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Z. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 142 (2015) 188–195
(m, 2H, AOH), 2.69 (d, 2H, AOH), 2.34 (m, 4H, ACH2), 1.23 (m, 6H,
ACH3). ESI-MS (DMSO) m/z: 2029.17432 (100%, [MꢂH]+).
For 2: Yield: 23.8 mg, 44%. Calc. for C84H64N8O18Yb4: C, 46.59%;
H, 2.98%; N, 5.17%; found: C, 46.41%; H, 2.78%; N, 5.14%. IR (KBr,
cmꢂ1): 2928 (w), 2871 (w), 1650 (vs), 1609 (w), 1580 (w), 1557
(w), 1538 (m), 1505 (m), 1472 (m), 1462 (s), 1431 (w), 1415 (m),
1373 (s), 1334 (w), 1297 (w), 1273 (w), 1201 (s), 1190 (s), 1109
(w), 1081 (s), 972 (w), 872 (w), 865 (m), 832 (w), 784 (w), 733
(w), 674 (m), 647 (m), 566 (w), 471 (w), 456 (w). ESI-MS (DMSO)
m/z: 2188.44387 (100%, [MꢂNa]+).
least-squares techniques against F2 using SHELXTL [20]. All other
non-hydrogen atoms were refined with anisotropic thermal para-
meters. Absorption corrections were applied using SADABS [21].
All hydrogen atoms were placed in calculated positions and refined
isotropically using a riding model. Crystallographic data for com-
plexes 2ꢁDMF and 5ꢁDMFꢁ2MeOHꢁ9H2O are presented in Table 1,
and relevant atomic distances and bond angles are collected in
Table 1S, respectively.
Results and discussion
For 3: Yield: 24.7 mg, 47%. Calc. for C84H64N8O18Gd4: C, 47.99%;
H, 3.07%; N, 5.33%; found: C, 47.81%; H, 3.06%; N, 5.28%. IR (KBr,
cmꢂ1): 2934 (w), 2875 (w), 1650 (vs), 1612 (w), 1581 (w), 1556
(w), 1537 (m), 1505 (m), 1472 (m), 1461 (s), 1435(w), 1419 (m),
1376 (s), 1332 (w), 1292 (w), 1278 (w), 1200 (s), 1193 (s), 1106
(w), 1085 (s), 971 (w), 872 (w), 865 (m), 832 (w), 785 (w), 730
(w), 673 (m), 644 (m), 566 (w), 471 (w), 453 (w). ESI-MS (DMSO)
m/z: 2102.1134 (100%, [MꢂH]+).
Synthesis and characterization
As shown in Scheme 1, reaction of o-phenylenediamine with
2,3-dihydroxylbenzaldehyde in 1:2 M ratio afforded the dihy-
droxylated (OH)2-Salophen ligand H4L in 61% yield. Further
through the self-assembly of equimolar amounts of H4L with LnX3ꢁ
6H2O (Ln = La, Yb, or Gd; Xꢂ = NO3ꢂ or Clꢂ) in the presence of Et3N
from the different mixed solvents (MeCN–EtOH or MeCN–DMF),
two series of anion-independent while pseudo-polymorphic
Synthesis of complexes [Ln4(H2L)2(L)2(DMF)2] (Ln = La, 4; Ln = Yb, 5 or
Ln = Gd, 6)
The synthesis of orange microcrystallines products of complex-
es 4–6 was in the same way as that of corresponding complexes 1–
3 except that mixed solvents MeCN–DMF (v/v = 1/1) while not
MeCN–EtOH (v/v = 1/1) were used.
homoleptic
tetranuclear
complexes
[Ln4(H2L)2(L)2(EtOH)2]
(Ln = La, 1; Ln = Yb, 2 or Ln = Gd, 3) and [Ln4(H2L)2(L)2(DMF)2]
(Ln = La, 4; Ln = Yb, 5 or Ln = Gd, 6) were obtained, respectively.
The (OH)2-Salophen ligand H4L and its two series of complexes
1–3 and 4–6 were well characterized by EA, FT-IR, 1H NMR and ESI-
MS. In the FT-IR spectra, the similar strong characteristic absorp-
For 4: Yield: 18.8 mg, 36%. Calc. for C86H66N10O18La4: C, 49.59%;
H, 3.19%; N, 6.72%; found: C, 49.47%; H, 3.25%; N, 6.68%. IR (KBr,
cmꢂ1): 2927 (w), 2887 (w), 1654 (vs), 1612 (w), 1602 (w), 1575
(w), 1541 (m), 1506 (m), 1487 (m), 1454 (s), 1398 (s), 1386 (s),
1328 (w), 1292 (w), 1251 (m), 1213 (w), 1190 (w), 1159 (m),
1107 (w), 1085 (w), 1045 (m), 1033 (w), 979 (w), 935 (w), 879
(w), 856 (w), 831 (m), 788 (s), 761 (w), 736 (w), 671 (w), 648
(w), 628 (w), 615 (w), 588 (w), 561 (w), 509 (w), 482 (w), 462
(w), 447 (w). 1H NMR (400 MHz, DMSO-d6): d (ppm) 9.46 (s, 2H,
AOH), 8.62 (m, 4H, ACH@N), 8.50 (s, 4H, ACH@N), 8.01 (s, 8H,
APh), 7.68 (m, 4H, APh), 7.43 (m, 4H, APh), 7.28 (m, 4H, APh),
7.13 (m, 2H, APh), 6.98 (m, 4H, APh), 6.71 (m, 2H, APh), 6.49 (m,
12 H, APh), 6.27 (m, 2H, AOH), 3.17 (s, 6H, ACH3), 3.08 (s, 6H,
ACH3). ESI-MS (DMSO) m/z: 2105.69244 (100%, [MꢂNa]+).
