Polyoxometalate-like structure of new potassium triphenylsiloxides: [K6(OSiPh3)6(C3H7OH)(H2O)]·2C6H5CH3 and [K6(OSiPh3)6(H2O)2]

Abstract

The synthesis and structural characterization of two new potassium triphenylsiloxides, namely, aqua(propan-2-ol)hexakis(triphenylsilanolato)hexapotassium toluene disolvate, [K6(C18H15OSi)6(C3H8O)(H2O)]·2C7H8, and diaquahexakis(triphenylsilanolato)hexapotassium, [K6(C18H15OSi)6(H2O)2], are reported. Both compounds crystallize in the triclinic space group P-1. The structure in each case resembles an alkali metal polyoxometalate-like structure, in which electrostatic interactions are observed in the metal–oxygen core. Furthermore, both compounds also resemble a reverse micelles-like architecture, in which the hydrophilic core is enclosed in a hydrophobic shell. The cores of the complexes are flanked by hydrophobic aromatic rings derived from Ph3SiO− anions, where intramolecular π-interactions between the aromatic rings and potassium cations stabilize the cores of the crystals. Moreover, in both structures, the presence of hydrogen bonds is observed; until now, no crystal structures have been described containing K atoms and triphenylsiloxide molecules in which the presence of hydrogen bonds was confirmed. Thus, these coordination entities could be considered as attractive reagents for further synthetic protocols towards heterometallic complexes.