WO1990007513A1

WO1990007513A1 - Fluorinated phosphonic sulfonic acids and derivatives thereof

Info

Publication number: WO1990007513A1
Application number: PCT/US1990/000055
Authority: WO
Inventors: Donald J. Burton; Ramil Guneratne; Wenbiao Cen; Robert L. Kirchmeier; Anil S. Modak; William Anthony Sanderson; Jean'ne M. Shreeve; Debao Su
Original assignee: Gas Research Institute
Priority date: 1989-01-03
Filing date: 1990-01-03
Publication date: 1990-07-12
Also published as: EP0453484A4; JPH02184693A; CA2045151A1; AU4842190A; KR900011782A; EP0453484A1

Abstract

The present invention provides compounds comprising one or more fluorine atoms, sulfo radicals and phosphono radicals, each such radical being bonded to the same or different carbon atom, with the proviso that at least one sulfo radical and at least one phosphono radical are bonded to such carbon atoms through the sulfur atom and the phosphorus atom, respectively. These compounds are preferably non-polymeric, i.e. they have a molecular weight of about 5000 or less. Such compounds are useful as electrolytes, e.g. in fuel cells.

Description

FLUORINATED PHOSPHONIC SULFONIC ACIDS

AND DERIVATIVES THEREOF

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to fluorinated organic compounds having at least one phosphono substituent and at least one sulfo substituent. These compounds are useful as an electrolyte in hydrocarbon/air fuel cell or as an additive to phosphoric acid electroytes in such fuel cells.

2. Summary of the Art

Multifunctional acids wherein one acid group comprises sulfonic acid and another acid group comprises phosphonic acid are known as useful esterification catalysts. See U.S. Patent 2,776,985. In all of the acid compounds disclosed in this patent, the sulfonic acid and the phosphonic acid moieties are covalently bound to an aryl group. Moreover, there is no indication that these compounds are contemplated as fluorinated derivatives.

Multifunctional acids having the general formulae:

wherein R is an organo radical, n is 1 or 2, and z is 1 are disclosed in PCT/US87/00885 as useful for preparing solid acid catalysts by reaction with a tetravalent metal ion. BRIEF SUMMARY OF THE INVENTION

The present invention provides compounds comprising one or more fluorine atoms, sulfo radicals and phosphono radicals, each such radical being bonded to the same or different carbon atom, with the proviso that at least one sulfo radical and at least one phosphono radical are bonded to such carbon atoms through the sulfur atom and the phosphorus atom, respectively. These compounds are preferably non-polymeric, i.e. they have a molecular weight of about 5000 or less.

These compounds may be represented by compounds selected from the group of compounds represented by the general formula:

wherein R is an organo radical having at least one covalent carbon-fluorine bond, R¹ is selected from the group consisting of alkali metals, cadmium, zinc and hydrogen, R² is a hydrocarbyl radical, having up to 20 carbon atoms, e.g. a lower alkyl radical or is hydrogen, ris 2 or 3, y is an integer of from 1 to 3 and x is an integer of from 1 to 3, with the proviso that the phosphorus and the sulfur are covalently bonded to a carbon atom and when x is 1, then cadmium and zinc are 1/2.

DETAILED DESCRIPTION OF THE INVENTION

The above fluorinated phosphono sulfo compounds may be prepared by reacting a first reactant represented by the general formula (R⁴O)₃P with a second reactant represented by the general formula R³X_z to yield a first reaction product represented by the general formula

(R⁴O)₂P(O)R³X_z-1 In this general scheme, R⁴ may be a lower alkyl radical having up to six carbon atoms, e.g. methyl, ethyl, n- propyl or i-propyl, and preferably i-propyl or ethyl; R³ is an organo radical having at least one covalent fluorine bond; X is bromine or iodine and z is an integer of 2 or 3. The first reaction product may be synthesized in high yield merely by combining the first and second reactant in a sealed vessel at a temperature of from -50°C to 200°C, e.g. from 0 to 120°C, i.e. conveniently from 0°C to about 25°C. Reaction time may vary from 1 to 100 hours, e.g. 48 hours. Of course, increasing the reaction temperature can lower the reaction time to 2 to 10 hours, e.g. about 3 hours.

The reaction can be carried out neat or in the presence of an inert solvent. Conveniently, an ether solvent may be used. In particular, diethylether is useful as a solvent for this reaction.

