Claims
- 1. A compound of the formula ##STR2## wherein A and B are members independently selected from the group consisting of N(R), N(R)CH.sub.2, O, OCH.sub.2, S and SCH.sub.2 ; R is a member selected from the group consisting of H, lower alkyl, aryl and [(CH.sub.2).sub.f E].sub.g R.sup.4 ; D is a member selected from the group consisting of H, SH, OH, NH(R), lower alkyl and N(R)[CH.sub.2 CHR.sup.1 CH.sub.2 O].sub.b (CH.sub.2).sub.a SiXYZ; X, Y and Z are members independently selected from the group consisting of Cl, O-matrix, OCH.sub.3, OC.sub.2 H.sub.5, methyl, ethyl and halogenated substituents thereof; R.sup.1, R.sup.2 and R.sup.3 are members independently selected from the group consisting of H, SH, OH, lower alkyl, aryl, dialkylphosphino, diarylphosphino, dialkylarsino, diarylarsino and [(CH.sub.2).sub.f E].sub.g R.sup.4 ; E is selected from the group consisting of S, Se and Te; R.sup.4 is a member selected from the group consisting of H, lower alkyl and aryl; a is an integer from 2 to about 10; b is an integer of 0 or 1; c is an integer from 1 to about 2000; d is an integer from 0 to about 2000; f is an integer from 2 to about 10; g is an integer from 1 to about 20; matrix is selected from the group consisting of sand, silica gel, glass, glass fibers, alumina, zirconia, titania and nickel oxide; with the following provisos: (1) if A is selected from the group consisting of O, OCH.sub.2, S and SCH.sub.2, then B must be selected from the group consisting of N(R) and N(R)CH.sub.2, (2) that at least one of the groups R, R.sup.1, R.sup.2 and R.sup.3 must be present in the compound as a member independently selected from the group consisting of SH, dialkylphosphino, diarylphosphino, dialkylarsino, diarylarsino and [(CH.sub.2).sub.f E].sub.g R.sup.4, and (3) d can be the integer 0 only if A is selected from the group consisting of N(R) and N(R)CH.sub.2.
- 2. A compound as defined in claim 1, wherein R.sup.1 is OH.
- 3. A compound as defined in claim 1, wherein a is 3, b is 1, c is 1, d is 1, R.sup.1 is OH, R.sup.2 and R.sup.3 are both H, A is N(R), B is NH and D is SH.
- 4. A compound as defined in claim 1, wherein a is 3, b is 1, c is 1, d is 0, R.sup.1 is OH, R.sup.2 and R.sup.3 are both H, A contains nitrogen, d is 0, and D is ##STR3##
- 5. A compound as defined in claim 1, wherein a is 3, b is 1, c is 4, d is 1, R.sup.1 is OH, R.sup.2 and R.sup.3 are both H, A contains nitrogen, B contains nitrogen, ##STR4##
- 6. A compound as defined in claim 1, wherein X, Y and Z are (O-matrix).
INTRODUCTION
This application is a continuation-in-part of U.S. application Ser. No. 07/236.763, filed Aug. 26, 1988.
The present invention relates to novel compositions and the use of such compositions in a process of recovering and concentrating desired ions from solutions containing other ions in addition to the desired ions.
The novel compositions comprise nitrogen containing hydrocarbons that are modified with at least one of the elements selected from the group consisting of sulfur, phosphorus and arsenic. These hydrocarbons are further covalently bonded to an inorganic solid support, such as sand, silica gel, glass, glass fibers, titania, zirconia, alumina and nickel oxide. The compositions bonded to the solid suppor are particularly useful in a process for removing and concentrating desired ions, such as noble metal ions and other transition metal ions, from solutions thereof. The solutions containing the desired ions may or may not contain other ions. When the solutions contain other ions, the other ions may or may not be present in much higher concentrations than the desired ions. The process of removing and concentrating the desired ions is accomplished by forming a complex of the desired ions with a complexing agent comprising the novel compositions of this invention. The complex can be formed by contacting the solutions with the complexing agent. Advantageously, the solutions flow through a column packed with the complexing agent. Following the formation of the complex, a receiving liquid, which can be of much smaller volume than the volume of the starting solution, is brought into contact with the loaded complexing agent to remove and concentrate the desired ions in the receiving liquid. The desired ions are then recovered from the receiving liquid.
