How metal ions link in metal–organic frameworks: dots, rods, sheets, and 3D secondary building units exemplified by a Y(iii) 4,4′-oxydibenzoate

In the field of metal-organic frameworks, the use of yttrium(iii) cations and the formation of 3D inorganic building units are rather rare. Here we report an yttrium(iii) metal-organic framework based on the V-shaped ditopic linker 4,4′-oxydibenzoate, oba2−: [Y16(μ-OH2)(μ3-OH)8(oba)20(dmf)4]·7H2O·7dmf, 1, which was solvothermally prepared, with single crystal X-ray diffraction revealing an unusual 3D metal secondary building unit. When activated at 200 °C, 1 desolvated to form compound 2, [Y16(μ-OH2)(μ3-OH)8(oba)20]·6H2O, retaining the same structure with a 3% shrinkage in unit cell volume.