Synthesis and characterization of a series of new asymmetric salphen mono-and binuclear metal complexes

Article abstract of DOI:10.1002/cjoc.201090175

Two novel asymmetric salen ligands H₂L¹ [N-phenyl-N-(2-hydroxy-5-methylphenyl)-N'-(2-hydroxy-3-methoxylphenyl)-o-phenyldiamine] and H₂L² [N-phenyl-N-(2-hydroxy-5-chlorophenyl)-N'-(2-hydroxy-3-methoxylphenyl)-o-phenyldiamine] and their metal complexes MLⁿ (M=Zn, Co, Ni, Cu; n=1, 2) have been prepared and characterized by elemental analyses, ¹H NMR, ESI-MS, FT-IR and UV-Vis spectra. In particular, the complex ZnL¹, the binuclear monosalphen complex, was synthesized and studied in detail using ¹H NMR and ESI-MS techniques. For other metal complexes under the same reaction conditions, only mononuclear complexes were obtained. The results are relevant to both the metal ions and the structure of ligands.

Full text of DOI:10.1002/cjoc.201090175

FULL PAPER
Synthesis and Characterization of a Series of New Asymmetric
Salphen Mono- and Binuclear Metal Complexes
Li, Jiayuan(李佳媛)
Guo, Liqin(郭莉芹)
Ruan, Wenjuan*(阮文娟)
Zhu, Zhiang(朱志昂)
Department of Chemistry, Nankai University, Tianjin 300071, China
Two novel asymmetric salen ligands H2L1 [N-phenyl-N-(2-hydroxy-5-methylphenyl)-N'-(2-hydroxy-3-meth-
oxylphenyl)-o-phenyldiamine] and H2L2 [N-phenyl-N-(2-hydroxy-5-chlorophenyl)-N'-(2-hydroxy-3-methoxyl-
phenyl)-o-phenyldiamine] and their metal complexes MLn (M＝Zn, Co, Ni, Cu; n＝1, 2) have been prepared and
characterized by elemental analyses, 1H NMR, ESI-MS, FT-IR and UV-Vis spectra. In particular, the complex ZnL1,
the binuclear monosalphen complex, was synthesized and studied in detail using 1H NMR and ESI-MS techniques.
For other metal complexes under the same reaction conditions, only mononuclear complexes were obtained. The
results are relevant to both the metal ions and the structure of ligands.
Keywords binuclear and mononuclear salphen complexes, synthesis, NMR spectroscopy, UV/Vis spectroscopy,
IR spectroscopy
Introduction
cance. Besides, when the metal ions of the center of the
salen complexes are different, the oxidation-reduction
potential, non-linear optical property and other proper-
ties will change, which provide us with vast design
space.
In this paper, we synthesized and characterized two
novel salen ligands H2L1 [N-phenyl-N-(2-hydroxy-5-
methylphenyl)-N'-(2-hydroxy-3-methoxylphenyl)-o-ph-
enyldiamine] and H2L2 [N-phenyl-N-(2-hydroxy-5-chlo-
rophenyl)-N'-(2-hydroxy-3-methoxylphenyl)-o-phenyl-
diamine] and their asymmetric metal complexes MLn
(M＝Zn, Co, Ni, Cu; n＝1, 2), as shown in Scheme 1.
Both the right part of the ligands are fixed using
o-vanillin, but we use ketone having different substitu-
ent in the left part to change the electronic environment
of the part, thus change the electronic environment of
the whole molecules.
Inspired from the structure of porphyrin, salen is
developed as a tetradentate Schiff base system. Salens
and their metal complexes have been investigated in a
variety of applications because of their ease of prepara-
tion, diverse structure, low-cost, and so on. With the
lone-pair electron afforded by the basic structure of C＝
N structure, salen complexes have been of interest for
their bioactivity,1,2 and can identify both imidazole,
pyridine, amino acids and other nitrogen-containing
small molecules and complex molecular system such as
carbohydrates, DNA molecules.3-5 Most notably, they
have been found to be of great utility in the develop-
ment of chiral catalysts, and have been used to increase
the stereoselectivity of products in a variety of reactions
including asymmetric nitroaldol reaction,6,7 asymmetric
epoxidation,8-10 ring-opening of epoxides, and so on.
