Metal complex catalysts and uses thereof
View Patent ↗The invention relates to novel metal complexes useful as catalysts in redox reactions (such as, hydrogen (H 2 ) production). In particular, the invention provides novel transition metal (e.g., cobalt (Co) or nickel (Ni)) complexes, in which the transition metal is coupled with N,N-Bis(2-pyridinylmethyl)-2,2′-Bipyridine-6-methanamine (DPA-Bpy), 6′-((bis(pyridin-2-ylmethyl)amino)methyl)-N,N-dimethyl-2,2′-bipyridin-6-amine (DPA-ABpy), N,N-bis((isoquinolin-1-yl)methyl)(6-(pyridin-2-yl)pyridin-2-yl)methanamine (DIQ-Bpy), or a derivative thereof. The invention also relates to a method of producing H 2 from an aqueous solution by using the metal complex as a catalyst. In certain embodiments, the invention provides a metal complex of the formulae as described herein.
1. A metal complex of formula (I):
[M(G)Y] m (X) n (L) a (I)
wherein
M is a transition metal;
G is N,N-bis((isoquinolin-1-yl)methyl)(6-(pyridin-2-yl)pyridin-2-yl)methanamine (DIQ-Bpy);
Y, for each occurrence, independently is a halogen group or a water moiety;
X, for each occurrence, independently is an anion;
m is the number of cations per metal complex;
n is the number of anions per metal complex;
L is absent or a neutral molecule; and
a is the number of neutral molecules per metal complex.
2. The metal complex of claim 1 , wherein said metal is cobalt.
3. The metal complex of claim 2 , wherein Y is chloride.
4. The cobalt complex of claim 3 , wherein a is 0; and X is Cl − .
5. A metal complex of formula (III):
[M(G)Y] m (X) n (L) a (III)
or a salt, solvate or hydrate thereof;
wherein
M is a transition metal;
G is 6′-((bis(pyridin-2-ylmethyl)amino)methyl)-N,N-dimethyl-2,2′-bipyridin-6-amine (“DPA-ABpy”), or N,N-bis((isoquinolin-1-yl)methyl)(6-(pyridin-2-yl)pyridin-2-yl)methanamine (DIQ-Bpy);
Y, for each occurrence, independently is absent, a halogen group or a water moiety;
X, for each occurrence, independently is an anion;
m is the number of cations per metal complex;
n is the number of anions per metal complex;
L is absent or a neutral molecule; and
a is the number of neutral molecules per metal complex.
6. The metal complex of claim 5 , wherein M is Co, Ru, Ni, or Fe.
7. The metal complex of claim 6 , wherein G is DPA-ABpy.
8. The metal complex of claim 6 , wherein Y is absent or a water moiety.
9. The metal complex of claim 6 , wherein said metal complex is [Ni(DPA-ABpy)(OH 2 )](BF 4 ) 2 or [Co(DPA-ABpy)](PF 6 ) 2 , or a salt, solvate or hydrate thereof.
10. A catalyst comprising a metal complex of claim 1 .
11. A process for producing hydrogen from an aqueous solution comprising a step of adding a catalyst of claim 10 to said aqueous solution.
12. The process of claim 11 , further comprising a step of carrying out electrolysis or photolysis on the aqueous solution containing the catalyst.
13. The process of claim 12 , wherein said aqueous solution comprises ascorbic acid.
14. The process of claim 11 , wherein said catalyst comprises [Ni(DPA-ABpy)(OH 2 )](BF 4 ), or [Co(DPA-ABpy)](PF 6 ) 2 .
15. The metal complex of claim 1 , wherein G is N,N-bis((isoquinolin-1-yl)methyl)(6-(pyridin-2-yl)pyridin-2-yl)methanamine (DIQ-Bpy).
16. N,N-bis((isoquinolin-1-yl)methyl)(6-(pyridin-2-yl)pyridin-2-yl)methanamine.
17. A metal complex comprising N,N-bis((isoquinolin-1-yl)methyl)(6-(pyridin-2-yl)pyridin-2-yl)methanamine, and a transition metal; or a salt, solvate, or hydrate thereof.
18. The metal complex of claim 17 , wherein the transition metal is Co, Ru, Ni, or Fe.
19. The metal complex of claim 17 , wherein the complex further comprises an anion.
20. The complex of claim 17 , wherein the complex is [Ru(DIQ-Bpy)(Cl)](PF 6 ).