Synthesis and Properties of Cobalt/Nickel-Iron-Antimony(III, V)-Oxo Tartrate Cluster-Based Compounds.

Two types of isostructural iron-cobalt/nickel-antimony-oxo tartrate cluster-based compounds, namely (H 3 O)(Me 2 NH 2 )[ M (H 2 O) 6 ] 2 [Fe II 2 Sb III 12 ( μ 4 -O) 3 ( μ 3 -O) 8 (tta) 6 ]·6H 2 O ( M = Co ( 1 ); Ni ( 3 )), H 5/3 [Co 2.5 Fe II 4/3 Fe III 3 (H 2 O) 13 Sb V 1/3 Fe III 2/3 ( μ 4 -O) 2 ( μ 3 -O) 4 Sb III 6 ( μ 3 -O) 2 (tta) 6 ]·2H 2 O ( 2 ) and H 2 [Ni 2.25 Fe II 1.5 Fe III 3 (H 2 O) 14 Sb V 0.25 Fe III 0.75 ( μ 4 -O) 2 ( μ 3 -O) 4 Sb III 6 ( μ 3 -O) 2 (tta) 6 ]·2H 2 O ( 4 ) (H 4 tta = tartaric acid) were synthesized via simple solvothermal reactions. All the clusters in the structures adopt sandwich configurations, that is, bilayer sandwich configuration in 1 and 3 and monolayer sandwich configuration in 2 and 4 . Interestingly, the monolayer sandwiched compounds 2 and 4 represent rare examples of cluster-based compounds containing mixed-valence Sb(III, V), whose center of the intermediate layer is the co-occupied [Fe x Sb V 1- x ]. This is different from that of previously reported sandwich-type antimony-oxo clusters in which the center position is either occupied by a transition metal ion or a Sb(V) alone. Thus, the discovery of title compounds 2 and 4 makes the evolution of center metal ion more complete, that is, from M , M x Sb V 1- x to Sb V . All the title compounds were fully characterized, and the photocatalysis, proton conduction and magnetism of compounds 2 and 4 were studied.