Ionic liquids and their use as solvents

• US 7,183,433 B2
• Filed: 09/26/2001
• Issued: 02/27/2007
• Est. Priority Date: 09/27/2000
• Status: Expired due to Term

• Current Assignee: Scionix
• Original Assignee: Scionix
• Inventors: Abbott, Andrew P., Davies, David L., Tambyrajah, Vasuki, Rasheed, Raymond K., Capper, Glen
• Primary Examiner(s): Jiang; Shaojia Anna
• Assistant Examiner(s): PUTTLITZ, KARL J
• Application Number:
  US10/381,060
• Publication Number:
  US 20040097755A1
• Time in Patent Office: 1,980 Days
• Field of Search: 564/281, 564/282, 564/284, 564/291, 564/292, 564/293, 564/294
• US Class Current: 564/282
• CPC Class Codes: B01J 2231/125 Radical (co)polymerisation, e.g. mediators therefor
• CPC Class Codes: B01J 2231/4261 Heck-type, i.e. RY + C=C, in which R is aryl
• CPC Class Codes: B01J 31/006 comprising organic radicals, e.g. TEMPO
• CPC Class Codes: B01J 31/0249 Ureas (R2N-C(=O)-NR2)
• CPC Class Codes: B01J 31/0279 the cationic portion being acyclic or nitrogen being a substituent on a ring
• CPC Class Codes: B01J 31/0284 of an aromatic ring, e.g. pyridinium
• CPC Class Codes: B01J 31/04 containing carboxylic acids or their salts B01J31/0277 - B01J31/0298 take precedence; multi-metal carboxylate complexes like Pd (II) acetate, i.e. Pd3 (OAc) 6 or Cr(II)acetate, i.e. Cr2(OAc)4 B01J31/2226
• CPC Class Codes: C07C 275/02 Salts; Complexes; Addition compounds
• CPC Class Codes: C07C 41/30 by increasing the number of carbon atoms, e.g. by oligomerisation
• CPC Class Codes: C07C 43/215 having unsaturation outside the six-membered aromatic rings
• CPC Class Codes: C25D 3/02 from solutions C25D5/34 - C25D5/46 take precedence
• CPC Class Codes: C25F 3/16 Polishing
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: Y02P 20/54 using solvents, e.g. supercritical solvents or ionic liquids

Abstract

Ionic compounds with a freezing point of up to 100° C. are formed by the reaction of an one amine salt of formula (I) R¹R²R³R⁴N⁺X⁻, such as choline chloride with an organic compound (II) capable of forming a hydrogen bond with X; such as urea, wherein the molar ration of I to II is from 1:1.5 to 1:2.5. R¹, R², R³ and R⁴ may be H, optionally substituted C₁ to C₅ alkyl, optionally substituted C₆ to C₁₀ cycloalkyl, optionally substituted C₆ to C₁₂ aryl, optionally substituted C₇ to C₁₂ alkaryl, or R¹ and R² taken together may represent a C₄ to C₁₀ optionally substituted alkylene group, thereby forming with the N atom of formula I a 5 to 11-membered heterocyclic ring and all of R¹, R², R³ and R⁴ are not identical, X⁻ may be NO₃⁻, F, Cl⁻, Br⁻, I⁻, BF₄⁻, ClO₄⁻, CN⁻, SO₃CF₃⁻, or COOCF₃⁻. The ionic compounds are useful as solvents, and electrolytes for example in electroplating, electrowinning, and electropolishing, and as catalysts.

Claims

1. An ionic compound, having a freezing point of up to 100°

C. formed by the reaction of at least one amine salt of the formula

R¹R²R³R⁴N⁺X⁻

 

 

(I)

with at least one organic compound (II) which is capable of forming a hydrogen bond with X⁻

, wherein R¹, R², R³ and R⁴ are each independently;

-

H,

optionally substituted C₁ to C₅ alkyl,

optionally substituted C₆ to C₁₀ cycloalkyl,

optionally substituted C₆ to C₁₂ aryl

optionally substituted C₇ to C₁₂ alkaryl, or wherein

R¹ and R² taken together represent a C₄ to C₁₀ optionally substituted alkylene group, thereby forming with the N atom of formula (I) a 5 to 11-membered heterocyclic ring, X⁻

