Construction of Inorganic Crown Ethers by s‐Block‐Metal‐Templated Si−O Bond Activation

We herein report the synthesis, structures, coordination ability, and mechanism of formation of silicon analogs of crown ethers. An oligomerization of (2)D(2) (I) ((2)D(n),=(Me(4)Si(2)O)(n)) was achieved by the reaction with GaI(3) and MI(x) (M=Li, Na, Mg, Ca, Sr). In these reactions the metal cations serve as template and the anions (I(−)/[GaI(4)](−)) are required as nucleophiles. In case of MI(x)=LiI, [Li((2)D(3))GaI(4)] (1) is formed. In case of MI(x)=NaI, MgI(2), CaI(2), and SrI(2) the compounds [M((2)D(4))(GaI(4))(x)] (M=Mg(2+) (3), Ca(2+) (4), Sr(2+) (5) are obtained. Furthermore the proton complex [H((2)D(3))][Ga(2)I(7)] (6) was isolated and structurally characterized. All complexes were characterized by means of multinuclear NMR spectroscopy, DOSY experiments and, except for compound 3, also by single crystal X‐ray diffraction. Quantum chemical calculations were carried out to compare the affinity of M(+) to (2)D(n) and other ligands and to shed light on the formation of larger rings from smaller ones.