Under the background of energy conservation, secu-
rity and green chemistry, the efficient and recyclable
catalyst of salen type becomes an on-going research
focus.11-13 In order to prevent the loss of active site of
catalyst of small molecules via oxidation reaction gen-
erating oxygen-bridged dimer of the µ-oxo-Mn(IV), to
design novel structures of salen complexes that can
more effectively improve the reaction yield and selec-
tivity is an urgent need to be addressed in addition to
immobilized catalyst on the carrier.14 Both simulation of
biocatalysis and industrial asymmetric catalytic oxida-
tion need asymmetric catalyst, so the synthesis of new
asymmetric salen metal complexes has great signifi-
Experimental
Materials and chemicals
N,N-Dimethyl formamide (DMF) and chloroform
(CHCl3) were purified by standard methods, while the
other solvents were analytical grade and used as re-
ceived. o-Phenylenediamine was purified by standard
methods. Zinc(II) acetate, nickel(II) acetate, cooper(II)
acetate, cobalt(II) acetate and the other reagents were
commercial products used without further purification.
Physical measurements
1H NMR spectra were recorded on a Bruker AV300
*
E-mail: wjruan@nankai.edu.cn
Received September 12, 2009; revised and accepted February 26, 2010.
Project supported by the National Natural Science Foundation of China (No. 20671053).
938
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Chin. J. Chem. 2010, 28, 938— 942

New Asymmetric Salphen Mono- and Binuclear Metal Complexes
Scheme 1 Synthesis of ligands H2L1 and H2L2 and their metal complexes
NMR spectrometer (300 MHz), using Me4Si as internal
standard. Elemental (C, H and N) analyses were carried
out with a Perkin-Elmer 240C elemental analyzer. FT-
IR spectra were performed on a Shimadzu IR-408 in-
frared spectrophotometer in the range of 4000—400
6.876 (t, J＝7.5 Hz, 1H, Ar-H), 6.939 (s, 1H, Ar-H),
6.965 (s, 1H, Ar-H), 7.004 (q, J＝3.9 Hz, 3H, Ar-H),
7.077 (d, J＝6.6 Hz, 4H, Ar-H), 7.213 (t, J＝7.2 Hz, 2H,
Ar-H), 7.276 (d, J＝2.7 Hz, 1H, Ar-H), 7.306 (d, J＝2.4
Hz, 1H, Ar-H), 8.319 (s, 1H, CH＝N), 13.06＋8 (s, 1H,
OH); ESI-MS m/z (%): 457.3 (100, [M＋H] ). Anal.
calcd for C27H21ClN2O3: C 70.97, H 4.63, N 6.13; found
C 70.50, H 4.51, N 6.13.
－1
cm . Electrospray mass spectra (ESI-MS) were re-
corded on a Trace DSQ instrument. UV-Vis spectra
were measured on a UV-2450 spectrophotometer with a
thermostated cell compartment TCC-240A in the range
of 200—600 nm using solutions with the concentration
Synthesis of MLn (M＝Zn, Co, Ni, Cu)
General method 0.2 mmol of ligand H2Ln was
dissolved in 30 mL of hot methanol, and 0.6 mmol of
metal acetate salt in 5 mL of methanol was added drop-
wise under stirring. After the addition was completed,
the mixture was stirred at room temperature. The reac-
tion was monitored by TLC until disappearance of all
ligands was observed. The solvent was evaporated un-
der vacuum to obtain the solid. The solid was purified
by chromatograph on silica gel column and dried in
vacuum.
－5
of 1×10 mol/L in DMF.
Synthesis of H2Ln (n＝1, 2)
The ligand H2L1 (or H2L2) was prepared according
to the literature method15 with some modifications. 2.0
mmol of HMBP-PHEN (or HCBP-PHEN) was sus-
pended in hot methanol (30 mL). 0.3043 g (2.0 mmol)
of o-vanillin was added to the suspension stepwise un-
der stirring. After the addition was completed, the mix-
ture was stirred and refluxed for 8 h. The orange prod-
uct precipitated from solution. The solution was allowed
to cool to room temperature and the products were col-
lected by filtration. The orange solid was purified by
chromatography on silica gel column using dichloro-
methane as eluent and dried in vacuum.
