Long-range proton–¹⁹F spin–spin coupling interactions in phenyltrifluorosilane

Abstract

Analysis of the proton magnetic resonance spectrum of phenyltrifluorosilane yields the spin–spin coupling constants between the fluorine nuclei and the protons. These are compared with the analogous long-range coupling constants in benzotrifluoride, toluene, and phenylsilane and are rationalized in terms of coupling mechanisms. The coupling over six bonds is assessed as a base point for the estimation of hindered rotation about the carbon–silicon bond.

Fluorine exchange between four-, five-, and six-coordinate silicon compounds

“…SiF4 was prepared from SiCI, and SbF3 in a stainless steel cylinder. C6H5SiF3 was prepared from C6H,SiC13 and SbF3 in tetramethylene sulfone solvent (15). (n-C3H7)4NF (16), (n-C3H7)4N+SiF5-(2), (n-C3H7)4N+CH3SiF4-(1, 3), and (n-C3H7)4N+C6H5SiF4-(3) were prepared by literature methods and characterized by their mp, ir, and nmr spectra.…”

Perfluorinated Taddol phosphoramidite as an L,Z-ligand on Rh(i) and Co(−i): evidence for bidentate coordination via metal–C6F5 interaction

“…In the static DFT calculations, ortho fluorines F 1 , F 2 and F 3 appear to be coupling to phosphorus through long-range (5-bond) coupling, 29 but in solution, aryl rotation likely disrupts long-range coupling for F 1 and F 2 because such coupling is sensitive to the molecule’s conformation. 30 However, coordination of the C 6 F 5 bearing F 3 to rhodium will limit rotation of this C 6 F 5 and rigidify the phosphoramidite overall. Rigidification of the phosphoramidite through Rh–C 6 F 5 interaction could allow 31 P– 19 F coupling to occur either through-bond or through-space.…”