Potassium chlorido­tris­­(hypersil­­oxy)aluminate dimer

The tris­(tri­methyl­silylsiloxide) ligand, also known as hypersiloxide, is an extremely bulky group. In an attempt to make the monomeric Al(OSi(SiMe3)3)3, AlCl3 was combined with 3 equiv. of potassium hypersiloxide. The crystalline product isolated (40% yield), namely di-μ3-chlorido-bis­[μ2-tris­(tri­methyl­sil­yl)silanolato]tetra­kis­[tris­(tri­methyl­sil­yl)silanolato]dialuminium­dipotassium, [Al2K2Cl2(C19H27OSi4)6], is a KCl adduct of aluminium tris(hypersilyloxide) that is dimerized through a planar K2Cl2 ring, with K—Cl distances of 3.1131 (8) and 3.319 (3) Å, and ring angles of 77.41 (2) and 102.60 (2)°. This ring is on an inversion center, and there is no supra­molecular coordination.