Predicting Ion-Solvent Clustering in Differential Mobility Spectrometry using Anharmonic Thermochemistry

Computed dispersion plot models can provide a window to understanding differential mobility spectrometry on a fundamental level and thus can be used as a complementary model to compare with experimental data obtained in a laboratory setting. However, current computational methods yield semi-quantitative agreement with experiment, specifically in solvated environments. Previous studies have assessed the shift in agreement of dispersion models and experimental data by employing different orders of 2-temperature theory. Results show qualitative accuracy in the modeled dispersion curves where the curve shape is comparable to that of experimental data, however, there remains a shift in SV or CV between the two. In this study, we employ anharmonic treatments of solvent-cluster thermochemistry, and assess its affect on dispersion plot accuracy of ions in solvated environments.