The first reaction product is recovered by methods known in the art, e.g. distillation at a reduced pressure.

The first reaction product may be reacted with (R⁵)₂S₂O₄, wherein R⁵ is an alkali metal ion, e.g. a sodium ion, to yield a second reaction product represented by the general formula

(R⁴O)₂P(O)R³X_z-1-p(SO₂R⁵)_p wherein p is an integer of 1 or 2. This reaction is conveniently carried out by combining the first reaction product and the above dithionite in a basic aqueous solution comprising, as a cosolvent, acetonitrile or the like. The reaction may be effected at an elevated temperature of from 50 to 100°C, e.g. about 80°C, and a reaction time of from 1 to 20 hours, e.g. 2 to 12 hours. The second reaction product may be recovered by evaporation of the excess solvent and purified by extraction with acetonitrile or a like solvent.

Suitable fluorinated organo radicals (R³) for the above reaction scheme include alkylene radicals, both cyclic and acyclic radicals, which may be interrupted with hetero atoms such as nitrogen, oxygen and sulfur, alkenylene radicals, both cyclic and acyclic, which may also be interrupted with heteroatoms such as nitrogen, oxygen and sulfur, and arylene radicals, including heteroaryl, e.g. nitrogen, sulfur and oxygen-containing heteroarylene radicals, mono and poly arylene radicals, e.g. condensed arylene radicals having from 2 to 5 aryl rings, biphenyl, etc. The above fluorinated organo radicals may comprise from one to about 100 carbon atoms, e.g. from 1 to about 20 carbon atoms and preferably from 1 to about 10 carbon atoms. Such radicals will comprise one or more covalently bonded fluorine and may be perfluorinated, i.e. all of the carbon bonds, other than the sulfur or phosphorus bonds, may be filled by fluorine radicals.

The above fluorinated organo radicals may also be substituted with inert substituents such as halo, nitro, amino, oxy, hydroxy, carboxy, thio, etc. Preferably, the fluorinated organo radicals will be either halo substituted or unsubstituted, i.e. all the carbon bonds other than the bonds to the fluoro, sulfo or phosphono radicals, as required by the, above general formula, will be filled by hydrogen radicals or halo radicals (other than fluoro radicals).

One class of suitable fluorinated organo radicals are chloro or bromo-substituted or unsubstituted alkylene radicals having from 1 to 6 carbon atoms and chloro or bromo-substituted or unsubstituted arylene radicals having from 6 to 10 carbon atoms.

Another class of suitable fluorinated organo radicals are alkyleneoxyalkylene radicals, wherein the alkylene moieties comprise from 2 to 4 carbon atoms.

Particularly preferred are lower alkylene radicals, including alkyleneoxyalkylene radicals such as methylene, ethylene, propylene, butylene, methyleneoxymethylene, ethyleneoxyethylene, butyleneoxyethylene radicals, etc.

Specifically, R³ may be

The second reaction product may be oxidized to yield a third reaction product having the general formula

(R⁴O)₂P(O)R³X_z-1-p(SO₃R⁵)_p by contacting said second reaction product with an oxidizing agent at oxidizing conditions. For example, H₂O₂ or similar oxidizing agent may be provided in molar excess directly to the second reaction product or to an aqueous solution thereof. For example, a sufficient amount of a 30% aqueous H₂O₂ solution may be combined with the second reaction product to provide an aqueous solution, H₂O₂ comprising from 1.1 to 5 moles of per mole of the second reaction product, at a temperature of from 0° to 25°C and such aqueous solution allowed to react for 1 to 10 hours, e.g. about 4 to 5 hours. The third reaction product is conveniently recovered by evaporation of the excess solvent.

In this manner

(R⁴O) ₂P(O) CF₂ (SO₂R⁵) is reacted to (R⁴O)₂P(O)CF₂(SO₃R⁵), (R⁴O)₂P(O)CFBr(SO₂R⁵) is reacted to (R⁴O)₂P(O)CFBr(SO₃R⁵), and

( R⁴O)₂P(O)CHF(SO₂R⁵) is reacted to (R⁴O)₂P(O)CHF(SO₃R⁵). As an alternate route to one of the novel fluorinated phosphonosulfo compounds of the present invention,(R⁴O)₂P(O)CFBr(SO₃R⁵) may be reduced to (R⁴O)₂P(O)CHF(SO₃R⁵) by a reducing agent, for example metallic zinc, in a suitable inert solvent, for example tetrahydrofuran. Such reduction may be effected at an elevated temperature, e.g. about 60°C and a ratio of Zn to the bromo product of about 1 to about 2, e.g. about 1.1 and the reduced product recovered by extraction with water.

