U.S. patent application number 09/832139 was filed with the patent office on 2001-10-18 for particulate solid supports functionalized with polyhydroxypyridinone ligands.
Invention is credited to Bruening, Ronald L., Krakowiak, Krzysztof E..
Application Number | 20010031233 09/832139 |
Document ID | / |
Family ID | 23289956 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010031233 |
Kind Code |
A1 |
Bruening, Ronald L. ; et
al. |
October 18, 2001 |
Particulate solid supports functionalized with
polyhydroxypyridinone ligands
Abstract
Compositions and methods for selectively binding metal ions from
a source solution comprise using a polyhydroxypyridinone-containing
ligand covalently bonded to a particulate solid support through a
hydrophilic spacer of the formula SS-A-X-L (HOPO).sub.n where SS is
a particulate solid support such as silica or a polymeric bead, A
is a covalent linkage mechanism, X is a hydrophilic spacer
grouping, L is a ligand carrier, HOPO is a hydroxypyridinone
appropriately spaced on the ligand carrier to provide a minimum of
six functional coordination metal binding sites, and n is an
integer of 3 to 6 with the proviso that when SS is a particulate
organic polymer, A-X may be combined as a single covalent linkage.
The separation is accomplished by passing a source solution
containing the ions to be separated through a column containing the
particulate composition, causing the selected ions to be complexed
to the HOPO ligands and subsequently removing the selected ions
from the column by passing an aqueous receiving solution through
the column and quantitatively stripping the selected ions from the
HOPO ligand.
Inventors: |
Bruening, Ronald L.;
(American Fork, UT) ; Krakowiak, Krzysztof E.;
(American Fork, UT) |
Correspondence
Address: |
M. Wayne Western
THORPE, NORTH & WESTERN, L.L.P.
P.O. Box 1219
Sandy
UT
84091-1219
US
|
Family ID: |
23289956 |
Appl. No.: |
09/832139 |
Filed: |
April 6, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09832139 |
Apr 6, 2001 |
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09330477 |
Jun 11, 1999 |
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6232265 |
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Current U.S.
Class: |
423/70 ; 423/100;
423/112; 423/139; 423/21.5; 502/401 |
Current CPC
Class: |
B01J 20/3255 20130101;
B01J 20/3219 20130101; B01J 45/00 20130101; B01J 20/321 20130101;
B01J 20/3204 20130101; B01J 20/3251 20130101 |
Class at
Publication: |
423/70 ;
423/21.5; 423/100; 423/112; 423/139; 502/401 |
International
Class: |
B01D 015/04 |
Claims
What is claimed is:
1. A composition for selectively binding metal ions comprising a
polyhydroxypyridinone-containing ligand covalently bonded to a
particulate solid support through a hydrophilic spacer having the
formula:SS-A-X-L(HOPO).sub.nwhere SS is a particulate solid
support, A is a covalent linkage mechanism, X is a hydrophilic
spacer grouping, L is a ligand carrier, HOPO is a hydroxypyridinone
appropriately spaced on the ligand carrier to provide a minimum of
six functional coordination metal binding sites, and n is an
integer of 3 to 6 with the proviso that when SS is a particulate
organic polymer, A-X may be combined as a single covalent
linkage.
2. A composition according to claim 1 wherein ligand carrier L is
configured such that there are at least two atoms on carrier L
separating the attached HOPO groups to provide the appropriate
stereoconfiguration to optimize the HOPO metal binding sites.
3. A composition according to claim 2 wherein HOPO is a member
selected from the group consisting of 3-hydroxy-2(1H)-pyridinone,
1-hydroxy-2(1H)-pyridinone and 3-hydroxy-4(1H)-pyridinone
covalently bonded to ligand carrier L through a functionality other
than the hydroxy or carbonyl moieties on the pyridinone ring.
4. A composition according to claim 3 wherein SS is a inorganic
solid support selected from the group consisting of sand, silica
gel, glass, glass fibers, alumina, zirconia, titania, and nickel
oxide and combinations thereof.
5. A composition according to claim 4 wherein A is a member
selected from the group consisting of Si(Z,Z)-O, wherein Z can
independently represent members selected from the group consisting
of Cl, Br, I, lower alkyl, lower alkoxy, substituted lower alkyl or
substituted lower alkoxy and O-SS.
6. A composition according to claim 5 wherein X is a member
represented by the formula:(CH.sub.2)
(OCH.sub.2CHR.sup.1CH.sub.2).sub.bwherein R.sup.1 is a member
selected from the group consisting of H, SH, OH, lower alkyl, and
aryl; a is an integer from 3 to about 10; and b is an integer of 0
or 1.
7. A composition according to claim 3 wherein SS is a particulate
polymeric organic solid support matrix selected from the group
consisting of polyacrylate, polystyrene, and polyphenol and
combinations thereof.
8. A composition according to claim 7 wherein A and X combined are
represented by the
formula:--(CH.sub.2).sub.x--(Y).sub.y--(CH.sub.2).sub.- z--where y
is an integer of 0 or 1; x and z are independently integers between
0 and 10; and Y is member selected from the group consisting of O,
S, C.dbd.N, CO, CONH, CSNH, COO, CSO, NH, NR, SO, SO.sub.2,
SO.sub.2NH, C.sub.6H.sub.4 and CH.sub.2C.sub.6H.sub.4 where R is
lower alkyl with the proviso that at least one of x, y and z must
be at least 1.
9. A composition according to claims 6 or 8 where L is a polyamine
carrier.
10. A composition according to claim 9 wherein each HOPO group on
the L carrier is separated by at least four non-hydrogen atoms.
11. A composition according to claim 10 wherein y is 1 and Y is
CONH.
12. A composition according to claim 10 where n is 3.
13. A composition according to claim 10 where n is 4.
14. A method for concentrating, removing, and separating selected
ions from a source solution comprising the steps of: (a) contacting
said source solution having a first volume with a composition
comprising a polyhydroxypyridinone-containing ligand covalently
bonded to a particulate solid support through a hydrophilic spacer
having the formula:SS-A-X-L(HOPO).sub.nwhere SS is a particulate
solid support, A is a covalent linkage mechanism, X is a
hydrophilic spacer grouping, L is a ligand carrier, HCOO is a
hydroxypyridinone appropriately spaced on the ligand carrier to
provide a minimum of six functional coordination metal binding
sites, and n is an integer of 3 to 6 with the proviso that when SS
is a particulate organic polymer, A-X may be combined as a single
covalent linkage; wherein said L(HOPO).sub.n portion of the
composition has an affinity for said selected ions such as to form
a complex between said selected ions and said HOPO moieties of said
composition; (b) removing the source solution from contact with
said composition to which said selected ions have been complexed;
and (c) contacting said composition having said selected ions
complexed thereto with a smaller volume of an aqueous receiving
solution in which said selected ions are either soluble or which
has greater affinity for such selected ions than does the ligand
portion of the composition thereby quantitatively stripping such
selected ions from the ligand and recovering said selected ions in
concentrated form in said receiving solution.
15. A method according to claim 14 wherein, in said composition,
said ligand carrier L is configured such that there are least two
atoms on carrier L separating the attached HOPO groups to provide
the appropriate steroconfiguration to optimize the HOPO metal
binding sites.
16. A method according to claim 15 wherein, in said composition,
HOPO is a member selected from the group consisting of
3-hydroxy-2(1H)-pyridinone, 1-hydroxy-2(1H)-pyridinone and
3-hydroxy-4(1H)-pyridinone covalently bonded to ligand carrier L
through a functionality other than the hydroxy or carbonyl moieties
on the pyridinone ring.
