Structural Analysis of Perfluoropropanoyl Fluoride in the Gas, Liquid, and Solid Phases

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2016-04, Vol.120 (15), p.2420-2430
• Main Authors: Berrueta Martínez, Yanina, Reuter, Christian G, Vishnevskiy, Yury V, Bava, Yanina B, Picone, A. Lorena, Romano, Rosana M, Stammler, Hans-Georg, Neumann, Beate, Mitzel, Norbert W, Della Védova, Carlos O
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/acs.jpca.6b00424

The coexistence of two conformers in perfluoropropanoyl fluoride, CF3CF2C­(O)­F, differing in the CC–CF dihedral angle (gauche 85(10)% and anti 15(10)%), has been determined by means of gas-phase electron diffraction (GED). Quantum-chemical calculations performed at the MP2 and B3LYP approximations and cc-pVTZ basis sets reproduce the experimental values with confidence. By contrast, FTIR spectra give no clear evidence for the anti-conformer in the gas phase. Information on this less abundant but stable rotamer is obtained from matrix-isolation/FTIR spectroscopy and liquid Raman spectroscopy. In situ crystallization and single-crystal X-ray diffraction (XRD) data reveal the presence of solely the gauche-conformation in the solid state. A set of intermolecular interactions including CO···CO, C–F···F–C, and F···CO is detected. The nature of bonding and the relative stabilities of gauche- and anti-conformers are explored using natural bond orbitals.