For 5: Yield: 21.6 mg, 39%. Calc. for C86H66N10O18Yb4: C, 46.54;
H, 3.00; N, 6.31%; found: C, 46.47; H, 3.08; N, 6.24%. IR (KBr, cmꢂ1):
2947 (w), 2898 (w), 1656 (vs), 1606 (w), 1581 (w), 1546 (m), 1514
(m), 1483 (m), 1460 (s), 1394 (s), 1331 (w), 1253 (m), 1193 (w),
1156 (m), 1103 (w), 1080 (w), 1051 (m), 1039 (w), 981 (w), 933
(w), 885 (w), 858 (w), 839 (m), 785 (s), 738 (w), 649 (w), 632
(w), 621 (w), 595 (w), 559 (w), 513 (w), 491 (w), 463 (w), 449
(w). ESI-MS (DMSO) m/z: 2242.36147 (100%, [MꢂNa]+).
tions of the
m
(C@N) vibration at 1650–1652 cmꢂ1 for 1–3 or
1654–1656 cmꢂ1 for complexes 4–6 are distinctively blue-shifted
by 32–34 or 36–38 cmꢂ1 relative to that (1618 cmꢂ1) of the free
(OH)2-Salophen ligand HL, which should be attributed to the coor-
dination of Ln3+ ions. As to the room temperature 1H NMR spectra
(in Fig. 1S) of the two anti-ferromagnetic [La4((OH)2-Salophen)4]
-arrayed complexes 1 and 4 in DMSO-d6, besides the disappearance
of the typically intramolecular resonance-assisted hydrogen bond-
ed (RAHB) OAHꢁ ꢁ ꢁN proton resonances (d = 13.55 ppm) of the free
H4L ligand, the resonances of the deprotonated ligands (d = 9.45–
1.23 ppm for 1 or d = 9.46–3.08 ppm for 4) are clearly more spread
relative to those (d = 8.63–5.93 ppm) of the free ligand HL up coor-
dination of Ln3+ ions. Moreover, the resonances of two kinds of
down-field shifted free OH-based protons (d = 9.45 and 6.29 ppm
for 1 or d = 9.46 and 6.27 ppm for 4) are retained, showing the par-
Table 1
Crystallographic data and structure refinement for 2ꢁDMF and 5ꢁDMFꢁ2MeOHꢁ9H2O.
Complexes
2ꢁDMF
87H71N9O19Yb4
2238.69
Monoclinic
P2(1)/c
20.52(3)
18.65(2)
29.70(4)
90
5ꢁDMFꢁ2MeOHꢁ9H2O
C91H99N11O30Yb4
2518.97
Monoclinic
P2(1)/c
20.264(6)
18.236(5)
29.037(8)
90
104.050(4)
90
10,409(5)
4
Empirical formula
Formula weight
Crystal system
Space group
a (Å)
C
For 6: Yield: 23.2 mg, 43%. Calc. for C86H66N10O18Gd4: C, 47.90%;
H, 3.08%; N, 6.50%; found: C, 47.81%; H, 3.16%; N, 6.48%. IR (KBr,
cmꢂ1): 2939 (w), 2896 (w), 1654 (vs), 1604(w), 1579 (w), 1543
(m), 1506 (m), 1485 (m), 1456 (s), 1398 (s), 1327 (w), 1287 (w),
1257 (m), 1210 (w), 1105 (w), 1083 (w), 1035 (m), 981 (w), 937
(m), 875 (w), 854 (w), 833 (w), 786 (w), 738 (w), 651 (w), 630
(w), 619 (w), 593 (w), 561 (w), 511 (w), 493 (w), 472 (w), 445
(w). ESI-MS (DMSO) m/z: 2179.44569 (100%, [MꢂNa]+).
b (Å)
c (Å)
a
(°)
b (°)
103.223(16)
90
11,066(24)
4
c
(°)
V (Å3)
Z
q
(g cmꢂ3
)
1.344
1.607
Structure determination
Crystal size (mm)
0.31 ꢃ 0.28 ꢃ 0.25
0.34 ꢃ 0.30 ꢃ 0.26
l
(Mo-K )
a
) (mmꢂ1
3.407
3.639
Single crystals of complexes [Yb4(H2L)2(L)2(EtOH)2]ꢁDMF
(2ꢁDMF) recrystallized from EtOH-DMF and [Yb4(H2L)2(L)2(DMF)2]ꢁ
DMFꢁ2MeOHꢁ9H2O (5ꢁDMFꢁ2MeOHꢁ9H2O) recrystallized from
MeOH-DMF of suitable dimensions were mounted onto thin glass
fibers. All the intensity data were collected on a Bruker SMART
Data/restraints/parameters
Quality-of-fit indicator
No. unique reflections
No. observed reflections
19,225/70/1072
1.080
19,225
116,789
R1 = 0.0710
WR2 = 0.1880
R1 = 0.1050
WR2 = 0.2041
23,836/27/1225
1.061
23,836
180,409
Final R indices [I > 2
r
(I)]
R1 = 0.0563
WR2 = 0.1233
R1 = 0.1305
WR2 = 0.1538
CCD diffractometer (Mo-K
scan modes. Structures were solved by Direct methods followed
by difference Fourier syntheses, and then refined by full-matrix
a radiation and k = 0.71073 Å) in U and
R indices (all data)
x