The reactions of a Zn( ii ) ion with ligands containing two 1,3-benzene dicarboxylate residues resulted in isoreticular MOFs based on a rhombic dodecahedral MOP, in which the MOP was built using [Zn 2 (COO) 4 ] clusters as a 4-c SBU and [Zn 2 (COO) 3 ] clusters as a 3-c SBU.