[CH₃ NH₃ ]₄ Ga₄ SbS₉ S_0.28 O_0.72 H: A Three-Dimensionally Open-Framework Heterometallic Chalcogenidoantimonate Exhibiting Ni²⁺ Ion-Exchange Property

An open-framework chalcogenidoantimonate, namely, [CH₃ NH₃ ]₄ Ga₄ SbS₉ S_0.28 O_0.72 H (1), has been solvothermally synthesized and structurally characterized. Interestingly, 1 showed Ni²⁺ ion-exchange properties and wide pH resistance, with a maximum exchange capacity of 76.9 mg g^-1 . To the best of our knowledge, this is the first example of amine-directed three-dimensional (3D) heterometallic chalcogenidometalates for highly selective Ni²⁺ ion capture with a high distribution coefficient (K_d =1.65×10⁵ mL g^-1 ).