New tetranuclear manganese clusters with [Mn II3MnIII] and [Mn II2Mn III2] metallic cores exhibiting low and high spin ground state

Abstract

Two tetranuclear mixed-valent clusters, [Mn^II₃Mn^IIICl(Ph₃CCOO)₄(CH₃OCH₂CH₂O)₄(CH₃CN)]·0.4C₆H₅CH₃·0.6CH₃CN (1) with an unprecedented [Mn^II₃Mn^III] core and [Mn^II₂Mn^III₂Cl₄(CH₃OCH₂CH₂O)₆] (2), were synthesized and characterized by single-crystal X-ray diffraction and magnetic measurements. Their properties were analyzed in the framework of phenomenological modelling and DFT calculations, showing acceptable agreement between theory and experiment. Both building blocks [Mn^II₃Mn^III] and [Mn^II₂Mn^III₂] provide good examples of bipartite systems with the lowest S_T = 1/2 and highest S_T = 9 magnetic ground states available for them. The topology of the magnetic interactions in the [Mn^II₃Mn^III] core provides a suitable template for the molecular qubit implementation and the stability of the spin-1/2 ground state strongly depends on the antiferromagnetic Mn^II–Mn^II coupling.