Many parameters are known to affect the crystal morphology. Here, we evaluated the relationship between the type of metal center and the crystal appearance. Therefore, three other first-row metal nitrate hydrate salts (Ni, Co, and Mn) were also reacted with AdDB under identical conditions used for the formation of the flower-like crystals (Cu-AdDB, metal-to-ligand ratio = 0.5:1 using the conditions detailed in section A). Their known coordination chemistry with pyridine ligands forms octahedral complexes, as with Cu, and isomorphous crystal structures are formed. SEM imaging showed the formation of rounded, only slightly faceted crystals with Ni(NO3)2, and hexagonal prisms with Co(NO3)2 and Mn(NO3)2 (Figure , S6). The four metal salts all form crystals that exhibit external hexagonal symmetry. The metal cations influence the crystallization; the four metals result in different crystal morphologies; however, the uniformity is high for each individual system. The double-decker flowers obtained with Cu(NO3)2 are somewhat larger than the crystals formed with Ni(NO3)2 (13 ± 4 µm), Co(NO3)2 (32 ± 6 µm), and Mn(NO3)2 (8 ± 1 µm). Smaller crystals are usually indicative of a faster nucleation process. The solvothermal growth of these and other related MOFs are likely to proceed via a series of morphological transformations, as shown for the double-decker flowers (vide infra, Figure ).