New inorganic discrete 8-membered wheel clusters: Organically directed titanium sulfate supermolecules

Two organically directed titanium sulfates (C4N3H16)5 (H3O)[TiO(SO4)2]8·15H2O (I) and (C4N2H12)8 [TiO(SO4)2]8·23H2O (II), have been synthesized and characterized. I crystallizes in the orthorhombic space group Pnma, crystal data: a = 16.5834 Å, b = 19.9129 Å, c = 29.1383 Å, V = 9622.15 Å3, and Z = 4; II crystallizes in the monoclinic space group C2/c, crystal data: a = 23.1596(17) Å, b = 28.786(2) Å, c = 20.7720(15) Å, β = 121.0930(10)°, V = 11858.6(15) Å3, and Z = 4. Two compounds are featured as uncommon discrete [TiO(SO4)2]8 wheel clusters encapsulating different amines. The amines with linear and cyclic structures are located in different positions, respectively, involving host–guest interaction.