TERT-BUTYLBENZAMIDATE DIRUTHENIUM(II, III) COMPOUNDS - CRYSTAL-STRUCTURE OF [RU-2(MU-HNOCC6H4-P-CME(3))(4)(OPPH(3))(2)]BF4

The reaction between RU(2)Cl(mu-O2CCH3)(4) and molten p-tert-butylbenzamide led to the formation of Ru2Cl(mu-HNOCC6H4-p-CMe(3))(4). The polymeric structure of this insoluble compound was broken with AgBF4, in anhydrous thf, giving [Ru-2(mu-HNOCC6H4-p-CMe(3))(4)(thf)(2)]BF4. The reaction of this cationic complex with OPPh(3) gave [Ru-2(mu-HNOCC6H4-p-CMe(3))(4)(OPPH3)(2)]BF4. The compounds have been characterized by elemental analysis, spectroscopic data and magnetic measurements and the crystal structure of [Ru-2(mu 1-HNOCC6H4-p-CMe(3))(4)(OPPh(3))(2)]BF4 was determined by X-ray crystallography. The asymmetric unit is composed of halves of two different crystallographically independent centrosymmetric cations. Each ruthenium(II,III) dimer is bonded to four bridging p-tert-butylbenzamidate ligands and to two axial triphenylphosphine oxide molecules. The Ru-Ru distances in the two dimeric cations of the unit cell are 2.281(2) and 2.280(2) Angstrom. The compound has a non-polar 2:2 arrangement of the tert-butylbenzamidate ligands.