Transition metal complexes with bidentate ligand having an imidazole ring

• US 20040040840A1
• Filed: 08/11/2003
• Published: 03/04/2004
• Est. Priority Date: 11/15/1999
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Therasense Incorporated (Abbott Laboratories Incorporated)
• Inventors: Heller, Adam, Mao, Fei
• Granted Patent: US 7,090,756 B2
• Time in Patent Office: Days
• US Class Current: 204/403.04
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: C07F 15/0026 without a metal-carbon linkage
• CPC Class Codes: C07F 15/0053 without a metal-carbon linkage
• CPC Class Codes: C07F 15/025 without a metal-carbon linkage
• CPC Class Codes: C07F 15/065 without a metal-carbon linkage
• CPC Class Codes: C07F 9/005 Compounds of elements of Group 5 of the Periodic Table without metal-carbon linkages
• CPC Class Codes: C08F 8/42 Introducing metal atoms or metal-containing groups
• CPC Class Codes: C08F 8/44 Preparation of metal salts or ammonium salts
• CPC Class Codes: C09B 57/10 Metal complexes of organic compounds not being dyes in uncomplexed form
• CPC Class Codes: C12Q 1/004 mediator-assisted

Abstract

Novel transition metal complexes of iron, cobalt, ruthenium, osmium, and vanadium are described. The transition metal complexes can be used as redox mediators in enzyme based electrochemical sensors. In such instances, transition metal complexes accept electrons from, or transfer electrons to, enzymes at a high rate and also exchange electrons rapidly with the sensor. The transition metal complexes include at least one substituted or unsubstituted biimidazole ligand and may further include a second substituted or unsubstituted biimidazole ligand or a substituted or unsubstituted bipyridine or pyridylimidazole ligand. Transition metal complexes attached to polymeric backbones are also described.

Claims

1. A transition metal complex having the formula:

2. The transition metal complex of claim 1, wherein both R₁, R₁′

, and R₂ are unsubstituted C1 to C12 alkyl.

3. The transition metal complex of claim 1, wherein R₃, R₄, R₅ and R₆ are —

H.

4. The transition metal complex of claim 1, wherein L₁ is a monodentate ligand.

5. The transition metal complex of claim 1, wherein L₁ comprises a heterocyclic compound containing at least one nitrogen atom.

6. The transition metal complex of claim 1, wherein L₁ comprises a heterocyclic compound coupled to a polymeric backbone.

7. The transition metal complex of claim 6, wherein L₁ and L₂ in combination form a bidentate ligand.

8. The transition metal complex of claim 1, wherein L₁ and L₂ in combination form a bidentate ligand.

9. The transition metal complex of claim 8, wherein the bidentate ligand comprises a 2,2′

-bipyridine having the following formula;

10. The transition metal complex of claim 1, wherein L₁ and L₂ in combination form a first bidentate ligand and L₃ and L₄ in combination form a second bidentate ligand.

11. The transition metal complex of claim 10, wherein at least one of the first and second bidentate ligands is selected from the group consisting of substituted and unsubstituted 2,2′

-bipyridines, 2,2′

-biimidazoles, and 2-(2-pyridyl)imidazoles.

12. The transition metal complex of claim 1, wherein M is osmium and the transition complex has the following formula:

13. A redox mediator having the formula:

14. The redox mediator of claim 13, wherein L is selected from the group consisting of:

15. The redox mediator of claim 13, wherein L₁ comprises a heterocyclic compound containing at least one nitrogen atom.

16. The redox mediator of claim 13, wherein L₁ comprises a heterocyclic compound coupled to a polymeric backbone.

17. The redox mediator of claim 13, wherein at least one of L, L₁, L₂, L₃ and L₄ is coupled to a polymeric backbone.

18. A sensor comprising:

a working electrode;

a counter electrode; and

a redox mediator disposed proximate to the working electrode, the redox mediator having the formula;

wherein M is iron, cobalt, ruthenium, osmium, or vanadium;

L is a bidentate ligand comprising at least one imidazole ring;

c is an integer selected from −

1 to −

5 or +1 to +5 indicating a positive or negative charge;

X represents at least one counter ion;

d is an integer from 1 to 5 representing the number of counter ions, X; and

L₁, L₂, L₃ and L₄ are ligands.