Process for removing radioactive isotopes from aqueous fluids by fluorine containing reagents, fluorine containing, water-insoluble salts of the radioactive isotopes, and their use as therapeutic agents

Abstract

The present invention refers to a process for removing Cs, and optionally Rb, from aqueous fluids including body fluids by fluorine containing reagents, the synthesis of fluorine containing, water-insoluble salts of said Cs isotopes and their use as therapeutic agents.

Claims

1. A pharmaceutical composition comprising a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein: M.sup.I is selected from H(OH.sub.2).sub.n, Li, Na, K, ½Mg, MgY, Mg(OH), ½Ca, Ca(OH), wherein Y is a halide, (solv) represents a solvating ligand capable of coordinating to M.sup.I, L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, and wherein X is selected from halide, OH.sup.−, or NH.sub.2.sup.−.

2. A method for treating and/or preventing radiation damage, or for counteracting contamination with radioactive isotopes, or for treating Tl-poisoning, said method comprising administering to a patient in need thereof an effective amount therefor of a complex according to claim 1.

3. Complex of the formula [M.sup.I].sup.+L.sup.−, wherein: M.sup.I is Cs, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, OH.sup.−, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−.

4. Complex of the formula [M.sup.I].sup.+L.sup.−, wherein M.sup.I is Cs in the form of a radioactive isotope, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, OH.sup.−, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−.

5. Process for preparing a complex of the formula [M.sup.I].sup.+L.sup.− according to claim 4, wherein: M.sup.I is Cs, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, OH.sup.−, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−, wherein the process comprises reacting a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein: M.sup.I is selected from H(OH.sub.2).sub.n, Li, Na, K, ½Mg, MgY, Mg(OH), ½Ca, Ca(OH), wherein Y is a halide, (solv) represents a solvating ligand capable of coordinating to M.sup.I, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, OH.sup.−, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.− and Y is a halide, with a Cs salt in an aqueous medium.

6. A method of treating a tumor disease, said method comprising administering to a patient in need thereof an effective amount therefor of a complex according to claim 4.

7. A method of conducting brachytherapy or afterload therapy, said method comprising administering to a patient in need thereof an effective amount therefor of a complex according to claim 4.

8. A method of sterilizing waste water sewage, food, packings, clean rooms, and construction monitoring purposes using a complex according to claim 3.

9. Method of using a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein: M.sup.I is selected from H(OH.sub.2).sub.n, Li, Na, K, ½Mg, MgY, Mg(OH), ½Ca, Ca(OH), wherein Y is a halide, (solv) represents a solvating ligand capable of coordinating to M.sup.I, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, OH.sup.−, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−, for the removal of Cs or Rb from aqueous liquids.

10. A process for separating cesium from a cesium containing aqueous fluid, wherein the process comprises either Sequence I or Sequence II, wherein Sequence I is: a. reacting a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein M.sup.I is selected from Li, Na, K, ½ Mg, Mg(OH), ½ Ca, Ca(OH), (solv) represents a solvating ligand capable of coordinating to M.sup.I, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−, with a cesium containing aqueous fluid, whereby a complex of the formula Cs.sup.I+L.sup.− is precipitated from the aqueous solution; b. separating the precipitated complex of the formula Cs.sup.I+L.sup.− from the aqueous phase and drying the obtained precipitated complex of the formula Cs.sup.I+L.sup.−; c. dissolving the separated complex of the formula Cs.sup.I+L.sup.− in an anhydrous organic solvent selected from a dialkyl ether R.sub.2O and alcohol ROH wherein R is C.sub.1 to C.sub.6; d. treating said organic solvent containing the complex of the formula Cs.sup.I+L.sup.− with an anhydrous acid HA, where HA is HCl, HBr, H.sub.2SO.sub.4, H.sub.3PO.sub.4 or a compound R.sub.A.sup.−H.sup.+, in which R.sub.A.sup.− is a carboxylic acid residue and R.sub.A.sup.− is sufficiently basic to form an ion-pair CsR.sub.A, whereby CsA is precipitated, and separating the precipitated CsA from said organic solvent; and e. recycling said organic solvent containing a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein M.sup.I is H(OR.sub.2).sub.n and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, to step a; and the Sequence II is: a. reacting a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein M.sup.I is selected from Li, Na, K, ½ Mg, Mg(OH), ½ Ca, Ca(OH), (solv) represents a solvating ligand capable of coordinating to M.sup.I, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−, in an organic solvent immiscible with water with a cesium containing aqueous fluid, whereby a complex of the formula Cs.sup.I+L.sup.− is extracted from the aqueous solution into the organic solvent; b. drying the obtained organic solvent containing the complex of the formula Cs.sup.I+L.sup.−; c. treating said organic solvent containing the complex of the formula Cs.sup.I+L.sup.− with an anhydrous acid HA, where HA is HCl, HBr, H.sub.2SO.sub.4, H.sub.3PO.sub.4 or a compound R.sub.A.sup.−H.sup.+, in which R.sub.A.sup.− is a carboxylic acid residue and R.sub.A.sup.− is sufficiently basic to form an ion-pair CsR.sub.A, whereby CsA is precipitated, and separating the precipitated CsA from said organic solvent; and d. recycling said organic solvent containing a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein M.sup.I is H(OR.sub.2).sub.n and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, to step a.