The third reaction product may be reacted, e.g. hydrolyzed, to yield the corresponding phosphonic acid. For example, the third reaction product may be hydrolyzed in an aqueous solution of a strong acid, e.g. concentrated hydrochloric acid, wherein said hydrolysis is effected at an elevated temperature, e.g. at reflux, in the presence of excess strong acid, e.g. from about 1.1 to 10 moles, i.e. 3 moles of strong acid per equivalent of R⁴. Again, the hydrolysis product or the fourth reaction product may be recovered by evaporation of excess solvent.

The fourth reaction product may be further reacted to exchange hydrogen ions for R⁵. In particular, the fourth reaction product may be passed through an ion exchange column, e.g. a strong acid such as an acidified sulfonated polystyrene resin such as Amberlite 1R-120 to exchange hydrogen ions for the alkali ions.

Compounds of the invention, wherein R⁵ may be Cd or Zn, (represented by M, below) may be prepared according to the following scheme:

(1) (R⁴O)₃P + R³X_z → (R⁴O)₂P(O)R³X_z-1

(2) (R⁴O)₂P(O)R³X_z-1 + M → (R⁴O)₂P(O)R³MX_z-1

(3) (R⁴O)₂P(O)R³MX_z-1 + SO₂ → [(R⁴O)₂P(O)R³SO₂]₂M (4) [(R⁴O)₂P(O)R³SO]₂M + H₂O₂ → [(R⁴O)₂P(O)R³SO₃]₂M

(5) [(R⁴O)₂P(O)R³SO₃]₂M + NaOH → [R⁴O)₂P(O)2³SO₃Na]

Step (1) is carried out as described above.

Step (2) may be carried out by dissolving or suspending the reactants in an anhydrous solvent, e.g. dimethylformamide (DMF) under nonoxidizing conditions, i.e. N₂ atmosphere, and agitating while allowing the reaction to occur. To this reaction product, SO₂ may be added and Step (3) may thus be effected. After excess SO₂ and solvent are removed, the remaining reaction product may be recovered by washing with water and filtering. Recrystallization from hot isopropanol yields the product of Step (3). Step (4) may also be carried out as described above. Finally, the resulting reaction product of Step (4) may be converted into an alkali salt by reaction with the appropriate aqueous alkali solution, e.g. an aqueous NaOH solution, and the metal, M, removed as an insoluble hydroxide, M(OH)₂.

If it is desirable to further purify the hydrogen ion-exchanged reaction product, i.e.

(HO)₂P(O)R³X_z-1-p(SO₃H)_P sulfate ion contamination may be removed by reacting an aqueous solution thereof with an excess of barium ions to precipitate barium sulfate. The filtrate, comprising the acid-exchanged reaction product and sodium and barium ions is then passed through the acid form of an ion exchange column, to remove such ions and a purified solution of such acid-exchanged reaction product is recovered. In addition, if the above precipitation is effected at a sufficiently high pH, e.g. at 11 or greater, phosphate contaminants can also be removed as an insoluble product. Finally, the acid-exchanged reaction product may be converted to the corresponding phosphonylsulfonyl chloride by reaction with sufficient PCl₅ to yield such phosphonylsulfonyl chloride which can be recovered by distillation. Any or all of the sulfonic acid and phosphonic acid moieties of the acid-exchanged reaction product may be converted into the corresponding acid chloride by reaction with an amount of PCl₅ equivalent to from 1 to all of the acid moieties in the acid-exchanged reaction product. When the conversion of the acid-exchanged reaction product is for the purpose of recovering a purified product, sufficient PCl₅ to convert all of the acid moieties to the acid halide will be provided and the resulting acid halide recovered, by distillation, and hydrolyzed to yield a further purified fluorinated phosphonicsulfonic acid.

It is noted that the above reaction scheme utilizes a monophosphono reactant. Compounds within the scope of the present invention, wherein polyphosphono functionality are desired, e.g. wherein y is 2 or 3, may be prepared by reacting supra molar amounts of (R⁴O)₃P with R³X_Z wherein z is from 3 to 6 and proceeding according to the above illustrative reaction scheme.

