Ultrafast Terahertz Spectroscopy: Measuring Low- Frequency Vibrational Modes of Hydrogen-Bonded Systems

2000 ◽  
Author(s):  
D. A. McWhorter ◽  
A. L. Migdali ◽  
E. J. Heilweil
1999 ◽  
Vol 19 (1-4) ◽  
pp. 145-148
Author(s):  
Richard McElroy ◽  
Klaas Wynne

Ultrafast time-resolved visible-pump, far-IR (THz) probe spectroscopy has been developed in our lab and has been applied to study carrier dynamics in photoexcited GaAs and dipole solvation dynamics in betaine and p-nitroaniline. This type of spectroscopy enables us to study for the first time the nonequilibrium interaction between excited electronic states and low frequency vibrational modes.


2016 ◽  
Vol 4 (47) ◽  
pp. 18516-18523 ◽  
Author(s):  
K. T. Butler ◽  
B. J. Dringoli ◽  
L. Zhou ◽  
P. M. Rao ◽  
A. Walsh ◽  
...  

We explore ultrafast carrier dynamics and interactions of photoexcited carriers with lattice vibrational modes in BiVO4 using time-resolved terahertz spectroscopy and first-principles phonon spectrum calculations.


Author(s):  
Wei Zhang ◽  
Jefferson Maul ◽  
Diana Vulpe ◽  
Peyman Z. Moghadam ◽  
David Fairen-jimenez ◽  
...  

<div>The identification of low-frequency vibrational motions of metal-organic frameworks (MOFs) allows for a full understanding of their mechanical and structural response upon perturbation by external stimuli such as temperature, pressure, and adsorption. Here, we describe the unique combination of an experimental temperature- and pressure-dependent terahertz spectroscopy system with state-of-the-art quantum mechanical simulation to measure and atomistically assign specific low-frequency vibrational modes that directly drive the mechanochemical properties of this important class of porous materials. Our work highlights the complex interplay between structural, vibrational, and mechanochemical phenomena, all of which are key to the effective exploitation of MOFs. We demonstrate the critical importance of terahertz vibrational motions on the function of MOFs, and how this information can be measured and interpreted in a method that can be applied widely to any supramolecular materials. </div><div><br></div>


2018 ◽  
Author(s):  
Wei Zhang ◽  
Jefferson Maul ◽  
Diana Vulpe ◽  
Peyman Z. Moghadam ◽  
David Fairen-jimenez ◽  
...  

<div>The identification of low-frequency vibrational motions of metal-organic frameworks (MOFs) allows for a full understanding of their mechanical and structural response upon perturbation by external stimuli such as temperature, pressure, and adsorption. Here, we describe the unique combination of an experimental temperature- and pressure-dependent terahertz spectroscopy system with state-of-the-art quantum mechanical simulation to measure and atomistically assign specific low-frequency vibrational modes that directly drive the mechanochemical properties of this important class of porous materials. Our work highlights the complex interplay between structural, vibrational, and mechanochemical phenomena, all of which are key to the effective exploitation of MOFs. We demonstrate the critical importance of terahertz vibrational motions on the function of MOFs, and how this information can be measured and interpreted in a method that can be applied widely to any supramolecular materials. </div><div><br></div>


1994 ◽  
Vol 269 (49) ◽  
pp. 31047-31050
Author(s):  
S Jeyarajah ◽  
L M Proniewicz ◽  
H Bronder ◽  
J R Kincaid

Soft Matter ◽  
2021 ◽  
Author(s):  
Brian Tighe ◽  
Karsten Baumgarten

We determine how low frequency vibrational modes control the elastic shear modulus of Mikado networks, a minimal mechanical model for semi-flexible fiber networks. From prior work it is known that...


1977 ◽  
Vol 81 (24) ◽  
pp. 2237-2240 ◽  
Author(s):  
J. N. Spencer ◽  
Judy R. Sweigart ◽  
Michael E. Brown ◽  
Ronald L. Bensing ◽  
Thomas L. Hassinger ◽  
...  

2009 ◽  
Vol 08 (04) ◽  
pp. 691-711 ◽  
Author(s):  
FENG FENG ◽  
HUAN WANG ◽  
WEI-HAI FANG ◽  
JIAN-GUO YU

A modified semiempirical model named RM1BH, which is based on RM1 parameterizations, is proposed to simulate varied biological hydrogen-bonded systems. The RM1BH is formulated by adding Gaussian functions to the core–core repulsion items in original RM1 formula to reproduce the binding energies of hydrogen bonding of experimental and high-level computational results. In the parameterizations of our new model, 35 base-pair dimers, 18 amino acid residue dimers, 14 dimers between a base and an amino acid residue, and 20 other multimers were included. The results performed with RM1BH were compared with experimental values and the benchmark density-functional (B3LYP/6-31G**/BSSE) and Möller–Plesset perturbation (MP2/6-31G**/BSSE) calculations on various biological hydrogen-bonded systems. It was demonstrated that RM1BH model outperforms the PM3 and RM1 models in the calculations of the binding energies of biological hydrogen-bonded systems by very close agreement with the values of both high-level calculations and experiments. These results provide insight into the ideas, methods, and views of semiempirical modifications to investigate the weak interactions of biological systems.


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