High nuclearity manganese(III) compounds containing phenol-pyrazole ligands: the influence of the ligand on the core geometry

Three high-nuclearity manganese(III) clusters have been synthesized and characterized: [Mn8(μ4-O)4(phpzH)8(thf)4] (1), [Mn8(μ4-O)4(phpzH)4(EtOH)4]·2EtOH (2), and [Mn6(μ3-O)4(μ3-Br)2(HphpzEt)6(phpzEt)] (3). Compounds 1 and 2 contain a [Mn8(μ4-O4)(phpzH)8] core in which antiferromagnetic interactions between the manganese(III) ions are found. Compound 3 is a hexanuclear manganese(III) cluster in which weak ferromagnetic interactions appear to be operative. The formation and the stability of the cluster cores in relation to the type of phenol-pyrazole ligand and the reaction conditions are discussed.