Synthesis, characterization, and crystal structure of a novel acetate-bridged polynuclear Schiff base copper(II) complex

Article abstract of DOI:10.1080/15533170701563947

A novel acetate-bridged polynuclear Schiff base copper(II) complex, [CuL(CH3COO)]n (L=4-nitro-2-[(2-methylaminoethylimino)methyl]phenol), has been synthesized and characterized by elemental analysis, IR spectrum and single crystal X-ray diffraction. Each Cu atom in the complex is five-coordinate in a trigonal-bipyramidal configuration, with one imine N atom and two acetate O atoms defining the basal plane, and one phenolate O and one amine N atoms occupying the axial positions. The [4-nitro-2-[(2-methylaminoethylimino)methyl] phenolato]copper(II) units are linked by the bridging acetate ligands, forming polymeric chains running along the c axis.

Full text of DOI:10.1080/15533170701563947

This article was downloaded by: [University of Connecticut]
On: 05 October 2014, At: 12:49
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
Synthesis and Reactivity in Inorganic, Metal-Organic,
and Nano-Metal Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/lsrt20
Synthesis, Characterization, and Crystal Structure
of a Novel Acetate‐bridged Polynuclear Schiff Base
Copper(II) Complex
Chenyi Wang a
a Department of Chemistry , Huzhou University , Huzhou, P. R. China
Published online: 14 Sep 2007.
To cite this article: Chenyi Wang (2007) Synthesis, Characterization, and Crystal Structure of a Novel Acetate‐bridged
Polynuclear Schiff Base Copper(II) Complex, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry,
37:7, 573-576
To link to this article: http://dx.doi.org/10.1080/15533170701563947
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained
in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the
Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and
should be independently verified with primary sources of information. Taylor and Francis shall not be liable for
any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever
or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of
the Content.
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any
form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://
www.tandfonline.com/page/terms-and-conditions

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 37:573–576, 2007
Copyright # 2007 Taylor & Francis Group, LLC
ISSN: 1553-3174 print/1553-3182 online
DOI: 10.1080/15533170701563947
Synthesis, Characterization, and Crystal Structure of a Novel
Acetate-bridged Polynuclear Schiff Base Copper(II) Complex
Chenyi Wang
Department of Chemistry, Huzhou University, Huzhou, P. R. China
The acetate ligand readily bridges different metal ions
A novel acetate-bridged polynuclear Schiff base copper(II) through the O atoms. We report herein the synthesis, character-
complex, [CuL(CH3COO)]n (L 5 4-nitro-2-[(2-methylaminoethy-
limino)methyl]phenol), has been synthesized and characterized by
elemental analysis, IR spectrum and single crystal X-ray diffrac-
tion. Each Cu atom in the complex is five-coordinate in a
trigonal-bipyramidal configuration, with one imine N atom and
two acetate O atoms defining the basal plane, and one phenolate
O and one amine N atoms occupying the axial positions. The
[4-nitro-2-[(2-methylaminoethylimino)methyl]phenolato]copper(II)
units are linked by the bridging acetate ligands, forming polymeric
chains running along the c axis.
ization and crystal structure of a novel acetate-bridged poly-
nuclear Schiff base copper(II) complex [CuL(CH3COO)]n.
EXPERIMENTAL
Materials and Measurements
Commercially available 5-nitrosalicylaldehyde and
N-methylethane-1,2-diamine were purchased from Sigma and
used without further purification. Other solvents and reagents
were made in China and used as obtained. C, H and N elemen-
tal analyses were performed with a Perkin-Elmer 240C
elemental analyzer. The IR spectra were measured with a
FT-IR 170-SX (Nicolet) spectrophotometer.
