation-induced enhancement of CPL characteristics in the solid state. The crystal structures of the coupling products were also evaluated by single crystal X-ray analysis and the well-ordered intermolecular stacking arrangements appeared to be responsible for the enhanced CPL.

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.

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 ◽  
...  
Keyword(s):  
Mirror Image ◽  
Organic Ligands ◽  
Circularly Polarized ◽  
Bulk Powder ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence

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.

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.

Synthesis of a helical π-conjugated polymer with a dynamic hydrogen-bonded network in the helical cavity and its circularly polarized luminescence properties

2018 ◽  
Vol 9 (13) ◽  
pp. 1541-1546 ◽  
Author(s):  
Tomoyuki Ikai ◽  
Seiya Awata ◽  
Ken-ichi Shinohara
Keyword(s):  
Conjugated Polymer ◽  
Luminescence Properties ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Hydrogen Bonded

We have succeeded in developing a circularly polarized luminescent π-conjugated polymer with a dynamic hydrogen-bonded network in the helical cavity.

scholarly journals Deep-red circularly polarized luminescent C70 derivatives

2020 ◽  
Author(s):  
Haruka Kano ◽  
Hironobu Hayashi ◽  
Kyohei Matsuo ◽  
Michiya Fujiki ◽  
Hiroko Yamada ◽  
...  
Keyword(s):  
Chiral Recognition ◽  
Addition Reaction ◽  
Optical Resolution ◽  
Mirror Image ◽  
Chiral Hplc ◽  
Circularly Polarized ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Nanocarbon Materials ◽  
One Step

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.

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