T(d) B(BO)4(-): a tetrahedral boron oxide cluster analogous to boron hydride T(d) BH4(-).

A density functional theory and wave function theory investigation on the geometrical and electronic structures of B5O4(0/-) clusters has been performed in this work. B5O4(-) anion proves to possess a perfect tetrahedral ground state of T(d) B(BO)4(-) ((1)A1) analogous to BH4(-) with four equivalent -BO terminals around the B center, while B5O4 neutral favors a slightly off-planed C(s) B(BO)4 ((2)A') which contains three -BO terminals and one -O- bridge. An intramolecular BO radical transfer occurs from T(d) B(BO)4(-) to C(s) B(BO)4 when one electron is detached from the anion. The one-electron detachment energies of the anion and characteristic stretching vibrational frequencies of -B=O groups at about 2000 cm(-1) have been calculated to facilitate future experimental characterization of these clusters.