scholarly journals Time-Resolved Linear Dichroism Measurements of Carbonmonoxy Myoglobin as a Probe of the Microviscosity in Crowded Environments

2017 ◽  
Vol 121 (29) ◽  
pp. 7064-7074 ◽  
Author(s):  
Eefei Chen ◽  
David S. Kliger
Author(s):  
Richard A. Palmer ◽  
Susan E. Plunkett ◽  
Pingyun Chen ◽  
James L. Chao ◽  
Thomas J. Tague

2003 ◽  
Vol 81 (6) ◽  
pp. 567-574
Author(s):  
Dustin Levy ◽  
Bradley R Arnold

Time-resolved linear dichroism spectroscopy has been used to study the influence of solvent on the charge transfer complex formed between hexamethylbenzene and 1,2,4,5-tetracyanobenzene. It was shown that cyano-substituted solvents induce a 1500 cm–1 increase in the charge transfer transition energies relative to those observed in chlorinated solvents. Furthermore, the angle between the charge transfer absorption transition moments and the photochemically produced radical anion absorption transition moment, after relaxation, has been measured for this complex in several solvents. A simple model was used to correlate the angles measured using time-resolved linear dichroism spectroscopy with the extent of localized excitation mixed into the charge transfer transitions. These measurements reveal that different charge transfer transitions borrow intensity from the localized excitation to different extents. By using different excitation wavelengths, the partitioning of the borrowed intensity among the charge transfer transitions of this complex could be evaluated for the first time.Key words: 1,2,4,5-tetracyanobenzene, hexamethylbenzene, donor–acceptor complex, photoinduced electron transfer, photoselection.


1989 ◽  
Vol 36 (3-4) ◽  
pp. 267
Author(s):  
W.H. Woodruff ◽  
R.B. Dyer ◽  
J.J. López-Garriga ◽  
'O. Einarsdóttir ◽  
P.M. Killough

1988 ◽  
Vol 42 (2) ◽  
pp. 203-216 ◽  
Author(s):  
Isao Noda ◽  
A. E. Dowrey ◽  
Curtis Marcott

A spectrometer for detecting dynamic infrared linear dichroism (DIRLD) induced by a small-amplitude oscillatory strain is described. The strain-induced dynamic variations of absorbance and linear dichroism, as well as the normal static absorbance and dichroism, are measured simultaneously as functions of IR wavenumber, temperature, and strain frequency. The phase (temporal) relationships between the dynamic optical signals and the applied strain are also obtained. The instrument is sensitive enough to detect dynamic optical signals on the order of 10−4 absorbance units with a time resolution of about 14 μs. The dynamic dichroism signals arise from the strain-induced temporary reorientation of dipole-transition moments associated with the molecular vibrations of chemical functional groups. Both the rate and extent of reorientations are strongly influenced by the local molecular environment of the functional groups. Because of the specificity of IR absorbance bands to the individual submolecular structures, DIRLD spectroscopy is especially suited for the study of the intra- and intermolecular interactions and the detection of subtle changes in the local molecular environment. Example DIRLD spectra of atactic polystyrene are presented to demonstrate the potential utility of this spectroscopic technique.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
H. C. Zhao ◽  
H. Xia ◽  
S. Hu ◽  
Y. Y. Lv ◽  
Z. R. Zhao ◽  
...  

AbstractThe time-resolved magneto-optical (MO) Voigt effect can be utilized to study the Néel order dynamics in antiferromagnetic (AFM) materials, but it has been limited for collinear AFM spin configuration. Here, we have demonstrated that in Mn3Sn with an inverse triangular spin structure, the quench of AFM order by ultrafast laser pulses can result in a large Voigt effect modulation. The modulated Voigt angle is significantly larger than the polarization rotation due to the crystal-structure related linear dichroism effect and the modulated MO Kerr angle arising from the ferroic ordering of cluster magnetic octupole. The AFM order quench time shows negligible change with increasing temperature approaching the Néel temperature (TN), in markedly contrast with the pronounced slowing-down demagnetization typically observed in conventional magnetic materials. This atypical behavior can be explained by the influence of weakened Dzyaloshinskii–Moriya interaction rather than the smaller exchange splitting on the diminished AFM order near TN. The temperature-insensitive ultrafast spin manipulation can pave the way for high-speed spintronic devices either working at a wide range of temperature or demanding spin switching near TN.


2018 ◽  
Vol 122 (49) ◽  
pp. 11381-11389 ◽  
Author(s):  
Eefei Chen ◽  
Raymond M. Esquerra ◽  
Philipp A. Meléndez ◽  
Sita S. Chandrasekaran ◽  
David S. Kliger

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