CuL1: Eluent: dichloromethane. Color: brown. Yield
53%. IR (KBr) ν: 573.28, 538.04 (M—O), 487.43,
－1
427.28 (M—N) cm ; ESI-MS m/z (%): 498.3 (100,
[M＋H]＋), 1017.0 (100, [2M＋Na]＋). Anal. calcd for
C28H22N2CuO3•4H2O: C 58.99, H 5.30, N 4.91; found C
58.63, H 5.01, N 4.36.
H2L1: Yield 86%. 1H NMR (CDCl3) δ: 2.130 (s, 3H,
CH3), 3.885 (s, 3H, OCH3), 6.751 (t, J＝4.2 Hz, 1H,
Ar-H), 6.779 (s, 1H, Ar-H), 6.863 (t, J＝8.1 Hz, 1H,
Ar-H), 6.977 (t, J＝9.3 Hz, 4H, Ar-H), 7.036—7.068
(m, 2H, Ar-H), 7.097 (d, J＝8.1 Hz, 2H, Ar-H), 7.138 (s,
1H, Ar-H), 7.203 (t, J＝8.1 Hz, 2H, Ar-H), 7.257—
7.338 (m, 1H, Ar-H), 8.354 (s, 1H, CH＝N), 13.085＋(s,
1H, OH); ESI-MS m＋/z (%): 437.3 (100, [M＋H] ),
894.8 (100, [2M＋Na] ). Anal. calcd for C28H24N2O3: C
77.04, H 5.54, N, 6.42; found C 76.43, H 5.32, N 6.94.
H2L2: Yield 85%. 1H NMR (CDCl3) δ: 3.911 (d, J＝
10.2 Hz, 3H, OCH3), 6.777 (t, J＝4.8 Hz, 1H, Ar-H),
CuL2: Eluent: chloroform. Color: brown. Yield 54%.
IR －(KBr) ν: 575.90, 539.21 (M—O), 489.66 (M—N)
＋
1
cm ; ESI-MS m/z (%): 518.2 (100, [M＋H] ＋), 1036.7
(100, [2M＋H]＋), 1058.8 (100, [2M＋Na] ). Anal.
calcd for C27H19ClN2CuO3•5H2O: C 53.29, H 4.80, N
4.60; found C 53.13, H 4.75, N 4.60.
NiLn: The brown solid was redissolved completely
in CHCl3, washed with water three times and dried in
vacuum before purified by chromatograph on silica gel
column using chloroform as eluent. Brown power was
obtained.
Chin. J. Chem. 2010, 28, 938— 942
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939

Li et al.
FULL PAPER
NiL1: Yield 45%. 1H NMR (CDCl3) δ: 1.982 (s, 3H,
CH3), 3.757 (s, 3H, OCH3), 6.066 (t, J＝8.4 Hz, 1H,
Ar-H), 6.448—6.534 (m, 3H, Ar-H), 6.640 (d, J＝7.2
Hz, 1H, Ar-H), 6.844 (q, J＝8.4 Hz, 2H, Ar-H), 6.940
(d, J＝8.1 Hz, 2H, Ar-H), 7.015 (d, J＝8.7 Hz, 2H,
Ar-H), 7.368—7.474 (m, 5H, Ar-H), 8.067 (s, 1H,
CH＝N); IR (KBr) ν: 578.20, 542.90 (M—O), 449.62,
The deep red solid was purified by chromatography on
silica gel column and dried in vacuum.
CoL1: Eluent: dichloromethane. Yield 43%. IR (KBr)
ν: 578.81, 540.79 (M—O), 487.80, 445.61 ＋(M—N)
－1
cm ; ESI-MS＋m/z (%): 493.2 (100, [M＋H] ), 986.0
(100, [2M＋H] ). Anal. calcd for C28H22N2CoO3•6H2O:
C 55.91, H 5.70, N 4.66; found C 55.82, H 5.61, N 4.42.