17. A method according to claim 16 wherein, in said composition, SS
is a inorganic solid support selected from the group consisting of
sand, silica gel, glass, glass fibers, alumina, zirconia, titania,
and nickel oxide and combinations thereof.
18. A method according to claim 17 wherein, in said composition, A
is a member selected from the group consisting of Si(Z,Z)-O,
wherein Z can independently represent members selected from the
group consisting of Cl, Br, I, lower alkyl, lower alkoxy,
substituted lower alkyl or substituted lower alkoxy and O-SS.
19. A method according to claim 18 wherein, in said composition, X
is a member represented by the
formula:(CH.sub.2).sub.a(OCH.sub.2CHR.sup.1CH.s- ub.2).sub.bwherein
R.sup.1 is a member selected from the group consisting of H, SH,
OH, lower alkyl, and aryl; a is an integer from 3 to about 10; and
b is an integer of 0 or 1.
20. A method according to claim 16 wherein, in said composition, SS
is a particulate polymeric organic solid support matrix selected
from the group consisting of polyacrylate, polystyrene, and
polyphenol and combinations thereof.
21. A method according to claim 20 wherein, in said composition, A
and X combined are represented by the
formula:--(CH.sub.2).sub.x--(Y).sub.y--(C- H.sub.2).sub.z--where y
is an integer of 0 or 1; x and z are independently integers between
0 and 10; and Y is member selected from the group consisting of O,
S, C.dbd.N, CO, CONH, CSNH, COO, CSO, NH, NR, SO, SO.sub.2,
SO.sub.2NH, C.sub.6H.sup.4 and CH.sub.2C.sub.2H.sub.4 where R is
lower alkyl with the proviso that at least one of x, y and z must
be at least 1.
22. A method according to claims 19 or 21 wherein, in said
composition, L is a polyamine carrier.
23. A method according to claim 22 wherein, in said composition,
each HOPO group on the carrier is separated by at least four
non-hydrogen atoms.
24. A method according to claim 23 wherein, in said composition, y
is 1 and Y is CONH.
25. A method according to claim 23 wherein, in said composition, n
is 3.
26. A method according to claim 23 wherein, in said composition, n
is 4.
27. A method according to claim 16 wherein said selected ion is a
member selected from the group consisting of transition,
post-transition, actinide and lanthanide metal ions.
28. A method according to claim 27 wherein said selected ion is a
member selected from the group consisting of transition metal ions,
lanthanide series ions and actinide series ions.
29. A method according to claim 27 wherein said selected ions are
transition metal ions.
30. A method according to claim 27 wherein said selected ions are
lanthanide series ions.
31. A method according to claim 27 wherein said selected ions are
actinide series ions.
32. A method according to claim 27 wherein said source solution is
a nitric acid solution and said selected ions are members selected
from the group consisting of Pu(IV), Th(IV), Zr(IV) and Hf(IV).
33. A method according to claim 27 wherein said source solution is
neutral to slightly acidic and said selected ions are members
selected from the group consisting of Cu(II), Al(III), Ga(III),
Ni(II), Zn(II), Cd(II), Pb(II), Ag(I), and Hg(II).
34. A method according to claim 27 wherein said source solution is
a 1 to 5% HF and NH.sub.4 solution and said selected ion is
Fe(III).
Description
BACKGROUND OF THE INVENTION
[0001] Effective methods for the recovery and/or separation of
particular ions such-as the transition, post-transition, lanthanide
and radioactive actinide metal ions from solution mixtures of these
and other metal ions, are of great importance in modern technology.
It is particularly difficult to remove these particular metal ions
in the presence of moderate to strong acids and soluble complexing
or chelating agents, such as the halide ions, which have a high
affinity for the desired metal ions. It is also difficult to remove
the mentioned desired metal ions when they are present at low
concentrations in solutions containing other metal ions at much
greater concentrations. Hence, there is a real need for a process
to selectively concentrate certain transition, post-transition,
lanthanide and actinide metal ions when present at low
concentrations and in the presence of acid solutions and other
complexing agents.
[0002] It is known that siderophores (compounds manufactured by
microorganisms to sequester Fe.sup.3- ions) are commonly composed
of hydroxamate- and catecholate-containing molecules. Formulas 1
and 2 show these structures. 1
[0003] A modern review of the siderophores is found in an article
by J. R. Telford and K. N. Raymond, "Comprehensive Supramolecular
Chemistry," vol. 10, Ed. by D. N. Reinhoudt, Pergamon Press, 1996,
pp. 245-266. Many synthetic iron chelating agents have been Lao
prepared in an effort to find pharmaceutical compounds that will
increase the excretion of iron from iron-overloaded patients. Some
of the synthetic chelating agents contain the hydroxypyridinone
structure as depicted by 3-hydroxy-2(1H)-pyridinone (Formula 3),
1-hydroxy-2(1H)-pyridinone (Formula 4), and
3-hydroxy-4(1H)-pyridinone (Formula 5). 2
[0004] These chelating agents often have other substituents, such
as carboxyl groups in positions 3, 4, 5, or 6 of the compound in
Formula 4 or alkyl and carboxymethyl groups on the nitrogen atoms
of the compounds in Formulas 3 and 5. These hydroxypyridinone
structures are excellent complexing agents for Fe .sup.3 because
the pyridone carbonyl oxygen atoms withdraw electron density and
have a partial negative charge as shown in the resonance structures
for 1-hydroxy-2(1H)-pyridinone below. 3
[0005] Thus, these materials resemble the hydroxamate molecules
that have a high affinity for Fe.sup.3+. The synthesis and
Fe.sup.3+ ion-complexing properties of these types of compounds are
found in the article by K. N. Raymond and his coworkers, "Ferric
Ion Sequestering Agents. 13. Synthesis, Structures, And
Thermodynamics of Complexation of Cobalt(III) And Iron(III) Tris
Complexes of Several Chelating Hydroxypyridinones," Inorganic
Chemistry, Volume 24, 1985, pp. 954-967; and in the article by P.
D. Taylor and his Coworkers, "Novel 3-hydroxy-2(1H)-pyridinones.
Synthesis, Iron(III)-chelating Properties And Biological Activity,"
Journal of Medicinal Chemistry, Volume 33, 1990, pp. 1749-1755. K.
N. Raymond and his coworkers have found that having more than one
of these chelating groups bonded to a polyamine such as
1,5,10,14-tetraazatetradec- ane improves their affinity for
Fe.sup.3+ and allows complex formation with the actinides. Bonding
to the polyamine is through the formation of amide bonds as shown
in following Formula 6. 4
[0006] The octadenate ligand shown above in Formula 6 has a high
affinity for Fe(III), Am(III), Pu(IV) and Np(V) as reported in
articles by K. N. Raymond and coworkers, "Specific Sequestering
Agents For The Actinides. 21. Synthesis And Initial Biological
Testing of Octadentate Mixed Catecholate-hydroxypyridinoate
Ligands," Journal of Medicinal Chemistry, Volume 36, 1993, pp.
504-509; and "In Vivo Chelation of Am(III), Pu(IV), Np(V) Ad U(VI)
in Mice by Tren-(Me-3,2-HOPO)," Radiation Protection Dosimetry,
Volume 53, pp. 305-309. A similar polyamine material containing
three Formula 3 HOPO molecules formed strong interactions with
gadolinium, calcium and zinc as shown in the article by J. Xu, S.
