Macrocycle‐Encapsulated Tetranuclear Nickel(II) Complexes: Synthesis, Structures, and Magnetic Properties

Tetranuclear nickel(II) complexes with 36‐membered macrocyclic octaaminotetraphenol ligand H 4 L g , [Ni 4 (L g )(µ‐H 2 O) 4 ](ClO 4 ) 4 ·8DMF ( 1 ), and [Ni 4 (L g )(µ‐H 2 O) 3 (μ‐OH)](BF 4 ) 3 ·2CH 3 OH·4H 2 O ( 2 ) were synthesized and characterized. The X‐ray crystal structures of 1 and 2 reveal that the four octahedral nickel(II) centers are located in a rectangle with alternately arranged singly‐µ‐phenoxido‐ and triply‐µ‐phenoxido‐di‐µ‐aqua‐bridges or triply‐µ‐phenoxido‐µ‐aqua‐µ‐hydroxido‐bridges. Magnetic susceptibility data were analyzed by Heisenberg model H = – J 1 ( S Ni1 · S Ni2’ + S Ni1’ · S Ni2 ) – J 2 ( S Ni1 · S Ni2 + S Ni1’ · S Ni2’ ) to obtain the exchange interaction parameters with a combination of strong antiferromagnetic interaction and ferromagnetic interaction: J 1 = −67 cm –1 and J 2 = 14 cm –‍1 for 1 and J 1 = −62 cm –1 and J 2 = 17 cm –1 for 2 . DFT calculation results are in accordance with the magnetic analysis.