This incompletely condensed cage is the essential substrate in the synthesis of fully condensed, cubic silsesquioxanes by the corner-capping reaction.
References: [1] D. B. Cordess, P. D. Lickiss, F. Rataboul, Chem. Rev., 2010, 110, 2081; [2] P. D. Lickiss, F. Rataboul, Fully Condensed Polyhedral Oligosilsesquioxanes (POSS): From Synthesis to Application, Advances in Organometallic Chemistry, Tom 57, ed. A. F. Hill, M. J. Fink, Academic Press, 2011