J. Franklin, D. W. Whisenhunt, Jr., and K. N. Raymond, "Gadolinium
Complex of
Tris[(3-hydroxy-1-methyl-2-oxo-1,2-didehydropyridine-4-carboxamido)eth-
yl]amine: A New Class of Gadolinium Magnetic Resonance Relaxation
Agents," Journal of the American Chemical Society, Volume 117,
1995, pp. 7245-7246. The synthesis of hydroxypyridinonate chelating
agents, such as that shown above in Formula 6, is shown by Raymond
et al., U.S. Pat. No. 4,698,431, issued Oct. 6, 1987. The materials
described in this patent and the above cited articles are directed
only to the hydroxypyridonate molecules or those bound to simple
amines. Attachment of from one to four HOPO rings to a molecular or
polymeric backbone through amide linkages is taught by Raymond et
al., U.S. Pat. No. 5,624,901, issued Apr. 29, 1997. At least one of
the HOPO rings must be a 3,2-HOPO ligand. Tetra-, hexa- and
octadentate ligands (i.e. two to four HOPO substituents) are
illustrated being attached to a polyamine linking backbone. There
is also an allegation that a polymeric backbone, such as
poly(styrenedivinylbenze- ne), agarose and polyacrylamide, having
amine functionalities, can be used to which a HOPO substituent can
be directly bonded via an amide-type linkage. There is no teaching
or suggestion that a tetra-, hexa- or octadentate HOPO ligands,
attached to a backbone carrier, can be covalently attached to a
polymeric or inorganic solid support through the backbone carrier
by appropriate linkage means.
[0007] The ability to complex Fe.sup.3+, Pu.sup.4+, Th.sup.4+,
Zr.sup.4-, lanthanides, actinides and other metal ions under
increasing acidities and competing matrix complexers or chelants
requires the interactive strength of six to eight donor atoms, of
which there are two per HOPO ring, and the proper molecular spacing
of these HOPO rings. The ability to use this interactive strength
to perform an actual separation requires that three or more HOPO
moieties with appropriate molecular spacing be attached via a
stable covalent bond to a solid support in such a manner that the
HOPO moieties cooperate in such a manner to maximize their
collective binding abilities.
SUMMARY OF THE INVENTION
[0008] The present invention provides a composition and method for
the removal of desired transition, post-transition, actinide and
lanthanide metal ions present in low concentrations from a solution
utilizing compositions comprising three or more
hydroxylpyridinonate (HOPO) containing ligands the composite of
which are appropriately spaced so as to contain the interactive
strength of six or more coordination binding sites, preferably six
to eight. The HOPO containing ligands are covalently bonded to a
particulate solid support via an appropriate hydrophilic
hydrocarbon spacer.
[0009] This invention also provides a composition and method of
maximizing the complexing abilities of ligands containing three or
more HOPO binding moieties by the preparation of ligands wherein
the HOPO moieties are properly spaced on a ligand carrier and the
ligand is attached to an inorganic or organic particulate solid
support via an appropriate hydrophilic hydrocarbon spacer.
[0010] The compositions of the present invention comprise suitable
ligands containing three or more HOPO groups, such as the HOPO
groups noted above, which are covalently bonded through a
hydrophilic spacer grouping to a silicon, carbon, nitrogen, oxygen
or sulfur atom and further covalently bonded to a particulate
inorganic or polymeric organic solid support and are represented by
the following Formula 7:
SS-A-X-L(HOPO).sub.n Formula 7
[0011] wherein SS is a solid support, A is a covalent linkage
mechanism, X is a hydrophilic spacer grouping, and L(HOPO)3 is a
ligand comprising a ligand carrier L having bound thereto three or
more HOPO groups, wherein the ligand carrier L is configured such
that the HOPO groups are appropriately spaced on the ligand carrier
to provide six or more functional coordination binding sites.
[0012] In the above Formula 7, n is an integer of at least three
and may range from about 3 to 6. Preferably n is an integer of 3 or
4. Preferably, the HOPO groups are positioned on carrier L such
that there are at least two and preferably at least four atoms on
carrier L separating the attached HOPO groups to provide the
appropriate stereoconfiguration to optimize the HOPO binding sites.
When considering the atoms separating the HOPO groups, the hydrogen
atom is not taken into consideration. When the ligand carrier L is
non-cyclic the HOPO groups on the carrier will preferably be spaced
apart by 4 to 6 atoms and when the ligand carrier is an amine the
HOPO groups will separated by four or more non-hydrogen atoms.
Preferably the carrier is a polyamine wherein an amine
functionality on the ligand carrier interacts with an active
functional group on the hydroxypyridinone to form a covalent bond.
Representative ligand carriers illustrated in the examples below
include members selected from the group consisting of
tetrakis(aminomethyl)methan- e;
tetrakis(5-amino-2-oxa-pentyl)methane;
25,26,27,28-tetrakis[(aminobutyl- )oxy]calix[4]arene;
1,4,8,12-tetrazacyclopendadecane and triethylenetetraamine. The
above ligand carriers are exemplary only and any carrier to which a
HOPO moiety can be appropriately spaced and bonded, such that the
metal coordination sites of the HOPO moiety can be utilized in ion
binding, are within the scope of the invention.
[0013] Functional hydroxypyridinone structures are shown in
Formulas 3, 4 and 5 and, regardless of their positions on the
pyridinone ring, always comprise adjacent hydroxy and oxo
groupings. This provides the HOPO group with a sequestering
functionality similar to the siderophores shown in Formulas 1 and
2. Formula 3 shows a 3-hydroxy-2(1H)-pyridinone, Formula 4 shows a
1-hydroxy-2(1H)-pyridinone and Formula 5 shows a
3-hydroxy-4(1H)-pyridinone. In addition to the hydroxy and oxo
functions, at least one other ring atom contains a functional
grouping through which a covalent bond can be formed to attach the
HOPO group to the ligand carrier to provide the overall multi HOPO
containing ligand. Preferably, when attached to a carbon atom of
the HOPO ring, the functional group will be a carboxylic acid group
that will react through amidation or esterification with an amino
or hydroxy group of the ligand carrier. When the functional group
is attached to the nitrogen atom of the pyridinone ring it will
preferably be an alkyl or carboxyalkyl group. Carboxylic acid
functional groups that react with an amine function on the ligand
carrier forming an amide bond are particularly preferred.
[0014] In order for the HOPO groups of the -L(HOPO).sub.n portion
of Formula 7 to function with optimal binding selectivity, it is
important that the stereoconfiguration of the HOPO moieties be such
that the coordination sites of each HOPO ring can function
optimally for the binding and removal of the desired ions. At the
same time, it is vital that the -L(HOPO).sub.n functionality be
firmly anchored to a solid support such that desired ions removed
from solutions can be complexed to the binding ligands and then,
optionally, subsequently released in such a manner that the
binding/release process can be repeatedly utilized as desired. This
is accomplished by means of a SS-A-X- portion of Formula 7.
[0015] The SS-A-X- portion of Formula 7 is well known for use with
ion binding ligands. Preferably solid support "SS" is an inorganic
and/or organic particulate support material selected from the group
consisting of silica, silica gel, silicates, zirconia, titania,
alumina, nickel oxide, glass beads, phenolic resins, polystyrenes
and polyacrylates. However, other organic resins or any other
hydrophilic organic and/or inorganic support materials meeting the
above criteria can also be used.
[0016] The use of organic ion binding ligands attached to an
SS-A-X-solid support by means of a covalent linkage spacer grouping
is illustrated in U.S. Pat. Nos. 4,943,375; 4,952,321; 4,959,153;
4,960,882; 5,039,419; 5,071,819; 5,078,978; 5,084,430; 5,173,470;
5,179,213; 5,182,251; 5,190,661; 5,244,856; 5,273,660; and
5,393,892. These patents, which disclose various spacers that can
be used in forming an organic ligand attached to a solid support,
are incorporated herein by reference.