11. Process according to claim 10, wherein the organic solvent is an ether having 4 to 10 carbon atoms.

12. Process according to claim 10, wherein any amount of a Cs′L.sup.− complex precipitated in step a. of Sequence I is transferred to the organic solvent by adding a sufficient amount of the organic solvent.

13. Process according to claim 10, wherein the cesium containing aqueous fluid is selected from brines obtained from digestion of cesium ores, used cesium containing drilling fluids, and fluids containing Cs-131 or Cs-134/135/137 isotopes, either as solutions from a synthesis process, a reprocessing process, or as wastewaters from atomic plant facilities.

14. Process for separating cesium and rubidium from an aqueous fluid, wherein the process comprises: a. reacting a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein M.sup.I is selected from Li, Na, K, ½ Mg, Mg(OH), ½ Ca, Ca(OH), and L.sup.− is [XB.sub.2(C.sub.6F.sub.5).sub.6].sup.−, wherein X is selected from halide, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−, with a Cs and Rb containing aqueous fluid whereby a complex of the formula Cs.sup.I+L.sup.− is precipitated from the aqueous solution; b. separating the precipitated complex of the formula Cs.sup.I+L.sup.− from the aqueous phase and drying the obtained precipitated complex of the formula Cs.sup.I+L.sup.−; c. dissolving the separated complex of the formula Cs.sup.I+L.sup.− in an anhydrous organic solvent selected from a dialkyl ether R.sub.2O and alcohol ROH wherein R is C.sub.1 to C.sub.6; d. treating said organic solvent containing the complex of the formula Cs.sup.I+L.sup.− with an anhydrous acid HA, where HA is HCl, HBr, H.sub.2SO.sub.4, H.sub.3PO.sub.4 or a compound R.sub.A.sup.−H.sup.+, in which R.sub.A.sup.− is a carboxylic acid residue and R.sub.A.sup.− is sufficiently basic to form an ion-pair CsR.sub.A, whereby CsA is precipitated, and separating the precipitated CsA from said organic solvent; e. recycling said organic solvent containing a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein M.sup.I is H(OR.sub.2).sub.n and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, to step a; f. treating the aqueous phase obtained in step b. with M.sup.+[B(C.sub.6F.sub.5).sub.4].sup.−, M being H, Li, Na, K, ½ Mg, Mg(OH), ½ Ca, Ca(OH), optionally solvated, whereby Rb[B(C.sub.6F.sub.5).sub.4] is selectively and almost quantitatively precipitated, g. separating the precipitated complex of the formula Rb[B(C.sub.6F.sub.5).sub.4] from the aqueous phase and drying the obtained precipitated complex of the formula Rb[B(C.sub.6F.sub.5).sub.4]; and optionally h. dissolving the separated complex of the formula Rb[B(C.sub.6F.sub.5).sub.4] in an anhydrous organic solvent selected from a dialkyl ether R.sub.2O and alcohol ROH wherein R is C.sub.1 to C.sub.6; i. treating said organic solvent containing the complex of the formula Rb[B(C.sub.6F.sub.5).sub.4] with an anhydrous acid HA, where HA is HCl, HBr, H.sub.2SO.sub.4, H.sub.3PO.sub.4 or a compound R.sub.A.sup.−H.sup.+, in which R.sub.A.sup.− is a carboxylic acid residue and R.sub.A.sup.− is sufficiently basic to form an ion-pair RbR.sub.A, whereby RbA is precipitated, and separating the precipitated RbA from said organic solvent; j. recycling said organic solvent containing a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein M.sup.I is H(OR.sub.2), and L.sup.− is [B(C.sub.6F.sub.5).sub.4].sup.−, to step f.