CoL2: Eluent: chloroform. Yield 42%. IR (KBr)－ν:
－1
410.06 (M—N) cm ; ESI-MS＋m/z (%): 493.3 (100,
[M＋H]＋), 515.2 (100, [M＋Na] ), 1007.0 (100, [2M＋
Na]＋). Anal. calcd for C28H22N2NiO3•4H2O: C 59.50, H
5.35, N 4.96; found C 60.01, H 5.29, N 4.66.
576.08, 542.01 (M—O), 463.52, 431.58 (M—N) cm .
1
ESI-MS m/z (%): 513.2 (100, [M＋H]＋), 1031.8 (100,
[2M＋H]＋). Anal. calcd for C27H19ClN2CoO3•5H2O: C
53.70, H 4.84, N 4.64; found C 54.47, H 4.44, N 4.44.
NiL2: Yield 46%. 1H NMR (CDCl3) δ: 3.788 (d, J＝
21.9 Hz, OCH3), 6.050 (d, J＝8.7 Hz, 1H, Ar-H),
6.464—6.528 (m, 2H, Ar-H), 6.646 (d, J＝7.2 Hz, 1H,
Ar-H), 6.658 (s, 1H, Ar-H), 6.744 (s, 1H, Ar-H),
6.808—6.948 (m, 2H, Ar-H), 7.011 (d, J＝8.4 Hz, 3H,
Ar-H), 7.393—7.479 (m, 4H, Ar-H), 8.052 (s, 1H,
CH＝N); IR (KBr) ν: 575.01, 543.53 (M—O), 451.49,
Results and discussion
1H NMR
1
The data of the H NMR in CDCl3 or DMSO-d6 are
given in Table 1. The data of H2Ln shows characteristic
peak of azomethine (CH＝N) as singlet at about δ 8.4
and proton of hydroxy group at about δ 13.0. Integration
of peak area and the value of the chemical shifts are in
line with the target compounds (Schiff base). This indi-
cates the reaction of aldehyde and amine to generated
ligands effectively. Moreover, the characteristic peaks
of hydroxy group of metal complexes can not be found
which proves the occurrence of coordination reaction as
well as the purity of the product.
－1
410.98 (M—N) cm ; ESI-MS, m/z ＋(%): 513.2 (100,
[M＋H]＋ ), 1026.8 (100, [2M＋H] ), 1048.8 (100,
[2M＋Na]＋). Anal. calcd for C27H19ClN2NiO3•2H2O: C
59.00, H 4.22, N 5.10; found C 59.05, H 4.29, N 5.27.
ZnLn 0.2 mmol of ligand H2Ln was dissolved in 30
mL of hot methanol, and 0.1749 g (0.6 mmol) of zinc(II)
acetate in 10 mL of methanol was added dropwise. The
mixture was stirred at room temperature for 12 h. Then
the solvent was removed under vacuum to obtain a yel-
low solid. The solid was washed with hot methanol and
water three times respectively, and dried in vacuum.
Zn2(L1)(OAc)2: Yield 46%. 1H NMR (DMSO-d6) δ:
1.777 (s, 6H, OAc), 1.964 (s, 3H, CH3), 3.730 (s, 3H,
OCH3), 6.438 (q, J＝7.5 Hz, 2H, Ar-H), 6.682 (t, J＝
8.1 Hz, 2H, Ar-H), 6.823 (t, J＝8.4 Hz, 2H, Ar-H),
6.971—7.070 (m, 3H, Ar-H), 7.219 (s, 2H, Ar-H), 7.400
(s, 3H, Ar-H), 7.542 (d, J＝7.8 Hz, 1H, Ar-H), 8.830 (s,
1H, CH＝N); IR (－KBr) ν: 576.42, 530.44 (M—O),
The structure of complex Zn2(L1)(OAc)2 is shown in
1
Figure 1. The data of the H NMR in DMSO-d6 are
1
given in experimental section. The H NMR spectrum
of Zn2(L1)(OAc)2 shows characteristic peak of acetate
(OAc) as singlet at about δ 1.777 and the result, 6H, of
integration of peak area and chemical shifts is consistent
with the data of ESI-MS (701.9). This indicates that the
structure of the compound is the same as we presumed
and is also in line with the literature.16 The isolation of
bimetallic monosalphen structures is relevant to both the
transmetalation of Zn(salen) complexes and the struc-
ture of salen ligands.16 Containing o-pheylenediamine
which forms a rigidity of the salphen system increasing
Lewis acidity behavior of the Zn(II) ion and o-vanillin
leading the salen complexes equipped with additional
alkoxy donor groups at the 3-position of the sali-
cylideneimine groups, the Zn(II) ion allows the ligation
of an axial ligand OAc. But as a result of the effect of
the substituent of chlorine, the complex ZnL2 did not
form such compound.
