Self-assembly and X-ray crystal structures of new copper complexes with similar O,N-donor schiff base ligands and ammonium thiocyanate

Article abstract of DOI:10.1080/15533174.2012.757751

The self-assembly of one equivalent each of copper bromide and ammonium thiocyanate with O,N-donor Schiff base ligands 2-bromo-6-[(2- dimethylaminoethylimino)methyl]phenol (L¹) and 2-bromo-6-[(2- ethylaminoethylimino)methyl]phenol (L²

Full text of DOI:10.1080/15533174.2012.757751

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Self-Assembly and X-Ray Crystal Structures of New
Copper complexes with Similar O,N-Donor Schiff Base
Ligands and Ammonium Thiocyanate
Jin-Long Hou a , Ye Bi a , Hong-Yuan Wu a & Cheng-Li Han a
a College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, P. R.
China
Accepted author version posted online: 17 Apr 2013.
To cite this article: Jin-Long Hou , Ye Bi , Hong-Yuan Wu & Cheng-Li Han (2013): Self-Assembly and X-Ray Crystal Structures
of New Copper complexes with Similar O,N-Donor Schiff Base Ligands and Ammonium Thiocyanate, Synthesis and Reactivity in
Inorganic, Metal-Organic, and Nano-Metal Chemistry, DOI:10.1080/15533174.2012.757751
To link to this article: http://dx.doi.org/10.1080/15533174.2012.757751
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Self-Assembly and X-Ray Crystal Structures of New Copper complexes with Similar O,N-Donor
Schiff Base Ligands and Ammonium Thiocyanate
Jin-Long Hou*, Ye Bi, Hong-Yuan Wu, Cheng-Li Han
College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, P. R.
China
Corresponding author email: houjinlong09@163.com
Abstract
The self-assembly of one equivalent each of copper bromide and ammonium thiocyanate with
O,N-donor Schiff base ligands 2-bromo-6-[(2-dimethylaminoethylimino)methyl]phenol (L1) and
2-bromo-6-[(2-ethylaminoethylimino)methyl]phenol (L2) in methanol under aerobic conditions
provide two mononuclear copper(II) complexes [CuL1(NCS))] (1) and [Cu(L2)2]·2Br (2). The
complexes have been characterized by analytical and spectroscopic measurements. The crystal
structures of the complexes have been determined by X-ray crystallography. In both complexes,
the metal centers are in square planar coordination geometries. The L1 ligand coordinates the
metal ion through the three N,N,O donor atoms, while the L2 ligand coordinates the metal ion
merely through the imine-N and the phenolate-O atoms. Slight change in the terminal groups of
the Schiff base ligands as well as the formation of hydrogen bonds can lead to totally different
structures during the self-assembly processes.
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Keywords: Copper complexes; Crystal structures; Self-assembly; Mononuclear complexes;
Hydrogen bond
Introduction
Studies on supramolecular interactions and the self-assemblies resulting from them have
attracted remarkable attention in recent years [1-5]. Among Schiff bases, those derived from the
mono-condensation of organic amines with carbonyl compounds, are a group of classical mono-
negative N,N,O donor ligands [6-8]. These ligands react readily with copper salts to occupy its
three equatorial coordination sites whereas several anionic or neutral ligands can be coordinated
to the fourth coordination site of the square plane to yield different type of complexes [9-11].
Among the co-ligands, thiocyanate has received remarkable attention because it can coordinate
to the metal centers through versatile modes, such as end-on, end-to-end or a combination of
both modes [12,13]. To date, a few thiocyanate-coordinated complexes have been prepared from
the compartmental Schiff base ligands obtained on condensation of halido-substituted
salicylaldehyde with N-alkyl-substituted organic amines [14-16]. However, there still no explicit
method to prepare such complexes with aiming structures. Herein, we report the synthesis and
crystal structures of two new copper(II) complexes, [CuL1(NCS))] (1) and [Cu(L2)2]·2Br (2),
where L1 = 2-bromo-6-[(2-dimethylaminoethylimino)methyl]phenol, L2 = 2-bromo-6-[(2-
ethylaminoethylimino)methyl]phenol.
