MOClx

MOClx is a designation used in inorganic chemistry to denote a family of metal oxychloride compounds in which a central metal is coordinated to both oxide and chloride ligands. The symbol x indicates the variable number of chlorine ligands, and the exact stoichiometry depends on the specific metal and synthesis conditions. The term is commonly applied to transition‑metal species where oxide and chloride ligands coexist in the same compound or in extended solid‑state structures.

Representative members include molybdenum oxychloride MoOCl2 and vanadium oxychloride VOCl3; other transition metals can form analogous MOClx species. These compounds may exist as discrete molecules or as extended, layered networks in the solid state. They are typically moisture sensitive and can hydrolyze or decompose upon contact with water, sometimes releasing hydrogen chloride.

MOClx compounds are usually prepared by controlled chlorination or oxidation of metal oxides or metal chlorides. Common routes include oxidation of metal chlorides under an oxychlorination environment, reaction of metal oxides with hydrogen chloride gas at elevated temperature, or hydrolysis of higher chlorides in the presence of oxide sources. Purification and handling often require inert atmospheres due to sensitivity to moisture and air.

Structural motifs vary widely: coordination geometries range from distorted octahedral to other arrangements, and ligands can bridge to form polymeric networks. The compounds are typically Lewis acidic and can serve as reactive intermediates in subsequent transformations.

Applications for MOClx include serving as precursors to metal oxides, acting as catalysts in oxidation or hydrolysis reactions, and providing volatile or solid‑state sources for thin‑film deposition and materials synthesis. Research interest focuses on tuning their composition and structure to optimize reactivity and stability.