Layered 2D materials like chalcogenide-based materials that possess tunable and defined crystallographic structures and elemental compositions offer a broad portfolio of potential applications. The lacking control of large scale and homogeneous formation of 2D layered materials MX₂ (X = S, Se) in commercial formation processes motivated us to develop new concepts and designing matters by unique synthetic approaches to layered chalcogenide based functional materials.

Herein we report a uniform synthesis of molecular building blocks to form (air)stable precursor classes [M{S(C₂H₄)₂NMe}_x] (M = Mo^IV, W^IV, Ti^IV, Zr^IV, Hf^IV, Nb^IV, Ta^IV, Sn^IV, x = 2; M = Ge^II, Sn^II, x = 1), which reliably delivered layered 2D van der Waals heterostructures.

Following a simple synthetic protocol, the reaction of tridentate SNS donor ligand with suitable metal compounds resulted in (air)stable molecular precursors, which have been characterized on an atomic scale. These precursors enabled the formation of homogeneous crystalline layered chalcogenide based 2D structures of MoS₂, WS₂ and TiS₂ from the gas-phase or SnS₂/Se₂ as well as SnS/Se materials can be generated from solution-based decomposition using molecular precursors, respectively. These molecular building blocks provide an extraordinary synthetic pathway to an extraordinary molecular precursor class, which delivered reliable approach for large scale synthesis to chalcogenide-based van der Waals materials for specific applications.

Dr. Veronika Brune