The formation of the flower-like double decker morphology of Cu-AdDB was investigated. Cu(NO3)2•3H2O was reacted with AdDB at 105 °C in a 1:0.5 molar ratio in a chloroform/dimethylformamide (DMF) solution (1:3 v/v) in a pressure tube. Samples of ~5 L were taken as a time course during the solvothermal crystal growth process and the removed samples were analyzed by SEM. At 5 min, the product solution already contained a solid having an undefined shape. After 1.5 h, two populations of crystals were observed: small plates with rounded sides (l = 1-3 µm) and larger hexagonal prisms that exhibit what appears to be a medial seam (h= 4-5 µm, w = 8-13 µm) (Figure ). Their side facets are slightly concave and lateral views show that the center is domed. The small rounded plates are not observed at later stages of the reaction, indicative of an Ostwald ripening process, whereas the small crystals disappear as the prisms continue to develop into larger, welldefined morphologies. The rough surface texture of the 1.5 h prisms allows the speculation that a fusion process might play a role in the crystal growth, with the small plates eventually fused into the prisms. Similar fusion processes have been seen with an analogous ligand. The prisms that appear at 1.5 h are probably the basis for the more elaborate double-decker flowers seen in the SEM images taken on samples beginning at 2 h. At 10 h, the width of these structures increases from ~19 µm (2 h) to ~25 µm (10 h), reaching a final width of ~35 µm (48 h). After 48 h, the double-decker flowers are the main product and no further changes in crystal morphology are detected. Large dendritic crystals are also observed (Figure ).