An Unusual LnIII‐Based Metal‐Organic Framework with Dinuclear Nodes Exhibiting Single‐Molecular Magnet Behavior

Three Ln III ‐based metal‐organic frameworks (MOFs), namely [(Me 2 NH 2 )[Ln(OBA) 2 ](Hatz)(H 2 O) 1.5 ] n [Ln = Dy ( 1 ), Er ( 2 ), Ho ( 3 ); H 2 OBA = 4, 4'‐oxybis(benzoate) acid, Hatz = 3‐amino‐1,2,4‐triazole], were synthesized with Hatz as the template. In the structure of the three MOFs, the dinuclear Ln III nodes are bridged by four oxygen atoms from syn, syn ‐carboxylate groups and this model result in a long distance between Dy–Dy, about 4.143(7) Å. In addition, the terminal carboxylate groups force a sandwich‐like coordination environment. Slow relaxation of the magnetization can be observed for 1 , indicative of a single‐molecule magnet (SMM) behavior.