[0017] When the solid support SS is an inorganic material such as
silica, silica gel, silicates, zirconia, titania, alumina, nickel
oxide and glass beads the covalent linkage A is a silane such that
A-X may be represented by the formula: 5
[0018] where X is a spacer grouping having the formula:
(CH.sub.2).sub.a(OCH.sub.2CHR.sup.1CH.sub.2).sub.b Formula 9
[0019] wherein R.sup.1 is a member selected from the group
consisting of H, SH, OH, lower alkyl, and aryl; a is an integer
from 3 to about 10; and b is an integer of 0 or 1. Each Z is
independently selected from the group consisting of Cl, Br, I,
lower alkyl, lower alkoxy, substituted lower alkyl or substituted
lower alkoxy and S. As used herein, lower alkyl or lower alkoxy
means a group having 1 to 8 carbon atoms.
[0020] When the particulate solid support (SS) is an organic resin
or polymer, such as phenolic resins, polystyrenes and
polyacrylates, it will generally be a hydrophilic polymer or
polymer derivatized to have a hydrophilic surface and contain polar
functional groups. The ligand L(HOPO).sub.n will then generally
contain a functional grouping reactive with an activated polar
group on the polymer. The covalent linkage A and spacer X will then
be integrated, and may actually be a single linkage, formed by the
covalent bonding formed by the reaction between the activated polar
group from the polymer and the functional group from the ligand and
may be represented by formula:
--(CH.sub.2).sub.x--(Y).sub.y--(CH.sub.2).sub.z-- Formula 10
[0021] where c is an integer of 0 or 1, d and e are independently
integers between 0 and 10 and Y is a functional group or aromatic
linkage such as an ether(O), sulfide(S), imine(C.dbd.N),
carbonyl(CO), ester(COO), thioester(CSO), amide(CONH),
thioamide(CSNH), amine(NH), lower alkylamine(NR), sulfoxide(SO),
sulfone(SO.sub.2), sulfonamide (SO.sub.2NH), phenyl
(C.sub.6H.sub.4), benzyl(CH.sub.2C.sub.6h.sub.4), and the like. At
least one of x, y or z must be 1.
[0022] It is to be emphasized that the present invention does not
reside in the discovery of the SS-A-X- portion of Formula 7.
Rather, it is the discovery that the ion-binding capabilities of
the L(HOPO).sub.n ligand, when attached to an SS-A-X based solid
substrates, are optimized.
[0023] The properly spaced polyhydroxypyridinone ligands covalently
bonded to solid supports as shown in Formula 7 are characterized by
high selectivity for and removal and separation of desired metal
ions or groups of desired metal ions, such as several transition,
post-transition, lanthanide and actinide metal ions, including
particularly Fe.sup.3+, Al.sup.3+, Zr.sup.4+, Th.sup.4-, Pu.sup.4+,
AM.sup.3-, Cm.sup.3-, Ac.sup.3-, and the lanthanides present at low
concentrations from source solutions containing a mixture of these
desired metal ions with the ions one does not desire to remove
which may be present in much greater concentrations in the source
solution including hydrogen ions. The separation is effected in a
separation device such as a column through which the source
solution is flowed. The process of selectively removing and
concentrating the desired metal ions is characterized by the
ability to selectively and quantitatively complex the desired metal
ions to the properly spaced polyhydroxypyridinone ligand portion of
the solid support system, from a large volume of solution, even
though the desired metal ions may be present at low concentrations.
The desired ions thus separated can, optionally, be subsequently
recovered from the separation column by flowing through it a small
volume of a receiving phase which contains a solubilized reagent
which need not be selective, but which will quantitatively
dissociate the desired ions from the hydroxypyridinone ligands. The
recovery of the desired metal ions from the receiving phase is
easily accomplished by known procedures.
[0024] Moreover, the above described ligands covalently bonded to
particulate solid supports as shown in Formula 7 provide a means
for separating parts-per-billion (ppb) to parts-per-million (ppm)
levels of Fe.sup.3- from 1% to 5% HF or NH.sub.4F by using the
separation techniques described above. The solid supported ligands
of this invention are also useful in separating Pu(IV), Th(IV),
Zr(IV), and Hf(IV) from >1M nitric acid solutions and in
separating other acid solutions of actinides and lanthanides
containing large amounts of other cations. The above described
solid supported ligands are also effective in separating Cu, Ni,
Zn, Cd, Pb, Ag, Hg and others as wastes from less acidic feed
streams such as potable water or industrial effluents.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As summarized above, the present invention is drawn to novel
properly spaced polyhydroxypyridinone-containing ligands covalently
bound to particulate solid support materials to form the
compositions of Formula 7. The invention is also drawn to the
concentration and removal of certain desired metal ions, such as
certain transition, post-transition, lanthanide and actinide metal
ions, from other metal ions in water supplies and waste solutions,
such as ions of Fe, Pu, Th, Zr, Hf, other lanthanides and
actinides, Bi, and Sb from acidic and/or highly complexing or
chelating matrices and Cu, Al, Ga, Ni, Zn, Cd, Pb, Ag, and Hg ions
from slightly acidic to neutral pH matrices and other chelating
matrices. Moreover, the above described ligands covalently bonded
to particulate solid supports as shown in Formula 7 provide a means
for separating ppb to ppm levels of Fe from concentrated 1% to 5%
HF and NH.sub.4F by using the separation techniques described
above. The process of the invention is particularly adaptable to
recovery of metal ions from solutions containing large amounts of
hydrogen ions and other ligating anions such as fluoride. Such
solutions from which such ions are to be concentrated and/or
recovered are referred to herein as "source solutions." In many
instances the concentration of desired ions in the source solutions
will be much less than the concentration of other metal ions from
which they are to be separated.
[0026] The concentration of desired ions is accomplished by forming
a complex of the desired ions with a
polyhydroxypyridinone-containing ligand particulate solid support
composition shown in Formula 7 and flowing a source solution
containing the desired ions through a column packed with a
polyhydroxypyridinone ligand-solid support composition to attract
and bind the desired metal ions to the polyhydroxypyridinone ligand
portion of such composition to form a ligand-metal ion complex, and
subsequently dissociating the ligand-metal ion complex by flowing a
receiving liquid in much smaller volume than the volume of source
solution passed through the column to remove and concentrate the
desired ions in the receiving liquid solution. The receiving liquid
or recovery solution forms a stronger complex with the desired
transition, post-transition lanthanide or actinide metal ions than
does the polyhydroxypyridinone ligand and thus the desired metal
ions are quantitatively stripped from the hydroxypyridinone
ligand-containing solid support composition in concentrated form in
the receiving solution. The recovery of desired metal ions from the
receiving liquid can be accomplished by known methods.
EXAMPLES
[0027] The following examples illustrate the preferred embodiments
of the invention that are presently best known. However, other
embodiments may be made within the scope of the disclosure. In
certain of she examples, reaction schemes are given that are
general in nature and reference to the text of each example may be
necessary to clarify each reactant, reaction step, reaction
condition and product obtained. Reactants utilized and/or products
prepared are identified by the number of the example followed by an
alphabetical designation in which each was first used, i.e. "1A" is
the first reactant or product identified in Example 1, "1B" is the
second, etc. All NMR spectra were obtained on QE 300 (300 MHZ)
spectrophotometer.
