A unified topology approach to dot-, rod-, and sheet-MOFs
Francoise M. Amombo Noa, Maria Abrahamsson, Elisabet Ahlberg, Ocean Cheung, Christian R. Göb, Christine J. McKenzie, Lars Öhrström
Abstract
Metal-organic frameworks made from 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 types of units based on structures containing Y 3+ , Ce 3+ , or Gd 3+ linked by benzene-1,2,4,5-tetracarboxylate to give crystals of a dot-MOF in H 2 NMe 2 [Y(btec)(H 2 O)] CTH-14 , a sheet-MOF in [Ce 3 (btec)(Hbtec)(OAc)(HCO 2 )] CTH-15 , and a rod-MOF in 4,4′-azopyridinium[Gd 2 (btec) 2 ] CTH-16 . Cyclic voltammetry shows that CTH-15 stabilizes Ce(IV). Given the fact that sheet-MOFs represent an intellectual advance in the evolution of MOFs, 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 < rod < sheet. For CTH-14-16, the sheet- and the rod-MOF have higher thermal stability. We suggest sheet-MOFs as an additional strategy for making robust MOFs.