The radical anion of octa-tert-butyloctasilacubane was generated and isolated. The EPR spectrum showed the satellites due to the tertiary (13)C nuclei of the eight tert-butyl groups. The X-ray crystallographic analysis showed that the Si-Si bonds are shortened and the Si-C bonds are elongated compared with those of octa-tert-butyloctasilacubane. These results are well explained by the distribution of an unpaired electron in the singly occupied molecular orbital (SOMO).

The radical anion of octa-tert-butyloctasilacubane was generated and isolated. The EPR spectrum showed the satellites due to the tertiary 13 Cn uclei of the eight tert-butyl groups.T he X-rayc rystallographic analysis showed that the SiÀSi bonds are shortened and the SiÀCb onds are elongated compared with those of octa-tert-butyloctasilacubane.T hese results are well explained by the distribution of an unpaired electron in the singly occupied molecular orbital (SOMO).