15. Process for preparing a complex of the formula [M.sup.I].sup.+L.sup.− according to claim 4, wherein: M.sup.I is Cs in the form of a radioactive isotope, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, OH.sup.−, O.sub.2H.sub.3.sup.− or NH.sub.2.sup.−, wherein the process comprises reacting a complex of the formula [M.sup.I(solv)].sup.+L.sup.−, wherein: M.sup.I is selected from H(OH.sub.2).sub.n, Li, Na, K, ½ Mg, MgY, Mg(OH), ½ Ca, Ca(OH), wherein Y is a halide, (solv) represents a solvating ligand capable of coordinating to M.sup.I, and L.sup.− is [(C.sub.6F.sub.5).sub.3B—X—B(C.sub.6F.sub.5).sub.3].sup.−, wherein X is selected from halide, OH.sup.−, O.sub.2H.sub.3.sup.− or NH.sub.2 and Y is a halide, with a Cs salt wherein Cs in the form of a radioactive isotope in an aqueous medium.

16. A method of sterilizing waste water sewage, food, packings, clean rooms, and construction monitoring purposes using a complex according to claim 4.

Description

(1) The invention is further illustrated by the attached Figures and Examples.

(2) In the Figures, it is shown:

(3) FIG. 1: the conformation of the inventive Cs complex (2)

(4) FIG. 2: the unit cell of the inventive Cs complex (2)

(5) FIG. 3: the CsF.sub.16 coordination in the inventive Cs complex (2)

(6) FIG. 4: a flowchart for the “FAB process” for the exploitation of cesium-containing mineral brines (FAB=fluoroarylboronate anion)

(7) FIG. 5: the unit cell of the Cs complex Cs[H(HO).sub.2B.sub.2(C.sub.6F.sub.5).sub.6] (5)

(8) FIG. 6: the unit cell of the inventive complexes M[B(C.sub.6F.sub.5).sub.4] with M being Rb (8) or Cs (7).

(9) The interest of the inventors in weakly coordinating anions (WCAs) has led them to synthesize the new cesium salt, Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (2). The inventors realized that (2) is insoluble in water and that it is instantaneously formed by mixing any aqueous solution containing Cs.sup.+ with virtually any source of the [H.sub.2NB.sub.2(C.sub.6F.sub.5)].sup.− anion. The reaction is 100% specific for Cs.sup.+, since only in this case [H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6].sup.− changes its usual asymmetric conformation to an “inverse C.sub.2 symmetric” conformation to form a specific 3D lattice. The X-ray structure of (2) reveals that in the crystal 16 F atoms of five [H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6].sup.− anions surround the Cs.sup.+ cation, which corresponds to a record-setting Werner coordination number of CN=16 for any ligand element, including hydrogen, as represented in FIG. 1 to 3.

(10) In the CsF.sub.16 structure of (2), the largest and least electrophilic monoatomic cation is combined with a (perfluoroaryl)boronate (FAB) WCA of extremely low basicity, paired with high hydrophobicity. The low electrophilicity entails a low solvation enthalpy of Cs.sup.+, and so the perfectly fitting WCA can compete with the water at Cs.sup.+ on electrostatic grounds. Because of the weak and long Cs.sup.+ . . . F coordination bonds the coordination sphere is large; thus, many F atoms can interact with Cs.sup.+. The high number of cation-anion interactions stabilizes the given 3D network. Based on these findings a cyclic process for the extraction of cesium has been developed by the inventors which process enables quantitative extraction of cesium from water or acidic solutions which may contain Cs.sup.+ in concentrations as low as a few ppm. FIG. 4 gives a flowchart for the process. By reacting the Cs.sup.+ containing aqueous brine with [M.sup.I(solv)].sup.+[FAB].sup.− (1) (here: FAB=H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6) as a reagent in a stoichiometric amount, the polymeric, insoluble, and solvent-free Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (2) precipitates or can be extracted (A). Remarkably, once (2) is isolated from the aqueous brine (B), it can be cleaved, e.g., by HCl gas in diethyl ether (OEt.sub.2) to quantitatively precipitate pure CsCl, with recovery of the FAB WCA in the form of [H(OEt.sub.2).sub.2].sup.+[FAB].sup.− (C, D). Feeding [H(OEt.sub.2).sub.2].sup.+[FAB].sup.− back to an aqueous Cs.sup.+ brine and evaporating the organic solvent allows for a cyclic process in which Cs.sup.+ is 100% selectively and quantitatively extracted from any aqueous or acidic Cs.sup.+ solution and converted into, e.g., pure CsCl without formation of byproducts.

