This title appears in the Scientific Report :
2016
Please use the identifier:
http://hdl.handle.net/2128/12830 in citations.
How do hydrogen bonds influence thermophoresis?
How do hydrogen bonds influence thermophoresis?
So far there is only a limited microscopic understanding of thermodiffusion for fluids. Especially inaqueous systems the situation is complicated due to charge effects and strong specific crossinteractions. On the other hand a detailed understanding of aqueous systems would be valuable due toimporta...
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Personal Name(s): | Niether, Doreen |
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Dhont, Jan K.G. / Wiegand, Simone (Corresponding author) | |
Contributing Institute: |
Weiche Materie; ICS-3 |
Imprint: |
2016
|
Conference: | 4th International Soft Matter Conference, Grenoble (France), 2016-09-12 - 2016-09-16 |
Document Type: |
Conference Presentation |
Research Program: |
Functional Macromolecules and Complexes |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
So far there is only a limited microscopic understanding of thermodiffusion for fluids. Especially inaqueous systems the situation is complicated due to charge effects and strong specific crossinteractions. On the other hand a detailed understanding of aqueous systems would be valuable due toimportant applications in biotechnology, where the response to temperature gradients is successfullyemployed to monitor reaction kinetics of large proteins with small ligand molecules [1]. The strongsensitivity of proteins and other water soluble biomolecules is probably caused by a change in thehydration layer, which is influenced by subtle conformation changes induced by the binding of theligand molecule. One key parameter is the understanding of hydrogen bonds in the thermophoreticprocess [2]. To gain a better understanding of underlying physical process we systematicallyinvestigated various hydrogen bond formers (urea, acetamide, formamide, methylformamide) in waterby a holographic grating method called infrared thermal diffusion forced Rayleigh scattering (IRTDFRS).We elucidate the often found typical temperature dependence of the Soret coefficient ofsolute molecules in water and claim that this simple empirical approach to describe the temperaturedependence breaks down at higher solute concentrations, when interactions between different solutemolecules start to play a role. Additionally the concept also requires a hydrogen bond network withoutmicro-heterogeneities or cage structures. For nucleotides we found a correlation between the partitioncoefficient logP and the measured Soret coefficient [3]. As the logP parameter is one of the propertieswhich is included in the so called Lipinski's rule of five for selecting drug compounds, we check thiscorrelation for a number of simple heterocyclic compounds (pyridine, diazines, triazine). Thesenitrogen heterocycles, especially pyrimidine, are partial structures found in many biologically relevantsubstances such as nucleobases, vitamins, alcaloids and drugs (e.g. barbiturates and antibiotics).[1] M. Jerabek-Willemsen, T. André, W. Wanner et al., J. Mol. Struct., 1077, 101 (2014).[2] K. Maeda, N. Shinyashiki, S. Yagihara et al., J. Chem. Phys., 143, 124504 (2015).[3] Z. Wang, H. Kriegs and S. Wiegand, J. Phys. Chem. B, 116, 7463 (2012). |