Chiral 2D Organic Inorganic Hybrid Perovskite with Circular Dichroism Tunable Over Wide Wavelength Range

2020 ◽  
Vol 142 (9) ◽  
pp. 4206-4212 ◽  
Author(s):  
Jihoon Ahn ◽  
Sunihl Ma ◽  
Ji-Young Kim ◽  
Jihoon Kyhm ◽  
Wooseok Yang ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Inorganic Hybrid ◽  
Hybrid Perovskite ◽  
Wide Wavelength Range ◽  
Circular Dichroïsm

Circulardichroismusuntersuchungen von Polyalkohol- und Zucker-Vanadat(V)-Komplexen / Circular Dichroism Studies of Polyalcohol and Sugar Vanadate(V) Complexes

1989 ◽  
Vol 44 (11) ◽  
pp. 1464-1472 ◽  
Author(s):  
Hermann Bauer ◽  
Jeanine Brun ◽  
Alexius R. Hernanto ◽  
Wolfgang Voelter ◽  
Spyridon Paraskewas
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Optically Active ◽  
Hydroxyl Groups ◽  
Pyranose Ring ◽  
Cotton Effects ◽  
Circular Dichroïsm

The complexes of tetravanadate ions with optically active polyols and carbohydrates with suitable steric properties show up to four separate cotton effects in the wavelength range of λ = 200-350 nm. Thus it is possible to classify pyranoses into four groups according to their circular dichroitic behaviour and determine the configuration and the conformation of the hydroxyl groups attached to the pyranose ring.

A Microprocessor Controlled Near-Infrared Circular Dichroism Spectrophotometer

1979 ◽  
Vol 33 (6) ◽  
pp. 563-569 ◽  
Author(s):  
Mark E. Koehler ◽  
F. L. Urbach
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Indium Antimonide ◽  
Near Infrared ◽  
Computer Control ◽  
Optical Element ◽  
Signal Enhancement ◽  
Hard Copy ◽  
Microprocessor System ◽  
Circular Dichroïsm

A near-infrared circular dichrometer was constructed to cover the wavelength range 0.5 to 2.1 μm. The instrument employed a commercial photoelastic modulator with an infrasil quartz optical element to provide quarter-wave modulation throughout the range of the instrument. An indium antimonide [In(Sb)] doped photovoltaic detector was used at Λ > 1 μm, and a near-IR sensitive photomultiplier detector was used at Λ < 1 μm. Phase- and frequency-sensitive detection was employed and an automatic normalization circuit was used to extract the circular dichroism from the detector signal. The level of artifactual signals was reduced by the use of a passive depolarizing element. The instrument was interfaced with a microprocessor system which provided experimental control and signal enhancement capability. Data were transferred to a minicomputer system which provided bulk storage and both numeric and graphic hard copy output. The instrument, with its computer control capabilities, represents a significant improvement over previously existing instruments operating in this wavelength range in its facility for digital signal enhancement and data analysis.

scholarly journals Measurement of Circular Dichroism Spectra without Control of a Phase Modulator using Retardation Domain Analysis

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1418
Author(s):  
Hiroshi Satozono
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Linear Dichroism ◽  
Domain Analysis ◽  
Phase Modulator ◽  
Cd Spectra ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm ◽  
Modulation Degree

This study investigated the measurement of circular dichroism (CD) spectra without controlling a phase modulator. In a conventional CD system, the peak retardation of the phase modulator must remain constant over the observed wavelength range. Thus, the phase modulator must be controlled to maintain an appropriate modulation degree at an observed wavelength. In contrast, CD obtained using retardation domain analysis is not affected by peak retardation. Consequently, CD spectra can be measured without control of the phase modulator, which was experimentally demonstrated in this study. Additionally, linear dichroism spectra were obtained using retardation domain analysis.

The circular dichroism of a,b-unsaturated ketones. I. Circular dichroism in the singlet-singlet and singlet-triplet n «p* transitions of steroidal 4-en-3-ones

1980 ◽  
Vol 33 (10) ◽  
pp. 2189 ◽  
Author(s):  
AF Beecham ◽  
DJ Collins
Keyword(s):  
Circular Dichroism ◽  
Structure Analysis ◽  
Wavelength Range ◽  
Cotton Effect ◽  
Electronic Transitions ◽  
Positive Contribution ◽  
X Ray ◽  
Unsaturated Ketones ◽  
Negative Cotton Effect ◽  
Circular Dichroïsm

The circular dichroism from 22 steroidal 4-en-3-ones in cyclohexane solution has been recorded through the wavelength range 400-265 nm. It is shown that both the singlet-triplet and the singlet-singlet n → π* electronic transitions contribute. Through examination of evidence from c.d. and X-ray structure analysis, it is concluded that the conformation of the chromophore and its immediate environment remains constant under the conditions of measurement. In three of the 6β- substituted compounds the normal, highly structured, negative Cotton effect from the singlet-singlet n → π* transition is modified by positive c.d. with the same vibrational structuring. The origin of the positive contribution is discussed.

