Per- and polyfluoroalkyl compounds (PFAS) accumulate in the environment and organisms due to their chemical inertness and widespread use, leading to serious health problems. PFAS include fluorinated alcohols, which have different structural properties than their non-fluorinated analogues. In the framework of this Master’s thesis, we measured the small-and-wide-angle X-ray scattering of liquid 3,3,3-trifluoropropan-1-ol and performed molecular dynamics simulations of this model liquid fluorinated alcohol using six different force fields (AMBER, CHARMM, GROMOS-AA, GROMOS-UA, OPLS and TraPPE). From the simulation results, theoretical X-ray scattering intensities were calculated using the complement system approach and compared with the experimental data. The TraPPE and OPLS models best described the scattering peak position, while the GROMOS models performed the worst. From the calculated theoretical partial scattering, we found that the average distance between the polyfluoroalkyl chains in the hydrophobic parts of the liquid is mostly responsible for the position of the overall scattering peak. The density of the real system was best described by the AMBER and TraPPE models, and worst by GROMOS-AA. From the radial pair distribution functions, we observed that the TraPPE model shows a higher tendency toward hydrogen bonding than the OPLS model, and the GROMOS models show a higher tendency of model molecules toward hydrogen bonding than all the other models used. Based on the intermolecular spatial distribution functions, we found that the GROMOS models show a significantly more spatialy directed hydrogen bonding than the others, and that hydrogen bonding is also spatialy directed in the TraPPE model and in the OPLS model. From the intramolecular spatial distribution functions and the end-to-end distance distribution of the molecule, we observed that the model molecules in the TraPPE model are more flexible and more compact than in the OPLS model. The latter shows the most rigid and least compact molecules out of the models tested. From the size distributions of the molecular aggregates, we observed that the OPLS, CHARMM and AMBER models show a greater probability for shorter, and the TraPPE, GROMOS-AA and -UA models for longer linear aggregates. In all model systems, cyclic aggregates of 5 molecules were the most common, with the exception of the GROMOS-AA model, where 9-molecule cyclic aggregates were the most common.
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