An alternate method for making certain of the fluorinated phosphonosulfo compounds of the present invention comprises reacting a first reactant having the general formula

IR⁶SO₂F with a second reactant represented by the general formula

(R⁴O)₂POP(OR⁴)₂ in the presence of a peroxide and a solvent, CF₂ClCFCl₂, to yield a first reaction product represented by the general formula

(R⁴O)₂P(O)R⁶SO₂F and reacting said second reaction product with a third reactant represented by the general formula

R₂ ⁵S₂O₄ to yield a second reaction product represented by the general formula

(R⁴O)₂P(O)R⁶SO₂R⁵ wherein R⁴ is a lower alkyl radical, R⁶ is a fluorinated polyalkylene oxide radical, and R⁵ is an alkali metal ion.

The first reactant may be prepared by reacting

CF₂ = CF₂ in the presence of KF and ICl according to the method disclosed in SCIENTIA SINICA, 1978, 21, 773.

The second reaction product may be treated as described above to yield the corresponding third and fourth reaction product, as well as the hydrogen ion-exchanged reaction product.

Finally, certain of the fluorinated phosphonosulfo compounds of this invention may be prepared according to the following scheme: (R²O)₂P(O)CF₂Br + Na₂SO₃ →

(R²O)₂P(O)CF₂SO₃Na + NaBr wherein R² is defined above. Note that CF₂ may be any other fluorinated organo radical disclosed, herein. That is, CF₂ may be R as defined above. This reaction is effected in water or aqueous ethanol at reflux and provides a third reaction product which can be subsequently treated as described above.

The fluorinated phosphonosulfono compounds of the present invention may be utilized as electrolytes, e.g. in fuel cells, in the same manner as perfluorosulfonic acids are now used. See for example. Fuel Cell Reactions in Super Acid Electrolytes. (Annual Rept. 1 June '82 - 31 May 83). Prepared in cooperation with Brookhaven National Lab., Upton, New York; Fuel Cell Reactions in Super Acid Electrolytes. Final Report June 1982 - December 1985, sponsored by Gas Research Inst., Chicago, IL. and New Catalysts and New Electrolytes for Acid Fuel Cells 188. Meeting of the American Chemical Society, Philadelphia, PA, USA, 26 August 1984, all available from NTIS and hereby incorporated in their entirety by this reference.

EXAMPLE 1

Preparation of (HO)₂P(O)CF₂SO₃H:

(a) 12.4 mmols of (C₂H₅O)₃P was combined with 13.1 mmoles of CF₂Br₂ in a 75 cc. steel bomb, which was sealed and allowed to react at room temperature for 48 hours.

A 100% yield of (C₂H₅O)₂P(O)CF₂Br(I) was obtained by distilling the resultant reaction product at 10-20 microns. (b) 39.9 mmoles of I was combined with 79.8 mmoles of Na₂S₂O₄ in 100 mL of a 50/50, by volume, solution of water and acetonitrile. (79.8 mmols. of NaHCO₃ had been previously dissolved in such aqueous acetonitrile solution.) After heating at 80°C for 12 hours (C₂H₅O)₂P(O)CF₂SO₂Na(II) was recovered by evaporation of the filtered solution at 80% yield.

(c) An aqueous solution of 30% H₂O₂ was added to II, dropwise with stirring, at 0°C until the molar ratio of H₂O₂ to II was about 1.75. The resulting solution was allowed to react for 4 hours. (C₂H₅O)₂-P(O) CF₂SO₃Na (III) was recovered after evaporation of the solvent at 56.3% yield.

(d) The product from (c) was refluxed with concentrated hydrochloric acid (mole ratio 1:6) for 12 hours. (HO)₂P(O)CF₂SO₃Na (IV) was recovered at 78.9% yield by evaporating the solvent, extracting with acetonitrile and evaporation.

(e) An aqueous solution of IV was passed through a packed column of Amberlite IR-120 (an acidic sulfonated polystyrene resin) having the dimensions 3cm × 35 cm., at a flow rate of about 0.3 ml/min. The effluent was evaporated and the residue was distilled at about 10-20 microns to recover (HO)₂P(O)CF₂SO₃H.

EXAMPLE 2

Preparation of (HO)₂P(O)CFHSO₃H:

(a) 50 mmols of (C₂H₅O) ₃P and 50 mmols of CFBr₃ were reacted in accordance with the method of Example 1 (a) (except that the reaction was carried out at 0°C for 4 hours i n a 4 0ml vessel ) to yield 76 . 9 % o f (C₂H₅O) ₂P (O) CFBr₂ (VI) .

