Pb(II) coordination and synergistic ion-exchange extraction by combinations of sulfonamide chelates and 2,2′-bipyridine

Article abstract of DOI:10.1021/ic050047r

The disulfonamide ligands 1,2-C₆H₄(NH ₂SO₂C₆H₅)₂ (1) and 1,2-C₆H₄(NH₂SO₂C₆H ₄-p-Bu^t)₂ (2), which are readily available in good yields from o-phenylenediamine and the corresponding sulfonyl chlorides, efficiently extract Pb(II) from water into 1,2-dichloroethane when used in synergistic combinations with 2,2′-bipyridine via an ion-exchange mechanism. The extraction was shown to proceed via the formation of a ternary Pb-sulfamido-2,2′-bipyridine complex. The X-ray crystal structure of the binary Pb-sulfamido complex 3 shows a coordination polymer with a stereochemically active lone pair on Pb formed by S=O-Pb axial coordination.

Full text of DOI:10.1021/ic050047r

Inorg. Chem. 2005, 44, 2573
−2575
Pb(II) Coordination and Synergistic Ion-Exchange Extraction by
Combinations of Sulfonamide Chelates and 2,2 -Bipyridine
′
Konstantinos Kavallieratos,*,† Jay M. Rosenberg,† and Jeffrey C. Bryan‡
Department of Chemistry and Biochemistry, Florida International UniVersity,
1
1200 SW 8th Street, CP 326, Miami, Florida 33199, and Department of Chemistry,
UniVersity of Wisconsin-La Crosse, 1725 State Street, La Crosse, Wisconsin 54601
Received January 12, 2005
9
The disulfonamide ligands 1,2-C
6
H
4
(NH
2
SO
2
C
6
H
5
)
2
(1) and 1,2-
favorable complexation-decomplexation kinetics. Notwith-
standing the strong interest in Pb(II) coordination chemistry,
there is yet to be discovered a practical Pb(II) ion-exchange
extractant that would take advantage of the preference of
Pb(II) in lower coordination numbers for irregular “hemi-
C
6 4
H
(NH SO (2), which are readily available in good
2
2
C
6
H
4
-p-But)
2
yields from o-phenylenediamine and the corresponding sulfonyl
chlorides, efficiently extract Pb(II) from water into 1,2-dichloroethane
when used in synergistic combinations with 2,2
ion-exchange mechanism. The extraction was shown to proceed
via the formation of a ternary Pb-sulfamido-2,2 -bipyridine complex.
The X-ray crystal structure of the binary Pb-sulfamido complex 3
shows a coordination polymer with a stereochemically active lone
pair on Pb formed by SdOsPb axial coordination.
′-bipyridine via an
1
0
directed” coordination geometries with a stereochemically
5
a
active lone pair. Herein, we report efficient synergistic
Pb(II) ion-exchange extraction, from water into 1,2-dichlo-
roethane (DCE), by combinations of 2,2′-bipyridine (bipy)
and simple ionizable disulfonamides derived from o-phenyl-
enediamine. The ternary Pb(II)-bipy-sulfamido complex was
′
1
identified by H NMR in the organic phase after extraction.
1
2
3
(5) (a) Claudio, E. S.; Godwin, H. A.; Magyar, J. S. Prog. Inorg. Chem.
The selective complexation, extraction, and sensing of
toxic heavy metal cations, such as Pb(II), Cd(II), and Hg(II),
is exceedingly important because of their economic, environ-
2
003, 51, 1. (b) Powers, R. E.; Fuller, W. L.; Raymond, K. N.
ComprehensiVe Supramol. Chem. 1996, 10, 537. (c) Parr, J. Polyhe-
dron 1997, 16, 551. (d) Bridgewater, B. M.; Parkin, G. J. Am. Chem.
Soc. 2000, 122, 7140. (e) Claudio, E. S.; ter Horst, M. A.; Forde, C.
E.; Stern, C. L.; Zart, M. K.; Godwin, H. A. Inorg. Chem. 2000, 39,
1391. (f) Reger, D. L.; Wright, T. D.; Little, C. A.; Lambda, J. J. S.;
Smith, A. D. Inorg. Chem. 2001, 40, 3810. (g) Hino, S.; Brynda, M.;
Phillips, A. D.; Power, P. P. Angew. Chem., Int. Ed. 2004, 43, 2655.