Keywords synthesis, crystal structure, Schiff base, copper complex,
polynuclear complex
Synthesis of L
INTRODUCTION
The ligand L was prepared by the condensation of 5-nitrosa-
licylaldehyde (1.0 mmol, 167.1 mg) with N-methylethane-1,2-
diamine (1.0 mmol, 74.1 mg) in methanol (30 mL) at room
temperature. Anal. Calcd. for C10H13N3O3 (FW 223.2): C,
53.81; H, 5.87; N, 18.82. Found: C, 53.60; H, 5.95; N,
18.73%. Yield, 171.0 mg (76.7% on the basis of 5-nitrosalicy-
laldehyde). Selected IR data (KBr, cm21): 3428 (m), 3217 (m),
2982 (m), 2937 (m), 2871 (m), 1655 (s), 1535 (s), 1354 (s),
1230 (m), 720 (m).
Polynuclear complexes play an important role in the devel-
opment of coordination chemistry related to magnetism and
molecular architectures.[1–5] The prime strategy for designing
these molecular materials is to use suitable bridging ligands
that determine the nature of the magnetic interactions.[6–9]
One to the versatile coordination modes of the acetate ligand
and the wide range of magnetic coupling mediated by the
acetate bridges, this ligand has become one of the most exten-
sively studied building blocks in the field.[10–12]
In this paper, the author designed and synthesized the
flexible tridentate Schiff base ligand 4-nitro-2-[(2-methylami-
noethylimino)methyl]phenol (L). The complexes derived
from the Schiff base ligand 2-[2-(methylamino)ethylimino-
methyl]phenol[13] as well as its derivatives[14,15] have been
widely studied; however, to our knowledge those from the
similar Schiff base ligand L have never been reported so far.
Synthesis of [CuL(CH3COO)]n
To a stirred methanol solution (10 mL) of L (0.1 mmol,
22.3 mg) was added an aqueous solution (3 mL) of
.
Cu(CH3COO)2 H2O (0.1 mmol, 19.9 mg). The mixture was
stirred for 30 min at room temperature to give a deep blue
solution. Blue block-shaped crystals of the complex, suitable
for X-ray single crystal analysis, were formed at the bottom
of the vessel on slow evaporation of the solvent for a week.
The isolated crystals were washed three times with cold
methanol, and dried in a vacuum over anhydrous CaCl2.
Anal. Calcd. for C12H15CuN3O5 (FW 344.8): C, 41.80; H,
4.38; N, 12.19. Found: C, 42.05; H, 4.50; N, 12.03%. Yield,
18.0 mg (52.2% on the basis of L). Selected IR data (KBr,
Received 21 February 2007; accepted 23 April 2007.
This project was financially supported by the Science and Technol-
ogy Plan of Huzhou (No. 2007YZ06).
Address correspondence to Chenyi Wang, Department of Chem-
istry, Huzhou University, Huzhou 313000, P. R. China. E-mail:
chenyi_wang@163.com.
573

574
C. WANG
cm21): 3451 (m), 2982 (m), 2935 (m), 2872 (w), 1618 (s), 1573
(s), 1532 (s), 1408 (s), 1345 (s), 1180 (s), 623 (s).
TABLE 2
˚
Selected bond lengths (A) and bond angles (8) for the complex
Cu1-N1
Cu1-O1
Cu1-O5A
2.062(2)
2.068(2)
2.020(2)
108.3(1)
128.7(1)
84.9(1)
Cu1-N2
Cu1-O4
2.186(2)
1.986(2)
DATA COLLECTION, STRUCTURAL DETERMINATION
AND REFINEMENT
O4-Cu1-O5A
O5A-Cu1-N1
O5A-Cu1-O1
O4-Cu1-N2
N1-Cu1-N2
O4-Cu1-N1
O4-Cu1-O1
N1-Cu1-O1
O5A-Cu1-N2
O1-Cu1-N2
122.7(1)
95.3(1)
86.1(1)
92.2(1)
160.2(1)
Crystal Structure Determination
104.2(1)
80.5(1)
Diffraction intensities for the complex were collected at
298(2) K using a Bruker SMART APEXII CCD area-detector
˚
with MoKa radiation (l ¼ 0.71073 A). The collected data
were reduced using the SAINT program,[16] and multi-scan
absorption corrections were performed using the SADABS
program.[17] The structure was solved by direct method and
refined against F2 by full-matrix least-squares method using
the SHELXTL program.[18] All of the non-hydrogen atoms
were refined anisotropically. Atom H2 attached to N2 was
located in a difference Fourier map and refined isotropically,
data for the complex has been deposited with the Cambridge
Crystallographic Data Centre (CCDC 637666).
