A new type of heterometallic silsesquioxane is reported in which Ln (Ln = Y
b or Y) is coordinated to one (C6H11)(7)Si7O123- ligandandone(C6H11)(7)Si7O
11(OSiMe3)(2-) ligand. Two Li atoms are incorporated into the structure, on
e bonded to two siloxy O atoms and the other to one siloxy O atom, one fram
ework O atom, and one OSiMe3 O atom.