6) (a) Crego-Calama M.; Reinhoudt, D. N. AdV. Mater. 2001, 13, 1171.
(b) Kerper, L. E.; Hinkle, P. M. J. Biol. Chem. 1997, 272, 8346. (c)
Deo, S.; Godwin, H. J. Am. Chem. Soc. 2000, 122, 174. (d) Liu, J.
W.; Lu, Y. J. Am. Chem. Soc. 2003, 125, 6642. (e) Metivier, R.; Leray
I.; Valeur, B. Chem. Commun. 2003, 996.
4
mental, and biological roles. Lead is still the most commonly
encountered toxic metal pollutant in the environment, and
therefore, there is a need for exploiting the unique coordina-
tion chemistry of Pb(II) for the development of practical
ligands as extractants, lead-poisoning treatment agents, and
sensors. Numerous examples of coordination and extraction
of Pb(II) by macrocycles have been reported. Ionizable
chelates, which extract metals via ion exchange, present
potential advantages, including versatility, synthetic ease, and
5
(
6
7
8
(7) (a) Lindoy, L. F. The Chemistry of Macrocyclic Ligand Complexes;
Cambridge University Press: Cambridge, U.K., 1990. (b) Hancock,
R. D.; Maumela, H.; de Sousa, A. S. Coord. Chem. ReV. 1996, 148,
315. (c) Rogers, R. D.; Bond, A. Inorg. Chim. Acta 1992, 192, 163.
*
To whom correspondence should be addressed. E-mail: kavallie@fiu.edu.
Florida International University.
University of Wisconsin.
(d) Adams, H.; Bailey, N. A.; Fenton, D. E.; Good, R. J.; Moody, R.;
Rodriguez de Barbarin, C. O. J. Chem. Soc., Dalton Trans. 1987, 207.
(e) Izatt, R. M.; Terry, R. E.; Haymore, B. L.; Hansen, L. D.; Dalley,
N. K.; Avondet A. G.; Christensen, J. J. J. Am. Chem. Soc. 1976, 41,
7620. (f) Yordanov, A. T.; Whittlesey, B. R.; Roundhill, D. M. Inorg.
Chem. 1998, 37, 3526. (g) Arranz, P.; Bazzicalupi, C.; Bencini, A.;
Bianchi, A.; Ciattini, S.; Fornasari, P.; Giorgi C.; Valtancoli, B. Inorg.
Chem. 2001, 40, 6383. (h) van der Veen, N. J.; Egberink, R. J. M.;
Engbersen. J. F. J.; van Veggel F. C. J. M.; Reinhoudt, D. N. Chem.
Commun. 1999, 681. (i) Vicente, M.; Bastida, R.; Lodeiro, C.; Macias,
A.; Parola, A. J.; Valencia L.; Spey, S. E. Inorg. Chem. 2003, 42,
6768.
†
‡
(
(
(
1) (a) Lindoy, L. F. Pure Appl. Chem. 1997, 69, 2179. (b) Hancock, R.
D.; Martell, A. E. Chem. ReV. 1989, 89, 1875. (c) Lehn, J.-M.;
Montavon, F. HelV. Chim. Acta 1978, 61, 67.
2) (a) Yordanov, A. T.; Roundhill, D. M. Coord. Chem. ReV. 1998, 170,
9
3. (b) Choudhary, S.; Morrow, J. R. Angew. Chem., Int. Ed. 2002,
41, 4096.
3) (a) Valeur, B.; Leray, I. Coord. Chem. ReV. 2000, 205, 3. (b) Prasanna
de Silva, A.; Fox, D. B.; Huxley, A. J. M.; McClenaghan, N. D.;
Roiron, J. Coord. Chem. ReV. 1999, 185-186, 297. (c) Plaschke, M.;
Czolk R.; Ache, H. J. Anal. Chim. Acta 1995, 304, 107. (d) Lloris, J.
M.; Martinez-M a´ n˜ ez, R.; Padilla-Tosta, M. E.; Pardo, T.; Soto, J.;
Beer, P. D.; Cadman, J.; Smith, D. K. J. Chem. Soc., Dalton Trans.
