The new crystals are prepared by the reaction of the ligand (AdDB), and cadmium nitrate in dimethylformamide (DMF) under solvothermal conditions (105 °C) for 24 hours (Scheme 1). The used molar ratio of ligand-to-metal salt is 1:4.6. An acid (HCl) was added to grow micrometer-sized, colorless crystals. The acid can slow down the crystallization process by protonation of the pyridine moieties, hence hampering the rapid coordination of the ligand to the metal centers. The crystals were collected in high yield (89% based on the ligand) by vacuum filtration and subsequent washedwith methanol.