Pb-free organic-inorganic hybrid compounds are emerging as a versatile class of light-emitting materials, due to their optoelectronic, magneto-optic, field-sensing properties, low toxicity, and natural abundance. Particularly, ionic Mn2+ chlorido organic-inorganic hybrid compounds display high photoluminescent quantum yields, large Stokes shift, and are considered a structurally rich class of materials. A carefully selected wide variety of organic cations can be combined with MnCl64- octahedra to obtain low-dimensional organic-inorganic structures such as two-dimensional (2D) sheets, one-dimensional (1D) chains, or zero-dimensional (0D) isolated octahedra, where each structure dimensionality displays unique photoluminescent properties. In this mini-review, the focus is on the structure-property relationships in ionic low-dimensional compounds containing MnCl64- octahedra and a variety of organic cations. Specifically, we explore how the choice of organic cations can influence not only the characteristic red-orange emissions but also the emergent coupled functionalities, including ferroelectricity and magnetism. Conceptual connections are established to better understand the structural and property-related phenomena that govern these compounds as next-generation multifunctional materials.
Bothma et al. (Wed,) studied this question.