A metal–organic framework via the reaction of benzoate with a cationic inorganic material

Our research group previously reported a two-dimensional cationic inorganic material (BING-5, Pb₃F₅NO₃) where nitrate resides in the interlamellar space and can be anion exchanged. Investigation of the possible exchange of nitrate for benzoate led to the discovery of a layered metal–organic framework, lead benzoate hydrate [Pb(C₆H₅CO₂)₂(OH₂)]. The compound crystallizes as colourless plates in the monoclinic space group P2₁/c. The two dimensional lead–oxygen layers contain bridging benzoate oxygen atoms, with bridging water molecules further supporting the layers. The benzoate molecules are positioned perpendicular to the layers and form a hydrophobic bilayer region. The material shows basic character when immersed in various solvents suggesting potential as a base catalyst.