(8) (a) Abu-Dari, K.; Karpishin, T. B.; Raymond, K. N. Inorg. Chem.
1993, 32, 3052. (b) Hayashita, T.; Sawano, H.; Higuchi, T.; Indo, M.;
Hiratani, K.; Zhang Z.; Bartsch, R. A. Anal. Chem. 1999, 71, 791.
(9) Reichwein-Buitenhuis, E. G.; Visser, H. C.; de Jong, F.; Reinhoudt,
D. N. J. Am. Chem. Soc. 1995, 117, 3913.
1
999, 2359. (e) Talanova, G. G.; Elkarim, N. S. A.; Talanov V. S.;
Bartsch R. A. Anal. Chem. 1999, 71, 3106.
(
4) (a) Zenz, C. Occupational Medicine: Principles and Practical
Applications, 2nd ed.; Year Book Medical Publishers: Chicago, IL,
(10) (a) Shimoni-Livny, L.; Glusker, J. P.; Bock, C. W. Inorg. Chem. 1998,
37, 1853. (b) Hancock, R. D.; Shaikjee, M. S.; Dobson, S. M.;
Boeyens, J. C. A. Inorg. Chim. Acta 1988, 154, 229. (c) Di Vaira,
M.; Mani F.; Stoppioni, P. J. Chem. Soc., Dalton Trans. 1998, 3209.
1
988; p 547. Christensen, J. M. Sci. Total EnViron. 1995, 166, 89. (b)
Godwin, H. A. Curr. Opin. Chem. Biol. 2001, 5, 223.
1
0.1021/ic050047r CCC: $30.25
© 2005 American Chemical Society
Inorganic Chemistry, Vol. 44, No. 8, 2005 2573
Published on Web 03/12/2005

COMMUNICATION
The X-ray crystal structure of the binary Pb(II)-sulfamido
complex shows a hemidirected10 geometry on Pb with a
stereochemically active lone pair. A polymeric network is
formed in the solid state via axial coordination of the
SdO oxygen atoms to Pb.
Figure 1. ORTEP representation (50% probability ellipsoids) of the
extended structure of 3. For clarity, hydrogen atoms and all but the ipso
carbon atoms on the sulfonyl phenyl rings have been omitted.
The aryl sulfonamide ligands 1,2-C
6 4 2 2 6 4 2
and 1,2-C H (NH SO C H -p-Bu ) (2) are readily available
6
H
4
(NH
2 2 6 5 2
SO C H ) (1)
t
in good yields from o-phenylenediamine and the correspond-
ing sulfonyl chlorides.11 They are soluble in relatively less
polar organic solvents, such as DCE, and they are weakly
Table 1. Selected Bond Distances (Å) and Angles (deg) for 3
distance (Å)
angle (deg)
Pb-N(1)
Pb-N(2)
Pb-O(2)′
Pb-O(4)′′
Pb‚‚‚O(1)
Pb‚‚‚O(3)
Pb‚‚‚S(1)
Pb‚‚‚S(2)
SdO(avg)
S-N(avg)
2.296(4)
2.329(4)
2.599(4)
2.524(3)
2.869(4)
3.043(3)
3.221(1)
3.314(1)
1.45
N(1)-Pb-N(2)
N(1)-Pb-O(1)
N(1)-Pb-O(2)′
N(1)-Pb-O(3)
N(1)-Pb-O(4)′′
N(2)-Pb-O(1)
N(2)-Pb-O(2)′
N(2)-Pb-O(3)
N(2)-Pb-O(4)′′
O(2)′-Pb-O(4)′′
68.4(1)
53.7(1)
95.0(1)
119.5(1)
81.5(1)
120.4(1)
89.6(1)
51.2(1)
92.5(1)
175.0(1)
12
a
acidic (typical pK values range between 7.9 and 8.5), thus
being able to form complexes under mildly basic conditions.
Despite these advantages, only a few examples of Pb(II)
coordination by sulfonamides involving N-sulfonyl amino
13
2
acids with one ionizable SO NH group have been reported.
In these cases, higher coordination numbers are observed
with a monodentate coordination through the carboxylate
oxygen or a N,O-bidentate coordination.