(11) For selective separation of rubidium from a mineral brine containing both Cs.sup.+ and Rb.sup.+, a tandem process can be envisaged. In the first step of FIG. 4, Cs.sup.+ is extracted by the [H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6].sup.− or [H(HO).sub.2B.sub.2(C.sub.6F.sub.5).sub.6].sup.− anions to obtain the Cs-depleted brine (stage B). For this brine, which still contains Rb.sup.+, the process according to FIG. 4 is repeated, now with Li[B(C.sub.6F.sub.5).sub.4] as the extracting reagent. This second extracting step allows to selectively and nearly quantitatively precipitate Rb[B(C.sub.6F.sub.5).sub.4]. Reaction of the latter with an anhydrous acid in ethereal solution affords precipitation of, e.g., pure RbCl together with the recycled anion in ethereal solution.

(12) By a tandem set-up of two cycles of the given flowchart as shown in FIG. 4, the first cycle with [H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6].sup.− or [H(HO).sub.2B.sub.2(C.sub.6F.sub.5).sub.6].sup.− as an extracting anion for Cs.sup.+ and the second with [B(C.sub.6F.sub.5).sub.4].sup.− as the extracting anion for Rb.sup.+, any brine containing, inter alia, Cs.sup.+ and Rb.sup.+ (but free from Tl.sup.+) may be exploited for these elements in a cyclic process, allowing selective and quantitative isolation of pure salts CsA and RbA. The inventors suggest the term “FAB process” for referring to the Cs.sup.+ and Rb.sup.+ extraction by fluoroarylboronate anions.

EXAMPLES

Preparation Example 1—Synthesis of Extracting Reagent [Na(Et.SUB.2.O).SUB.x.][H.SUB.2.NB.SUB.2.(C.SUB.6.F.SUB.5.).SUB.6.]

(13) Sodium amide, NaNH.sub.2 (3.9 g, 0.10 mol), and perfluoro-triphenylborane, B(C.sub.6F.sub.5).sub.3 (105 g, 0.205 mol), mixed in 1.0 L of diethyl ether, are stirred until all NaNH.sub.2 is dissolved. The solution contains 0.10 mol of dinuclear [Na(Et.sub.2O).sub.x][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] and is used for the cesium separation process.

Preparation Example 2—Synthesis of Extracting Reagent (C.SUB.6.F.SUB.5.).SUB.3.B(OH.SUB.2.).SUB.n .from (C.SUB.6.F.SUB.5.).SUB.3.B and Water

(14) (C.sub.6F.sub.5).sub.3B is a well-established strong Lewis-acid. It is known that (C.sub.6F.sub.5).sub.3B forms various hydrates with up to three molecules of water, (C.sub.6F.sub.5).sub.3B(OH.sub.2).sub.n (n=1-3). While (C.sub.6F.sub.5).sub.3B is air-sensitive, this is not the case for (C.sub.6F.sub.5).sub.3B(OH.sub.2).sub.n. The inventors have found it most convenient to prepare the adduct for n=1 and use it for the reactions. (C.sub.6F.sub.5).sub.3B (51.2 g, 0.1 mol) was dissolved in 1 L of petrol ether (pentane), and water (1.8 mL, 0.1 mol) was added at ambient temperature. The mixture was stirred until a clear solution was obtained, if necessary by heating to reflux. When cooled, colorless (C.sub.6F.sub.5).sub.3B(OH.sub.2) precipitated which was isolated by filtration and dried by air or vacuum; yield of the product is quantitative (53 g). The process can be carried out batchwise or continuously in the recovered solvent.

(15) In the inventive process any typical aqueous solution of cesium salts can be used, largely irrespective of further cations and the type of anions. The solution may be industrial brine obtained from mineral digestion or wastewaters, but must have been freed from insoluble material. There appears to be no explicit pH dependency, but acidic to neutral solutions are preferred. Separate procedures are described for laboratory scale and technical preparations of CsCl in cyclic processes.

