A Unified Approach to Dot-, Rod-, and Sheet-MOFs and Electrochemistry of Exemplars Containing Y, Ce, Gd, and Benzene-Tetracarboxylate

Abstract

Metal-Organic Frameworks made from discrete multi-metal-ion units in the shape of clusters and rods (termed dot-MOFs and rod-MOFs) are well-known. Here, we introduce MOFs with multi-metallic units in the form of sheets, sheet-MOFs. We show exemplars of all three type of units based on structures containing Y3+, Ce3+, or Gd3+ linked by benzene-1,2,4,5-tetracarboxylate to give crystals of a dot-MOF in H2NMe2[Y(btec)(H2O)] CTH-14, a sheet-MOF in [Ce3 (btec)(Hbtec)(NO3)2]·½dmf CTH-15, and a rod-MOF in [Gd2(Hbtec)2](4,4’-azopyridine) CTH-16. Cyclic voltammetry shows that sheet-MOF CTH-15 stabilize the Ce(IV) oxidation state and suggests catalytic ability for electrochemical nitrate reduction. Given the fact that sheet-MOFs represent an intellectual advance in the evolution of the MOF field, a unified approach is proposed for the topological classification of dot-, rod- and sheet-MOFs. It is suggested that the stability of MOFs follow in the trend dot