It is known that macrocyclic polythioethers and certain other sulfur containing hydrocarbon ligands present as solutes in a solvent such as water are characterized by their ability to selectivity form strong bonds with the noble metal, platinum group metal, and mercury ions or groups of these ions present as solutes in the same solvent. In an article by R. M. Izatt, R. E. Terry, L. K. Hansen, A. G. Avondet, J. S. Bradshaw, K. K. Dalley, T. E. Jensen and J. J. Christensen, A CALORIMETRIC TITRATION STUDY OF UNI- AND BIVALENT METAL ION INTERACTION WITH SEVERAL THIA DERIVATIVES OF 9-CROWN-13, 12-CROWN-4, 15-CROWN-5, 18-CROWN-6, 24-CROWN-8, AND SEVERAL OXATHIAPENTADECANES IN WATER OR WATER-METHANOL SOLVENTS AT 25.degree. C., Inorganica Chimica Acta, 1978, Vol. 20, 1-8, the complexation of silver and mercury ions by open chain sulfur containing hydrocarbons is disclosed. In another article by S. R. Cooper, CROWN THIOETHER CHEMISTRY, Accounts of Chemical Research, 1988, Vol. 21, 141-146, the complexation of rhodium and silver ions by macrocyclic sulfur containing ligands is disclosed. However, researchers have not previously been able to incorporate nitrogen containing hydrocarbon ligands modified with sulfur, phosphorus and arsenic into separation systems where the behavior of the modified ligands in the separation systems is unchanged in comparison to the ligand as a solute and/or the modified ligand will remain in the separation system. Articles such as those entitled SILANE COMPOUNDS FOR SILYLATING SURFACES by E. P. Plueddeman, in "Silanes, Surfaces and Interfaces Symposium, Snowmass, 1985," Ed. by D. E. Leyden, Gordon and Breach, Publishers, 1986, pp. 1-25, and SILANE COUPLING AGENTS by E. P. Plueddemann, Plenum Press, 1982, pp. 1-235, list many different types of organic materials which have been attached to silane compounds and discusses some of their properties. The preparation and uses of nitrogen containing hydrocarbons that have been modified with sulfur, phosphorus and arsenic and which are attached to silane or silica have not been disclosed in the prior art, including the above mentioned articles or in any existing patents of which we are aware. The unique complexing properties of the modified nitrogen containing hydrocarbons disclosed herein and the ability to attach these modified nitrogen containing hydrocarbons to an inorganic solid support without reducing their ability to complex selected metal ions are significant accomplishments of the present invention.
The novel compositions of the present invention comprise certain sulfur and nitrogen containing hydrocarbon ligands covalently bonded to an inorganic solid support, e.g., sand, silica gel, glass, glass fibers, titania, zirconia, alumina or nickel oxide. The compounds are shown by the structural formula (1). ##STR1##
In formula (1), A and B are members independently selected from the group consisting of N(R), N(R)CH.sub.2, O, OCH.sub.2, S and SCH.sub.2, with the proviso that if A is selected from the group consisting of O, OCH.sub.2, S and SCH.sub.2, then B must be selected from the group consisting of N(R) and N(R)CH.sub.2 ; D is a member selected from the group consisting of H, NH(R), SH, OH, lower alkyl and N(R)[CH.sub.2 CH(R.sup.1)CH.sub.2 O].sub.b (CH.sub.2).sub.a SiXYZ; X, Y and Z are members independently selected from the group consisting of Cl, O-matrix, OCH.sub.3, OC.sub.2 H.sub.5, methyl, ethyl and halogenated substituents thereof; R is a member selected from the group consisting of H, lower alkyl, aryl and [(CH.sub.2).sub.f E].sub.g R.sup.4 ; R.sup.1, R.sup.2 and R.sup.3 are members independently selected from the group consisting of H, SH, OH, lower alkyl, [(CH.sub.2).sub.f E].sub.g R.sup.4, dialkylphosphino, diarylphosphino, dialkylarsino, diarylarsino and aryl, such as phenyl, naphthyl and pyridyl; E is selected from the group consisting of S, Se and Te; R.sup.4 is a member selected from the group consisting of hydrogen, lower alkyl and aryl; a is an integer from 2 to about 10; b is an integer of 0 or 1; c is an integer from 1 to about 2000; d is an integer from 0 to about 2000; f is an integer from 2 to about 10; g is an integer from 1 to about 20; and matrix is selected from the group consisting of sand, silica gel, glass, glass fibers, alumina, zirconia, titania and nickel oxide. Two further provisos must be met in the compounds of formula (1). First, at least one of the groups R, R.sup.1, R.sup.2 and R.sup.3 must be present in the compound as a member independently selected from the group consisting of SH, dialkylphosphino, diarylphosphino, dialkylarsino, diarylarsino and [(CH.sub.2).sub.f E].sub.g R.sup.4. Second, d can be the integer 0 only if A is selected from the group consisting of N(R) and N(R)CH.sub.2.
