2H, CH2NHCH2), 3.48 (q, J = 6.5 Hz, 2H, CH2NHCO), 3.48
(m, 1H, CHOH), 6.95 (t, J = 8 Hz, 1H, C(5)H), 6.98 (d, J =
8 Hz, 1H, C(3)H), 7.47 (t, J = 8 Hz, 1H, C(4)H), 7.95 (d, J =
pentane into the dichloromethane solution. Yield: 0.43 g (53%).
Anal. Calcd for C35H55CuGdN2O7: (836.63) C, 50.2; H, 6.6; N, 3.3.
Found: C, 49.5; H, 6.5; N, 3.1. IR (ATR): 3251w, 2958 m, 1610
m, 1592 m, 1570 s, 1538 s, 1505 m, 1469w, 1448w, 1398 s, 1356
m, 1314w, 1259w, 1225 m, 1179w, 1138 m, 1094w, 1044w, 1029w,
978w, 936w, 896w, 867 m, 792w, 763 m, 709w, 655w, 635w cm-1.
1
8 Hz, 1H, C(6)H), 9.13 (s, 1H, NHCO). 13C{ H} NMR (62.896
MHz, 20 ◦C, dmso d6): d 10.2 (s, CH3), 28.0 (s, CH3CH2), 39.2 (s,
CH2NHCO), 48.6 (s, CH2CH2NHCO), 55.1 (s, CHCH2NH), 70.5
(CHOH), 116.1 (s, ArC), 117.8 (s, ArC(3)H), 118.9 (s, ArC(5)H),
128.3 (s, ArC(6)H), 133.4 (s, ArC(4)H), 161.0 (s, ArC(2)OH),
168.8 (s, OCNH).
[L2CuTb(thd)2]2 (4)
Yield: 0.40 g (49%). Anal. Calcd for C33H55CuN2O7Tb: (838.30)
C, 50.1; H, 6.6; N, 3.3. Found: C, 49.7; H, 6.5; N, 3.4. IR (ATR):
3252w, 2958 m, 1610 m, 1592 m, 1569 s, 1538 s, 1504 m, 1470w,
1449w, 1397 s, 1356 m, 1313w, 1261w, 1225 m, 1177w, 1138 m,
1101w, 1044w, 1027w, 978w, 936w, 895w, 867 m, 792w, 763 m,
710w, 655w, 635w cm-1.
[L2CuK(H2O)]
A mixture of 2-(2-hydroxybutylamino)-ethylamine (1.32 g, 1 ¥ 10-2
mol) and of phenylsalicylate (2.14 g, 1 ¥ 10-2 mol) was heated for
30 min without any solvent. After cooling, acetone was added to
the syrupy product, followed by copper acetate (2.0 g, 1 ¥ 10-2
mol) and piperidine (1.0 g, 1.1 ¥ 10-2 mol). The stirred solution
was heated for 30 min. Addition of potassium hydroxide (0.6 g,
1.1 ¥ 10-2 mol) and stirring at room temperature for 3 h yielded a
green precipitate that was washed with acetone and then air dried.
Yield:2.2 g (59%). Anal. Calcd for C13H19CuGdN2O4: (369.95) C,
42.2; H, 5.2; N, 7.6. Found: C, 41.7; H, 4.9; N, 7.3. IR (ATR):
3250w, 3050w, 2968 m, 2897 m, 1599 s, 1570 s, 1536 m, 1472w,
1446 m, 1391 s, 1324w, 1265 m, 1246 m, 1155w, 1127 m, 1097w,
1045w, 1018w, 963w, 936w, 888w, 760 m, 704w, 668w, 651w, 619w,
605w cm-1.
Materials and methods
All starting materials were purchased from Aldrich and were used
without further purification. Elemental analyses were carried out
by the Service de Microanalyse du Laboratoire de Chimie de
Coordination, Toulouse (C, H, N). IR spectra were recorded on a
Spectrum 100 FT-IR Perkin-Elmer spectrophotometer using the
ATR mode. 1D 1H NMR spectra were acquired at 250.13 MHz on
1
a Bruker WM250 spectrometer. 1D 13C spectra using H broad-
1
13
band decoupling { H} C and gated 1H decoupling with selective
proton irradiation were performed with a Bruker WM250 facility
working at 62.89 MHz. Chemical shifts are given in ppm versus
TMS (1H and 13C) using (CD3)2SO as solvent. Magnetic data were
obtained with a Quantum Design MPMS SQUID susceptometer.