1.57
The Pb(II) complexes Pb[1,2-C
Pb[1,2-C H (NSO C H -p-Bu )
6 4 2 6 4 2
6
H
4
(NSO
] (4) were synthesized from
ligands 1 and 2, respectively, by adding NH(i-Pr) and Pb-
NO in MeOH at room temperature. The X-ray crystal
structure of 3 (Figure 1 and Table 1) shows Pb(II)
2 6 5 2
C H ) ] (3) and
dinates to the metal in a bidentate fashion through the two
nitrogen atoms, and no polymeric structure is formed.17
The lead cation forms short bonds to both nitrogen atoms
of a single disulfonamide ligand [2.296(4) and 2.329(4) Å].
These bonds are slightly shorter than those reported for
t
2
(
3 2
)
1
4
1
3,15
coordination to the sulfonamide ligand via two short
Pb-N bonds and to two neighboring sulfonamide complexes
13
related Pb(II)-sulfonamide complexes. Pb(II) also forms
short bonds to the two “axial” oxygen atoms on two
neighboring sulfonamide groups [2.524(3) and 2.599(3) Å,
O(2)′-Pb-O(4)′′ angle ) 175.0°]. It is through these bonds
that the structure forms a polymer as illustrated in Figure 1.
These Pb-O distances are comparable to those previously
as well, giving a coordination polymer with a hemidirected
1
0
geometry on Pb. Because of its relatively large size and
its strongly ionic nature, the coordination environment of
1
6
Pb(II) tends to be complex, and polymeric structures
typically exhibit higher coordination numbers. Curiously, in
all previously reported structures of metals bound to a N,N′-
,2-arenebis(benzenesulfonamide), the ligand simply coor-
observed for related complexes (ranging from 2.46 to 2.96
15,18
Å).
Longer distances are observed between Pb and the
1
other two sulfonyl oxygen atoms O(1) [2.869(4) Å] and O(3)
[
3.043(3) Å]. These bonds, though weak, close a Pb-N-
(
11) (a) Hinsberg, O.; Strupler, J. Justus Liebigs Ann. Chem. 1891, 265,
S-O four-membered ring and draw the sulfur atoms close
enough to the lead cation that some Pb-S bonding interac-
tions might also be taking place. Chelation of a sulfonamide
to Pb(II) through both its N and O atoms has been previously
178. (b) Amundsen, L. H. J. Am. Chem. Soc. 1937, 59, 1466.
(
(
12) Dauphin, G.; Kergomard, A. Bull. Soc. Chim. Fr. 1961, 3, 486.
13) (a) Battistuzzi, G.; Borsari, M.; Menabue L.; Saladini, M. Inorg. Chem.
1996, 35, 4239. (b) Iacopino, D.; Menabue L.; Saladini, M. Aust. J.
Chem. 1999, 52, 741.
(14) Crystal structure for 3: monoclinic, space group P21/n, a ) 9.8201(15)
19
reported.
Å, b ) 19.358(3) Å, c ) 9.8553(12) Å, â ) 99.828(10)°, V )
3
3
1
)
)
846.0(5) Å , temperature ) 100(2) K, Z ) 4, Dcalc ) 2.14 g/cm , µ
All of the coordination around Pb takes place in one
hemisphere, leaving most of the other hemisphere apparently
-
1
9.393 mm , reflections collected ) 7764, independent reflections
3935 (Rint ) 0.036), R1 (I > 2σI) ) 0.028, wR2 (all data) ) 0.075
at 100 K.
(
(
15) Holloway C. E.; Melnik, M. Main Group Met. Chem. 1997, 20, 399.
16) (a) Harrison, P. G. In ComprehensiVe Coordination Chemistry;
Wilkinson, G., Grillard, R. D., McCleverty, J. A., Eds.; Pergamon
Press: Oxford, U.K., 1987; Vol. 3, p 183. (b) Harrowfield, J.;
Miyamae, H.; Skelton, B. W.; Soudi A. A.; White, A. H. Aust. J.
