1,4-Benzenedicarboxylate derivatives as links in the design of paddle-wheel units and metal-organic frameworks

The square grid structure of MOF-2, constructed from paddle-wheel units of Zn(II) and 1,4-benzenedicarboxylate (BDC) links, persists for 2-amino-1,4-benzenedicarboxylate (ABDC) links but not for the sterically demanding 2,3,5,6-tetramethyl-1,4-benzenedicarboxylate (TBDC); the dihedral angle between planes of the benzene and carboxylate groups play a determining role in the formation of the paddle-wheel motif.