, is NO₃⁻

, F⁻

, Cl⁻

, Br⁻

, I⁻

, BF₄⁻

, ClO₄⁻

, CN⁻

, SO₃CF₃⁻

, or COOCF₃⁻

, and wherein the term “

optionally substituted”

means that the group in question may or may not be substituted with one or more groups selected from OH, SH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, CHO, COR⁵ and OR⁵, wherein R⁵ is a C₁ to C₁₀ alkyl or cycloalkyl group,

wherein all of R¹, R², R³ and R⁴ are not identical, and

wherein compound (II) is a compound of the formula R⁶COOH, R⁷R⁸NH, R⁹CZNH₂, or R¹⁰OH, wherein;

-R⁶, R⁷, R⁸, R¹⁰ are each H, a C₁–

C₈ alkyl group, an aryl group, or a C₇–

C₁₂ alkaryl group optionally substituted with from 0 to 6 group selected from OH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, COR⁵ and OR⁵, wherein R⁵ is H, a C₁–

C₁₀ alkyl or cycloalkyl group, R⁹ is a C₁–

C₈ alkyl group, C₁–

C₁₂ an aryl group, or a C₇–

C₁₂ alkaryl group optionally substituted with from 0 to 6 groups selected from OH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, COR⁵ and OR⁵, wherein R⁵ is H, a C₁ to C₁₀ alkyl or cycloalkyl group, or wherein R⁹ is NHR¹¹, wherein R¹¹ is H or a C₁–

C₆ alkyl group, and Z is O and wherein formula (I) and compound (II) are utilized in a molar ration from 1;

1.5 to 1;

2.5

2. The ionic compound of claim 1, wherein compound (II) is an organic compound which is solid at 20°

C.

3. The ionic compound of claim 1, wherein compound (II) is urea, acetamide, glyoxylic acid, malonic acid, oxalic acid dihydrate, trifluoroacetic acid, benzoic acid, benzyl alcohol, phenol p-methyl phenol, o-methyl phenol, m-methyl phenol, p-chloro phenol, D-fructose, or vanillin.

4. The ionic compound of claim 1, wherein compound (II) is urea, aniline or a substituted aniline, a C₁–

C₆ hydroxyaliphatic acid, or a dicarboxylic acid of the formula HOOC(CH₂)_nCOOH, wherein n is 0 or 1, acetamide, a phenol or a substituted phenol, an alkylene glycol, or citric acid.

5. The ionic compound of claim 1, wherein compound (II) is urea, acetamide;

oxalic acid dihydrate, phenol, ethylene glycol, or citric acid.

6. The ionic compound of claim 1, wherein compound (II) has a freezing point of less than 160°

C.

7. The ionic compound of claim 5, wherein compound (II) has a freezing point of 20°

C. or less.

8. The ionic compound of claim 1, wherein compound (II) contains only one type of functional group capable of acting as hydrogen bond donor.

9. The ionic compound of claim 1, wherein the molar ratio of formula (I) to compound (II) is about 1:

2.

10. The ionic compound of claim 1, wherein R⁴ is a C₁ to C₁₀ alkyl or a cycloalkyl group, substituted with at least one group selected from OH, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, COR⁵, CHO and OR⁵.

11. The ionic compound of claim 1, wherein each of R¹ , R², R³, independently is a C₁–

C₅ alkyl or a cycloalkyl group, and R⁴ is hydroxyl-alkyl.

12. The ionic compound of claim 7, wherein each of R¹, R², R³, is methyl, and R⁴ is hydroxyethyl.

13. The ionic compound of claim 1, wherein X⁻

is chloride.

14. The ionic compound of claim 1, wherein R¹, R², R³, and R⁴ have the one of following meanings

17. A method of recovering a metal from a metal oxide, which method comprises forming a solution of the metal oxide in the ionic compound of claim 1, and electrolysing the solution to recover the metal.

18. The method of claim 17, wherein the metal is platinum or palladium.

19. A method of electropolishing a metal article, which method comprises immersing the metal article in the ionic compound of claim 1, and applying a voltage to the metal article to electropolish the metal.

