Year: 2026
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Trifluoroacetic acid (TFA), the most atmospherically abundant perfluorocarbocylic acid, is a molecule of increasing environmental and biological significance. In this paper, we examine TFA’s role in new particle formation (NPF), a critical yet lesser-understood step in cloud formation in which aerosols that act as cloud condensation nuclei are formed. We used conformational sampling to find low-energy structures for TFA- n H 2 O ( n = 1–8) clusters and determined accurate DLPNO–CCSD(T)/haug-cc-pV5Z//ωB97X-D/6–31++G** enthalpies at 0 K and Gibbs free energies at 216.65, 273.15, and 298.15 K. Then, atmospheric concentrations were determined at relevant atmospheric temperatures. Rotational constants for the lowest energy n = 1–3 structures corroborate existing microwave spectroscopic data, validating our methodology. Additionally, spectroscopic properties for n = 4–8 structures were identified for comparison with future experimental findings. All lowest energy structures were found to have neutral, rather than ion-pair monomers. Near Earth's surface, we predict significant concentrations of n = 1–2 clusters (2.06 × 10 5 molecules cm –3 and 1.13 × 10 4, respectively); however, the absence of larger clusters indicates that TFA likely serves a negligible role in NPF.
Institution: Furman University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Awards: G2549950936, G482627864, G5089649737, RUI: Thermodynamics of Nucleation: Pathways to Atmospheric Aerosols, Equipment: MRI: Track 1 Acquisition of Expansion of the Molecular Education and Research Consortium in Undergraduate Computational Chemistry (MERCURY), G8111583226, MRI: Expansion of the Molecular Education and Research Consortium in Undergraduate Computational ChemistRY (MERCURY) via Addition of High Performance Computers, G8745117432
OpenAlex ID: W7124847907