Example 1—Synthesis of Cs[H.SUB.2.NB.SUB.2.(C.SUB.6.F.SUB.5.).SUB.6.] (2)

(16) All operations were performed under argon. A two-necked round bottom flask, equipped with a reflux condenser, was filled with [Na(OEt.sub.2).sub.4][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (2.72 g, 2.00 mmol), CsF (0.32 g, 2.1 mmol), and CH.sub.2Cl.sub.2 (50 mL). The flask was placed in an ultrasonic bath and the suspension sonicated for 14 h; by cooling the bath the temperature was kept at 40° C. The excess of CsF and the precipitated NaF were removed by filtration and the volume of the solution was reduced to about 25 mL. Admixing pentane to the solution afforded separation of colorless crystals; yield 1.74 g (74%).

(17) .sup.1H NMR (CD.sub.2Cl.sub.2): δ 5.66 (broad, NH.sub.2). .sup.11B NMR (CD.sub.2Cl.sub.2): δ−8.2 (s). .sup.19F NMR (CD.sub.2Cl.sub.2): δ−132.8 (d, 2C, F.sub.ortho), −160.1 (t, 1C, F.sub.para), −165.6 (“t”, 2C, F.sub.meta). ESIpos MS (CH.sub.2Cl.sub.2): m/z (%)=133 ([Cs].sup.+, 100). ESIneg MS (CH.sub.2Cl.sub.2): m/z (%)=528 ([H.sub.2NB(C.sub.6F.sub.5).sub.3].sup.−, 2), 1040 ([H.sub.2NB.sub.2(C.sub.6F.sub.5)].sup.−, 100).

(18) Anal. Calcd for C.sub.36H.sub.2B.sub.2CsF.sub.30N (1172.9): C, 36.87; H, 0.17; B, 1.84; Cs, 11.33; F, 48.59; N, 1.19. Found: C, 36.77; H, 0.10; B, 1.64; Cs, 10.29; F, 47.15; N, 2.19.

Example 2—Isolation of Cs[H.SUB.2.NB.SUB.2.(C.SUB.6.F.SUB.5.).SUB.6.] (2)

(19) (a) Form Neat Water

(20) [Na(OEt.sub.2).sub.3][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (69.6 mg, 0.0541 mmol; FW=1285.4; c≈0.9.Math.10.sup.−4 M) was dissolved in 570 mL of water. CsCl (9.5 mg, 0.0564 mmol; FW=168.4) was added and after brief mixing the clear solution was left unstirred. Soon colorless crystals began to separate. The mixture was left overnight and the precipitate was isolated by filtration; yield of 2 42.1 mg (0.0359 mmol, 66%; FW=1172.9). The aqueous mother liquor was extracted once with 20 mL of CH.sub.2Cl.sub.2. Evaporation of the solvent gave an additional crop of 20 mg (0.0170 mmol, 32%). Total isolated yield was 62.1 mg (0.053 mmol; 98%). The IR spectra of the isolated solids were identical with that of pure Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (2).

(21) (b) Water, Containing Other Metal Salts

(22) To a water solution (450 mL), containing the inorganic salts listed below, was added [Na(OEt.sub.2).sub.3][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (27.5 mg, 0.0214 mmol; FW=1285.4; c≈4.75.Math.10.sup.−5 M) and the suspension was stirred overnight. A brown precipitate resulted (color presumably arising from Fe(OH).sub.3) which was filtered off and was washed with dichloromethane to extract 2. The solvent of the extract was evaporated to dryness to leave a colorless residue: yield 19.2 mg of 2 (0.0163 mmol, 76%; FW=1172.9), identified by comparison of the IR spectrum with that of pure 2. The experiment showed that 2 can be isolated selectively and in relatively high yield from a dilute aqueous solution containing a variety of other cations.

(23) List of Added Inorganic Salts

(24) TABLE-US-00001 mass mass concentration Salt FW [mg] [mmol] [mol/L] CsCl 168.4 3.8 0.0226 .sup. 5 .Math. 10.sup.−5 KCl 74.6 138.1 1.850 4.1 .Math. 10.sup.−3 PbCl.sub.2 278.1 121.3 0.436 1.0 .Math. 10.sup.−3 CrCl.sub.3•6H.sub.2O 266.4 66.3 0.249 0.55 .Math. 10.sup.−3  CaCl.sub.2 111 92.4 0.832 1.85 .Math. 10.sup.−3  FeCl.sub.3•6H.sub.2O 270.3 109.0 0.403 0.9 .Math. 10.sup.−3

