Stereochemical dependence of substituent γ‐effects in the 19F NMR shielding constants

• Published in: Magnetic resonance in chemistry 2022-09, Vol.60 (9), p.869-876
• Main Authors: Ukhanev, Stepan A., Fedorov, Sergei V., Krivdin, Leonid B.
• Format: Article
• Language: English
• Subjects: 19F NMR chemical shift; aug‐pcSseg‐3 and aug‐cc‐pV6Z basis sets; BHandHLYP functional; Fluorine; Mathematical analysis; NMR; Nuclear magnetic resonance; Shielding; small fluorine containing compounds; substituent and stereochemical effects
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/mrc.5275

The substituent α‐, β‐, and γ‐effects of the elements of the second and third periods on 19F NMR chemical shifts are evaluated including the establishment of stereochemical dependence of γ‐effect, the latter particularly important in stereochemical studies of fluorine‐containing compounds. Benchmark calculations performed for a series of 32 simple inorganic fluorine‐containing molecules demonstrated a markedly good correlation between calculated and experimental fluorine chemical shifts characterized by a mean absolute error of 22.5 ppm in the range of about 900 ppm, which corresponds to a 2.5% error in the percentage terms. The substituent α‐, β‐, and γ‐effects of the elements of the second and third periods on 19F NMR chemical shifts are evaluated including the establishment of stereochemical dependence of γ‐effect, the latter providing a particular importance in stereochemical studies of fluorine containing compounds.