Example 1
Preparation of 1-hydroxy-2-(IH)-pyridinone-6-carboxylic Acid
(1C)
[0028] 6
[0029] The starting material used for this reaction can be either
6-chloro or 6-bromo-pyridine-2-carboxylic acid. The chloro
derivative is preferred and is illustrated here. A 643 g (4.08
mole) portion of 6-chloro-pyridine-2-carboxylic acid (1A) was added
to a solution of 10.6 L of CF.sub.3COOH and 1530 mL of 30%
H.sub.2O.sub.2 and heated to 80.degree. C. for 6.5 hrs. The
reaction mixture was concentrated to about 2100 mL by rotary
evaporation and then added to 1 L of water. The product immediately
precipitated as a finely divided, white crystalline solid. It was
isolated by filtration, washed with water, and dried in vacuo. This
yielded 687 g of 2-chloropyridine-2-carboxylic acid (1B), mp
180.degree. C. dec. .sup.1HNMR (DMSO-d.sub.6): S 8.20 (m,2H), 7.80
(m,1H), -2.70 (broad S, 1H)
[0030] A 687 g (3.96 mole) portion of the
2-chloro-pyridine-6-carboxylic acid (1B) prepared above was
dissolved in 15 L of a 10% aqueous KOH solution, and the resulting
solution was maintained at 80.degree. C. overnight and then cooled
in an ice bath and treated with 7.2 L of concentrated HCl. The
white suspended solid was isolated by filtration, washed with
dilute HCl followed by three 1.3 liter portions of water, and then
dried in vacuo to yield 530 g (86%) of
1-hydroxy-2-(IH)-pyridinone-6- -carboxylic acid (1C). mp
216.degree. C. dec. .sup.1HNMR (DMSO-d6): S 13.02 (broad s, 2H),
7.44 (m, 1H), 6.73 (d, J=9.5 Hz, 1H), 6.65 (d, J=7.5 Hz, 1H).
[0031] Examples 2-4 illustrate the preparation of ligand
carriers.
Example 2
Preparation of Tetrakis(aminomethyl)methane (TAM) (2C)
[0032] 7
[0033] A 250-mL three-necked reaction flask, equipped with a
mechanical stirrer and a thermometer, was heated in an oil bath to
210.degree. C. Pentaery-thrityl tetrabromide (2A) was ground well
with the sodium salt of p-toluenesulfonamide and added in four
(equal) amounts to the preheated reaction vessel while stirring.
The reaction mixture formed a viscous melt within 40 minutes (oil
bath 230.degree. C. by electro-thermometer). The melt was
maintained under stirring at 210.degree. C. for 8 hrs.
Pentaerythrityl tetrabromide sublimity on the cooler parts of the
reaction flask was melted down occasionally by pumping hot oil from
the oil bath. The reaction mixture was cooled to 180.degree. C.
under stirring and then allowed to cool to room temperature. Acetic
acid (70% v/v, 60 mL) was added to the reaction flask equipped with
a reflux condenser and the contents refluxed until the hard
reaction mixture disintegrated into a fine white suspension. The
mixture was washed several times with hot water to remove sodium
bromide and p-toluenesulfonamide. The resulting white crystalline
powder weighed 50 g (62%) and was found to be pure tetratosylate of
TAM (2B). mp 248.degree. C. .sup.1HNMR (CHCl.sub.3): S 7.70 (d,
J=9.0 Hz, 8H), S 7.33 (d, J=9.0 Hz, 8H), 5.40 (t, J=6.7 Hz, 4H,
NH), 2.68 (d, J=6.7 Hz, 8H), 2.44 (S, 12H).
[0034] Concentrated sulfuric acid was taken in a three-necked flask
equipped with a mechanical stirrer and heated to 160.degree. C. in
an oil bath. The powdered tosylate (2B) from above was added in
small lots over 40 minutes. The tosylate dissolved immediately to
form a clear solution and the temperature rose to 180.degree. C.
The reaction mixture was maintained at 180.degree. C. for 30
minutes. After cooling to room temperature and pouring into 30% v/v
ethanol, the white crystalline solid formed was allowed to settle.
The supernatant was decanted off and the precipitate was dissolved
in a minimum amount of 10% sodium hydroxide and filtered to remove
any insoluble material. The filtrate was evaporated to dryness. The
residue was treated with methanol and the solid was filtered off
and the filtrate was evaporated to dryness with the help of
toluene. The pure TAM product (2C) was obtained by distillation at
110.degree. C./0.4 mm Hg in yield of 76% (2.50 g) mp 70.degree. C.
.sup.1H NMR (CDCl.sub.3): S 2.58 (S, 8H) , 1.11 (S, 8H,
NH.sub.2)
Example 3
Preparation of Tetrakis (5-amino-2-oxa-pentyl)methane (3C)
[0035] 8
[0036] A mixture of 13.62 g (0.10 mole) of pentaerythritol (3A) and
1 g of a 40% Ag/KOH catalyst was stirred while 42.45 g (0.80 mole)
of acrylonitrile was added at a rate such that the temperature did
not exceed 35.degree. C. The mixture was stirred an hour after all
the acrylonitrile was added and poured into 200 mL of water. The
resulting mixture was stirred for one hour, which allowed the
excess acrylonitrile to polymerize completely. The polymer was
removed by filtration and washed with chloroform. The chloroform
layer was washed with water two times more and dried over
MgSO.sub.4. The crude tetranitrile product (3B) (30 g) was produced
by the evaporation of chloroform and directly used for the next
reaction without further purification. .sup.1HNMR (CDCl.sub.3): S
3.78 (t, J=6.0 Hz, 8H), 3.59 (S, 8H), 2.69 (t, J=6.0Hz, 8H).
[0037] To a solution of the crude tetranitrile (3B) (30 g, 0.10
mole) in HPLC grade THF (6.5 L) was added dropwise BH.sub.3 (1M in
THF, 1.4 L, 1.4 mole) under nitrogen. The reaction mixture was
heated at 70.degree. C. overnight. After being cooled, the solution
was carefully quenched by the addition of water, and the mixture
was stirred for 30 minutes at room temperature. The solvent was
then distilled off, and the solid residue was heated to reflux in
6N HCl (800 mL) for 3 hrs while being cooled with an ice-water
bath, and the acidic solution was basified to pH 13 with solid
NaOH. The water was evaporated to dryness and the tetramine product
(3C) was extracted with methanol from the residue. The methanol
solution was evaporated to dryness again and trace water was
removed by azeotropic distillation with toluene. The residue was
treated with CH.sub.2Cl.sub.2 and filtered. The filtration was
dried over K.sub.2IO.sub.3. After filtration, the methylene
chloride solution was evaporated to dryness. The pure
tetrakis(5-amino-2-oxapentyl)methane (3C) was obtained by
distillation under vacuo at 210.degree. C./0.3 mmHg in a yield of
34% (10.7 g). .sup.1HNMR (CDCl.sub.3): S 3.43 (t, J=6.0 Hz, 8H),
3.35 (S, 8H), 2.76 (t, J=6.6 Hz, 8H), 1.67 (m, 8H).
Example 4
Preparation of 25,26,27,28-tetrakis[(aminobutyl)oxy] Calix[4]arene
(4D)
[0038] 9
[0039] Calix[4]arene (4A) (3.56 g, 85 mmol), 4-bromo-butyronitrile
(2.60 g, 17.6 mmol), and potassium carbonate (1.39 g, 10.1 mmol)
was refluxed in CH.sub.3CN (100 mL) for 5 days. The solvent was
evaporated and the residue was taken up in CH.sub.2Cl.sub.2 (400
mL), washed with 1N HCl (100 mL), H.sub.2O (60 mL), and brine (60
mL), and dried with MgSO.sub.4. The CH.sub.2Cl.sub.2 was evaporated
and the residue was recrystallized from CHCl.sub.3/MeOH yielding a
white solid 25,27-bis[(cyanopropyl)oxy]-2-
6,28-dihydroxycalix[4]arene product (4B). Yield: 2.61 g (56%).
