Substituent effect in theoretical VCD spectra

RSC Advances ◽  
2014 ◽  
Vol 4 (51) ◽  
pp. 27062-27066 ◽  
Author(s):  
Piotr F. J. Lipiński ◽  
Jan Cz. Dobrowolski
Keyword(s):  
Circular Dichroism ◽  
Substituent Effect ◽  
Vibrational Circular Dichroism ◽  
Correlational Study ◽  
First Time ◽  
Circular Dichroïsm

A correlational study shows for the first time a quantitative substituent effect on Vibrational Circular Dichroism intensity.

scholarly journals Assignment of protonated R-homocitrate in extracted FeMo-cofactor of nitrogenase via vibrational circular dichroism spectroscopy

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Lan Deng ◽  
Hongxin Wang ◽  
Christie H. Dapper ◽  
William E. Newton ◽  
Sergey Shilov ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Vibrational Circular Dichroism ◽  
Protonation State ◽  
Functional Theory ◽  
Femo Cofactor ◽  
Set Up ◽  
First Time ◽  
Circular Dichroïsm

Abstract Protonation of FeMo-cofactor (FeMo-co) is important for the process of substrate hydrogenation. Its structure has been clarified as Δ-Mo*Fe7S9C(R-homocit*)(cys)(Hhis) after the efforts of nearly 30 years, but it remains controversial whether FeMo-co is protonated or deprotonated with chelated ≡C − O(H) homocitrate. We have used protonated molybdenum(V) lactate 1 and its enantiomer as model compounds for R-homocitrate in FeMo-co of nitrogenase. Vibrational circular dichroism (VCD) spectrum of 1 at 1051 cm−1 is attributed to ≡C − OH vibration, and molybdenum(VI) R-lactate at 1086 cm−1 is assigned as ≡C − Oα-alkoxy vibration. These vibrations set up labels for the protonation state of coordinated α-hydroxycarboxylates. The characteristic VCD band of NMF-extracted FeMo-co is assigned to ν(C − OH), which is based on the comparison of molybdenum(VI) R-homocitrate. Density functional theory calculations are consistent with these assignments. To the best of our knowledge, this is the first time that protonated R-homocitrate in FeMo-co is confirmed by VCD spectra.

A vibrational circular dichroism (VCD) methodology for the measurement of enantiomeric excess in chiral compounds in the solid phase and for the complementary use of NMR and VCD techniques in solution: the camphor case

The Analyst ◽  
2018 ◽  
Vol 143 (6) ◽  
pp. 1406-1416 ◽  
Author(s):  
María Mar Quesada-Moreno ◽  
Albert Virgili ◽  
Eva Monteagudo ◽  
Rosa M. Claramunt ◽  
Juan Ramón Avilés-Moreno ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Solid Phase ◽  
Enantiomeric Excess ◽  
Vibrational Circular Dichroism ◽  
Solid Samples ◽  
Chiral Compounds ◽  
First Time ◽  
Circular Dichroïsm

For the first time, it is shown that VCD spectroscopy can be used to determine the % ee in chiral solid samples.

Measurement of Vibrational Circular Dichroism Using a Polarizing Michelson Interferometer

1990 ◽  
Vol 44 (1) ◽  
pp. 5-7 ◽  
Author(s):  
N. Ragunathan ◽  
N. S. Lee ◽  
T. B. Freedman ◽  
L. A. Nafie ◽  
C. Tripp ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Circular Dichroism ◽  
Signal To Noise Ratio ◽  
Michelson Interferometer ◽  
Vibrational Circular Dichroism ◽  
Signal To Noise ◽  
Ft Ir ◽  
First Time ◽  
Circular Dichroïsm ◽  
Double Modulation

Fourier transform infrared (FT-IR) vibrational circular dichroism (VCD) has been observed for the first time with the use of a polarizing Michelson interferometer (PMI). VCD spectra have been recorded for (–)- α-pinene between 900 and 1350 cm−1 at 4 cm−1 resolution with excellent signal-to-noise ratio. The FT-VCD spectra are virtually the same as those recorded for (–)- α-pinene under the same conditions with the use of the more conventional double modulation FT-IR approach.

ChemInform Abstract: Theory of Vibrational Circular Dichroism: trans-2,3-Dideuteriooxirane

ChemInform ◽  
1988 ◽  
Vol 19 (28) ◽  
Author(s):  
K. J. JALKANEN ◽  
P. J. STEPHENS ◽  
R. D. AMOS ◽  
N. C. HANDY
Keyword(s):  
Circular Dichroism ◽  
Vibrational Circular Dichroism ◽  
Abstract Theory ◽  
Circular Dichroïsm
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