An unprecedented pentanary chalcohalide with Mn atoms in two chemical environments: unique bonding characteristics and magnetic properties

Abstract

Mixed-anion chalcohalides have attracted significant attention lately, attributable to their unique structure compositions and captivating physicochemical properties. Herein, an unprecedented pentanary chalcohalide, Cs₂[Mn₂Ga₃S₇Cl] (1), was discovered by solid-state reaction at 1223 K. It is constructed by alternately stacked layers, each of which is made by a 2D [Ga₃S₉]⁹⁻ ribbon embedded with 1D [Mn₂S₈Cl]¹³⁻ chains. The coexistence of two Mn-coordinated polyhedra ([MnS₆] octahedra and hetero-ligand [MnS₃Cl] tetrahedra) in one material is surprisingly observed for the first time in the Mn-containing inorganic chalcogenides or chalcohalides. More interestingly, it exhibits ferrimagnetic (FIM) behaviour, which could be correlated to the magnetic sub-lattice sites with different coordination geometries. This work suggests a new route for designing and searching for unique functional chalcohalides with different chemical environments.