Chair-Shaped MnII2LnIII4 (Ln = Gd, Tb, Dy, Ho) Heterometallic Complexes Assembled from a Tricompartmental Aminobenzohydrazide Ligand

The reaction of a new compartmental ligand, H3L [H3L = N′-(2-hydroxy-3-methoxybenzylidene)-2-(-2-hydroxy-3-methoxybenzylideneamino)­benzohydrazide], with lanthanide salts followed by reaction of MnII salts in presence of triethylamine along with pivalic acid afforded heterometallic hexanuclear complexes, [{LMn­(Cl)­(μ3-OH)­Gd2(μ3-OH)­(μ-Piv)2}2·3MeCN·7MeOH·H2O] (1), [{LMn­(Cl)­(μ3-OH)­Tb2(μ3-OH)­(μ-Piv)2}2·8MeCN] (2), [{LMn­(Cl)­(μ3-OH)­Dy2(μ3-OH)­(μ-Piv)2}2·2Et2O·4MeCN·3H2O] (3), and [{LMn­(Cl)­(μ3-OH)­Ho2(μ3-OH)­(μ-Piv)2}2·8MeCN] (4). All of the complexes are isostructural, in which two trianionic ligands [L3–] hold the six metal ions, affording a chair-shaped hexametallic core. The asymmetric unit contains half of the molecule, where Mn­(II) ions occupy the inner coordination pocket of the ligand in a distorted square pyramidal geometry (NO3Cl) and the two lanthanide ions occupy the two outer-coordination pockets. Magnetic measurements reveal that antiferromagnetic interactions take place in complexes 1, 3, and 4. On the other hand, complex 2 shows the presence of ferromagnetic interactions.