# US 9,040,704 B2 · Fluorescent dyes with large stokes shifts

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- Number: US 9,040,704 B2
- Document ID: US9040704B2
- Status: Granted
- Kind: B2
- Application number: 14/238,640
- Filed: 2012-08-10
- Published: 2014-07-24
- Granted: 2015-05-26
- Earliest claimed: 2011-08-12
- Assignees: UTI Limited Partnership
- Applicants: Warren Edward Piers; Juan Felipe Araneda
- Inventors: Warren Edward Piers; Juan Felipe Araneda
- Web page: https://patentgrep.com/patent/US9040704B2

## CPC

- C09B 23/166: {containing two or more nitrogen atoms (hydrazon dyes -CH=N-N- C09B26/02)}
- C09B 57/00: Other synthetic dyes of known constitution
- C09B 57/10: Metal complexes of organic compounds not being dyes in uncomplexed form
- C09K 11/06: containing organic luminescent materials
- G01N 33/582: {with fluorescent label}
- C09K 2211/1007: Non-condensed systems
- C09K 2211/1011: Condensed systems
- C09K 2211/1029: containing one nitrogen atom as the heteroatom
- C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

Herein are disclosed fluorescent dyes based around a framework for a ligand comprising a pyridyl group linked to a diaryl anilido unit. A variety of ligands based on this framework are disclosed. The ligands chelate to a BF2 center to produce the fluorescent dye. The disclosed dyes combine longer Stokes shifts (approximately 100 nm) with increased quantum yields. They are also photostable in aqueous and organic solutions for several hours. These dyes may be used in the labeling of biomolecules for bioimaging and assays. Also disclosed are methods for the synthesis of these dyes.

## Claims

### Claim 1

A fluorophore shown by formula (1), or a salt thereof,
wherein bonds indicated by dotted lines may be independently present or absent; and each hydrogen atom may be independently substituted by an alkyl group.

### Claim 2 (depends on 1)

The fluorophore of claim 1, wherein at least one said hydrogen is substituted by a said alkyl group.

### Claim 3 (depends on 2)

The fluorophore of claim 2, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 4 (depends on 1)

The fluorophore of claim 1, wherein said fluorophore has a Stokes shift of about 70 nm to about 140 nm.

### Claim 5 (depends on 1)

The fluorophore of claim 1, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 6

A fluorophore shown by formula (2), or a salt thereof,
wherein each hydrogen atom may be independently substituted by an alkyl group.

### Claim 7 (depends on 6)

The fluorophore of claim 6, wherein at least one said hydrogen is substituted by a said alkyl group.

### Claim 8 (depends on 7)

The fluorophore of claim 7, wherein the hydrogen atoms at positions o and o′ are substituted by isopropyl.

### Claim 9 (depends on 8)

The fluorophore of claim 8 wherein said fluorophore has a Stokes shift of about 90 nm to about 100 nm.

### Claim 10 (depends on 7)

The fluorophore of claim 7, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 11 (depends on 6)

The fluorophore of claim 6, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 12

A fluorophore shown by formula (2), or a salt thereof,
wherein the hydrogen atoms at positions 1 and 2 are substituted by a —(CH2)4— group such that said group bridges positions 1 and 2, and wherein the hydrogen atoms at positions o and o′ are substituted by isopropyl.

### Claim 13 (depends on 12)

The fluorophore of claim 12 wherein said fluorophore has a Stokes shift of about 95 nm to about 105 nm.

### Claim 14

A fluorophore shown by formula (3), or a salt thereof,
wherein each hydrogen atom may be independently substituted by an alkyl group.

### Claim 15 (depends on 14)

The fluorophore of claim 14, wherein at least one said hydrogen is substituted by a said alkyl group.

### Claim 16 (depends on 15)

The fluorophore of claim 15, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 17 (depends on 14)

The fluorophore of claim 14 wherein the hydrogen atoms at o and o′ are substituted by isopropyl.

### Claim 18 (depends on 17)

The fluorophore of claim 17 wherein said fluorophore has a Stokes shift of about 98 nm to about 108 nm.

### Claim 19 (depends on 14)

The fluorophore of claim 14 wherein said fluorophore has a Stokes shift of about 114 nm to about 124 nm.

### Claim 20 (depends on 14)

The fluorophore of claim 14, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 21

A fluorophore shown by formula (4), or a salt thereof,
wherein each hydrogen atom may be independently substituted by an alkyl group.

### Claim 22 (depends on 21)

The fluorophore of claim 21, wherein at least one said hydrogen is substituted by a said alkyl group.

### Claim 23 (depends on 22)

The fluorophore of claim 22, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 24 (depends on 21)

The fluorophore of claim 21 wherein the hydrogen atoms at positions 6 and 9 are substituted by tert-butyl.

### Claim 25 (depends on 21)

The fluorophore of claim 21, wherein said alkyl group is a linear, branched or cyclic monovalent hydrocarbon radical having up to 20 carbon atoms.

### Claim 26

A method of producing a fluorophore shown by formula (1), said method comprising the steps of:
providing a ligand capable of chelating to a BF2 center,
mixing said ligand with a solution of triethyl amine, and
adding boron trifluoride etherate to said solution,
wherein formula (1) is as follows:
wherein bonds indicated by dotted lines may be independently present or absent; and each hydrogen atom may be independently substituted by an alkyl group.