Magnetic susceptibility measurements were performed in the
2-300 K temperature range in a 0.1 T applied magnetic field, and
diamagnetic corrections were applied by using Pascal’s constants.18
Isothermal magnetization measurements were performed up to
5 T at 2 K. The magnetic susceptibilities have been computed
by exact calculations of the energy levels associated to the
spin Hamiltonian through diagonalization of the full matrix
with a general program for axial symmetry,30 and with the
MAGPACK program package31 in the case of magnetization.
Least-squares fittings were accomplished with an adapted ver-
sion of the function-minimization program MINUIT.32 The ac
measurements were carried out in a 3.0 G ac field oscillating at
different frequencies (from 0.05 to 1500 Hz) and with a zero dc
field.
[L1CuGd(thd)2]2 (1)
A mixture of L1CuK(H2O)0.5 (0.16 g, 5 ¥ 10-4 mol), GdCl3·6H2O
(0.19 g, 5 ¥ 10-4 mol), tetramethylheptanedione (0.20 g, 1.1 ¥ 10-3
mol) and piperidine (0.1 g, 1.2 ¥ 10-3 mol) in methanol (15 mL)
was stirred and heated for twenty minutes, giving a glycin-colored
precipitate. After cooling at room temperature, the solution was
filtered off, yielding a solid that was washed with water, methanol,
diethyl ether and then dried. Yield: 0.25 g (61%). Anal. Calcd
for C33H51CuGdN2O7: (808.57) C, 49.0; H, 6.4; N, 3.5. Found: C,
49.0; H, 6.5; N, 3.4. IR (ATR): 3258w, 2953 m, 1608 m, 1592 m,
1568 s, 1537 s, 1504 m, 1472w, 1449w, 1398 s, 1385 s, 1354 m,
1316w, 1262w, 1226 m, 1180w, 1139 m, 1094 m, 1045w, 1027w,
953w, 933w, 894w, 867 m, 792w, 758 m, 710w, 654w, 636w cm-1.
[L1CuTb(thd)2]2 (2)
Yield: 0.23 g (57%). Anal. Calcd for C33H51CuN2O7Tb: (810.24)
C, 48.9; H, 6.3; N, 3.5. Found: C, 48.9; H, 6.4; N, 3.4. IR (ATR):
3257w, 2953 m, 1608 m, 1592 m, 1568 s, 1537 s, 1504 m, 1472w,
1449w, 1398 s, 1384 s, 1354 m, 1316w, 1262w, 1226 m, 1180w,
1140 m, 1094 m, 1044w, 1026w, 953w, 934w, 894w, 867 m, 792w,
758 m, 710w, 654w, 637w cm-1.
Crystallographic data collection and structure determination
for (3)
Crystals of 3 were kept in the mother liquor until they were
dipped into oil. The chosen crystals were mounted on a Mitegen
micromount and quickly cooled down to 180 K. The selected
crystals of 3 (light purple, 0.25 ¥ 0.07 ¥ 0.07 mm3) were
mounted on an Oxford-Diffraction XCALIBUR using a graphite
[L2CuGd(thd)2]2 (3)
A mixture of L2CuK(H2O) (0.37 g, 1 ¥ 10-3 mol), GdCl3·6H2O
(0.37 g, 1 ¥ 10-3 mol), tetramethylheptanedione (0.5 g, 2.6 ¥ 10-3
mol) and piperidine (0.34 g, 4 ¥ 10-3 mol) in methanol (15 mL)
was stirred and heated for twenty minutes, giving a glycin-colored
precipitate. After cooling at room temperature, the solution was
filtered off, yielding a solid that was dissolved in dichloromethane.
Crystals suitable for XRD were obtained by slow diffusion of
monochromator (l = 0.71073 A) and equipped with an Oxford
˚
Cryosystems cooler device. The data were collected at 180 K.
The unit cell determination and data integration were carried
out using the CrysAlis RED package.33,34 58482 reflections were
collected for 3, of which 15389 were independent (Rint = 0.0834).
The structure has been solved by Direct Methods using SIR92,35
and refined by means of least-squares procedures on a F2 with
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 4886–4892 | 4891
©