(b) 12 mmols of VI were reacted with 14.4 mmols of Na₂S₂O₄ in a solution comprising 14.4 mmols of NaHCO₃ dissolved in 5 mL of water and 5 mL of acetonitrile. After 4 hours at room temperature (C₂H₅O)₂P(O)CFBrSO₂Na (VII) was recovered in 64.4% yield by evaporating the solvent under vacuum, extracting the residue with acetonitrile and drying under vacuum to recover the product.

(c) 14.9 mmoles of VII was reacted with 26 mmoles of H₂O₂ which, was added dropwise, with stirring, as a 30% aqueous solution. After 5 hours, at room temperature, (C₂H₅O)₂P(O)CFBrSO₃Na (VIII) was recovered at 74.8% yield after evaporation of the solvent.

(d) 11.1 mmoles of VIII was reduced with excess Zn at 60°C, for 6 hours in 10ml. of tetrahydrofuran (THF). (The molar ratio of Zn to VIII was about 1.1) The resulting mixture was combined with 20 ml. of water and stirred to yield (C₂H₅O) ₂P (O) CFHSO₃Na (IX) at 61.2% yield.

(e) IX was hydrolyzed in accordance with the method of Example 1(d) to yield (HO)₂P(O)CFHSO₃Na (X) in 53.5% yield.

(f) X was passed through a packed column, according to the method of Example 1(e) to yield (HO)₂P(O)CFHSO₃H in 80% yield after evaporating the solvent under vacuum and drying the resulting product, under vacuum for 4 hours at 80°C. EXAMPLE 3

Preparation of (C₂H₅O)₂P(O)CF(SO₃Na)₂:

(a) (C₂H₅O)₃P and CFBr₃ were reacted in accordance with the method of Example 2(a) to provide (C₂H₅O)₂P(O)CFBr₂ (XI) at a 76.9% yield.

(b) XI was reacted in accordance with the method of example 2(b) to provide (C₂H₅O)₂P(O)CFBrSO₂Na XII at a 64.4% yield.

(c) XII was oxidized according to the method of Example 2(c) to provide (C₂H₅O)₂P(O)CFBrSO₃Na (XIII) at a 74.8% yield.

(d) 5.7 mmoles of XIII was dissolved in 2ml. of water and 2 ml. of acetonitrile and reacted with 8.5 mmols of Na₂S₂O₄ at 0°C for 4 hours in the presence of 8.5 mmols of NaHCO₃ to yield at a yield

of 90%. The product was recovered after evaporating the solvent under vacuum.

(e) 7.8 mmol of XIV dissolved in 3 ml. of water was oxidized by adding thereto 7.8 mmols of H₂O₂ (as a 30% aqueous solution) with stirring. The resulting mixture was held for 1 hour at - 15°C to obtain (C₂H₅O)₂P(O)CF(SO₃Na)₂ (XV) at a yield of 33%. The product was recovered by evaporating the solvent under vacuum and extracting the resulting residue with acetone and THF and drying. EXAMPLE 4

Preparation of (HO)₂P(O)(CF₂)₄O(CF₂)₂SO₃H:

(a) 38 mmol. of I (CF₂)₄O(CF₂)₂SO₂F, 57 mmol. (C₂H₅O)₂POP(OC₂H₅)₂ and 19 mmol. of (CH₃)₃COOC(CH₃)₃ were dissolved in 80 ml. of CF₂ClCFCl₂ and reacted in a 150cc steel bomb at 120°C for 3 hours. To the resulting reaction product, 45 ml. of (CH₃)₃COOH and 45 ml. of CH₃OH were added, dropwise, over 1 hour at from -10°C to 0°C to o b t a i n 18 mmo l s ('48 % y i e l d ) o f (C₂H₅O)₂P(O)[(CF₂)₄O(CF₂)₂SO₂F]. (XVI) The product was recovered by distilling under vacuum. (The boiling point of XVI is 133°C at l.lmm.

(b) 9.3 mmol of XVI were reacted with 18.6 mmol of Na₂S₂O₄ and 18.6 mmol of NaHCO₃ in a solution of 8 ml. of water and 4 ml. of acetonitrile. The reaction temperature was 85°C and the reaction time was 2 hours. (C₂H₅O)₂P(O)[(CF₂)₄O(CF₂)₂SO₂Na] (XVII) was recovered in 89% yield by repeated extraction of the solid from the evaporated solution with acetonitrile and evaporation of the acetonitrile solvent.

