Na8[B12(BSe3)6]: A Novel Selenoborato‐closo‐dodecaborate

Systematic studies on selenoborates containing a B12cluster entity and alkali metal cations led to the new crystalline phase Na8[B12(BSe3)6] which consists of a icosahedral B12cluster completely saturated with trigonal‐planar BSe3units and sodium counter‐ions. The new chalcogenoborate was prepared in a solid state reaction from sodium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 850 °C. Na8[B12(BSe3)6] crystallizes in the monoclinic space group P21/c (no. 14) with a = 10.990(1) Å, b = 16.279(1) Å, c = 11.490(1), β = 117.82(1)° and Z = 2.