Example 3—Synthesis of Cs[(C.SUB.6.F.SUB.5.).SUB.3.B(O.SUB.2.H.SUB.3.)B(C.SUB.6.F.SUB.5.).SUB.3.] (5) (Eq. 4)

(25) B(C.sub.6F.sub.5).sub.3 (5.12 g, 10.0 mmol) is treated in an inert solvent (hexane, toluene, CH.sub.2Cl.sub.2) with one equivalent of water (180 mg, 10.0 mmol) to give (C.sub.6F.sub.5).sub.3B(OH.sub.2) 4 as a colorless precipitate (4.80 g, 90%) which is isolated by filtration. Stirring (C.sub.6F.sub.5).sub.3B(OH.sub.2) 4 (2.65 g, 5.00 mmol) in 50 ml of water with CsCl (420 mg, 2.50 mmol) for 1 hour results in conversion of the solid into Cs[(C.sub.6F.sub.5).sub.3B(O.sub.2H.sub.3)B(C.sub.6F.sub.5).sub.3] 5 (2.80 g, 94%), containing traces of water only. The reaction may also be carried out as a one-pot reaction, starting from B(C.sub.6F.sub.5).sub.3, CsCl and water.

Example 4—Preparation of [Na(PEG-400).SUB.n.][H.SUB.2.NB.SUB.2.(C.SUB.6.F.SUB.5.).SUB.6.] for Oral Administration

(26) Polyethylene glycol 400 (PEG-400, Alfa Aesar) represents a polyethylene glycol mixture of average formula H(OC.sub.2H.sub.4).sub.8.67(OH) (FW=400).

(27) (a) The clear solution of [Na(Et.sub.2O).sub.3][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (12.85 g, 10.0 mmol) in 50 mL of dichloromethane is treated with PEG-400 (3.55 mL, 10.0 mmol) and the same volume of pentane is added. In the course of several days colorless needles separate which were analyzed as [Na(PEG-400)][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6]. Full removal of all volatiles from the mother liquor by vacuum leaves an additional colorless solid of same composition; total yield is quantitative.

(28) (b) The solution of [Na(Et.sub.2O).sub.3][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (12.85 g, 10.0 mmol) in 50 mL of dichloromethane is treated with PEG-400 (10.0 mL), 28.2 mmol). All volatiles are removed in a vacuum. The remaining liquid is extracted with 50 mL of pentane and the upper pentane phase is discarded. The lower phase is freed from residual pentane under vacuum to leave a colorless oil which has been analyzed for [Na(PEG-400)≈.sub.2.7][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6]; yield is quantitative. Both the solid and the liquid formulations of [Na(PEG-400).sub.n].sup.+[FAB].sup.− are ready for oral administration to the patient.

Example 5—Stepwise Laboratory Process for Cesium Separation

(29) Step 1

(30) 5.0 L of a 0.01 M aqueous solution of ionic cesium (0.05 mol) is combined with 500 mL of a 0.10 M solution of Na[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (0.05 mol) in diethyl ether. By raising the temperature to 50° C. diethyl ether is distilled off. A colorless precipitate of Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (55.7 g, 0.0475 mmol) is formed in the aqueous phase, which is isolated by filtration and washed with 20 mL of pure water. Crystallization of some residual Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] from the aqueous phase may be retarded. If desired, complete removal of cesium is achieved by extraction with diethyl ether. Otherwise, the aqueous phase is discarded. The recycled diethyl ether is best stored over Na.sub.2CO.sub.3 for complete removal of moisture; it can be used in step 2.

(31) Step 2

(32) The isolated Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] is re-dissolved in 500 mL of dry diethyl ether and treated with HCl gas (1.23 L of gas, 0.05 mol). Immediately, a colorless precipitate of CsCl (8 g, 0.0475 mol) is formed, which is separated by filtration and washed with some pure solvent. The precipitated microcrystalline CsCl is dried and stored as the isolated product or re-dissolved in a suitable solvent for further reaction. Purity of the isolated CsCl is about 99% (IR, NMR).

(33) The ethereal filtrate contains intermediately formed [H(OEt.sub.2).sub.2][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] (0.0475 mol) and some HCl gas. The filtrate can be directly used for the next reaction cycle, starting with step 1. Possible loss of [H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] in each reaction cycle, estimated to amount to about 1%, is to be replaced for the next cycle.

