| 초록 |
The construction of mixed-metal frameworks containing more than one type of metal element can provide further structural versatility and diversity. Herein, we report a synthetic strategy for the mixed transition- and alkali-metal frameworks, [Na2Co(PDA)2] (1, PDA = 2,6-pyridinedicarboxylate) and [K2Co(PDA)2] (2). The solid-state structures of these frameworks show that two PDA ligands chelate to a cobalt ion to form a Co(PDA)22- species, which in turn undergoes further assembly mediated by alkali-metal cations(Na+ or K+) to give mixed-metal framework structures. The {[KCo(PDA)2]–·[NH2(CH3)2]+} framework (3) is also prepared by a change in stoichiometry. The stepwise formation of these frameworks can be further evidenced by the reaction of as-synthesized H2Co(PDA)2 complexes with NaOH or KOH. |
