Hydrothermal versus Nonhydrothermal Synthesis for the Preparation of Organic−Inorganic Solids:  The Example of Cobalt(II) Succinate

Hydrothermal technique was used together with a room-temperature process for the synthesis of cobalt−succinate compounds. Four structures are described for two new compounds: K2Co(C4H4O4)2 and Co(H2O)4(C4H4O4). Whatever the solution conditions, carboxylate ligands, which possess a strong nucleophilic character, coordinate each metal ion. However, the coordination ability of carboxylate under hydrothermal conditions is different from that under mild ones. For high-temperature phases, carboxylic groups are multidentate and the organic acts as a “template” during the condensation of the oxygen−metal networks, whereas under room temperature conditions, they are unidentate and infinite structures are obtained via the bridging role of the ligand.