A theory of circular dichroism

1969 ◽  
Vol 47 (4) ◽  
pp. 577-579 ◽  
Author(s):  
V. Lawetz ◽  
D. A. Hutchinson
Keyword(s):  
Circular Dichroism ◽  
Radiation Field ◽  
Cross Sections ◽  
Classical Result ◽  
Absorption Coefficients ◽  
Circularly Polarized ◽  
The Difference ◽  
Scattering Cross Sections ◽  
Polarized Photons ◽  
Circular Dichroïsm

An expression for circular dichroism is derived by a method in which the radiation field, in addition to the molecules, is quantized. From the total scattering cross sections for right and for left circularly polarized photons, the respective absorption coefficients are determined. A formula for the circular dichroism is obtained from the difference between the absorption coefficients. The present result is in agreement with the semi-classical result of Condon, Altar, and Eyring.

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.

Correction method for the asymmetry of the tangential beam in Couette (or Searle) geometry used in rheo-small-angle neutron scattering

2004 ◽  
Vol 37 (3) ◽  
pp. 438-444 ◽  
Author(s):  
Florian Nettesheim ◽  
Ulf Olsson ◽  
Peter Lindner ◽  
Walter Richtering
Keyword(s):  
Neutron Scattering ◽  
Cross Sections ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Correction Method ◽  
Shear Cell ◽  
The Asymmetry ◽  
The Difference ◽  
Scattering Cross Sections ◽  
Final Expression

A method of correcting the asymmetry in the scattering of the tangential beam configuration in a rheo-small-angle neutron scattering experiment is proposed. The asymmetry of the scattering in the tangential beam configuration can be attributed to the difference in pathlength for neutrons that are scattered toward compared with those which are scattered away from the axis of rotation of the shear cell. The pathlength problem is solved and a final expression for the two-dimensional scattering intensity is given. The results from these calculations are compared with experimental data, which offer a different option to correct this asymmetry, namely by just measuring the scattering of H2O/D2O mixtures with absolute scattering cross sections identical to those of the respective samples. However, the situation for anisotropic media is more complex and the correction procedure described here is less effective.

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.

Magnetic Structure of Multilayers from Soft-X-Ray Magnetic Circular Dichroism

1994 ◽  
Vol 375 ◽  
Author(s):  
C. T. Chen ◽  
Y. U. Idzerda ◽  
C.-C. Kao ◽  
L. H. Tjeng ◽  
H.-J. Lin ◽  
...  
Keyword(s):  
Thin Films ◽  
Circular Dichroism ◽  
Magnetic Circular Dichroism ◽  
Magnetic Thin Films ◽  
X Rays ◽  
X Ray ◽  
Specific Manner ◽  
Left And Right ◽  
The Difference ◽  
Circular Dichroïsm

AbstractSoft-x-ray magnetic circular dichroism (MCD) is the difference between the absorptivity or reflectivity of left and right circularly polarized soft-x-rays at the magnetically interesting L2,3- edges of 3d transition metals or the M4,5-edges of the 4f rare earth elements. Thanks to its large absorption cross-section and strong MCD effect, this technique has become a powerful new means for probing, in an element- and site-specific manner, the magnetic properties of ultra-thin films and multilayers. Soft-x-ray MCD experiments, recently conducted at the Dragon beamline, are utilized to demonstrate the recent progress in this technique and its applications in the research of magnetic thin films.

Enantioselective femtosecond laser photoionization spectrometry of limonene using photoelectron circular dichroism

2015 ◽  
Vol 17 (14) ◽  
pp. 8614-8617 ◽  
Author(s):  
Mohammad M. Rafiee Fanood ◽  
Maurice H. M. Janssen ◽  
Ivan Powis
Keyword(s):  
Angular Distribution ◽  
Circular Dichroism ◽  
Femtosecond Laser ◽  
Multiphoton Ionization ◽  
Circularly Polarized ◽  
Chiral Asymmetry ◽  
Photoelectron Angular Distribution ◽  
Laser Photoionization ◽  
Circular Dichroïsm

Circularly polarized, femtosecond laser multiphoton ionization can clearly distinguish between the enantiomers of limonene from a 4% chiral asymmetry in the photoelectron angular distribution.

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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