Cubic silicon cluster

Abstract
A cubic silicon cluster having eight bonds each terminated by a tert‐butyl substituent, tert‐butyloctasilacubane (TBOSC), is studied. TBOSC was formed and isolated by chemical procedures. The optical properties of TBOSC were measured in comparison with those of bulk silicon. TBOSC is purple and its absorption edge (λg) is observed at 650 nm (1.9 eV) at room temperature. This λg is 0.8 eV larger than that of bulk silicon. It also shows photoluminescence extending to 850 nm at 77 K although bulk silicon shows no photoluminescence.