TY  - JOUR
AU  - Rudani, Binny
AU  - Jakubowski, Andre
AU  - Kriegs, Hartmut
AU  - Wiegand, Simone
TI  - Deciphering the guanidinium cation: Insights into thermal diffusion
JO  - The journal of chemical physics
VL  - 160
IS  - 21
SN  - 0021-9606
CY  - Melville, NY
PB  - American Institute of Physics
M1  - FZJ-2024-03529
SP  - 214502
PY  - 2024
AB  - Thermophoresis, or thermodiffusion, is becoming a more popular method for investigating the interactions between proteins and ligands due to its high sensitivity to the interactions between solutes and water. Despite its growing use, the intricate mechanisms behind thermodiffusion remain unclear. This gap in knowledge stems from the complexities of thermodiffusion in solvents that have specific interactions, as well as the intricate nature of systems that include many components with both non-ionic and ionic groups. {\color{red}To deepen our understanding, we reduce complexity by conducting systematic studies on aqueous salt solutions.} In this work, we focused on how guanidinium salt solutions behave in a temperature gradient, using thermal diffusion forced Rayleigh scattering experiments at temperatures ranging from 15 to 35°C. We looked at the thermodiffusive behavior of four guanidinium salts (thiocyanate, iodide, chloride, and carbonate) in solutions with concentrations from 1 to 3 mol/kg. The guanidinium cation is disk-shaped and is characterized by flat hydrophobic surfaces and three amine groups, which enable directional hydrogen bonding along the edges. We compare our results with the behavior of salts with spherical cations such as sodium, potassium and lithium. Our discussions are framed around how different salts are solvated, specifically in the context of the Hofmeister series, which ranks ions based on their effects on the solvation of proteins.
LB  - PUB:(DE-HGF)16
C6  - 38828819
UR  - <Go to ISI:>//WOS:001239198500004
DO  - DOI:10.1063/5.0215843
UR  - https://juser.fz-juelich.de/record/1026937
ER  -