.sup.1HNMR (CDCl.sub.3): S 7.80 (S, 2H, CH), 7.20 (d, J=7.2 Hz,
4H), 6.92 (d, J=7.2 Hz, 4H), 6.75 (t, J=7.2 Hz, 2H), 6.66 (t, J=7.2
Hz, 2H), 4.18 (d, J=12.6 Hz, 4H) 4.10 (t, J=6.6 Hz, 4H), 3.42 (d,
J=12.6 Hz, 4H), 3.10 (t, J=6.6 Hz, 4H), 2.40 (m, 4H).
[0040] NaH (1.13 g, 44.7 mmol) and the above
25,27-bis[(cyanopropyl)oxy]-2- 6,28-dihydroxycalix[4]arene (4B)
(2.50 g, 4.5 mmol) was stirred for 1 hr. at room temperature in DMF
(100 mL). 4-Bromobutyronitrile (6.63 g, 44.7 mmol) was added and
the mixture was stirred at 75.degree. C. for 20 hrs. The DMF was
evaporated and the residue was taken up with CH.sub.2Cl.sub.2 (200
mLs) and washed with 1N HCl (100 mL.times.2), saturated NH.sub.4Cl
in H.sub.2O (100 mL.times.3), and saturated NaCl in H.sub.2O (100
mL), and dried with MgSO.sub.4. After filtration, the
CH.sub.2Cl.sub.2 was evaporated and the residue was purified by
silica gel column (CH.sub.2Cl.sub.2/MeOH=250/)1 and then
recrystallized from MeOH with a yield of 0.43 g (15%) yield
25,26,27,28-tetrakis[(cyanopropyl)oxy]calix[4- ]arene (4C).
.sup.1HNMR (CDCl.sub.3): 6.64 (S, 12H), 4.32 (d, J=12.4 Hz, 4H),
4.05 (t, J=6.5 Hz, 8H), 3.24 (d, J=12.4 Hz, 4H) 2.60 (t, J=6.5 Hz,
8H), 2.20 (m, 8H).
[0041] A mixture of the tetranitrile (4C) (0.43 g, 0.02 mmol) and
1M BH.sub.3 in THF (10 mL, 10 mmol) was refluxed overnight. After
being cooled, the solution was carefully quenched by the addition
of water, and the mixture was stirred for 30 minutes at room
temperature. The solvent was then distilled off, and the solid
residue was heated to 65.degree. C. in conc. HCl (10 mL) and MeOH
(10 mL) for 2 hrs. After being cooled with an ice-water bath, the
acidic solution was basified to pH -13 with 2N NaOH. After removal
of CH.sub.3OH, the product was extracted with CH.sub.2Cl.sub.2 from
the aqueous solution. The CH.sub.2Cl.sub.2 solution was dried with
Na.sub.2SO.sub.4. After filtering, the filtrate was evaporated to
dryness to yield 0.36 g (82%) of 25,26,27,28-tetrakis[(amin-
obutyl)oxy]calix[4]arene. .sup.1H NMR CDCl.sub.3): 7.10-6.10 (m,
12H), 4.22 (d, J=12.2 Hz, 4H), 4.06-3.58 (m, 16H), 3.32-2.78 (m,
12H), 2.10-1.08 (m, 16H). FAB mass spectrum, tm/e 732 (M.sup.++Na,
18), 710 (M.sup.-+H, 46), 661 (M.sup.+
CH.sub.2CH.sub.2CH.sub.2NH.sub.2+H+Na, 41), 639 (M;
CH.sub.2CH.sub.2CH.sub.2NH.sub.2+2H, 100).
[0042] Examples 5-9 illustrate the preparation of tris(HOPO)amine
ligands.
Example 5
Preparation of the Tris-HOPO-Amine Ligands
[0043] 10
[0044] A solution of 1-hydroxy-2-(1H)-pyridinone-6-carboxylic acid
(1C) (1.55 g, 10 mmol) from Example 1 in DMAA (50 mL) was stirred
for 20 minutes. A solution of CDI (1.62 g, 10 mmol) in DMAA (50 mL)
was added dropwise into the above solution. The mixture was stirred
for 2 hrs. at room temperature. The ligand carrier tetrakis
(aminomethyl) methane (2C) (0.38 g, 2.9 mmol) from Example 2 was
added. The amidation reaction was allowed to go at room temperature
for three days. The solvent was evaporated and the residue was
dissolved in water (20 mL), then treated with THF (200 mL) to
precipitate the tris(HOPO)amine ligand (5A) shown above. The solid
was collected and washed with CHCl.sub.3. After drying under vacuum
at 50.degree. C., the ligand (5A) 1-aminoethyl-2[tris(6-meth-
yleneaminocarboxy-1-hydroxy-2-(1H)pyridinone)] weighed 1.35 g.
.sup.1HNMR (DMSO-d6): 9.50 (broad S, 3H), 7.46-7.26 (m, 3H),
6.70-6.50 (m, 6H), 3.52-2.94 (m, 8H), 2.40 (S, 5H).
Example 6
[0045] 11
[0046] A solution of r-hydroxy-2-(1H)-pyridinone-6-carboxylic acid
(1C) (96.64 g, 0.62 mol) from Example 1 in DMAA (5.5 L) was stirred
for 20 minutes and then a solution of CDI (103 g , 0.623 mol) in
DMAA (400 mL) was added dropwise over half an hour. The mixture was
stirred at room temperature for 2 hrs. The ligand carrier, tetrakis
(5-amino-2-oxy-pentyl)methane (3C) 65.07 g, 0.178 mol) from Example
3 was added and the amidation reaction was allowed to carry out at
room temperature for three days according to the reaction scheme
shown above. The solvent was evaporated under vacuum at 60.degree.
C. and the residue was dissolved in 100 mL of methanol. Ethyl ether
was poured into the methanol solution to precipitate the crude tris
(HOPO) amine ligand product (6A). After being decanted the oily
product was treated with a mixture of methanol and chloroform (1/1)
and the insoluble impurity was filtered off. The filtrate was
evaporated to dryness to afford 152 g of the purified
tris(HOPO)amine ligand (6A). .sup.1HNMR (DMSO-d6): S 9.20 (broad m,
3H), 8.40 (broad S, 3H), 7.34-7.15 (m, 3H), 6.54-6.32 (m, 6H),
3.48-3.18 (m, 24H), 2.88 (m, 2H), 1.84-1.58 (m, 8H).
EXAMPLE 7
[0047] 12
[0048] A solution of 1-hydroxy-2-pyridinone-6-carboxylic acid (1C)
(0.29 g, 1.78 mmol) from Example 1 in DMAA (30 mL) was stirred for
20 minutes and then a solution of CDI (0.29 g, 1.78 mmol) in DMAA
(30 mL) was added dropwise. The mixture was stirred at room
temperature for 2 hrs. A solution of the carrier ligand 25, 26, 27,
22-tetrakis[(aminobutyl)oxy]ca- lix[4] arene (4D) (0.36 g, 0.51
mmol) from Example 4 in DMAA (20 mL) was added and the reaction was
allowed to carry out at room temperature for three days as shown in
the above reaction scheme. The solvent was evaporated under vacuum
at 60.degree. C. and the residue was treated with ethyl ether.
After being decanted, the oily residue was dissolved in CHCl.sub.3.
Any insoluble impurity was removed by filtration and the filtrate
was concentrated to dryness to afford 0.62 g of the purified
tris(HOPO)amine ligand (7A). .sup.1HNMR (CDCl.sub.3): S 7.68 (m,
3H), 7.32-6.16 (m, 21H), 4.32 (m, 4H), 4.00-3.02 (m, 23H), 2.28
(broad S, 2H), 2.14-1.40 (m, 12H).
