P. Froidevaux et al.
brown residue was dissolved in CH2Cl2 (300 mL) and washed with water
(2300 mL), the organic layer dried over Na2SO4 and the solvent re-
moved. The crude product was dissolved in diethyl ether (250 mL), yield-
ing L2 as precipitate (1 g, 8%). After evaporation of the filtrate, 3 was
the solution was concentrated to half-volume, diethyl ether (150 mL) was
added and the solid was separated by filtration, rinsed with cold MeOH
and dried to give [Y(L1)3] (1 g, 90%). 1H NMR (400 MHz, [D6]DMSO):
d=8.40 (d, J=6.9 Hz, 1H), 8.38 (d, J=8.5 Hz, 1H), 8.30 (dd, J=6.9,
8.5 Hz, 1H), 7.93 (d, J=8.6 Hz, 2H), 7.56 (d, J=8.6 Hz, 2H), 6.73 (dd,
J=17.7, 10.7 Hz, 1H), 5.80 (d, J=17.7 Hz, 1H), 5.23 (d, J=10.7 Hz,
1H); 13C NMR (400 MHz, [D6]DMSO): d=162.0, 149.2, 140.4, 138.1,
136.5, 133.6, 127.0, 125.7, 121.3, 113.8; elemental analysis (%) calcd for
C45H33N6O9Y: C 60.68, H 3.73, N 9.44; found: C 60.79, H 4.31, N 9.11.
1
obtained as a pale yellow solid (10 g, 75%). H NMR (400 MHz, CDCl3):
d=10.09 (br, 1H, NH), 8.26 (d, J=7.8 Hz, 1H), 8.06 (d, J=7.7 Hz, 1H),
7.89 (dd, J=7.8, 7.7 Hz, 1H), 7.45 (d, J=8.6 Hz, 2H), 7.26 (d, J=8.6 Hz,
2H), 6.63 (dd, J=17.7, 10.9 Hz, 1H), 5.72 (d, J=17.7 Hz, 1H), 5.26 (d,
J=10.9 Hz, 1H), 4.52 (q, 2H, OCH2), 1.49 (t, 3H, CH3); elemental analy-
sis (%) calcd for C17H16N2O3·1.25H2O: C 64.04, H 5.85, N 8.79; found: C
64.09, H 5.77, N 8.67; ESI-MS: m/z: calcd for: 297.12; found: 297.58
[M+H]+.
Synthesis of [Y(L2)3]
hot and dry MeCN and this solution was added dropwise at RT under
vigorous stirring to a solution of Y(ClO4)3·2.8H2O (585 mg, 1.3 mmol) in
A
AHCTREUNG
MeCN (50 mL). The solution turned yellow and a precipitate formed.
After stirring for a further 1 h, the solution was concentrated to half its
initial volume and the solid was collected by filtration, rinsed with cold
6-(4-Vinylphenylcarbamoyl)pyridine-2-carboxylic acid methyl ester (4):
This compound was obtained in 72% yield by the procedure described
for 3, starting from diester 2. 1H NMR (400 MHz, CDCl3): d=10.07 (br,
2H, NH), 8.41 (d, J=7.8 Hz, 1H), 8.19 (d, J=7.7 Hz, 1H), 7.99 (dd, J=
7.8, 7.7 Hz, 1H), 7.72 (d, J=8.6 Hz, 2H), 7.35 (d, J=8.6 Hz, 2H), 6.63
(dd, J=17.7, 10.9 Hz, 1H), 5.62 (d, J=17.7 Hz, 1H), 5.13 (d, J=10.9 Hz,
1H), 3.97 (s, 3H, OMe); 13C NMR (400 MHz, [D6]DMSO): d=165.2,
161.49, 150.5, 146.7, 134.31, 137.4, 139.2, 127.8, 125.9, 127.2, 120.4, 136.5,
113.53, 53.43; elemental analysis (%) calcd for C16H14N2O3·0.25H2O: C
67.01, H 5.10, N 9.77; found: C 67.08, H 5.03, N 9.68; ESI-MS: m/z: calcd
for: 283.10; found 283.30 [M+H]+.
MeCN and dried to give [Y(L2)3](ClO4)3 (1 g, 89%). Elemental analysis
A
(%) calcd for C69H57Cl3N9O18Y: C 55.42, H 3.84, N 8.43; found: C 55.30,
H 4.06, N 8.40.
