MC3H2O42

MC3H2O42 is a condensed formula used in coordination chemistry to denote a metal malonate complex with two malonate ligands, i.e., M(C3H2O4)2. In this representation, M is a divalent metal cation such as Ca2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, or Zn2+. The compound class is typically encountered as solids, sometimes with water of crystallization.

The malonate ligand, C3H2O4^2−, derives from malonic acid and coordinates to metal centers through the oxygen atoms of the carboxylate groups. Binding modes can vary: carboxylate groups may act as chelating groups, bridge between metal centers, or adopt mixed modes. As a result, MC3H2O42 compounds often form polymeric networks in the solid state, and the coordination geometry around the metal is influenced by the specific metal and ligation pattern, commonly approaching octahedral for many transition metals.

Synthesis generally involves reaction of a soluble metal salt with a malonate source (such as malonic acid or sodium malonate) in water or a mixed solvent, often with heating to promote precipitation of the complex. Depending on conditions and the metal, hydrates of the complex may form, giving species written as MC3H2O42·nH2O in practice.

Properties and applications: these complexes are of interest in coordination chemistry as model systems for multidentate carboxylate binding and as precursors for metal oxides. Thermal decomposition or calcination of MC3H2O42-type complexes can yield metal oxides useful in materials science and catalysis. Safety follows standard handling for inorganic salts and organic ligands.