Example 6—Process for Cs-Recovery

(34) Method 1 (from Concentrated Cs.sup.+ Brine, Involving Intermediate Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] Isolation)

(35) 1.0 L of a 0.2 M aqueous brine of Cs.sup.+ (0.2 mol Cs), e.g., from mineral digestion, is combined with 2.0 L of a 0.1 M [Na(OEt.sub.2).sub.4][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] diethyl ether or MTBE solution (0.2 mol of reagent). The mixture is stirred and the organic solvent is distilled off. When the ether is removed and collected, pure Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6](175-200 g, 0.15-0.17 mol) precipitates from the aqueous phase. Precipitation may occur slowly so some resting time is advisable to increase the yield. The precipitated Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] is separated by filtration and washed with some clear water and dried with air or under vacuum. (The yield may be increased to quantitative by extracting the aqueous phase as described in method 2.) The collected ether is dried over Na.sub.2CO.sub.3. Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] is dissolved in said dried ether and the obtained solution is treated with gaseous HCl (4.9 L, 0.2 mol). Thereby, pure CsCl precipitates in nearly quantitative yield (25-29 g, 0.15-0.17 mol). CsCl is isolated by filtration, washed with ether, and dried under vacuum. The ethereal solution, containing [H(OEt.sub.2).sub.2][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] and excess HCl, can be used for a further reaction cycle. Excess of acid can be neutralized with Na.sub.2CO.sub.3.

(36) Method 2 (from dilute Cs.sup.+ solutions without separation of Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6])

(37) 5.0 L of a 0.01 M aqueous solution of Cs.sup.+, e.g., obtained from radiocesium reprocessing and containing a total amount of 0.05 mol Cs, is combined with 500 mL of 0.1 M diethyl ether solution of [Na(OEt.sub.2).sub.4][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] reagent (0.05 mol). The emulsion formed in the beginning is stirred for 30 min. After some resting time the ethereal phase is carefully separated from the aqueous phase. The aqueous phase has been nearly fully depleted from Cs.sup.+ and is discarded. The ethereal phase contains dissolved Cs[H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] and is treated with 5 g of Na.sub.2CO.sub.3 for removal of moisture. After separation from the desiccant by filtration, gaseous hydrogen chloride (1.23 L, 0.05 mol) is added to the solution, whereupon colorless CsCl precipitates (7.58-8.42 g, 0.045-0.05 mol). The product is separated by filtration, washed with dry ether, and dried under vacuum. Purity is about 99% (IR, NMR, MS). The ethereal solution, containing [H(OEt.sub.2).sub.2][H.sub.2NB.sub.2(C.sub.6F.sub.5).sub.6] and excess HCl, can be used for a further reaction cycle. Part of the Na.sub.2CO.sub.3 may be used for neutralizing the aqueous waste solution.

Example 7—Process for Cs Recovery Based on B(C.SUB.6.F.SUB.5.).SUB.3

(38) 5.0 L of a 0.01 M aqueous solution of Cs.sup.+ (0.05 mol Cs), is stirred with solid (C.sub.6F.sub.5).sub.3B(OH.sub.2) (53 g, 0.10 mol) for 6 hours. The colorless precipitate is isolated by filtration and dried to yield 55 g (0.046 mmol) of Cs[(H.sub.3O.sub.2)B.sub.2(C.sub.6F.sub.5).sub.6].0.1H.sub.2O. The compound may contain a trace of water. The compound is dissolved in 1 L of dry diethyl ether and treated with 1.2 L (0.049 mmol) of gaseous HCl. Immediately, a precipitate of CsCl (7.7 g, 0.045 mmol) is formed which is isolated by filtration. The ether filtrate contains recovered (C.sub.6F.sub.5).sub.3B(OH.sub.2).sub.n and any excess of HCl and can either be evaporated to dryness to recover solid (C.sub.6F.sub.5).sub.3B(OH.sub.2).sub.n (n=1-3) or be fed back as a solution for the next reaction cycle.

