scholarly journals Vibrational relaxation in simulated two-dimensional infrared spectra of two amide modes in solution

2007 ◽  
Vol 127 (19) ◽  
pp. 194505 ◽  
Author(s):  
Arend G. Dijkstra ◽  
Thomas la Cour Jansen ◽  
Robbert Bloem ◽  
Jasper Knoester
Keyword(s):  
Infrared Spectra ◽  
Vibrational Relaxation ◽  
Two Dimensional

Two-dimensional infrared spectroscopy from the gas to liquid phase: density dependent J-scrambling, vibrational relaxation, and the onset of liquid character

2019 ◽  
Vol 21 (38) ◽  
pp. 21249-21261 ◽  
Author(s):  
Greg Ng Pack ◽  
Matthew C. Rotondaro ◽  
Parth P. Shah ◽  
Aritra Mandal ◽  
Shyamsunder Erramilli ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Liquid Phase ◽  
Supercritical Fluids ◽  
Vibrational Relaxation ◽  
Rotational Relaxation ◽  
Two Dimensional ◽  
Relaxation Rates ◽  
Phase Density ◽  
Density Dependent ◽  
Two Dimensional Infrared Spectroscopy

Ultrafast 2DIR reveals rotational relaxation rates, critical slowing effects, and co-existence of free rotor and liquid populations in supercritical fluids.

Two-Dimensional Correlation Analysis, Fourier Self-Deconvolution, and Second-Derivative Studies on Assignments of the CH2 Stretching Bands for Cast Films of 2-Dodecyl-, 2-Pentadecyl-, and 2-Octadecyl-7,7,8,8-Tetracyanoquinodimethane

2000 ◽  
Vol 54 (5) ◽  
pp. 692-698 ◽  
Author(s):  
Hai-Shui Wang ◽  
Yukihiro Ozaki
Keyword(s):  
Infrared Spectra ◽  
Alkyl Chain ◽  
Second Derivative ◽  
Two Dimensional ◽  
Langmuir Blodgett ◽  
Cast Films ◽  
Band Region ◽  
Correlation Spectrum ◽  
Doublet Band ◽  
Different Origins

Infrared spectra have been measured for cast films of three kinds of 2-alkyl-7,7,8,8-tetracyanoquinodimethanes (C nTCNQ) prepared on KBr plates. Each infrared spectrum shows two components for the CH2 antisymmetric stretching band (2926 and 2918 cm−1), and the relative intensity of the two bands changes with the length of the alkyl chain. In contrast to the characteristic doublet band in the antisymmetric stretching band region, only one band seems to appear near 2850 cm−1 in the corresponding CH2 symmetric stretching band region. In order to reveal the number of the bands appearing in the CH2 antisymmetric and symmetric stretching regions and to explore the origins of these bands, Fourier self-deconvolution (FSD) and second-derivative methods have been applied to the infrared spectra of the cast films. The FSD analysis of the spectra for the three kinds of C nTCNQ derivatives measured at a 4 cm−1 resolution demonstrates that the CH2 symmetric stretching band also consists of two components (near 2853 and 2848 cm−1). The same conclusion has been obtained by the second derivative of the spectra measured at 1 cm−1 resolution. An asynchronous two-dimensional (2D) correlation spectrum created from time-dependent infrared spectra for a one-layer Langmuir–Blodgett (LB) film develops cross peaks at (2927 and 2916 cm−1) and (2854 and 2846 cm−1), suggesting that the bands at 2927 and 2916 cm−1 come from different species and those at 2854 and 2846 cm−1 also have different origins. The bands at 2918 and 2848 cm−1 may be due to the interdigitated part of the alkyl chain in the cast film, which has ordered ( trans-zigzag) form, while the bands near 2926 and 2853 cm−1 are probably ascribed to the noninterdigitated part of the alkyl chain, which has disordered form with several gauche conformations.

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