Knowledge Bank

The microwave spectrum of the normal species and of nine isotopic species of 1,6-dicarba-closa-oetaborane (8) ($1,6-C2B6H8$) has been studied in the ground state. Low J R-branch transitions in the 8-40 GHz region were assigned from their characteristic Stark effects. The structure is that of a dodecahedron with a pair of equivalent carbon atoms at positions 1 and 6. This geometry is essentially that suggested earlier on the basis of the $\mathrm{<mrow\; data-mjx-texclass="ORD">11</mrow>}B$ NMR spectrum which, however, requires an assumption of coincidental overlap of two non-equivalent boron resonances. From Stark effect measurements the dipole moment of 1.40 + 0.01D has been found.