(N,N-dimethylaminoxy)trifluorosilane: Strong, dipole moment driven changes in the molecular geometry studied by experiment and theory in solid, gas, and solution phases

(N,N-Dimethylaminoxy)trifluorosilane, F3SiONMe2 (1), was prepared by the reaction of LiONMe2 with SiF4 in Me2O at −96 °C as a colorless, air-sensitive liquid, which was identified by gas-phase IR spectroscopy and NMR spectroscopy of the nuclei 1H, 13C, 15N, 17O, 19F, and 29Si. The gas-phase geometry of 1, as determined by electron diffraction analysis refined in Cs symmetry, is influenced by weak attractive interactions between Si and N:  Si···N 2.273(17) A, Si−O−N 94.3(9)°, [Si−O 1.619(8) A, N−O 1.479(7) A, O−Si−Fin-plane 104.1(10)°, O−Si−Fout-of-plane 111.8(10)°]. X-ray diffraction analysis of 1 reveals that intramolecular Si···N interactions are much stronger in the solid state than in the gas phase:  Si···N 1.963(1) A, Si−O−N 77.1(1)° [Si−O 1.639(1) A, N−O 1.508(1) A, O−Si−Fin-plane 102.5(1)°, O−Si−Fout-of-plane 118.0(1)° and 120.1(1)°]. Using measured NMR chemical shifts in C6D6 solution, the geometry of 1 in solution was determined with the NMR/ab initio/DFT-IGLO method to fall between that of the g...