A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises: contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound; and removing water from the mixture in the absence of an azeotrope solvent to provide the metal salt of the hydroxy-substituted aromatic compound that contains less than 3,000 ppm of water.

A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises: contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound; and removing water from the mixture in the absence of an azeotrope solvent to provide the metal salt of the hydroxy-substituted aromatic compound that contains less than 3,000 ppm of water.

Coordination complexes can have a metal center with at least one unsubstituted catecholate ligand and at least one monosulfonated catecholate ligand or a salt thereof bound thereto. Some coordination complexes can have a formula of D.sub.gTi(L.sub.1).sub.x(L.sub.2).sub.y, in which D is a counterion selected from NH.sub.4.sup.+, Li.sup.+, Na.sup.+, K.sup.+, or any combination thereof; g ranges between 2 and 6; L.sub.1 is an unsubstituted catecholate ligand; L.sub.2 is a monosulfonated catecholate ligand; and x and y are non-zero numbers such that x+y=3. Methods for synthesizing such coordination complexes can include providing a neat mixture of catechol and a sub-stoichiometric amount of sulfuric acid, heating the neat mixture to form a reaction product containing catechol and a monosulfonated catechol or a salt thereof, and forming a coordination complex from the reaction product without separating the catechol and the monosulfonated catechol or the salt thereof from one another.

Coordination complexes can have a metal center with at least one unsubstituted catecholate ligand and at least one monosulfonated catecholate ligand or a salt thereof bound thereto. Some coordination complexes can have a formula of D.sub.gTi(L.sub.1).sub.x(L.sub.2).sub.y, in which D is a counterion selected from NH.sub.4.sup.+, Li.sup.+, Na.sup.+, K.sup.+, or any combination thereof; g ranges between 2 and 6; L.sub.1 is an unsubstituted catecholate ligand; L.sub.2 is a monosulfonated catecholate ligand; and x and y are non-zero numbers such that x+y=3. Methods for synthesizing such coordination complexes can include providing a neat mixture of catechol and a sub-stoichiometric amount of sulfuric acid, heating the neat mixture to form a reaction product containing catechol and a monosulfonated catechol or a salt thereof, and forming a coordination complex from the reaction product without separating the catechol and the monosulfonated catechol or the salt thereof from one another.

A method for producing an aqueous electrolyte comprising a redox-active coordination compound of a transition metal which comprises reacting an oxide of the corresponding transition metal in an aqueous reaction medium with a chelating agent in a hydrothermal reaction zone at a temperature in the range of from 100 C. to 160 C. for a period of from 4 hours to 48 hours.

A method for producing an aqueous electrolyte comprising a redox-active coordination compound of a transition metal which comprises reacting an oxide of the corresponding transition metal in an aqueous reaction medium with a chelating agent in a hydrothermal reaction zone at a temperature in the range of from 100 C. to 160 C. for a period of from 4 hours to 48 hours.

A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises: contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound; and removing water from the mixture in the absence of an azeotrope solvent to provide the metal salt of the hydroxy-substituted aromatic compound that contains less than 3,000 ppm of water.

A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises: contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound; and removing water from the mixture in the absence of an azeotrope solvent to provide the metal salt of the hydroxy-substituted aromatic compound that contains less than 3,000 ppm of water.

A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises: contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound; and removing water from the mixture in the absence of an azeotrope solvent to provide the metal salt of the hydroxy-substituted aromatic compound that contains less than 3,000 ppm of water.

A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises reacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in an aqueous medium to provide a mixture comprising water and a metal salt of the hydroxy-substituted aromatic compound; contacting the mixture with a substantially water-immiscible solvent at a temperature greater than the boiling point of water at a prevailing pressure; introducing an optionally substituted C1-6 aliphatic alcohol; and removing water and the alcohol to provide a slurry comprising the metal salt of the hydroxy-substituted aromatic compound and the water-immiscible solvent.