(c) 8.3 mmol of XVII were oxidized by 40 mmol of H₂O₂, added dropwise as a 30% aqueous solution. After stirring for 10 hours at room temperature (C₂H₅O)₂P(O)[(CF₂)₄O(CF₂)₂SO₃Na] (XVIII) was recovered at a yield of 92% after evaporation to dryness under vacuum.

(d) 7.7 mmol. of XVIII were hydrolyzed in accordance with the method of Example 1(d) to yield (HO)₂P(O)[(CF₂)₄O(CF₂)₂SO₃Na] (XIX) at a yield of 88%. (e) XIX was reacted according to the method of Example 1(e) to yield (HO)₂P(O)[(CF₂)₄O(CF₂)₂SO₃H]. H₂O (XX) at a yield of 78%.

EXAMPLE 5

Removal of Sulfate and Phosphate Ion

The product of Example 1(e), containing sulfate ions, was dissolved in water and an aqueous BaCl₂ solution was added thereto with stirring, until an excess was present, i.e. until additions caused no further precipitation of BaSO₄. After centrifugation, a supernatant was decanted, concentrated, and passed through a 4.5cm by 50 cm packed column of DOWEX M-31 (Dow Chemical Company), a styrenesulfonic acid resin, to recover an eluate containing no detectable sulfate.

Alternatively, Ba(OH)₂ may be used in place of BaCl₂ to obtain a similarly purified solution. Moreover, if the pH of said purification was adjusted to 11 or greater, by addition of Ba(OH)₂, the inorganic phosphate ion was reduced to a level undetectable by ³¹P NMR.

EXAMPLE 6

Preparation of Acid Halide

(a) 11.1 gms of the product of Example 1(e) dissolved in 10 ml of POCl₃ were combined with 35 gms of PCl₅ in a 100 ml flask and heated to 120°C. After holding at such temperature for one hour, the corresponding triacidhalide was recovered by distillation at 0.1mm. (At this pressure, the triacid halide - Cl₂P(O)CF₂SO₂Cl - had a boiling point of 76°C.

(b) A portion of the distillate was combined with water at 0°C to regenerate the product of Example 1(e) in a more purified condition, as evidenced by ³¹P and ¹³C NMR.

EXAMPLE 7

Preparation of [(RO)₂P(O)CF₂]₂Cd

To a dry, 3-necked, 100 mL flask fitted with a reflux condenser were successively added acid-washed Cd power (6.2 g, 55 mmol), dry DMF (50 mL), and (i-C₃H₇O)₂P(O)CF₂Br (14.8 g, 50 mmol) The mixture was stirred for 2 hr (initial exotherm), after which the greenish solution of (i-C₃H₇O)₂P(O)CF₂CdBr was filtered off from the excess Cd, via a Schlenk filter funnel under N₂ pressure, into another 100 mL flask. This flask was then fitted with a Dewar condenser filled with dry ice and isopropanol, and excess SO₂ gas introduced. The mixture was stirred for 15 min., during which time the solution turned yellow. The solvent and excess SO₂ were then removed under vacuum. The residual paste was washed with water (15 mL) and filtered. The solid was recrystallized from hot isopropanol, after filtration to remove an insoluble orange residue. The aqueous solution was allowed to stand overnight, filtered to remove precipitated inorganic matter, evaporated to near dryness, and the resulting solid also recrystallized from isopropanol. The white powdery product was washed with ether and dried under vacuum. The combined yield was 7.25 g (43%). The analogous compound [ (C₂H₅O)₂P(O)CF₂SO₂]₂Cd was similarly prepared from (C₂H₅O)₂P(O)CF₂Br, Cd, 1,4-dioxane and SO₂, and recrystallized from ethanol in 62% yield.

EXAMPLE 8

Preparation of [(i-C₃H₇O)₂P(O)CF₂SO₃]₂Cd

[(i-C₃H₇O)₂P(O)CF₂SO₂]₂Cd (5.03 g, 7.5 mmol) was suspended in water (10 mL) in a 25 mL flask. The mixture was cooled with rapid stirring in an ice water bath, and 50% H₂O₂ (1.7 mL) added slowly, dropwise. The mixture was allowed to warm up to room temperature and stirred overnight, during which time the solid almost completely dissolved. The solution was filtered and concentrated to dryness on a rotary evaporator. The residual solid was washed with a little acetone and with ether and dried under vacuum. The yield was 3.32 g (63%).

