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 (HOC6H3Ph2-2,6) with nBuLi, NaH, KH, or Rb or Cs metal in benzene gives the solvent-free complexes [M(OAr)]x in excellent yield. The complex [Rb(OC6H3Ph2-2,6)]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) (angstrom). 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 [Cs2((mu)2-OAr)2] units, with nearly identical Cs-O distances of 2.945(2) and 2.947(2) (angstrom). The individual layers are held together solely by Cs-arene (pi)-interactions.