1
487.80 (M—N) cm ; ESI-MS m/z (%): 701.9 (100,
[M＋H]＋). Anal. calcd for C28H22N2Zn2O3•2OAc•2H2O:
C 53.43, H 4.48, N 3.89; found C 52.15, H 4.22, N 3.67.
1
ZnL2: Yield 48%. H NMR (DMSO-d6) δ: 3.732 (s,
3H, OCH3), 6.415 (t, J＝7.2 Hz, 1H, Ar-H), 6.506 (d,
J＝9.0 Hz, 1H, Ar-H), 6.826 (q, J＝8.4 Hz, 4H, Ar-H),
6.992 (d, J＝8.4 Hz, 1H, Ar-H) 7.083—7.185 (m, 2H,
Ar-H), 7.283 (s, 2H, Ar-H), 7.435 (s, 2H, Ar-H), 7.565
(d, J＝7.5 Hz, 1H, Ar-H), 8.844 (s, 1H, CH＝N); IR
(KBr) ν: 587.74, 530.44 (M—O), 490.48, 412.40 (M＋—
－1
N) cm ; ESI-MS m/z＋(%): 521.2 (100, [M＋H] ),
1041.0 (100, [2M＋H] ). Anal. calcd for C27H19Cl-
N2ZnO3•5H2O: C 63.13, H 4.79, N 4.59; found C 62.82,
H 4.22, N 4.31.
CoLn 0.2 mmol of ligand H2Ln was dissolved in 30
mL of hot methanol, and 0.1494 g (0.6 mmol) of co-
balt(II) acetate in 10 mL of methanol was added drop-
wise under nitrogen protection. After the addition was
completed, the mixture was stirred at room temperature
for 12 h. The reaction was monitored by TLC until dis-
appearance of all ligand was observed. The solvent was
evaporated under vacuum to obtain a deep red solid.
Figure 1 Structure of complex Zn2(L1)(OAc)2.
940
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© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2010, 28, 938— 942

New Asymmetric Salphen Mono- and Binuclear Metal Complexes
Table 1 Some 1H NMR chemical shift (δ) data of ligands and their complexes
Compd.
H2L1
Zn2(L1)(OAc)2
NiL1
H2L2
ZnL2
OH
CH＝N
OCH3
3.885 (s, 3H)
CH3
OAc
13.085 (s, 1H)
8.354 (s, 1H)
8.830 (s, 1H)
8.067 (s, 1H)
8.319 (s, 1H)
8.844 (s, 1H)
8.052 (s, 1H)
2.130 (s, 3H)
1.964 (s, 3H)
1.982 (s, 3H)
3.730 (s, 3H)
1.777 (s, 6H)
3.757 (s, 3H)
13.068 (s, 1H)
3.911 (d, J＝10.2 Hz, 3H )
3.732 (s, 3H)
NiL2
3.788 (d, J＝21.9 Hz, 3H)
UV-Vis spectra
plexation with metal ions, the spectra shows variations
with respect to the position and intensity, compared
with the spectra of their ligands. For salen metal com-
plexes, initial peaks of π-π∗ transitions of azomethine
(CH＝N) blue shift for the reason as follows. Although
the charge density has been dispersed and the whole
energy declines, the energy level difference between the
bonding orbital and anti-bonding orbital of π-π∗ in-
creases after the coordination of e-participation of C＝N.
In addition, a new absorbtion band of the visible region
should be attributed to metal-to-ligand charge-transfer
character. The impact to the diversity of the spectra of
the salen complexes involves the different metal center.