RESULTS AND DISCUSSION
Preparation of the Ligand and the Complex
˚
with N-H distance restrained to 0.90(1) A. All other H atoms
The author herein designed and synthesized the flexible
Schiff base ligand L (as shown in Scheme 1). The acetate
anion can bridge different metal ions through the two O
atoms,[13–15] forming polynuclear structures. The copper(II)
complex was synthesized according to the procedure as
shown in Scheme 2.
in the complex were placed in calculated positions and con-
strained to ride on their parent atoms. The crystallographic
data for the complex are summarized in Table 1. Selected
bond lengths and angles are given in Table 2. Crystallographic
When compared to the structure the author had reported
recently,[14] we can obviously found that the acetate anion is
a good bridging group, and play an important role in the for-
mation of the polymeric structure.
TABLE 1
Crystallographic and experimental data for the complex
Formula
C12H15CuN3O5
Stability in Air and Solubility in General Solvents
FW
344.81
Crystal shape/colour
Crystal size/mm
Crystal system
Space group
Block/blue
0.30 ꢀ 0.23 ꢀ 0.22
Monoclinic
P21/c
The Schiff base ligand L are yellow crystallite, stable in air
at room temperature. It is soluble in polar organic solvents,
such as MeOH, EtOH, MeCN and Me2CO, but insoluble in
water and Et2O. The complex is also stable in air at room
˚
a/A
14.057(2)
11.091(2)
9.341(1)
92.149(2)
1455.3(3)
4
˚
b/A
˚
c/A
b/8
3
˚
V/A
Z
SCH. 1.
˚
l (MoKa)/A
T/K
0.71073
298(2)
1.525
m/mm21 (Mo 2 Ka)
Tmin
Tmax
0.658
0.730
Reflections/parameters
Independent reflections
F(000)
3319/195
2756
708
Goodness of fit on F2
R1, wR2 [I ꢁ 2s(I)]a
R1, wR2 (all data)a
1.046
0.0356, 0.1069
0.0434, 0.1122
P
P
P
P
aR1 ¼ jjFoj 2 jFcjj/ jFoj,
wR2 ¼ [ w(Fo2 2 Fc2)2/
w
(Fo2)2]1/2
.
SCH. 2.

NOVEL ACETATE-BRIDGED POLYNUCLEAR SCHIFF BASE
575
temperature, soluble in DMF, DMSO, MeOH, EtOH and
MeCN, insoluble in water and Et2O.
Structure Description of the Complex
The molecular structure and the molecular packing of the
complex are shown in Figure 1 and Figure 2, respectively.
The complex is
a novel acetate-bridged polynuclear
copper(II) compound. Each Cu atom in the complex is five-
coordinate in a trigonal-bipyramidal configuration, with one
imine N atom and two acetate O atoms defining the basal
plane, and one phenolate O and one amine N atoms occupying
the axial positions. The significant distortion of the trigonal-
bipyramid is revealed by the bond angles between the axial
and basal donor atoms. The O1-Cu1-N2 bond angle in the
complex deviates from 1808 by 19.8(1)8, as a result of the
strain created by the five-membered chelate ring Cu1/N1/
C8/C9/N2. The angles between the two axial donors and the
three equatorial donor atoms range from 80.5(1)8 for the N1-
Cu1-N2 angle to 104.2(1)8 for the O4-Cu1-N2 angle. The
FIG. 1. The structure of the complex, showing the atom-numbering scheme.
