Liquid exfoliation was achieved through ultrasonication of layered ZIF-7-III for 2 h in a 1:1 methanol/n-propanol mixture. Ultrathin nanosheets of 0.6 nm mean height and approximately 630 nm length were obtained, as indicated by atomic force microscopy (AFM) images (Figure and Figure ). Dynamic light scattering (DLS) reported a spherical equivalent diameter of 1063 nm (Figure ). The second MON system, ZIF-7-NH2 was inspired by the work of Lopez-Cabrelles et al., who produced an isoreticular series of iron-based ZIFs incorporating a range of functional groups. However, initial attempts to prepare 100% ZIF-7-NH2 via the route reported for ZIF-7 resulted in only partial conversion to ZIF-7-NH2-III during reflux of ZIF-7-NH2-I in water, resulting in mixed phase material (Figure ). A mixed ligand system was therefore produced by adding 50 mol% of 5- amino-benzimidazole alongside benzimidazole in the initial step (see section 3.3 in the Supporting Information). The XRPD pattern for the final material matched that reported for ZIF-7-III, confirming successful formation of this novel layered material (Figure ). Introducing the amine group produced a small shift in the [002] peak, which is attributed to an increase in the inter-layer distance owing to incorporation of this bulky group (Figure ). The presence of both ligands within the MOF was confirmed by IR spectroscopy as well as mass spectrometry analysis of the MOF after acid digestion. H NMR spectroscopy of the digested material indicated the presence of 20% bim-NH2: this is consistent with a Zn2(bim)3.2(bim-NH2)0.8 composition, as calculated from elemental microanalysis (Figure ). ZIF-7-NH2 nanosheets were accessed in the same way as for ZIF-7. AFM studies indicated mean heights and lengths of 1.6 nm and 400 nm respectively for ZIF-7-NH2 (Figure and Figure ). ZIF-7-NH2 nanosheets had a relatively broad lateral size distribution reaching lengths of 2 μm but the mean height only ranged from 1 to 5 nm. DLS studies indicated a slight increase in the apparent z-average diameter for ZIF-7-NH2 with a narrower particle size distribution compared to ZIF-7 (Figure ). A third MON system was also evaluated. A wide range of nanosheets formed from tricarboxylate linkers connected to Zr6 or Hf6 clusters have been reported for use in catalytic, and photo-or radio-dynamic therapy applications. Here Hf-BTB-NH2, was prepared by modifying the synthetic protocol reported by Ling et al. to introduce Hf6 metal clusters. Accordingly, hafnium chloride and BTB-NH2 linker were dissolved in DMF then water and formic acid were added as modulating agents. This mixture was heated for 48 h at 120 °C and the resulting pale viscous colloidal suspension became a homogeneous suspension after washing. Figure shows the XRPD pattern obtained for the Hf-BTB-NH2 system compared to Hf-BTB (NUS-8) which contains the same key features. The only difference is the introduction of the amine group on the central benzene ring of the BTB linker, see Figure . Further comparison to studies by Ling et al. can be found in Figure , which shows a good match to a simulated pattern for Hf6-BTB MON. The bulk material was then ultrasonicated in water (37 KHz, 12 h) to access nanosheets. The AFM image in Figure shows an example of Hf-BTB-NH2 nanosheets (average height = 2.7 nm, mean length = 504 nm) with DLS reporting an apparent z-average diameter of 493 nm (Figure ).