The UV-Vis spectra of all complexes in DMF were
recorded in the region of 200—700 nm, as shown in
Figures 2 and 3. Exhibiting three bands, the spectra at
about 260 and 290 nm can be assigned to the π-π∗ tran-
sitions of aromatic ring and the azomethine (CH＝N)
respectively, and peaks at about 350 nm are assigned to
n-π∗ transitions.17-19
Table 2 UV-Vis spectra data of ligands and their complexes in
DMF at room temperature
Compd.
H2L1
H2L2
λ/nm [ε/(104 L•mol－ 1•cm－ 1)]
273 (1.13), 286 (1.41), 296 (1.44), 340 (1.66)
273 (0.93), 286 (1.47), 296 (1.58), 335 (1.61)
Zn2(L1)(OAc)2 303 (1.63), 342 (1.27), 392 (1.11)
ZnL2
CoL1
CoL2
307 (1.89), 402 (1.90), 419 (2.35)
Figure 2 UV-Vis spectra of ligands H2L1 and H2L2 in DMF.
274 (1.07), 355 (0.39), 424 (1.39), 520 (0.12)
284 (2.10), 338 (1.27), 390 (0.85), 478 (0.30)
268 (2.33), 282 (1.68), 375 (1.80), 462 (0.68),
590 (0.15)
NiL1
NiL2
CuL1
CuL2
269 (2.36), 379 (1.59), 470 (0.57), 599 (0.14)
318 (1.57), 363 (1.08), 425 (2.34), 560 (0.07)
271 (0.74), 318 (1.69), 359 (1.24), 436 (1.08)
IR spectra
Table 3 gives some IR data of ligands and their
complexes. The band of IR spectra 1600—1620 and
－
1
1170—1200 cm are assigned to ν N, and ν O vibra-
＝
—
C
C
tion respectively, which show band characteristic for
salen ligands and complexes. This is good agreement
with the literature.20,21 The IR spectra show peaks
Figure 3 UV-Vis spectra of ligand H2L2 and its metal com-
plexes ML2 (M＝Zn, Co, Ni, Cu) in DMF.
－
1
around 1570 cm assigned to benzene ring ν C vibra-
＝
C
It can be seen from Table 2 and Figures 2 and 3 that
the spectrum of the free ligand H2L2 is similar to that of
H2L1, but the peak at around 340 nm shifts to the
short-wave direction by 5 nm, as a result of ligand H2L2
having a chloro-group, a weak acceptor, which lowered
the density of electron cloud of benzene ring and mag-
－
tion, and round 1130 cm 1 assigned to ν N vibration.22
In addition, the coordination of the metal ions to ligands
is supported by the appearance of peaks during 400 and
—
C
－
1
600 cm . This indicates the reaction of aldehyde and
amine generating ligands, then ligands and metal gener-
ating metal complexes effectively.
∗
nified the orbital energy of n-π transition. After com-
Chin. J. Chem. 2010, 28, 938— 942
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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Li et al.
FULL PAPER
Table 3 Some IR data (ν/cm－ 1) of the ligands and their complexesa
Compd.
H2L2
C＝N
Ph-ring C＝C
C—O
C—N
M—O
M—N
1607.31 (s)
1564.91 (s)
1173.94 (m)
1120.04 (m)
—
—
587.74 (w)
530.44 (m)
576.08 (w)
542.01 (m)
575.01 (w)
543.53 (m)
575.90 (w)
539.21 (m)
—
490.48 (w)
412.40 (w)
463.52 (w)
431.58 (w)
451.49 (w)
410.98 (w)
ZnL2
CoL2
NiL2
1613.72 (s)
1617.75 (s)
1607.31 (s)
1572.07 (s)
1575.84 (s)
1578.40 (m)
1183.31 (s)
1181.02 (s)
1180.50 (m)
1118.98 (m)
1130.03 (m)
1147.91 (m)
CuL2
1608.18 (s)
1610.23 (s)
1616.39 (s)
1576.38 (m)
1567.95 (s)
1567.47 (s)
1185.54 (s)
1188.95 (s)
1184.20 (m)
1145.34 (m)
1124.31 (m)
1127.63 (w)
489.66 (w)
H2L1
—
556.42 (w)
530.44 (w)
578.81 (w)
540.79 (w)
578.20 (w)
542.90 (m)
573.28 (m)
538.04 (m)
487.80 (w)
—
Zn2(L1)(OAc)2
469.68 (w)
445.61 (w)
449.62 (w)
410.06 (w)
487.43 (w)
427.28 (w)
CoL1
NiL1
CuL1
1608.95 (s)
1604.72 (s)
1606.53 (s)
1578.07 (m)
1577.70 (m)
1573.97 (m)
1178.27 (m)
1199.10 (m)
1184.03 (m)
1145.20 (m)
1144.43 (m)
1142.46 (m)
a Abbreviations: s, strong; m, medium; w, weak.