Experimental Section
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Materials and physical measurements
The ligands L1 and L2 were prepared in over 90% yields by condensation reactions of 3-
bromosalicylaldehyde with N,N-dimethylethylenediamine and N-ethylethylenediamine,
respectively, in methanol. All other chemicals were commercially available and used as received.
Elemental analysis was carried out using model 2400 Perkin–Elmer CHN analyzer. Infrared
spectra were collected by using KBr pellets on a Jasco-5300 FT-IR spectrophotometer. Solution
electrical conductivities were measured with a Digisun DI-909 conductivity meter.
Preparation of complex 1
A solution of copper bromide (0.22 g, 1 mmol) in methanol (20 mL) was added dropwise to a
stirred solution of L1 (0.27 g, 1 mmol) and ammonium thiocyanate (0.076 g, 1 mmol) in
methanol (20 mL). The reaction mixture was stirred for ca. 2 h, during which time the color of
the solution changed from yellow to deep blue. Addition of water at this point precipitated a
large quantity of solid, which was filtered, washed with a little volume of methanol, and dried in
a vacuum containing anhydrous CaCl2. The yield is 0.27 g (69%). The solid was re-dissolved in
a minimum volume of methanol, which was left to slow evaporate for several days, to yield X-
ray quality single crystals. Anal. Calcd for C12H14BrCuN3OS: C, 36.79; H, 3.60; N, 10.73.
Found: C, 36.60; H, 3.72; N, 10.81.
Preparation of complex 2
A solution of copper bromide (0.22 g, 1 mmol) in methanol (20 mL) was added dropwise to a
stirred solution of L2 (0.27 g, 1 mmol) and ammonium thiocyanate (0.076 g, 1 mmol) in
methanol (20 mL). The reaction mixture was stirred for ca. 2 h, during which time the color of
the solution changed from yellow to deep blue. Addition of water at this point precipitated a
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large quantity of solid, which was filtered, washed with a little volume of methanol, and dried in
a vacuum containing anhydrous CaCl2. The yield is 0.63 g (82%). The solid was re-dissolved in
a minimum volume of methanol, which was left to slow evaporate for several days, to yield X-
ray quality single crystals. Anal. Calcd for C22H30Br4CuN4O2: C, 34.51; H, 3.95; N, 7.32. Found:
C, 34.63; H, 4.04; N, 7.26.
X-ray crystallography
Three-dimensional X-ray data for the complexes were collected on a Bruker SMART Apex CCD
single crystal diffractometer at 298(2) K, equipped with a graphite monochromator and a Mo Kα
fine-focus sealed tube (λ = 0.71073 Å) by the ω scan method. Reflections were corrected for
Lorentz and polarization effects, and for absorption by semi-empirical methods based on
symmetry-equivalent and repeated reflections. The SMART software was used for data
acquisition and the SAINT-PLUS software was used for data extraction [17]. The absorption
corrections were performed with the help of SADABS program [18]. The structures were solved
by direct methods and refined on F2 by full-matrix least-squares procedures. All non-hydrogen
atoms were refined using anisotropic thermal parameters. The hydrogen atoms were included in
the structure factor calculations at idealized positions by using a riding model but not refined.
The SHELX-97 programs [19] were used for structure solution and refinement. Selected
crystallographic data for the complexes are listed in Table 1.
CCDC Nos. 912054 and 912055 contain the supplementary crystallographic data for this paper.
These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data request/cif. Crystal data and details of the data collection and
refinement for the complexes are collected in Table 1.
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Results and discussion
Synthesis
Both complexes were prepared from methanolic media by reacting copper bromide with Schiff
base ligands and ammonium thiocyanate in 1:1:1 mole ratio. The elemental analysis data are
consistent with the general molecular formulae of the complexes. In complex 1, the thiocyanate
anion coordinates to the Cu atom as a terminal ligand, while in complex 2, it did not participate
in coordinating. Since the only difference of the starting materials is the N-substituted terminal
groups of the Schiff base ligands, viz. double methyl-substituent groups for 1 and single ethyl-
substituent group for 2, it can be roughly estimated that such differences of the Schiff base
ligands may influence the coordination or not of the co-ligand NCS during the self-assembly
processes. This phenomenon is also supported by other copper(II) complexes with similar Schiff
bases [20-22].
