Purified Metal Complex Having Oxalic Acid as Ligand, and Method For Producing Purified Solution of Said Metal Complex in Non-Aqueous Solvent

A method for producing a purified non-aqueous solvent solution of a metal complex having oxalic acid as a ligand, from a non-aqueous solvent solution of a metal complex having oxalic acid as a ligand and containing oxalic acid as an impurity by decomposing and removing oxalic acid contained as an impurity in the non-aqueous solvent solution of a metal complex having oxalic acid as a ligand and containing oxalic acid as an impurity,

• wherein the oxalic acid contained in the solution as an impurity is decomposed by a reaction with a thionyl halide in a non-aqueous solvent;
• and a decomposition product of the reaction and an unreacted thionyl halide are removed by deaeration.