The compositions of formula (1) are characterized by high selectivity for and removal of desired metal ions or groups of metal ions such as the noble metal ions present at low concentrations from a source phase containing a mixture of the desirable metal ions and other undesirable ions which are often in much greater concentrations in the solution than the desirable ions. The compounds of formula (1) have the ability to quantitatively complex desired ion(s) from a large volume of solution in which the desired ion(s) are present at low concentrations. Thus, the compositions of formula (1) are ideally suited to be used in a novel process of selectively and quantitatively removing and concentrating a selected ion or group of ions present at low concentrations from a plurality of other ions in a multiple ion solution in which the other ions may be present at much higher concentrations. The ions to be recovered and/or concentrated can be noble metal type, e.g., gold, silver and the platinum metals, e.g., platinum, palladium, rhodium and iridium. When noble metals are not present, ions of mercury, lead, zinc, and other transition metals can be recovered and/or concentrated. The process of recovering and/or concentrating the selected ions comprises bringing the multiple ion solution into contact with a compound of formula (1) to complex the desired ion(s) with the compound, breaking the complex with a receiving liquid to render the ion(s) soluble in the receiving solution and then recovering the ion(s) from the receiving solution.
The preferred embodiment disclosed herein involves carrying out the process by bringing a large volume of the multiple ion solution into contact with a compound of formula (1) in a separation column. The multiple ion solution flows through the column and the desired ion or ions form a complex with the compound of formula (1). A smaller volume of a receiving liquid such as aqueous NH.sub.3, for example, is then passed through the column to break the complex by chemical or thermal means. The receiving liquid further dissolves the desired ions and carries them out of the column. Instead of using a column, the compound of formula (1) may be slurried in a suitable liquid, e.g., water. The multiple ion mixture can be present in the slurring liquid or subsequently added to the slurry. The desired ions(s) complex with the compound of formula (1) in the slurry and the slurry is then filtered. The resulting solids are washed with a receiving liquid to break the complex and recover the desired ion(s) in the receiving liquid. The desired metal ions are recovered from the receiving liquid by well known procedures.
In a particularly preferred embodiment of the process a covalent chemical bond is formed between an inorganic solid support, preferably, sand or silica gel, and at least one of the compounds of formula 1. The resulting bonded silica compound of formula is placed in a contacting device such as a tall column. The multiple ion mixture is passed through the column, with the desired metal ions from the multiple ion mixture forming a complex with the bonded silica to separate the desired metal ions from the rest of the mixture which flows out of the column. A small volume of the receiving liquid is thereafter passed through the column to break the complex as well and as to dissolve and carry out of the column the desired metal ions. The desired metal ions are then recovered from the receiving liquid by well known procedures.
US Referenced Citations (1)
| Number |
Name |
Date |
Kind |
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4767670 |
Cox et al. |
Aug 1988 |
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Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 276138 |
Jul 1988 |
EPX |
Continuation in Parts (1)
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Number |
Date |
Country |
| Parent |
236763 |
Aug 1988 |
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Patent Grant
5084430
