Vibrational relaxation of adsorbed molecules: Comparison with relaxation rates of model compounds

1987 ◽  
Vol 5 (4) ◽  
pp. 469-472 ◽  
Author(s):  
R. R. Cavanagh ◽  
M. P. Casassa ◽  
E. J. Heilweil ◽  
J. C. Stephenson
Keyword(s):  
Vibrational Relaxation ◽  
Relaxation Rates ◽  
Model Compounds ◽  
Adsorbed Molecules

Zur Protonenrelaxation von Wasser an Silikagelen

1967 ◽  
Vol 22 (11) ◽  
pp. 1751-1760 ◽  
Author(s):  
D. Michel
Keyword(s):  
Water Clusters ◽  
Relaxation Times ◽  
Dipolar Interaction ◽  
Relaxation Mechanism ◽  
Silica Gels ◽  
Proton Relaxation ◽  
Relaxation Rates ◽  
Proton Proton ◽  
Adsorbed Molecules ◽  
Paramagnetic Impurities

In most cases the proton relaxation of adsorbed liquids and gases is caused by the proton-proton dipolar interaction and the coupling between protons and paramagnetic impurities (e. g. Fe3+-ions) of the adsorbent. The latter relaxation mechanism, however, has been neglected up till now although in some commercial silica gels it’s contribution can be the most important one (see Section 2.2). Consequently, motional phenomena of adsorbed molecules can only be studied by NMR techniques if the relative largeness of these two relaxation rates has been estimated, as can be done by investigating the dependence of proton relaxation-times on the H/D-ratio. Relaxation-time measurements in the temperature range from —100° to +80°C indicate that proton transfers occur between surface hydroxils and adsorbed particles. In a sample of 3/4 statistical monolayer the presence of two different types of water, clusters containing 95% of the adsorbed molecules with correlation time τc2=2.7 · 10-10 s (0°C), and more individually adsorbed particles with τc1 ⪆ 2.3 ·10-8 (0°C), has been inferred (see Section 2.1).

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.

The role of CN and CO ligands in the vibrational relaxation dynamics of model compounds of the [FeFe]-hydrogenase enzyme

2011 ◽  
Vol 13 (21) ◽  
pp. 10295 ◽  
Author(s):  
Spyridon Kaziannis ◽  
Joseph A. Wright ◽  
Marco Candelaresi ◽  
Rafal Kania ◽  
Gregory M. Greetham ◽  
...  
Keyword(s):  
Vibrational Relaxation ◽  
Relaxation Dynamics ◽  
Model Compounds ◽  
Hydrogenase Enzyme
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