EXAMPLE 8
[0049] 13
[0050] A solution of 1-hydroxy-2-(1H)-pyridinone-6-carboxylic acid
(1C) (1.55 g, 10 mmol) from Example 1 in DMAA (50 mL) was stirred
for 20 min. Then a solution of DCI (1.62 g, 10 mmol) in DMAA (50
mL) was added dropwise. The mixture was stirred at room temperature
for 2 hrs. A solid ligand carrier,
1,4,8,12-tetraazacyclopentadecane, (8A) (0.61 g, 2.9 mmol) was
added and the amidation reaction was allowed to carry out at room
temperature for three days as shown in the above reaction scheme.
The tris(HOPO)cyclam ligand (8B), as shown, results from the
amidation reaction between the 6 carboxylic acid on the HOPO ring
with three of the N-H functionalities of the
tetraazacyclopendadecane. The solvent was evaporated under vacuum
at 60.degree. C. and the residue was treated with methanol. The
solid was collected and washed with methanol and chloroform. After
being dried under vacuum at 50C it afforded 1.96 g of
tris(HOPO)cyclam ligand (8B). .sup.1HNMR (DMSO-16): 7.42-7.04 (m,
3H), 6.56-5.98 (m, 6H), 3.8-2.56 (m, 20H), 2.12-1.60 (m, 6H).
EXAMPLE 9
[0051] 14
[0052] A solution of 1-hydroxy-2-(1H)-pyridinone-6-carboxylic acid
(1C) (1.55 g, 10 mmol) from Example I in DMAA (50 mL) was stirred
for 20 minutes and then a solution of CDI (1.62 g, 10 mmol) in
DMAA2 (50 mL) was added dropwise. The mixture was stirred at room
temperature for 2 hrs. Triethylenetetraamine (9A) (0.42 g, 2.86
mmol) was added as the ligand carrier and the resulting mixture was
allowed to stir at room temperature for three days as shown in the
above reaction scheme. Ligand 9B, as shown, results from the
amidation reaction between the 6 carboxylic acid on the HOPO ring
with three of the N-H functionalities of the triethylenetetramine.
The solvent was evaporated under vacuum at 60.degree. C. and the
residue was dissolved into a small amount of methanol. The
tris(HOPO)tetraamine (9B) was precipitated by adding ethyl ether
into the above methanol solution. After being decanted, the oily
product was dissolved in a mixture of methanol and chloroform
(1/1). After being filtered, evaporation of solvents give 1.45 g of
the tris(HOPO)tetraamine ligand (9B). .sup.1HNMR (DMSO-d6) 9.60 (S
1H) 7.42-7.19 (m, 3H), 6.58-6.25 (m, 6H) 3.74-2.96 (m, 14H),
2.82-2.62 (m, 2H).
[0053] Examples 10-12 show the attachment of a HOPO ligand to a
solid support by means of a covalent linkage.
EXAMPLE 10
Attachment of a Tris(HOPO)tetramine Ligand Onto Silica Gel
[0054] 15
[0055] A mixture of silica gel (10A) (35-60 mesh, 28.2 g) in
toluene (110 ml) was refluxed with
3-glycidoxypropyltrimethoxysilane (10B) (13.33 g, 56.4 mmol)
overnight. The functionalized silica gel (10C) was collected by
filtration and washed with MeOH. After being dried in vacuum at
50.degree. C. overnight it was ready for the ligand attachment.
[0056] A mixture of the functionalized silica gel (10C) (1 g) and
the tri(HOPO)tetramine ligand (6A) of Example 6 in water was gently
stirred at 50.degree. C. for three days. The resulting product
(10D) was collected by filtration and washed with water and MeOH.
After being dried at 50.degree. C. in vacuum the composition was
ready for analytical testing.
[0057] The composition (10D) prepared by this Example corresponds
to Formula 7 wherein SS is silica gel, A is a silane linkage
(Formula 8), X is a glycidoxypropyl spacer (Formula 9 where a is 3,
b is 1 and R: is OH) and L(HOPO).sub.3 is the tris(HOPO)tetramine
ligand of Example 6.
Example 11
Attachment of Tris(HOPO)tetramine Onto Polyacrylate Beads
[0058] 16
[0059] Polyacrylate beads (11A) were activated as follows. The pH
of 50 mL of double distilled water was adjusted to between 4.9 and
5.1 with 4-morpholine ethane sulfonic acid. One gram of
polyacrylate beads (11A) were then added to the above solution.
Then 0.35 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide
hydrochloride (EDC) (11B) was added. After 5 minutes another 0.35 g
portion of EDC was added. After being stirred for 15 minutes at
room temperature, the activated beads were collected by filtration
and were ready for the ligand attachment.
[0060] The activated beads were plunged into 0.1M of the
tris(HOPO)tetramine of Example 6 (6A) in 25 mL of water and gently
stirred overnight. The ligand loaded beads were collected by
filtration and washed with water, then MeOH. After being dried, the
ligand containing beads (11C) were ready for analytical
testing.
[0061] The composition (11C) prepared by this Example corresponds
to Formula 7 wherein SS is polyacrylate, A and X are represented by
the carbonyl group (Formula 10 where d is 0, c is 1, e is 0 and Y
is carbonyl) covalently bonding SS to the L(HOPO).sup.3 ligand
which is the tris(HOPO)tetramine ligand of Example 6.
Example 12
Attachment of Tris(HOPO)tetramine Onto Polystyrene Beads
[0062] 17
[0063] A mixture of activated polystyrene beads (1.0 g, 2 mmol Cl)
and tris(HOPO)tetramine (6A) (1.55 g, 2 mmol) in water (7 ml) and
THF (14 ml) was gently stirred with NaHCO.sub.3 (0.84 g, 10 mmol)
at 50-55.degree. C. for three days. The ligand loaded polystyrene
beads (12B) were collected by filtration and washed with water and
MeOH. After being dried, the ligand containing beads (12B) were
ready for analytical testing.
[0064] The composition (12B) prepared by this Example corresponds
to Formula 7 wherein SS is polystyrene, A and X are represented by
the methylene group (Formula 10 where d is 1, c is 0 and e is 0),
covalently bonding SS to the L(HOPO).sub.3 ligand which is the
tris(HOPO)tetramine ligand of Example 6.
[0065] The process of selectively and quantitatively concentrating
and removing a desired ion or group of desired ions present at low
concentrations from a plurality of other undesired ions in a
multiple ion source solution in which the undesired ions may be
present at much higher concentrations comprises bringing the
multiple ion containing source solution into contact with a
polyhydroxypyridinone-containing particulate solid support material
shown in Formula 7 which causes the desired metal ion(s) to complex
with the polyhydroxypyridinone portion of the composition and
subsequently breaking or stripping the desired ion from the complex
with a receiving solution which forms a stronger complex with the
desired ions than does the polyhydroxypyridinone ligand. The
receiving or recovery solution contains only the desired metal ions
in a concentrated form. Preferably the hydroxypyridinone ligand
solid support composition will be contained in a column wherein the
source and receiving solutions can flow through by gravity. If
desired, the flow rate of these solutions can be increased by
applying pressure (with a pump) on the top of the column or by
applying a vacuum in the receiving vessel.
[0066] The hydroxypyridinone-ligand solid support functions to
attract the desired metal cations according to Formula 11:
SS-A-X-L(HOPO).sub.n+DI.fwdarw.SS-A-X-L(HOPO).sub.n:DI Formula
11
[0067] Except for DI, Formula 8 is the same as Formula 7 wherein SS
stands for solid support, A is a covalent linkage mechanism, X is a
hydrophilic spacer grouping, and L(HOPO).sub.n is a ligand
comprising a ligand carrier L, n is an integer of 3 to 6 and L
stands for a polyhydroxypyridinone-containing ligand. DI stands for
desired ion being removed.