Chem. 1996, 49, 1165. (c) Mann, K. L. V.; Jeffery, J. C.; McCleverty,
J. A.; Ward, M. D. Polyhedron 1999, 18, 721. (d) Meng; X.; Song,
Y.; Hou, H.; Fan Y.; Zhu, Y. Inorg. Chem. 2003, 42, 1306. (e) Shi,
Y.; Li, L.; Li, Y.; Tai, X.; Xue Z.; You, X. Polyhedron 2003, 22,
(17) (a) Evans, C.; Henderson, W.; Nicholson, B. K. Inorg. Chim. Acta
2001, 314, 42. (b) Cheng, P.-H.; Cheng, H.-Y.; Lin, C.-C.; Peng, S.
M. Inorg. Chim. Acta 1990, 169, 19. (c) Cheng, H.-Y.; Cheng, P.-H.;
Lee, C.-F.; Peng, S. M. Inorg. Chim. Acta 1991, 181, 145.
(18) Based on a search of the Cambridge Structural Database (CSD) for
all Pb(II)-(NS(O)2C) fragments containing a Pb-O bond. Allen, F.
H. Acta Crystallogr. 2002, B58, 380. CSD reference codes FUYDOS,
IGIGEK, IGIGIO, TEZMIU, and XAQNAE were found.
(19) Moers, O.; Michailides, A.; Blaschette A.; Jones, P. G. Z. Anorg. Allg.
Chem. 2002, 628, 1437.
917.
2574 Inorganic Chemistry, Vol. 44, No. 8, 2005

COMMUNICATION
unoccupied. This is likely the location of the “lead(II) lone
pair”.10 Further examination of this space reveals that it is
filled, although somewhat awkwardly, with two phenyl rings
(
symmetry equivalents of the sulfonyl phenyl rings). The fit
6
is termed awkward because neither one forms an η interac-
tion with Pb. If Pb-π interactions are present, they are very
weak, as the three closest carbon atoms [C(14), 3.695(6) Å;
C(23), 3.786(5) Å; C(24), 3.724(5) Å] are beyond the sum
of the ionic radius of Pb(II) (1.5 Å for high coordination
2
0
numbers) and the van der Waals radius of carbon (1.70
2
1
Å). Although weak lead-arene interactions are fairly
common, the lead-carbon distances reported here are
generally longer than typically observed.1
Figure 2. Percent Pb extracted (defined as [Pb]org/[L]t) × 100%) vs [L]t
for 1 and 2. [Pb]t is constant at 6.30 mM. (Error in concentration is <5%).
0c,22
Comparison of the bond lengths in 3 with those in the
2
4
being present. These ternary complexes were also isolated
by reacting 3 or 4 with 2,2′-bipy. NMR titration of 5 with
increasing amounts of 1 or 2,2′-bipy showed slow exchange
with sulfonamide 1 and fast exchange with bipy.
free ligand 1 shows that the S-N bonds are significantly
shorter (averaging 1.64 Å in 1)23 when the ligand is bound
to Pb(II). However, a corresponding lengthening of the SdO
bond cannot always be observed because of the standard
uncertainties in the crystallographic data. Such lengthening
is expected based on the observed decrease of the SdO
The extraction of Pb(II) by 1 and 2 was investigated for
different ligand concentrations (Figure 2), as well as in
comparison with 18-crown-6 (18C6), using a stable initial
-
1
stretching frequency in the IR spectrum from 1336 cm (in
-
1
[Pb(II)]
tions gave distribution ratios of DPb(1) ) 0.926 and DPb(2)
0.941 for [L] /[Pb] ) 0.492, which correspond to 97.8%
t
of 6.30 mM. The sulfonamide/2,2′-bipy combina-
1
) to 1257 cm (in 3).
The sulfonamides 1 or 2 were shown to extract Pb(II) from
)
t
t
water into DCE via ion exchange, when used in synergistic
combinations with 2,2′-bipy, by forming the mixed-ligand
ternary complexes 5 and 6. The coordination of 2,2′-bipy
presumably interferes with the SdOsPb coordination ob-
served in the crystal structure of 3, dramatically enhancing
the solubility of 5 in DCE. The extraction of Pb(II) from
and 98.6% Pb extraction, respectively. This was 420 (for 1)
and 430 times (for 2) higher extraction than 18C6 or
combinations of 18C6 and bipy under the same conditions.
Ligands 1 and 2 were also very effective in the extraction
of micromolar Pb(II) concentrations from water into DCE.
