Potassium chlorido-tris-(hypersil-oxy)aluminate dimer.

The tris-(tri-methyl-silylsiloxide) ligand, also known as hypersiloxide, is an extremely bulky group. In an attempt to make the monomeric Al(OSi(SiMe(3))(3))(3), AlCl(3) was combined with 3 equiv. of potassium hypersiloxide. The crystalline product isolated (40% yield), namely di-μ(3)-chlorido-bis-[μ(2)-tris-(tri-methyl-sil-yl)silanolato]tetra-kis-[tris-(tri-methyl-sil-yl)silanolato]dialuminium-dipotassium, [Al(2)K(2)Cl(2)(C(19)H(27)OSi(4))(6)], is a KCl adduct of aluminium tris(hypersilyloxide) that is dimerized through a planar K(2)Cl(2) ring, with K-Cl distances of 3.1131†(8) and 3.319†(3)†à , and ring angles of 77.41†(2) and 102.60†(2)°. This ring is on an inversion center, and there is no supra-molecular coordination.