Exploring the anion-cation interaction in m-terphenyltetrafluorosilicates by using multinuclear NMR spectroscopy, X-ray diffraction, and ICR-FT-MS.

The synthesis of a series of m-terphenyl-substituted tetrafluorosilicates with different cations (Na(+), K(+), Rb(+), Cs(+), Ag(+), Tl(+)) is described and the interactions between the anion and cation are investigated in the solid, solution, and gas states by using multinuclear NMR spectroscopy, X-ray diffraction, and ion cyclotron resonance Fourier-transform mass spectrometry (ICR-FT-MS). In solution, heteronuclear NMR spectroscopy parameters show only limited sensitivity to the nature of the cation, which furthermore can be affected by solvent effects. More pronounced effects are observed in the structural data obtained from X-ray diffraction studies, which are in good agreement with experimental gas-phase data from ESIMS. ESIMS also reveals the existence of dimeric species of the type M(DmpSiF(4))(2) (Dmp = 2,6-dimesitylphenyl), the stability of which was determined by normalized collision energy experiments.