Example 8—Cyclic Process for Cs Recovery

(39) As shown in the scheme of FIG. 4, the aqueous or acidic Cs.sup.+ brine is treated in the mixer A with starting Na[FAB] dissolved in some ether (Et.sub.2O or MTBE); the ethereal solvent is distilled off and Cs[FAB] precipitates quantitatively. In separator B the precipitated Cs[FAB] is isolated (by filtration or centrifuge) and dried (airstream); the Cs.sup.+-depleted brine is discharged for other uses. In the small mixer C the isolated Cs[FAB] is redissolved in the ether distilled from A, and the concentrated solution is treated with HCl gas to precipitate CsCl. The product slurry is transferred to separator D for isolation of pure CsCl; the ether filtrate containing pure [H(OEt.sub.2).sub.2][FAB] (or MTBE solvate) is fed back to mixer A. Thus, besides the recycled stocks of [FAB] reagent and ether solvent, the only reagents which are consumed are the extracted Cs.sup.+ and the equimolar amount of HCl gas. In addition to gaseous HCl, the process is expected to work equally well with other non-aqueous acids such as HBr, H.sub.2SO.sub.4, RCOOH etc. to afford the corresponding Cs salts.

SUMMARY

(40) As illustrated before, the present invention allows various applications. There are numerous applications conceivable for the FAB process, notably for Cs: (a) Exploitation of Cs and Rb minerals. The FAB process avoids the otherwise numerous recrystallizations, handlings of large volumes, and environmental problems associated with current industrial processing of Cs and (less important) Rb. (b) Environmental issues. Viewing at current cesium production, full removal of Cs.sup.+ is a pressing problem because of environmental reasons. Using FAB reagents as an additive to a final settling basin for the brine will allow quantitative sedimentation of Cs[FAB] and Rb[FAB] and full exploitation of the contained Cs and Rb. (c) .sup.134/135/137Cs Fission Product Extraction (FPEX). Nuclear fuel reprocessing occurs by the PUREX and UREX processes. In the joined FPEX process, .sup.134/135/137Cs.sup.+ is currently apparently extracted by chlorinated cobalt bis(dicarbollide), [CCD].sup.−. Cs[FAB] extraction appears superior to current Cs[CCD] extraction, since the FAB reagents are more readily available, more selective, and only a single separation step is necessary, which simplifies the process, reduces costs and waste, and allows for saver execution. (d) .sup.137Cs technical and radiophamaceutical applications. The FAB process should allow ready preparation of pure .sup.137Cs[FAB] and other .sup.137CsA radioisotope compounds by the modified FPEX process (see c) and easier handling of the compounds. Typical commercial applications for .sup.137CsA compounds are, inter alia, sewage sludge sterilization, furnace lining controlling, and cancer afterloading therapy. (e) .sup.131Cs radiophamaceuticals. .sup.131Cs (t½=9.7 d) is used for cancer seed implantation (brachytherapy). For this purpose, .sup.131Cs is prepared by treating an aqueous .sup.130Ba.sup.2+ solution with neutrons to afford .sup.131Ba, which transforms into .sup.131Cs. The (slowly formed) .sup.131Cs must be continuously removed to avoid further neutron capture to give .sup.132Cs. Precipitating .sup.131Cs.sup.+ with [FAB].sup.− in aqueous solution is expected to allow for fast, quantitative, and continuous separation of pure .sup.131Cs[FAB] from .sup.130/131Ba.sup.2+. (f) .sup.134/135/137Cs decontamination. Waste waters from nuclear plants or discharges form nuclear plant accidents containing .sup.134/135/137Cs loadings can be reprocessed, with Cs[FAB] separation being effective down to the ppm level. .sup.134/135/137Cs decontamination of humans or mammals is also conceivable, challenging the current Prussian blue therapy.

(41) Therefore, the present invention is also directed to the following embodiments: It is claimed that compounds of types 1, 3, 4 and 6 can be used to precipitate Cs.sup.+ ions from aqueous solutions, containing Cs.sup.+ in low concentrations (10.sup.−5 molar or lower, such as 10 ppm); It is claimed that such precipitation allows removal of Cs-134/135/137 from radioactive waste waters in >75% yields. Extraction of such treated solutions with CH.sub.2Cl.sub.2, after or in place of the cesium salt precipitation, allows nearly quantitative separation of Cs-134/135/137 from waste solutions; It is claimed that such removal is specific for cesium; It is claimed that in particular compounds of type 1 can be used as an antidote for Cs-134/135/137 contamination of humans and animals, without uptake by the body or development of harmful side-effects (except minor effects such as constipation); It is claimed that the suggested therapy, in its administration regimen, corresponds largely to the PB therapy, but is more effective; It is claimed that compounds of type 2, 5, and 7, in particular those of type 2, can be prepared containing radioactive isotopes Cs-131 and Cs-137 and that these compounds have a favorable profile for use in therapy of various cancers. The advantage of such compounds is given by insolubility in water and easy preparation by precipitation from aqueous solutions.