Enneanuclear [Ni6Ln3] Cages: [Ln3III] Triangles Capping [Ni6II] Trigonal Prisms Including a [Ni6Dy3] Single-Molecule Magnet

The use of (2(beta-naphthalideneamino)-2-hydroxymethyl-1-propanol) ligand, H3L, in Ni/Ln chemistry has led to the isolation of three new isostructural [Ni(II)6Ln(III)3] metallic cages. More specifically, the reaction of Ni(ClO4)(2 center dot)6H(2)O, the corresponding lanthanide nitrate salt, and H3L in MeCN, under solvotherrnal conditions in the presence of NEt3, led to the isolation of three complexes with the formulas [Ni6Gd3(OH)(6)(HL)(6)(NO3)(3)]center dot 5.75MeCN center dot 2Et(2)O center dot 1.5H(2)O (1 center dot 5.75MeCN center dot 2Et(2)O center dot 1.5H(2)O), [Ni6Dy3(OH)(6)(HL)(6)(NO3)(3)]center dot 2MeCN center dot 2.7Et(2)O center dot 2.4H(2)O (2.2MeCN center dot 2.7Et2O center dot 2.4H(2)O), and [Ni6Er3(OH)(6)(HL)(6)(NO3)(3)]center dot 5.75MeCN center dot 2Et(2)O center dot 1.5H(2)O (3 center dot 5.75MeCN.2Et(2)O center dot 1.5H(2)O). The structure of all three clusters describes a [Ln(3)(III)] triangle capping a [Ni-6(II)] trigonal prism. Direct current magnetic susceptibility studies in the 5-300 K range for complexes 1-3 reveal the different nature of the magnetic interactions within the clusters: dominant antiferromagnetic exchange interactions for the Dy-III and Er-III analogues and dominant ferromagnetic interactions for the Gd-III example. Alternating current magnetic susceptibility measurements under zero external dc field displayed fully formed temperature- and frequency-dependent out-of-phase peaks for the [(Ni6Dy3III)-Dy-II] analogue, establishing its single molecule magnetism behavior with U-eff = 24 K.