Molecular structure of the nineteen-vertex selenaborane Se2B17H17(1). Displacement ellipsoids for non-hydrogen atoms are drawn at a 50 % probability level. The molecule has crystallographic inversion symmetry at the mid-point of the B(7)-B(8) vector; hence the asymmetric unit is half a molecule and the molecule is disordered. Interatomic distances (A): Se(9)-B(4) 2.097(15), Se(9)-B(5) 2.056(13), Se(9)-B(8) 2.133(16), Se(9)-B(10) 2.141(13), B(5)-B(6) 1.791(15), B(6)-B(7), B(7)-B(8) 1.823(17), B(7)-B(11) 1.910(18). Se(9')-B(4') 1.997(16), Se(9')-B(8') 1.864(17), Se(9')-B(10') 2.031(16), B(5')-B(10') 1.889(18) B(8')-B(8') 2.00(2).
