Einfluß des Kations auf die Struktur des [Si(O2C6H4)2F]⊖-Anions: Struktur von [K(18-Krone-6)][Si(O2C6H4)2F] / The Influence of the Cation on the Structure of the Anion [Si(O2C6H4)2F]⊖: The Structure of [K(18-Krone-6)][Si(O2C6H4)2F] (original) (raw)

Si(OMe)4 reacts with two equivalents of 1,2-(OH)2C6H4 in toluene at elevated temperature (70 °C) to yield a colorless microcrystalline product, which we believe to be Si(O2C6H4)2(MeOH)x (x = 1-2). [K(18-crown-6)][Si(O2C6H4)2F] has been prepared by the reaction of Si(O2C6H4)2(MeOH)x with KF and 18-crown-6 in THF and subsequent recrystallization from CH2Cl2/toluene. The title compound crystallizes orthorhombically in the space group P212121 (No. 19) with a = 10.373(1), b = 18.954(2), c = 13.993(2) Å and Z = 4. The structure was refined to a final R-value of 0.057 for 2037 reflections. The crystal structure shows the presence of close contact ion pairs [d(K –O) = 2.897(7), 2.806(8) A]. The influence of these interactions on the environment of the silicon atom is discussed and the structure of the anion compared with that of the free anion in NEt4[Si(O2C6H4)2F].