Synthesis of [Ln(L1)3] and [Ln(L2)3](ClO4)3 (Ln=La, Eu, Gd, Tb):
N
These complexes were synthesized according to the experimental proce-
dures described above. Elemental analysis (%) calcd for
[La(L1)3]·1.25H2O: C45H33N6O9La·1.25H2O: C 56.11, H 3.71, N 8.73;
found:
[Eu(L1)3]·H2O: C45H33N6O9Eu·H2O: C 55.62, H 3.63, N 8.65; found: C
55.62, 3.81, 8.47; elemental analysis (%) calcd for
[Gd(L1)3]·0.7H2O: C45H33N6O9Gd·0.7H2O: 55.63, 3.57, 8.65;
found: 55.62, 4.38, 8.53; elemental analysis (%) calcd for
[Tb(L1)3]·0.7H2O: C45H33N6O9Tb·0.7H2O: 55.53, 3.56, 8.64;
found: 55.55, 3.74, 8.44; elemental analysis (%) calcd for
[La(L2)3](ClO4)3·2H2O: C69H57Cl3N9O18La·2H2O: C 52.40, 3.89,
7.97; found: C 51.97, H 3.62, N 7.49; elemental analysis (%) calcd for
[Eu(L2)3](ClO4)3·0.5H2O: C69H57Cl3N9O18Eu·0.5H2O: C 52.87, H 3.73, N
8.04; found: C 52.57, H 3.98, N 8.59; elemental analysis (%) calcd for
[Gd(L2)3](ClO4)3·3.7H2O: C69H57Cl3N9O18Gd·3.7H2O: C 50.83, H 3.98, N
7.73; found: C 50.50, H 3.96, N 7.57; elemental analysis (%) calcd for
[Tb(L2)3](ClO4)3·2H2O: C69H57Cl3N9O18Tb·2H2O: C 51.75, H 3.84, N
C 56.13, H 3.91, N 8.36; elemental analysis (%) calcd for
6-(4-Vinylphenylcarbamoyl)pyridine-2-carboxylic acid (HL1): A suspen-
sion of monoethyl ester 3 (10 g, 37.1 mmol) or monomethyl ester 4 (9.5 g,
31.7 mmol) in EtOH (80 mL) was gently refluxed until complete dissolu-
tion, then left to cool to RT before addition of 0.2m NaOH (200 mL).
The solution was stirred for 10 min at RT, EtOH was removed under
vacuum at T<408C and water was added (300 mL). The aqueous phase
was washed twice with CH2Cl2 (150 mL) and acidified to pH 2–3. The
pale yellow precipitate was extracted with CH2Cl2 (3200 mL). The or-
ganic layer was dried over Na2SO4, the solvent removed and HL1 crystal-
lized from hot MeCN to give a pale brown solid (8.5 g, 95%). M.p. 166–
1688C; 1H NMR (400 MHz, [D6]DMSO): d=8.38 (d, J=7.3 Hz, 1H),
8.31 (d, J=7.6 Hz, 1H), 8.27 (dd, J=7.3, 7.6 Hz, 1H), 7.81 (d, J=8.5 Hz,
2H), 7.52 (d, J=8.5 Hz, 2H), 6.71 (dd, J=17.7, 11 Hz, 1H), 5.79 (d, J=
17.7 Hz, 1H), 5.22 (d, J=11 Hz, 1H); 13C NMR (400 MHz, [D6]DMSO):
d=165.66, 162.3, 150.1, 147.05, 141.2, 138.6, 137.0, 134.2, 128.0, 127.6,
126.8, 121.5, 114.4; elemental analysis (%) calcd for C15H12N2O3: C 67.16,
H 4.51, N 10.44; found: C 67.04, H 4.48, N 10.52; ESI-MS: m/z: calcd
for: 269.08; found: 269.86 [M+H]+.
H
N
C
H
N
C
H
N
C
H
N
C
H
N
A
H
N
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7.87; found: C 51.66, H 3.85, N 7.94.