Conclusions
8
9
Atwood, D. A.; Harvey, M. J. Chem. Rev. 2001, 101, 37.
Reger, T. S.; Janda, K. D. J. Am. Chem. Soc. 2000, 122,
6929.
In summary, we successfully synthesized a series of
new salen-type asymmetric complexes and these com-
pounds are characterized by elemental analysis, 1H
NMR, ESI-MS, FT-IR and UV-Vis spectra. In particular,
the salen-type complex Zn2(L1)(OAc)2, the binuclear
mono-salphen complexes, was synthesized and studied
10 Haikarainen, A.; Sipila, J.; Pietikainen, P. J. Chem. Soc.,
Dalton Trans. 2001, 991.
11 Thakur, S. S.; Li, W. J.; Shin, C. K.; Kim, G. J. Chirality
2006, 18, 37.
12 Thakur, S. S.; Chen, S. W.; Kim, G. J. J. Organomet. Chem.
2006, 691, 1862.
13 Li, W. J.; Thakur, S. S.; Chen, S. W. Tetrahedron Lett. 2006,
46, 2263.
1
in detail using H NMR and ESI-MS techniques. For
other metal complexes under the same reaction condi-
tions, only mononuclear complexes were obtained. The
results are relevant to both the metal ions and the struc-
ture of salen-type ligands.
14 Yang, H. Q.; Zhang, L.; Li, C. Angew. Chem., Int. Ed. 2007,
46, 6861.
15 Atkins, R.; Brewer, G. Inorg. Chem. 1985, 24, 127.
16 Feiices, L. S.; Benet, J. B. Inorg. Chem. 2009, 48, 846.
17 Boghaei, D. M.; Behzad, M. Synth. React. Inorg. Met.-Org.
Chem. 2005, 35, 261.
18 Khandar, A. A.; Shaabani, B.; Belaj, F.; Bakhtiari, A. Poly-
hedron 2006, 25, 1893.
19 Rabie, U. M.; Assran, A. S. A.; Abou-El-Wafa, M. H. M. J.
Mol. Struct. 2008, 872, 113.
20 Asadi, M.; Jamshid, K. A.; Kyanfar, A. H. Inorg. Chim.
Acta 2007, 360, 1725.
References
1
2
3
4
Cini, R.; Moore, S. J.; Marzilli, L. G. Inorg. Chem. 1998, 37,
6890.
Polson, S. M.; Cini, R.; Pifferi, C.; Marzilli, L. G. Inorg.
Chem. 1997, 36, 314.
Abe, A. M.; Helaja, J.; Koskinen, A. P. Org. Lett. 2006, 8,
4537.
Kim, H. J.; Kim, W.; Lough, A. J.; Kim, B. M.; Chin, J. J.
Am. Chem. Soc. 2005, 127, 16776.
21 Tas, E.; Kilic, A.; Konak, N.; Yilmaz, I. Polyhedron 2008,
27, 1024.
22 Pui, A.; Policar, C.; Mahy, J. P. Inorg. Chim. Acta 2007,
360, 2139.
5
6
Klärner, F.-G.; Kahlert, B. Acc. Chem. Res. 2003, 36, 919.
Kowalczyk, R.; Kwiatkowski, P.; Skar, J.; Jurczak, J. J. Org.
Chem. 2009, 74, 753.
7
Zulauf, A.; Mellah, M.; Schulz, E. J. Org. Chem. 2009, 74,
2242.
(E0909121 Li, L.)
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