Coordination complexes containing monosulfonated catecholate ligands and methods for producing the same

Patent metadata

Field	Value
Publication number	US-2017256811-A1
Application number	US-201615060493-A
Country	US
Kind code	A1
Filing date	Mar 3, 2016
Priority date	Mar 3, 2016
Publication date	Sep 7, 2017
Grant date	—

Abstract

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 g Ti(L 1 )(L 2 )(L 3 ), in which D is a counterion selected from H, NH 4 | , Li | , Na | , K | , or any combination thereof g ranges between 3 and 6; and L 1 , L 2 and L 3 are ligands, where at least one of L 1 , L 2 and L 3 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.

First claim

What is claimed is the following:

1 . A composition comprising:
a coordination complex having at least one monosulfonated catecholate ligand or a salt thereof bound to a metal center;
wherein the at least one monosulfonated catecholate ligand has a structure of

2 . The composition of claim 1 , wherein the metal center is a transition metal.

3 . The composition of claim 2 , wherein the transition metal is Ti.

4 . The composition of claim 3 , wherein the coordination complex has a formula of
D g Ti(L 1 )(L 2 )(L 3 ); wherein D is a counterion selected from H, NH 4 | , Li | , Na | , K | , or any combination thereof; g ranges between 3 and 6; and L 1 , L 2 and L 3 are ligands, at least one of L 1 , L 2 and L 3 being a monosulfonated catecholate ligand.

5 . The composition of claim 4 , wherein each of L 1 , L 2 and L 3 are monosulfonated catecholate ligands and g is 5 or 6.

6 . The composition of claim 4 , wherein one of L 1 , L 2 and L 3 is a monosulfonated catecholate ligand and g is 3 or 4.

7 . The composition of claim 6 , wherein two of L 1 , L 2 and L 3 are non-sulfonated catecholate ligands.

8 . The composition of claim 7 , wherein two of L 1 , L 2 and L 3 are unsubstituted catecholate ligands.

9 . The composition of claim 4 , wherein the coordination complex comprises both Na + and K + counterions.

10 . The composition of claim 4 , wherein two of L 1 , L 2 and L 3 are monosulfonated catecholate ligands, one of L 1 , L 2 and L 3 is a non-sulfonated catecholate ligand, and g is 4 or 5.

11 . The composition of claim 10 , wherein one of L 1 , L 2 and L 3 is an unsubstituted catecholate ligand.

12 . The composition of claim 4 , further comprising:
an aqueous solution in which the coordination complex is dissolved.

13 . The composition of claim 12 , wherein the aqueous solution has an alkaline pH.

14 . The composition of claim 1 , wherein the coordination complex has an overall negative charge and comprises both Na + and K + counterions.

15 . The composition of claim 1 , further comprising:
an aqueous solution in which the coordination complex is dissolved.

16 . The composition of claim 15 , wherein the aqueous solution has an alkaline pH.

17 . A flow battery comprising:
a first half-cell having a first electrolyte solution therein, the first electrolyte solution comprising an aqueous solution comprising the composition of claim 4 .

18 . The flow battery of claim 17 , further comprising:
a second half-cell having a second electrolyte solution therein, the second electrolyte solution comprising an aqueous solution comprising an iron hexacyanide complex.

19 . A method comprising:
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 a reaction product comprising 3,4-dihydroxybenzenesulfonic acid or a salt thereof.

20 . The method of claim 19 , wherein less than about 5% of the catechol is converted into 2,3-dihydroxybenzenesulfonic acid or a salt thereof.

21 . The method of claim 19 , wherein the neat mixture contains between about 0.8 and 1.2 stoichiometric equivalents of sulfuric acid.

22 . The method of claim 19 , wherein the neat mixture contains between about 0.3 and about 0.5 stoichiometric equivalents of sulfuric acid.

23 . The method of claim 19 , wherein the neat mixture is heated at a temperature ranging between about 80° C. and about 110° C.

24 . The method of claim 19 , wherein the neat mixture is heated at a temperature ranging between about 80° C. and about 100° C.

25 . The method of claim 19 , further comprising:
isolating the 3,4-dihydroxybenzenesulfonic acid or a salt thereof from the reaction product.

26 . The method of claim 25 , further comprising:
treating the reaction product with a base before isolating the 3,4-dihydroxybenzenesulfonic acid or a salt thereof.

27 . The method of claim 25 , further comprising:
reacting the 3,4-dihydroxybenzenesulfonic acid or a salt thereof with a transition metal compound to form a coordination complex having at least one sulfonated catecholate ligand bound to a metal center.

28 . The method of claim 27 , wherein a mixture of catechol and 3,4-dihydroxybenzenesulfonic acid or a salt thereof is reacted with the transition metal compound to form the coordination complex.

29 . The method of claim 27 , wherein the transition metal compound is a titanium compound.

Assignees

• Lockheed Martin Advanced Energy Storage Llc

Inventors

• HUMBARGER Scott Thomas
• Millard Matthew

Classifications

• H01B1/121

  Charge-transfer complexes · CPC title

• C07C37/00

  Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring · CPC title

• H01M10/36

  Accumulators not provided for in groups H01M10/05-H01M10/34 · CPC title

• C07F7/28

  Titanium compounds · CPC title

• H01M8/188 Primary

  by recharging of redox couples containing fluids; Redox flow type batteries · CPC title