Note. Crystal and molecular structure of 6,6′-bis(nido-decaboranyl) oxide (B10H13)2O

Abstract

The crystal and molecular structure of (B₁₀H₁₃)₂O has been determined by single-crystal X-ray diffractometry. The crystals are monoclinic with a = 24.838(6), b= 6.816(3), c= 10.132(3)Å, β= 98.43(2)°, U= 1 697(1)ų, Z = 4, D_c= 1.011 g cm^–3, F(000)= 536. Space group C2/c. The molecular structure comprises two B₁₀H₁₃ groups joined at the 6,6′-positions to the O atom. The molecule has crystallographic symmetry C₂ with B–O distances of 1.358(2)Å and a large B–O–B angle of 139.1(2)°. The conformation may be specified by the B(2)–B(6)–O–B(6′) torsion angle of –71°. The intra-cluster B–B distances are similar to those in B₁₀H₁₄, though there is a slight increase in the five B–B distances in each cluster involving those boron atoms [B(2), B(5), and B(7)] directly linked to B(6). There is also an enhanced asymmetry of the B–H–B(6) bridge bonds, with the H–B(6) being 0.14 Å longer than H–B(5) and H–B(7).