Russian Doll-like 3d–4f Cluster Wheels with Slow Relaxation of Magnetization †

The solvothermal reactions of LnCl(3)·6H(2)O and MCl(2)·6H(2)O (M = Co, Ni) with 2,2′-diphenol (H(2)L(1)) and 5,7-dichloro-8-hydroxyquinoline (HL(2)) gave three 3d–4f heterometallic wheel-like nano-clusters [Ln(7)M(6)(L(1))(6)(L(2))(6)(µ(3)-OH)(6)(OCH(3))(6)Cl(CH(3)CN)(6)]Cl(2)·xH(2)O (Ln = Dy, M = Co, x = 3 for 1; Ln = Dy, M = Ni, x = 0 for 2; Ln = Tb, M = Ni, x = 0 for 3) with similar cluster structure. The innermost Ln(III) ion is encapsulated in a planar Ln(6) ring which is further embedded in a chair-conformation M(6) ring, constructing a Russian doll-like 3d–4f cluster wheel Ln(III)⸦Ln(6)⸦M(6). 2 and 3 show obvious slow magnetic relaxation behavior with negligible opening of the magnetic hysteresis loop. Such a Russian doll-like 3d–4f cluster wheel with the lanthanide disc isolated by transition metallo-ring is rarely reported.