Unusual Two-Dimensional Sheet Structure of the Solvent-Free Cesium Aryloxide Complex CsO-2,6-i-Pr(2)C(6)H(3)

Poly[(μ(6)-6-oxidopyridinium-2-carboxyl-ato)caesium]

The asymmetric unit of the polymeric title salt, [Cs(C₆H₄NO₃)]_n, comprises a Cs⁺ cation and a 6-oxidopyridinium-2-carboxyl­ate anion. The Cs⁺ cation is six-coordinated by O atoms derived from two oxido and four carboxyl­ate O atoms; each O atom in the anion bridges two Cs⁺ cations. In the crystal, inter­molecular N—H⋯O hydrogen bonding is present and contributes to the stability of the three-dimensional network generated by the bridging O atoms.

Synthesis of group 1 metal 2,6-diphenylphenoxide complexes [M(OC6H3Ph2-2,6)] (M = Li, Na, K, Rb, Cs) and structures of the solvent-free complexes [Rb(OC6H3Ph2-2,6)]x and [Cs(OC6H3Ph2-2,6)x: one-dimensional extended arrays of metal aryloxides

Reaction of 2,6-diphenylphenol (HOC(6)H(3)Ph(2)-2,6) with (n)BuLi, NaH, KH, or Rb or Cs metal in benzene gives the solvent-free complexes [M(OAr)]x in excellent yield. The complex [Rb(OC(6)H(3)Ph(2)-2,6)](x)() exhibits a ladderlike structure in the solid state with triply bridging oxygen atoms and Rb-O distances of 2.743(3), 2.930(2), and 2.973(2) A. The Rb cations interact with the pi-electron cloud of the arene moieties, giving rise to a high Rb coordination number. The cesium-containing congener forms a layered, columnlike structure consisting of [Cs(2)(mu(2)-OAr)(2)] units, with nearly identical Cs-O distances of 2.945(2) and 2.947(2) A. The individual layers are held together solely by Cs-arene pi-interactions.