With initial conditions of [L]
t
) 3.30 mM, [2,2′-bipy]
) 7.26 mM, [Pb(II)] between 3 and
/[Pb(II)] between 8.89 and 970, ligand 1
t
)
Pb(NO
together with 1 equiv of 2,2′-bipy and 2.2 equiv of NH(i-
Pr) . The distribution ratios DPb ) [Pb] /[Pb]aq were deter-
mined by inductively coupled plasma mass spectrometry
3 2
) (aq) into DCE was investigated using 1 or 2
3
.30 mM, [NH(i-Pr)
2
]
t
t
3
00 µM, and [L]
t
t
2
o
extracted between 98.4% and 98.8% of Pb, and ligand 2
extracted between 99.5% and 100%.
In conclusion, synergistic extraction of Pb(II) from water
into DCE was demonstrated by synergistic combinations of
(
ICP-MS) of the aqueous phases after extraction (for [Pb]aq
and after stripping of the organic phases with 0.1 M HNO
for [Pb]
high as 97.5% (for [Pb(II)]
II)] /[1] ) 1.0). Double stripping of the organic phases
)
3
(
o
). The synergistic system gave Pb(II) extraction as
/[2] ) 1.0) and 95.0% (for [Pb-
2
,2′-bipy and simple sulfonamide ion exchangers. The
t
t
sulfonamide-Pb(II) complex 3 was shown to have a hemi-
directed geometry on Pb with a stereochemically active lone
pair and with axial SdOsPb coordination resulting in a
polymeric network in the solid state. These results set the
stage for using analogous sulfonamide chelates for extraction
of Pb(II) and other toxic metals, elucidating aspects of
selectivity, and determining the extraction mechanism in-
volved.
(
t
t
showed no increase in the values of DPb. Control experiments,
using 1 or 2 only, 2,2′-bipy only, diisopropylamine only, or
these compounds in pairs, demonstrated that the presence
of all three components in the organic phase is essential for
Pb(II) extraction. 1 and 2 were recoverable after extraction
1
(
>97% measured by H NMR spectroscopy with 4,4′-
dimethylbiphenyl as an internal standard). The pH of the
aqueous phase after contact was measured at 7.0 ((0.2). The
monosulfonamide analogue C H SO NHC H did not extract
6 5 2 6 5
at all under the extraction conditions. The NMR spectra of
the organic phases after extraction using 1 and 2 are
Acknowledgment. We thank Ms. Aileen Andreu for
experimental help and Drs. S. F. Wnuk, W. J. Lees, and R.
J. Alvarado for their helpful comments. This project was
supported by NIH-NIEHS/ARCH (S11 ES11181). J.M.R.
was supported by NIH-MBRS/RISE (R25 GM061347).
consistent with Pb[1,2-C ][2,2′-bipy] (5) and
6
H
4
(NSO
2
C
6
H
5
)
2
t
Pb[1,2-C (NSO -p-Bu ) ][2,2′-bipy] (6), respectively,
H
6 4
C H
2 6 4
2
Supporting Information Available: Crystal data, synthesis and
characterization information, and details on distribution experiments.
This material is available free of charge via the Internet at
http://www.pubs.acs.org.
(
(
(
20) Shannon, R. D. Acta Crystallogr. 1976, A32, 751.
21) Bondi, A. J. Phys. Chem. 1964, 68, 441.
22) (a) Edelmann, F. T.; Buijink, J.-K. F.; Brooker, S. A.; Herbst-Irmer,
R.; Kilimann U.; Bohnen, F. M. Inorg. Chem. 2000, 39, 6134 and
references therein. (b) No, K. H.; Kim, J. S.; Shon, O. J.; Yang, S.
H.; Suh, I. H.; Kim, J. G.; Bartsch R. A.; Kim, J. Y. J. Org. Chem.
IC050047R
2
001, 66, 5976.
23) Bryan, J. C.; Rosenberg, J. M.; Kavallieratos, K. Acta Crystallogr.
005, E61, o396.
(
(24) For an analogous example of a Pb ternary complex, see: Saladini,
2
M.; Iacopino, D.; Menabue, L. J. Inorg. Biochem. 2000, 78, 355.
Inorganic Chemistry, Vol. 44, No. 8, 2005 2575