SOLUBLE AND VOLATILE BARIUM ARYLOXIDE DERIVATIVES - SYNTHESIS AND MOLECULAR-STRUCTURE OF BA5(MU-5-OH)(MU-3-OAR)4(MU-2-OAR)4(OAR)(THF)5, [BA(MU-1,MU-2-DPM)(DPM)(HOAR)2(THF)]2 AND [BA(H2NCH2CH2OH)(MU-1,MU-2-H2NCH2CH2OH)(MU-2-OH)(MU-2-OAR) (HOAR)]INFINITY (AR = C6H3BUT2-3,5 DPM = BUTC(O)CHC(O)BUT)

Various barium aryloxide derivatives have been investigated. Ba5(mu5-OH)(mu3-OAr)4(mu2OAr)4(OAr)(THF)5 (1), obtained by the reaction of barium metal granules in THF with 3,5-di-tert-butylphenol using gaseous ammonia as a catalyst, has been characterized by X-ray diffraction. The high nuclearity of this square-pyramidal pentahydroxyaryloxide complex accounts for its poor volatility. Complex I reacts with dpmH or H2NCH2CH2OH (2 mol) to yield [Ba(mu1,mu2-dpm)(dpm)(HOAr)2(THF)]2 (II) and [Ba(H2NCH2 CH2OH)(mu1,mu2-H2NCH2CH2OH)(mu2-OH)(mu2-OAr)(HOAr)]infinity (III), respectively. The molecular structure of II shows a dimeric nature with two bridging-chelating beta-diketonate ligands. Each metal atom is eight-coordinated with dodecahedral geometry. This complex is volatile and dissociates upon heating into a barium containing compound for which the spectroscopic data are in accord with the formula [Ba(dPM)2(HOAr)]n, n greater-than-or-equal-to 2. Complex III consists of a chain structure based on the infinite repetition of [Ba(H2NCH2CH2OH)(mu1,mu2-H2NCH2CH2OH)(mu2-OH)(mu2-OAr)(HOAr)] units. This polymeric compound which presents some intramolecular hydrogen bonding is soluble but not volatile.