Synthesis,Crystal Structures,and Characterization of Two 3d‐3d Heterometallic Coordination Frameworks: [ZnCo(Hcit)Cl] and [ZnCo(Hcit)Br]

Reactions between CoO, ZnCl₂ (or ZnBr₂), and molten citric acid (Hcit) led to the formation of two 3d‐3d heterometallic coordination frameworks: ZnCo(Hcit)Cl] ( 1 ) and ZnCo(Hcit)Br] ( 2 ). X‐ray structure analyses show that both compounds 1 and 2 crystallize in the monoclinic space group P2₁/n 1 : a = 5.8699(5) Å, b = 17.7963(13) Å, c = 9.2152(8) Å, β = 106.806(4) °, Z = 4, V = 921.53(13) Å³; 2 : a = 5.909(3) Å, b = 17.798(8) Å, c = 9.302(5) Å, β = 106.374(7) °, Z = 4, V = 938.6(8) Å³]. The structures of the two compounds are almost the same except for the terminal halogen ligand. Both of them are 3D frameworks based on citric acid bridging ligands and a 1D backbone chain built of corner‐shared {CoO₆} and {ZnO₃Cl} polyhedra. Photoluminescence and thermal stabilities of the compounds were studied.