Circular Dichroism Spectral Similarity Plots to Extend Validation and Correction to All Measured Wavelengths

2022 ◽  
pp. 000370282110571
Author(s):  
Curtis W. Meuse
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Tertiary Structure ◽  
Spectral Intensity ◽  
Cd Spectra ◽  
Spectral Similarity ◽  
Interlaboratory Validation ◽  
Calibration Techniques ◽  
Spectral Intensities ◽  
Circular Dichroïsm

Interlaboratory comparisons of circular dichroism (CD) spectra are useful for developing confidence in the measurements associated with optically active molecules. These measurements also help define the higher-order (secondary and tertiary) structure of biopolymers. Unfortunately, the extent of the validity of these measurements has been unclear. In this work, a method is described to extend CD validation over the entire observed wavelength range using what will be called spectral similarity plots. The method involves plotting, wavelength by wavelength, all measured spectral intensities of a sample at one concentration against the intensity values of the same material at a different concentration or pathlength. These spectral similarity plots validate the instrument in terms of spectral shape and whether the shape is shifted in intensity and/or in wavelength. This comparison tests the linearity of instrument’s signal, the balance of its left and right polarizations, its wavelengths, and its spectral intensity scales. When the process is applied to materials with accepted and archived intensity values, the method can be linked to older single-wavelength and double-wavelength calibration techniques. Further, spectral similarity testing of CD spectra from samples with different concentrations run in different labs suggests that improved interlaboratory validation of CD data is possible. Since a database of archival CD measurements is available online, spectral similarity comparisons could possibly provide the ability to compare linearity, polarization balance, wavelength, and spectral intensity between all current CD instruments. If the preliminary results published here prove robust and transferable, then comparisons of full-wavelength range spectra to archived data using spectral similarity plots should become part of the standard process to validate and calibrate the performance of CD instruments.

A new class of chiral semiconductors: chiral-organic-molecule-incorporating organic–inorganic hybrid perovskites

2017 ◽  
Vol 4 (5) ◽  
pp. 851-856 ◽  
Author(s):  
Jihoon Ahn ◽  
Eunsong Lee ◽  
Jeiwan Tan ◽  
Wooseok Yang ◽  
Bokyung Kim ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Organic Molecule ◽  
Inorganic Hybrid ◽  
New Class ◽  
Circular Dichroïsm

Chiral organic–inorganic hybrid perovskites exhibiting circular dichroism were prepared as a new class of chiral semiconductors.

Ultraviolet circular dichroism studies on complexes of synthetic polynucleotides

1969 ◽  
Vol 47 (10) ◽  
pp. 977-981 ◽  
Author(s):  
Fred H. Wolfe ◽  
Kimio Oikawa ◽  
Cyril M. Kay
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Optically Active ◽  
Electronic Transitions ◽  
Molar Ratio ◽  
Circular Dichroism Spectra ◽  
Naturally Occurring ◽  
Polyadenylic Acid ◽  
Polyuridylic Acid ◽  
Circular Dichroïsm

The ultraviolet circular dichroism spectra of complexes of polyadenylic acid and polyuridylic acid in the molar ratio of 1:1 and 1:2, and that of polyguanylic acid and polycytidilic acid have been examined over the wavelength range of 300–185 mμ. Increased resolution of spectra below 225 mμ has revealed several new ellipticity bands for these complexes which should be of considerable value in the proper counting of optically active electronic transitions and their assignment in these systems, and with naturally occurring RNA's.

Characterization of Tamm-Horsfall Urinary Glycoprotein

1973 ◽  
Vol 31 ◽  
pp. 420-421
Author(s):  
John P. Robinson ◽  
J. David Puett
Keyword(s):  
Electron Microscopy ◽  
Circular Dichroism ◽  
Secondary Structure ◽  
Quaternary Structure ◽  
Normal Adult ◽  
Morphological Properties ◽  
Adult Males ◽  
Circular Dichroïsm ◽  
Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

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