The preparation of complexes 1 and 2 are depicted in Schemes 1 and 2, respectively.
N
N
L1
CuBr2
NH NCS
+
+
4
Cu
O
Br
NCS
Scheme 1. The preparation of complex 1.
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2
+
NH2
O
N
Br
_
.2Br
O
Cu
L2
NH NCS
4
CuBr2
+
+
Br
N
H2N
Scheme 2. The preparation of complex 2.
Both complexes are soluble in common organic solvents like dimethylsulphoxide,
dimethylformamide, methanol, and ethanol. In acetonitrile solutions, complex 1 is an electrically
non-conductor (23 Ω-1 cm2 mol-1), and complex 2 is an electrically 1:2 conductor (172 Ω-1 cm2
mol-1) [23].
Infrared spectra of the complexes
The absence of the O–H stretching and bonding vibrations from the spectra of the complexes
indicates coordination through the phenolate groups. Infrared spectra of complexes 1 and 2
display strong bands at ca. 1615 cm-1, which represent the C=N stretches of the Schiff base
ligands [24]. Infrared spectrum of complex 1 displays an intense band at 2072 cm-1, which
represents the typical absorption of the terminal thiocyanate ligand [25]. Infrared spectrum of
complex 2 displays a middle and sharp band at 3167 cm-1, which represents the typical N–H
stretches of the protonated amino group of L2 ligand. The phenolic ν(C–O) in the spectra of the
complexes appear in the 1215–1225 cm-1 region. The occurrence of new bands in the 410–580
cm-1 region confirms the presence of metal-nitrogen and metal-oxygen bonds, respectively [26].
Structure description of complex 1
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The molecular structure of complex 1 is depicted in Fig. 1. Bond parameters associated with the
metal atom are listed in Table 2. The copper atom is four-coordinated by the three NNO atoms of
the L1 and one N atom of thiocyanate ligand. The coordination polyhedron around copper atom
can be described as a square planar. The Cu1–N1, Cu1–N2, Cu1–N3 and Cu1–O1 distances are
1.929(4), 2.073(4), 1.938(4), and 1.912(4) Å, respectively, which are within the average values
observed in similar complexes [22,27]. The N1–Cu1–N3 and O1–Cu1–N2 bond angles are
167.1(2) and 172.5(2)°, respectively, indicating they are deviated from the ideal values for a
square pyramid geometry.
Structure description of complex 2
The molecular structure of complex 2 is depicted in Fig. 2. Bond parameters associated with the
metal atom are listed in Table 2. The complex possesses crystallographic inversion center
symmetry, with the Cu1 atom located at the inversion center. There contains one [Cu(L2)2]2+
cation and two bromide anions. The copper atom is four-coordinated by the phenolate O and
imine N atoms of two L2 ligands. The coordination polyhedron around copper atom can be
described as a square planar. The Cu1–N1 and Cu1–O1 distances are 1.947(4) and 2.019(5) Å,
respectively, which are within the average values observed in complex 1 and other similar
complexes [28,29]. There forms intramolecular N2–H2B···O1i hydrogen bonds [N2–H2B = 0.90
Å, H2B···O1i = 2.18 Å, N2···O1i = 2.848(6) Å, N2–H2B···O1i = 130.2(2)°; symmetry code for i:
– x, 2 – y, 2 – z], which might lead to the un-coordination of the amino groups.
References
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[1] D. Matoga, J. Szklarzewicz, W. Nitek, Effect of ligand substituents on supramolecular self-
assembly and electrochemical properties of copper(II) complexes with benzoylhydrazones: X-
ray crystal structures and cyclic voltammetry. Polyhedron, 2012, 36, 120-126.
