Titanium complexes containing catecholate ligands can be desirable active materials for flow batteries and other electrochemical energy storage systems. Such complexes can be formed, potentially on very large scales, through reacting a catechol compound in an organic solvent with titanium tetrachloride, and then obtaining an aqueous phase containing an alkali metal salt form of the titanium catechol complex. More specifically, the methods can include: forming a catechol solution and heating, adding titanium tetrachloride to the catechol solution, reacting the titanium tetrachloride with a catechol compound to evolve HCl gas and to form an intermediate titanium catechol complex, and adding an alkaline aqueous solution to the intermediate titanium catechol complex to form an alkali metal salt form titanium catechol complex that is at least partially dissolved in an aqueous phase. The aqueous phase can be separated from an organic phase. The resulting complexes can be substantially free of alkali metal halide salts.

Titanium complexes containing catecholate ligands can be desirable active materials for flow batteries and other electrochemical energy storage systems. Such complexes can be formed, potentially on very large scales, through reacting a catechol compound in an organic solvent with titanium tetrachloride, and then obtaining an aqueous phase containing an alkali metal salt form of the titanium catechol complex. More specifically, the methods can include: forming a catechol solution and heating, adding titanium tetrachloride to the catechol solution, reacting the titanium tetrachloride with a catechol compound to evolve HCl gas and to form an intermediate titanium catechol complex, and adding an alkaline aqueous solution to the intermediate titanium catechol complex to form an alkali metal salt form titanium catechol complex that is at least partially dissolved in an aqueous phase. The aqueous phase can be separated from an organic phase. The resulting complexes can be substantially free of alkali metal halide salts.

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 polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

A method of making an organic salt comprising: reacting a polyphenol with a base and optionally a dihaloaromatic compound. The polyphenol is resveratrol; dihydroresveratrol; 4,4-(but-2-ene-1,4-diyl)bis-2-methoxyphenol; 4,4-(1,4-butane-diyl)bis-2-methoxyphenol; 1-ethyl-2-methyl-3-(4-hydroxyphenyl)-5-hydroxyindane; 4,4-(ethane-1,1-diyl)diphenol; 5,5-methylenebis(2-methoxy-4-methylphenol); 4,4-methylenebis(5-isopropyl-2-methylphenol); 4,4-(1-ethyl-2-methyl-1,3-propanediyl)bisphenol; or 5,5-(ethane-1,1-diyl)bis(2-methoxy-4-methylphenol. The dihaloaromatic compound if present comprises a carbonyl group, a sulfonyl group, a sulfinyl group, or a phosphoryl group. There is a molar excess of the hydroxy groups of the polyphenol relative to halo groups of the dihaloaromatic compound if present. The corresponding phthalonitrile monomers and thermosets made from the organic salts are disclosed.

A method of making an organic salt comprising: reacting a polyphenol with a base and optionally a dihaloaromatic compound. The polyphenol is resveratrol; dihydroresveratrol; 4,4-(but-2-ene-1,4-diyl)bis-2-methoxyphenol; 4,4-(1,4-butane-diyl)bis-2-methoxyphenol; 1-ethyl-2-methyl-3-(4-hydroxyphenyl)-5-hydroxyindane; 4,4-(ethane-1,1-diyl)diphenol; 5,5-methylenebis(2-methoxy-4-methylphenol); 4,4-methylenebis(5-isopropyl-2-methylphenol); 4,4-(1-ethyl-2-methyl-1,3-propanediyl)bisphenol; or 5,5-(ethane-1,1-diyl)bis(2-methoxy-4-methylphenol. The dihaloaromatic compound if present comprises a carbonyl group, a sulfonyl group, a sulfinyl group, or a phosphoryl group. There is a molar excess of the hydroxy groups of the polyphenol relative to halo groups of the dihaloaromatic compound if present. The corresponding phthalonitrile monomers and thermosets made from the organic salts are disclosed.

A method of making an organic salt comprising: reacting a polyphenol with a base and optionally a dihaloaromatic compound. The polyphenol is resveratrol; dihydroresveratrol; 4,4-(but-2-ene-1,4-diyl)bis-2-methoxyphenol; 4,4-(1,4-butane-diyl)bis-2-methoxyphenol; 1-ethyl-2-methyl-3-(4-hydroxyphenyl)-5-hydroxyindane; 4,4-(ethane-1,1-diyl)diphenol; 5,5-methylenebis(2-methoxy-4-methylphenol); 4,4-methylenebis(5-isopropyl-2-methylphenol); 4,4-(1-ethyl-2-methyl-1,3-propanediyl)bisphenol; or 5,5-(ethane-1,1-diyl)bis(2-methoxy-4-methylphenol. The dihaloaromatic compound if present comprises a carbonyl group, a sulfonyl group, a sulfinyl group, or a phosphoryl group. There is a molar excess of the hydroxy groups of the polyphenol relative to halo groups of the dihaloaromatic compound if present. The corresponding phthalonitrile monomers and thermosets made from the organic salts are disclosed.

In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.