μ-Oxo-bis(triorganoantimon- und -bismutsulfonate). Kristallstructur von 2O>(O3SC6H5)2

Article abstract of DOI:10.1016/S0022-328X(00)99456-7

μ-Oxo-bis(triorganoantimony- and -bismutsulfonates) (R3MO3SR')2O and (Me3SbO3SR')2O*nH2O (n = 2, R' = CF3, Ph, 4-CH3C6H4; n = 0, R' = CH3, CH2CH2OH) have been prepared by reaction of (Ph3SbO)2 and Me3Sb(OH)2, respectively, with the appropriate sulfonic acids or with (R3MX)2O (R = Ph, benzyl; X = Cl, Br) and R'SO3H in the presence of Ag2O.The anhydrous compounds (Me3SbO3R')2O are obtained by heating the hydrates.Me3Sb(OH)2 and 2,4-(NO2)2C6H3SO3H react to give the hydroxosulfonate Me3Sb(OH)O3R'.CH3OH solvolyzes the products.A covalent structure, with pentacoordinated Sb or Bi atoms, unidentate O3SR' ligands and μ-oxygen in apical, and R in equatorial positions, is inferred from the vibrational data for all nonhydrated sulfonate compounds.A correlation between ν_as(Sb-O-Sb) vibration and Sb-O-Sb bond angles in hexaphenyl distiboxans was established, which indicates that the Sb-O-Sb bridges are linear in (Ph3SbO3SR')2O (R' = 2,4-(NO2)2C6H3, 2,4,6-(NO2)3C6H2) and bent inthe other compounds.Data also indicate that there is a linear Bi-O-Bi bridge in (Ph3BiO3SCH2CH2OH)2O.The hydrated compounds have a distinctly different ionic structure one H2O being coordinated apically to each of the pentacoordinated Sb atoms in the cation <(Me3SbOH2)2O>²⁺.This proposal is verified by the crystal structure determination of (Me3SbO3SPh)2O*2H2O which revealed an ionic structure: <(Me3SbOH2)2O>(O3SPh)2.The angles μ-O-Sb-O(H2O) of 171.7(2) and 171.0(2) degree and μ-O-Sb-C(CH3) of 98.3 degree (mean) reflect the distortion of the trigonal bipyramidal surrounding of the Sb atoms, and the long Sb-O(H2O) distance of 244.4(5) pm (mean) the rather weak bonding of the water molecules to Sb.The distances S-O <144.6(6) pm (mean)> and the angles O-S-O <112.6(4) degree (mean)> in the sulfonate anion are essentially identical.Hydrogen bonds exist between the water ligands and O atoms of the anions.