Inorganic Complexes Retain Diethyl Ether Well Above Its Boiling Point through OH₂···OEt₂ Hydrogen Bonding

The structures of [M(2,2‘-bpy)(SC{O}Ph)3(H2O)]·Et2O (M = La (1), Pr (2), and Sm (3); 2,2‘-bpy = 2,2‘-bipyridine) have an eight-membered hydrogen-bonded ring formed between two diethyl ether (Et2O) and two aqua ligands, and they retain Et2O above its boiling point despite the presence of channels in the lattice for Et2O to escape. The inception temperatures for the weight loss of Et2O, 82, 69, and 51 °C for 1, 2, and 3, respectively, appear to be controlled by the size of the metal ions. Et2O-free solid 1 is able to take back Et2O quantitatively.