Several [Gd-M] Heterometal-Organic Frameworks with [Gdn] as Nodes: Tunable Structures and Magnetocaloric Effect.

Tunable structures and magnetocaloric effect (MCE) of seven MOFs with [Gdn] as nodes are explored. The [Gdn] node is realized from mononuclear [Gd] to binuclear paddle-wheel [Gd2], tetranuclear tetrahedral [Gd4], and pentanuclear trigonal bipyramidal [Gd5]. Meanwhile, the magnetic entropy changes from 19.4 to 46.0 J·kg-1·K-1. The results reveal that the effect of magnetic density on MCE plays a dominant role for Gd3+-based compounds, and high spin ground state of Mn2+ (S = 5/2) is more favorable to achieve high MCE than that with Zn2+, Co2+, and Ni2+ (Co2+, S = 3/2; Ni2+, S = 1). To our knowledge, it is the first report that MCE is controlled by various clusters as nodes in MOFs.