Synthesis and characterization of the yttrium resins: Resin R-Y-L1: Com-
plex [Y(L1)3] (1 g, 1.12 mmol), DMSO (3 mL), divinylbenzene (3 mL),
pyridine (3 mL), allyl alcohol (3 mL) and of azobis(isobutyronitrile)
(25 mg) were introduced into a tube containing a magnetic stirrer. The
tube was purged under vacuum and filled with argon. It was placed in an
ultrasonic bath and sonicated for 15 min under argon to remove any
trace of oxygen. Caution must be taken never to stop agitation when de-
gassing the polymer mixture, otherwise a sticky precipitate appears which
can only be redissolved with difficulty. The tube was then sealed and
placed in an oil bath at 858C for 12 h. Polymerization was conducted
with vigorous stirring to allow for good dispersion of the complex into
the polymer. Finally, the tube was crushed; the crude product washed
with methanol and then coarsely crushed in a mortar. The bulk product
was washed successively in methanol, ethanol, and water/ethanol 90:10
several times. Finally, the product was washed with 5m HCl to remove
the yttrium template, then several times with water and allowed to dry.
The yttrium-free resin R-Y-L1 was finely ground in a mortar and the
fractions 60–120 mesh, 120–170 mesh, 170–230 mesh and >230 mesh
were separated with a set of minisieves.
Pyridine-2,6-dicarboxylic acid bis[(4-vinylphenyl)amide] (L2): n-Butyl-
lithium (1.6m in pentane, 11.8 mL, 18.7 mmol) was slowly added to vinyl-
phenylamine (95%, 2.35 g, 18.7 mmol) in anhydrous THF (100 mL) with
stirring at RT. The yellow solution was stirred for a further 30 min and
then added dropwise to
a solution of 2 (1.75 g, 9 mmol) in THF
(150 mL). The orange-brown solution was stirred overnight under N2 and
the solvents were removed. The brown residue was dissolved in CH2Cl2
(200 mL) and washed with water (3200 mL). The organic layer was
dried over Na2SO4 and the solvent evaporated. The crude product was
triturated in diethyl ether (150 mL), and the resulting solid was collected
by filtration and dissolved in a minimum of CH2Cl2. Adding diethyl ether
gave L2 as a white solid, which was dried (2.8 g, 83%). (The filtrate con-
tains mainly 6-(4-vinylphenylcarbamoyl)pyridine-2-carboxylic acid
methyl ester (12% after purification) which can be treated as described
for 3 and hydrolyzed to give HL1). M.p. >4108C; 1H NMR (400 MHz,
CDCl3): d=9.52 (br, 2H, NH), 8.48 (d, J=7.9 Hz, 2H), 8.14 (dd, J=7.9,
8.5 Hz, 1H), 7.74 (d, J=8.5 Hz, 4H), 7.46 (d, J=8.5 Hz, 4H), 6.71 (dd,
J=17.6, 10.8 Hz, 2H), 5.74 (d, J=17.6 Hz, 2H), 5.25 (d, J=10.8 Hz,
2H); 13C NMR (400 MHz, CDCl3): d=161.4, 149, 4, 140.0, 137.0, 136.4,
134.9, 127.5, 126.0, 120.5, 113.9; elemental analysis (%) calcd for
C23H19N3O2: C 74.78, H 5.18, N 11.37; found: C 74.27, H 5.07, N 11.29;
ESI-MS: m/z: calcd for: 370.15; found: 370.78 [M+H]+.
The other resins were synthesized by using a slightly modified procedure:
R-Y-L2 was obtained from [Y(L2)3](ClO4)3) (1 g, 0.67 mmol) and without
N
DMSO; for resin R, no complex was added; for resin R-L1, HL1
(900 mg, 3.26 mmol) was added instead of [Y(L1)3]; for resin R-L2, L2
(740 mg, 2 mmol) was added instead of [Y(L2)3]
A
dpa, [Cs3Eu(dpa)3] (468 mg, 0.448 mmol) was added instead of [Y(L1)3].
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Analytical measurements: Chromatographic elution profiles and yttrium
yield were determined by atomic absorption (410.2 nm) with a Perkin
Elmer 4100 atomic spectrometer using a N2O/acetylene flame. Calcium
(422.7 nm) and strontium (460.7 nm) were determined in the same way
using an air/acetylene flame. In the selectivity experiment Y, La, Nd, Eu,
Gd, Tb and Yb were determined by atomic emission with a Perkin
Synthesis of [Y(L1)3]: NaOH (175 mg) in MeOH (20 mL, 4.01 mmol)
was added to a solution of HL1 (1 g, 3.7 mmol) in MeOH (100 mL) and
the solution was stirred for 30 min at RT. A solution of Y(ClO4)3·2.8H2O
G
(544 mg, 1.2 mmol) in MeOH (50 mL) was added dropwise with vigorous
stirring and a yellow precipitate formed. After stirring for a further 1 h,
6862
ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2006, 12, 6852 – 6864