Displacement ellipsoids are drawn at the 30% probability level. H atoms have
been omitted for clarity. Atoms labeled with the suffix A are at the symmetry
positions x, 1/22 y, 1/2 þ z.
three equatorial angles range from 108.3(1)8 for O4-Cu1-O5 observed in other similar copper(II) complexes[19–21] and, as
expected, the bonds involving amine N atoms are longer than
to 128.7(1)8 for O5-Cu1-N1, showing only slight differences
from the ideal value of 1208. The bond lengths subtended at those involving imine N atoms. The acetate anions act as
the metal centers are comparable to the corresponding values bridging ligands and coordinate to the metals through the
FIG. 2. The molecular packing of the complex, viewed along the a axis.

576
C. WANG
complexes with Schiff bases containing NO and NN donor
atoms. Synth. React. Inorg. Met.-Org. Nano-Met. Chem. 2005,
34, 553–563.
two O atoms. The deviation of atom Cu1 from the least-squares
˚
plane defined by the three basal donors is 0.054(1) A.
In the crystal structure of the complex, the [4-nitro-2-[(2-
methylaminoethylimino)methyl]phenolato]copper(II) units are
linked by the bridging acetate ligands, forming polymeric
chains running along the c axis.
10. Koval, I. A.; Gamez, P.; Roubeau, O.; Driessen, W. L.; Lutz, M.;
Spek, A. L.; Reedijk, J. Century-known copper salt
Cu(OAc)(OMe) proven to be
a unique magnetic lattice
composed of tetranuclear copper(II) species with a rare binding
mode of the acetate anion. Inorg. Chem. 2003, 42, 868–872.
11. Clemente-Juan, J. M.; Chansou, B.; Donnadieu, B.; Tuchagues, J.-P.
Synthesis, structure, and magnetic properties of the low-symmetry
tetranuclear cubane-like nickel complex [Ni4(pypentO)(pym)(m3-
OH)2(m-Oac)2(NCS)2(OH2)]. Inorg. Chem. 2000, 39, 5515–5519.
12. Tangoulis, V.; Raptopoulou, C. P.; Terzis, A.; Paschalidou, S.;
Perlepes, S. P.; Bakalbassis, E. G. Octanuclearity in copper(II)
chemistry: Preparation, characterization, and magnetochemistry
REFERENCES
1. Eshel, M.; Bino, A.; Felner, I.; Johnston, D. C.; Luban, M.;
Miller, L. L. Polynuclear chromium(III) carboxylates. 1. Syn-
thesis, structure, and magnetic properties of an octanuclear
complex with
1376–1380.
a ring structure. Inorg. Chem. 2000, 39,
2. Jiang, Y.-B.; Kou, H.-Z.; Wang, R.-J.; Cui, A.-L.; Ribas, J. Syn-
thesis, crystal structure, and magnetic properties of oxime-bridged
polynuclear Ni(II) and Cu(II) complexes. Inorg. Chem. 2005, 44,
709–715.
.
.
.
of [Cu8(dpk OH)8(O2CCH3)4](ClO4)4 9H2O (dpk H2O ¼ the
hydrated, gem-diol form of di-2-pyridyl ketone). Inorg. Chem.
1997, 36, 3996–4006.
3. Escuer, A.; Goher, M. A. S.; Mautner, F. A.; Vicente, R. Three
new polynuclear copper(II) complexes with the symmetric
[Cu(m1,1 2 N3)2Cu]2þ core and pyridine derivatives: Syntheses,
structure, and magnetic behavior. Inorg. Chem. 2000, 39,
2107–2112.
13. Ma, J.-Y.; Lv, B.-L.; Gu, S.-H.; Guo, J.-W.; Yin, W.-P.
Dibromof2-[2-(methylamino)ethyliminomethyl]phenolatogzinc(II).