15. A method of preparing an ionic compound, having a freezing point of up to 100°

C., which method comprises reacting at least one amine salt of the formula

R¹R²R³R⁴N^+X−

 

 

(I)

with at least one organic compound (II) which is capable of forming a hydrogen bond with X⁻

, wherein R¹, R², R³ and R⁴ are each independently;

-

H,

optionally substituted C₁ to C₅ alkyl,

optionally substituted C₆ to C₁₀ cycloalkyl,

optionally substituted C₆ to C₁₂ aryl,

optionally substituted C₇ to C₁₂ alkaryl, or wherein

R¹ and R² taken together represent a C₄ to C₁₀ optionally substituted alkylene group, thereby forming with the N atom of formula (I) a 5 to 11-membered heterocyclic ring, X⁻

is NO₃⁻

, F⁻

, Cl⁻

, Br⁻

, I⁻

, BF₄⁻

, ClO₄⁻

, CN⁻

, SO₃CF₃⁻

, or COOCF₃⁻

, and wherein the term “

optionally substituted”

means that the group in question may or may not be substituted with one or more groups selected from OH, SH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, CHO, COR⁵ and OR⁵, wherein R⁵ is a C₁ to C₁₀ alkyl or cycloalkyl group,

wherein all of R¹, R², R³ and R⁴ are not identical, and

wherein compound (II) is a compound of the formula R⁶COOH, R⁷R⁸NH, R⁹CZNH₂, or R¹⁰OH, wherein;

-R⁶, R⁷, R⁸, R¹⁰ are each H, a C₁–

C₈ alkyl group, an aryl group, or a C₇–

C₁₂ alkaryl group optionally substituted with from 0 to 6 groups selected from OH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, COR⁵ and OR⁵, wherein R⁵ is H, a C₁ to C₁₀ alkyl or cycloalkyl group, R⁹ is a C₁–

C₈ alkyl group, C₁–

C₁₂ an aryl group, or a C₇–

C₁₂ alkaryl group optionally substituted with from 0 to 6 groups selected from OH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, COR⁵ and OR⁵, wherein R⁵ is H, a C₁ to C₁₀ alkyl or cycloalkyl group, or wherein R⁹ is NHR¹¹, wherein R¹¹ is H or a C₁–

C₆ alkyl group, and Z is O and wherein formula (I) and compound (II) have a molar ratio from 1;

1.5 to 1;

2.5.

16. The method of claim 15, further comprising heating the amine salt of formula (I) with the compound (II).

20. A method of forming a solution of a solute, which method comprises dissolving the solute in an ionic compound having a freezing point of up to 100°

C., the said ionic compound being formed by the reaction of at least one amine salt of the formula

R¹R²R³R⁴N^+X−

 

 

(I)

with at least one organic compound (II) which is capable of forming a hydrogen bond with X⁻

, wherein R¹, R², R³ and R⁴ are each independently;

-

H,

optionally substituted C₁ to C₅ alkyl,

optionally substituted C₆ to C₁₀ cycloalkyl,

optionally substituted C₆ to C₁₂ aryl,

optionally substituted C₇ to C₁₂ alkaryl, or wherein

R¹ and R² taken together represent a C₄ to C₁₀ optionally substituted alkylene group, thereby forming with the N atom of formula (I) a 5 to 11-membered heterocyclic ring, X⁻

is NO₃⁻

, F⁻

, Cl⁻

, Br⁻

, I⁻

, BF₄⁻

, ClO₄⁻

, CN⁻

, SO₃CF₃⁻

, or COOCF₃⁻

, and wherein the term “

optionally substituted”

means that the group in question may or may not be substituted with one or more groups selected from OH, SH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, CHO, COR⁵ and OR⁵, wherein R⁵ is a C₁ to C₁₀ alkyl or cycloalkyl group,

wherein all of R¹, R², R³ and R⁴ are not identical, and

wherein compound (II) is a compound of the formula R⁶COOH, R⁷R⁸NH, R⁹CZNH₂, or R¹⁰OH, wherein;

-R⁶, R⁷, R⁸, R¹⁰ are each H, a C₁–

C₈ alkyl group, an aryl group, or a C₇–

C₁₂ alkaryl group optionally substituted with from 0 to 6 groups selected from OH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, COR⁵ and OR⁵, wherein R⁵ is H, a C₁ to C₁₀ alkyl or cycloalkyl group, R⁹ is a C₁–

C₈ alkyl group, C₁–

C₁₂ an aryl group, or a C₇–

C₁₂ alkaryl group optionally substituted with from 0 to 6 groups selected from OH, SR⁵, Cl, Br, F, I, NH₂, CN, NO₂, COOR⁵, COR⁵ and OR⁵, wherein R⁵ is H, a C₁ to C₁₀ alkyl or cycloalkyl group, or wherein R⁹ is NHR¹¹, wherein R¹¹ is H or a C₁–

C₆ alkyl group, and Z is O and wherein formula (I) and compound (II) have a molar ratio from 1;

1.5 to 1;

2.5.