EXAMPLE 9

Preparation of (C₂H₅O)₂P(O)CF₂SO₂Na

To a 2-necked, 100 mL flask fitted with a reflux condenser were added 1,4-dioxane (8 mL), water (25 mL), Na₂SO₃ (25.3 g, 200 mmol), and (C₂H₅O)₂P(O)CF₂I (15.7 g, 50 mmol). The mixture was heated in an oil bath at 80- 85°C for 10 hr. It was then cooled to room temperature, the solvents evaporated off on a rotary evaporator, and the residue washed with acetone and dried. The yield was 85% by ¹⁹F NMR.

EXAMPLE 10

Preparation of (i-C₃H₇O)₂P(O)CF₂SO₂Na

[(i-C₃H₇O)₂P(O)CF₂SO₂]₂Cd (33.5 g., 50 mmol) was dissolved in water (200 mL), and NaOH pellets were added to the solution until the pH was slightly basic (ca. 8). The precipitated Cd(OH)₂ was filtered off, and the solution concentrated to dryness on a rotary evaporator, giving the product. The yield was 27.3 g (90%).

Claims

WHAT IS CLAIMED IS:

1. A compound comprising one or more fluorine atoms, sulfo radicals and phosphono radicals, each such radical being bonded to the same or different carbon atom, with the proviso that at least one sulfo radical and at least one phosphono radical are bonded to such carbon atom through the sulfur atom and the phosphorus atom, respectively.

2. A compound selected from the group of compounds represented by the general formula: ((R²O)₂P(O))_y R(SO_rR¹)_x wherein R is an organo radical having at least one covalent carbon-fluorine bond, R¹ is selected from the group consisting of alkali metals, cadmium, zinc and hydrogen, R² is a lower alkyl radical or is hydrogen, r is 2 or 3, y is an integer of from 1 to 3 and x is an integer of from 1 to 3, with the proviso that the phosphorus and the sulfur are covalently bonded to a carbon atom and when x is 1, than cadmium and zinc are 1/2.

3. The compound of claim 2 wherein R¹ and R² are hydrogen.

4. The compound of claim 3 wherein y is 1.

5. The compound of claim 4 wherein R is selected from the group comprising fluorinated alkylene and fluorinated alkyleneoxyalkylene radicals.

6. The compound of claim 5 wherein R is a radical selected from the group consisting of

7. The compound of claim 2 wherein R¹ is sodium, R² is ethyl or hydrogen, y is 1, x is 2 and r is 3.

8. The compound of claim 7 wherein R is

9. The compound of claim 1 wherein R¹ and R² are hydrogen, R

1 is 2, r is 3 and x is 1.

10. The compound of claim 1 wherein R¹ and R₂ are hydrogen, R is

1 is 2, r is 3 and x is 1.

11. The compound of claim 1 wherein R¹ and R² are hydrogen, R is CFBr, 1 is 2, r is 3 and x is l.

12. The compound of claim 1 wherein R¹ and R² are hydrogen, R is

1 is 2, r is 3 and x is 1.

13. The compound of claim 1 wherein R¹ is Na, R₂ is C₂H₅, R is . 1 is 2, r is 3 and x is 2.

14.

15. The hydrogen ion-exchanged product of claim 13.

16. A method for making a compound represented by the general formula

(R⁴O)₂P(O)R³X_z-1-p(SO₂R⁵)_p which comprises reacting a first reactant represented by the general formula (R⁴O)₃P with a second reactant represented by the general formula R³X_z to yield a first reaction product represented by the general formula

(R⁴O)₂P(O)R³X_z-1 and reacting said first reaction product with (R⁵)₂S₂O₄ to yield a second reaction product represented by the general formula

(R⁴O)₂P(O)R³X_z-1-p(SO₂R⁵)_p wherein R⁴ is a lower alkyl radical, R₃ is an organo radical having at least one covalent fluorine bond, R⁵ is selected from the group consisting of alkali metal ions, X is selected from the group consisting of bromine and iodine radicals, z is an integer of 2 or 3, and p is an integer of 1 or 2.

17. The method of claim 16 wherein R⁵ is sodium and R³ is selected from the group consisting of fluorinated alkylene and fluorinated alkyleneoxyalkylene radicals.

