Coordination Complexes Containing Monosulfonated Catecholate Ligands and Methods for Producing the Same

摘要

Flow batteries and other electrochemical systems can contain an active material that is a coordination complex having at least one monosulfonated catecholate ligand or a salt thereof bound to a metal center. The monosulfonated catecholate ligand has a structure of; ;More particularly, the coordination complex can be a titanium coordination complex with a formula of D_gTi(L₁)(L₂)(L₃), in which D is a counterion selected from H, NH₄⁺, Li⁺, Na⁺, K⁺, or any combination thereof; g ranges between 3 and 6; and L₁, L₂ and L₃ are ligands, where at least one of L₁, L₂ and L₃ is a monosulfonated catecholate ligand. Methods for synthesizing such monosulfonated catecholate ligands can include providing a neat mixture of catechol and up to about 1.3 stoichiometric equivalents of sulfuric acid, and heating the neat mixture at a temperature of about 80° C. or above to form 3,4-dihydroxybenzenesulfonic acid or a salt thereof.