Single-Component Magnetic Conductors Based on Mo₃S₇ Trinuclear Clusters with Outer Dithiolate Ligands

A trinuclear cluster complex containing the Mo3S7 central unit coordinated to dithiolate ligands, in particular the organic dmit (1,3-dithia-2-thione-4,5-dithiolate) anion, has been used to prepare a single-component molecular conductor formed by the threefold symmetry magnetic building block Mo3S7(dmit)3 (1). The [Mo3S7(dmit)3]2- ([1]2-) diamagnetic anion forms dimers by interaction between the electrophilic cluster axial sulfur atoms and the sulfur atoms of the outer dithiolate ligand. Additional contacts between adjacent dmit ligands result in chain formation. The two-electron oxidation of [1]2- yields to a three-dimensional molecular solid formed by neutral Mo3S7(dmit)3 (1) units with partially filled molecular orbitals, which exhibits sizable intermolecular electronic interactions together with a significant electron delocalization. It also contains large open channels. The interactions responsible for the conducting properties have been identified using a first-principle DFT approach and the calculated electronic structure has allowed us to model the magnetic behavior of the material with two competing antiferromagnetic interactions to produce a spin-frustrated extended network. The potential of this Mo3S7 cluster complex to be modified together with the capability of filling the open channels with doping species paves the way to an entirely new set of molecular conductors and/or magnets.