[0068] Once the desired metal ions are bound to the
polyhydroxypyridinone-containing ligand, they are subsequently
separated by use of a smaller volume of a receiving liquid
according to Formula 12:
SS-A-X-L(HOPO).sub.n:DI+receiving
liquid.fwdarw.SS-A-X-L(HOPO).sub.n+recei- ving liquid:DI Formula
12
[0069] The preferred embodiment disclosed herein involves carrying
out the process by bringing a large volume of the source multiple
ion solution into contact with a polyhydroxypyridinone ligand-solid
support composition of Formula 7 in a separation column through
which the mixture is first flowed to complex the desired metal ions
(DI) with the polyhydroxypyridinone ligand-solid support
composition as indicated by Formula 11 above, followed by the flow
through the column of a smaller volume of a receiving liquid, such
as aqueous solutions of HBr, HCl, EDTA, NH.sub.3, NaCl, NaI,
HNO.sub.3, H.sup.- and others which either form a stronger complex
with the desired metal ion than does the
hydroxypyridinone-containing ligand bound to the particulate solid
support and/or have greater affinity for the bound ligand under
these conditions than does the desired ion. In this manner, the
desired metal ions are carried out of the column in a concentrated
form in the receiving solution. The degree or amount of
concentration will obviously depend upon the concentration of
desired metal ions in the source solution and the volume of source
solution to be treated. The specific receiving liquid being
utilized will also be a factor. Generally speaking, the
concentration of desired transition, post-transition or actinide
metal ions in the receiving liquid will be from 20 to 1,000,000
times greater than in the source solution. Other equivalent
apparatus may be used instead of a column, e.g., a slurry which is
filtered and then washed with a receiving liquid to break the
complex and recover the desire metal ion(s). The concentrated
desired metal ions are then recovered from the receiving phase by
known procedures.
[0070] Illustrative of desired transition metal ions which have
strong affinities for polyhydroxypyridinone-containing ligands
bound to solid supports are Fe(III) from concentrated 1% to 5% HF
and NH.sub.3; Pu(IV), Th(IV), Zr(IV) and Hf(IV) from nitric acid
solutions; Cu(II), Zn(II), Ni(II), Cd(II), Ni(II), Pb(II), Ag(I),
Hg(II) from less acidic feed streams; and 3+ actinides,
lanthanides, Al(III), Ga(III) from slightly acidic solutions. This
listing of preferred cat ions is not comprehensive and is intended
only to show the types of preferred metal ions which may be bound
to polyhydroxypyridinone-containing ligands attached to solid
supports in the manner described above.
Removal of Desired Molecules With Cation-Ligand-Matrix
Compositions
[0071] The following examples demonstrate how the
polyhydroxypyridinone-co- ntaining ligand bound to a solid support
composition of Formula 7 may be used to concentrate and remove
desired ions. The polyhydroxypyridinone ligand-containing solid
support composition is placed in a column. An aqueous source
solution containing the desired metal ion or ions, in a mixture of
other metal ions which may be in a much greater concentration, is
passed through the column. The flow rate for the solution may be
increased by applying pressure with a pump on the top of the column
or by applying a vacuum in the receiving vessel. After the source
solution has passed through the column, a much smaller volume of a
recovery solution, i.e., an aqueous solution which has a stronger
affinity for the desired metal ions than does the
polyhydroxypyridinone-containing ligand, is passed through the
column. This receiving solution contains only the desired metal
ions in a concentrate form for subsequent recovery. As noted above,
suitable receiving solutions can be selected from the group
consisting of HBr, HI, HCl, NaI, NaCl, NaBr, Na.sub.4EDTA,
Na.sub.3NTA, NH.sub.3, NH.sub.4OH, ethylenediamine and mixtures
thereof. The preceding listing is exemplary and other receiving
solutions may also be utilized, the only limitation being their
ability to function to remove the desired metal ions from the
polyhydroxypyridinone ligands.
[0072] The following examples of separations and recoveries of
transition metal ions by the inorganic support-bound
hydroxypyridinone-containing ligands which were made as described
in Examples 10 through 12 are given as illustrations. These
examples are illustrative only, and are not comprehensive of the
many separations of metal ions that are possible using the
materials of Formula 7.
Example 13
[0073] A 0.1 g column (6 mm diameter.times.8 mm height) of
ligand-containing silica beads from Example 10 was prepared. The
column was cleaned with two aliquots of 5 mll of 98%
H.sub.2SO.sub.4 followed by two aliquots of 18.2 M.OMEGA. H.sub.2O
at .about.0.1 ml/min. The column was then loaded with 20 ml of
0.05M Zr(IV) as the NO.sub.2.sup.- salt in 5M HNO.sub.3. The Zr was
reduced from a 5 ppm feed input level to a <1 ppm output level.
The Zr removed by the column was then quantitatively recovered
(within analytical error) in 5 ml of 98% H.sub.2SO.sub.4 eluant at
a flowrate of 0.1 ml/min. The Zr analysis was performed using
Inductively Coupled Plasma Spectroscopy (ICP).
Example 14
[0074] The procedure of Example 13 was repeated, using the
ligand-containing acrylate beads of Example 11 in a 6 mm.times.12
mm column. The Zr was reduced from a 5 ppm level in the feed to a
<1 ppm exiting level and the Zr was quantitatively recovered in
the 98% H.sub.2SO.sub.4 eluant.
Example 15
[0075] The procedure of Example 14 was repeated, using the
ligand-containing acrylate beads of Example 11 in a 6 mm.times.12
mm column but with 10 ml of Fe(III) in 0.5% HF as the feed solution
and using 37% HCl as the cleaning and elution solution. Graphite
Furnace Atomic Absorption Spectroscopy was used for the analysis.
The 1 ppm Fe in the feed was reduced to <0.1 ppm Fe in the
output and the Fe was quantitatively recovered (within analytical
error) in the 37% HCl eluting solution.
[0076] From the foregoing, it will be appreciated that the
inorganic solid support bound polyhydroxypyridinone-containing
ligands of Formula 7 of the present invention provide a material
useful for he separation and concentration of the transition,
post-transition and actinide metal cations from mixtures of those
cations with other metal cations, H.sup.+ and soluble complexes
such as F.sup.-. The metal ions can then be recovered from the
concentrated recovery solution by standard techniques known in the
art. Similar examples have also been successfully established for
many other transition metal ions.
[0077] The variety of L(HOPO).sub.n ligands described by Formula 7
show significant improvement in interaction strength for several
specific separations such as Fe from HF. However, particular
spacing of the hydroxypyridinone moieties aids in obtaining even
greater interaction strengths. For example, the ligands of Examples
6, 7, and 8 have greater Fe(III) binding strength under the same
conditions than those of Examples 5 and 9. Hence, optimal use of
the invention in some cases also includes particular spacings
compared to others. Such may be readily determined through routine
experimentation by one skilled in the art. Additionally, in a
minority of cases, such as the complexing of very low
concentrations of iron in the presence of high concentrations of
fluoride, not all 6 coordination sites may be involved in the
complexing of iron. In cases such as this, for example, the iron
may bind to only 4 of the coordination sites leaving 2 fluorides
bound. However, the ligand is still fully complexed with iron and
fluoride and is functional for purposes of the present
invention.
[0078] Although the invention has been described and illustrated by
reference to certain specific solid support-bound
polyhydroxypyridinone-c- ontaining ligands of Formula 7 and
processes of using them; analogs, as above defined, of these
hydroxypyridinone-containing ligands are within the scope of the
compositions and processes of the invention as defined in the
following claims.
* * * * *