Acta Crystallogr. 2006, E62, m1322–m1323.
14. Wang, C.-Y. Bisf2-[2-(isopropylamino)ethyliminomethyl]–
4-nitrophenolatogcopper(II) dinitrate. Acta Crystallogr. 2007,
E63, m489–m491.
4. El-Behairy, M.; Khalil, S. M. E.; Ishak, M. F.; Abd El-
Halim, H. F. Tetra- and polynuclear metal complexes derived
from an oxamido homodinuclear Cu(II) complex as a chelating
agent. Synth. React. Inorg. Met.-Org. Nano-Met. Chem. 1997,
27, 907–920.
15. Sun, Y.-X. Synthesis, crystal structures and antibacterial activities
of two Schiff base copper(II) complexes. Synth. React. Inorg.
Met-Org. Nano-Met. Chem. 2006, 36, 621–625.
16. Bruker, SMART and SAINT. Bruker AXS Inc.: Madison, Wis-
consin, USA, 2002.
5. Manhas, B. S.; Sardana, A. K.; Kalia, S. B. Synthesis, magnetic
and spectroscopic characterization of copper(II) toluate com-
plexes with substituted piperazines. Synth. React. Inorg. Met.-
Org. Nano-Met. Chem. 2005, 35, 171–179.
17. Sheldrick, G. M. SADABS. Program for Empirical Absorption
¨
Correction of Area Detector; University of Gottingen:
Germany, 1996.
6. Salem, N. M. H. Synthesis and magnetic properties of copper(II)
complexes derived from dihydrazones. Synth. React. Inorg. Met.-
Org. Nano-Met. Chem. 2005, 35, 369–377.
18. Sheldrick, G. M. SHELXTL V5.1. Software Reference Manual;
Bruker AXS, Inc.: Madison, Wisconsin, USA.
19. Mikuriya, M.; Nakadera, K.; Lim, J.-W. m-Phenoxo-m-pyrazo-
lato-bridged dinuclear copper(II) complex with 2,6-bis(salicylide-
neaminomethyl)-4-methylphenol. Synth. React. Inorg. Met.-Org.
Nano-Met. Chem. 2002, 32, 117–125.
7. Dey, S. K.; Mondal, N.; El Fallah, M. S.; Vicente, R.; Escuer, A.;
Solans, X.; Font-Bardia, M.; Matsushita, T.; Gramlich, V.;
Mitra, S. Crystal structure and magnetic interactions in
nickel(II) dibridged complexes formed by two azide groups or
by both phenolate oxygen-azide, -thiocyanate, -carboxylate, or
–cyanate groups. Inorg. Chem. 2004, 43, 2427–2434.
8. Li, Y.-T.; Yan, C.-W.; Zhu, C.-Y.; Guan, H.-S. Synthesis and
magnetic studies of m-oxamido-bridged copper(II)-manganese(II)
heterobinuclear complexes. Synth. React. Inorg. Met.-Org. Nano-
Met. Chem. 2005, 34, 1165–1179.
20. Lashanizadegan, M.; Boghaei, D. M. Template synthesis and
X-ray structure determination of unsymmetrical tetradentate
Schiff base complexes of nickel(II) and copper(II). Synth.
React. Inorg. Met.-Org. Nano-Met. Chem. 2001, 31, 1519–1529.
21. Mohanan, K.; Devi, S. N.; Murukan, B. Complexes of copper(II)
with 2-(N-salicylideneamino)-3-carboxyethyl-4,5,6,7-tetrahydro-
benzo[b]thiophene containing different counter anions. Synth.
React. Inorg. Met.-Org. Nano-Met. Chem. 2006, 36, 441–449.
9. Dohlakiya, P. P.; Patel, M. N. tMetal complexes: Preparation,
magnetic, spectral, and biocidal studies of some mixed-ligand