18. The method of claim 16 wherein R³ is

19. The method of claim 16 wherein R³ is

20. The method of claim 19 wherein said second reaction product is reduced to yield a third reaction product wherein R³ is

21. The method of claims 16, 18, 19 or 20 wherein said second reaction product is oxidized to yield a third reaction product represented by the general formula

(R⁴O)₂P(O)R³X_z-1-p(SO₃R⁵)_p,

(R⁴O)₂P(O)CF₂(SO₃R⁵),

(R⁴O)₂P(O)CFBr(SO₃R⁵) or

(R⁴O)₂P(O)CHF(SO₃R⁵);

respectively.

22. The method of claim 21 wherein said third reaction product is reacted to yield a fourth reaction product comprising (HO)₂P- radicals in place of the designated (R⁴O)₂P- radicals.

23. The method of claim 22 wherein said fourth reaction product is reacted to exchange hydrogen ions for R⁵.

24. The method of claim 23 wherein said fourth reaction product is reacted with barium ions, in an aqueous solution, to precipitate inorganic sulfate ions as barium sulfate.

25. The method of claim 23 or 35 wherein said hydrogen ion-exchanged product is reacted with PCl₅ to yield the corresponding phosphonylsulfonyl chloride.

26. The method of claim 25 wherein said phosphonyl chloride is hydrolyzed to yield the corresponding phosphonic acid.

27. The method of claim 24 wherein said precipitation is effected at a pH sufficient to remove phosphate.

28. A method for making compounds having the general formula:

(R²O)₂P(O)RSO₃Na

wherein R² is a hydrocarbyl radical and R is an organo radical having at least one covalent carbon-fluorine bond which comprises reacting

(R²O)₂P(O)RBr

with Na₂SO₃

to yield

(R²O)₂P(O)RSO₃Na and NaBr.

29. The .method of claim 28 wherein R₂ is a lower alkyl radical and R comprises from 1 to about 20 carbon atoms.

30. A method for making compounds having the general formula

(R⁴O)₂P(O)R⁶SO₂R⁵ which comprises reacting a first reactant having the general formula

XR⁶SO₂F with a second reactant represented by the general formula

(R⁴O)₂POP(OR⁴)₂ in the presence of a peroxide to yield a first reaction product represented by the general formula

(R⁴O)₂P(O)R⁶SO₂F and reacting said first reaction product with a third reactant represented by the general formula

(R⁴O)₂P(O)R⁶SO₂R⁵ wherein R⁴ is a lower alkyl radical , R⁶ is a fluorinated polyalkylene oxide radical, and R⁵ is an alkali metal ion.

31. The method of claim 30 wherein R⁶ is (CF₂)₄O(CF₂)₂

32. The method of claim 30 wherein said first reactant is prepared by reacting

CF₂ = CF₂ in the presence of KF and ICl

33. The method of claims 30 or 31 wherein said second reaction product is oxidized to yield a third reaction product represented by the general formula

(R⁴O)₂P(O)R⁶SO₃R⁵ or

(R⁴O)₂P(O)[(CF₂)₄O(CF₂)₂SO₃R⁵]

34. The method of claim 33 wherein said third reaction product is hydrolyzed to yield a fourth reaction product comprising (HO)₂P(O)-radicals in place of the designated (R⁴O)₂P(O)-radicals.

35. The method of claims 34 wherein said fourth reaction product is reacted to exchange hydrogen ions for R5.

36. A method for making a compound represented by the general formula

[ (R⁴O)₂P(O)]_yR³(X)_z-y-s(SO₃R⁵)_s

which comprises reacting a first reactant represented by the general formula (R⁴O)₃P with a second reactant represented by the general formula R³X_Z to yield a first reaction product represented by the general formula [ (R⁴O) ₂P(O) ]_yR³ (χ) _z-y and reacting said first reaction product with (R⁵)₂S₂O₄ to yield a second reaction product represented by the general formula

[(R⁴O)₂P(O)]_yR(X)_z-y-s(SO₃R₅)_s wherein R⁴ is a lower alkyl radical, R₃ is an organo radical having at least one covalent fluorine bond, R⁵ is selected from the group consisting of alkali metal ions, X is selected from the group consisting of bromine and iodine radicals, z is an integer of from 2 to 6, y is an integer of from 1 to 3 and s is an integer of 1 to 3 and wherein y+s ≤ z.