[2] Y.-Z. Qiao, W.-Z. Fu, Y.-M. Yue, X.-C. Liu, Y.-Y. Niu, H.-W. Hou. Role of cooperative
templates in the self-assembly process of microporous structures: syntheses and characterization
of 12 new silver halide/thiocyanate supramolecular polymers. CrystEngComm, 2012, 14, 3241-
3249.
[3] L.-S. Song, H.-M. Wang, Y.-Y. Niu, H.-W. Hou, Y. Zhu. The anion exchange reaction of
bis(isoquinoline) ionic liquids: self-assembly, crystal structures and thermal properties of ten
novel d(10) metal (Cu, Ag) halide/thiocyanate supramolecular polymers. CrystEngComm, 2012,
14, 4927-4938.
[4] H.-Y. Gong, B.-M. Rambo, C. A. Nelson, W. Cho, V. M. Lynch, X. Y. Zhu, M. Oh, J. L.
Sessler. Multi component self-assembly: supramolecular organic frameworks containing metal-
rotaxane subunits (RSOFs). Dalton Trans., 2012, 41, 1134-1137.
[5] R. Chakrabarty, P. S. Mukherjee, P. J. Stang. Supramolecular coordination: Self-assembly of
finite two- and three-dimensional ensembles. Chem. Rev., 2011, 111, 6810-6918.
[6] S. Basak, S. Sen, C. Marschner, J. Baumgartner, S. R. Batten, D. R. Turner, S. Mitra.
Synthesis, crystal structures and fluorescence properties of two new di- and polynuclear Cd(II)
complexes with N2O donor set of a tridentate Schiff base ligand. Polyhedron, 2008, 27, 1193-
1200.
8
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
[7] C. Adhikary, D. Mal, K. Okamoto, S. Chaudhuri, S. Koner. Synthesis, characterization, X-
ray structure and magnetic study of the azido adducts of tridentate (NNO) Schiff base copper(II)
complexes. Polyhedron, 2006, 25, 2191-2197.
[8] D. Parker, E. S. Davies, C. Wilson, J. McMaster. The synthesis and characterisation of
phenolate complexes of Cu(II) and Ni(II) that are capable of supporting a phenoxyl radical
ligand. Inorg. Chim. Acta, 2007, 360, 203-211.
[9] C. Adhikary, R. Sen, J.-P. Tuchagues, S. Chaudhuri, S. Ianelli, M. Solzi, S. Koner. Ladder-
like azido-bridged copper(II) complexes: Synthesis, X-ray structure and magnetic study. Inorg.
Chim. Acta, 2009, 362, 5211-5218.
[10] Y.-J. Wei, F.-W. Wang, Q.-Y. Zhu. Synthesis, crystal structures, and antimicrobial activity
of a pair of isostructural dinuclear copper(II) complexes derived from 4-nitro-2-[(2-
diethylaminoethylimino)methyl]phenol. Transition Met. Chem., 2008, 33, 543-546.
[11] D. Mal, R. Sen, C. Adhikary, Y. Miyashita, K.-I. Okamoto, A. Bhattacharjee, P. Gutlich, S.
Koner. Synthesis, X-ray crystal structure and magnetic study of a µ1,5-dca bridged ferromagnetic
dimeric copper(II) complex. J. Coord. Chem., 2008, 61, 3486-3492.
[12] J. Carranza, J. Sletten, F. Lloret, M. Julve. Preparation, crystal structures and magnetic
properties of three thiocyanato-bridged copper(II) complexes with 2,2'-biimidazole or 2-(2'-
pyridyl)imidazole as terminal ligands. Polyhedron, 2009, 28, 2249-2257.
[13] S.-Z. Zhan, D. Li, X.-P. Zhou, X.-H. Zhou. Two polyknotted topological isomers of
copper(I) 3,5-bis(4-pyridyl) pyrazolates. Inorg. Chem., 2006, 45, 9163-9165.
9
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
[14] S. Banerjee, M. G. B. Drew, C.-Z. Lu, J. Tercero, C. Diaz, A. Ghosh. Dinuclear complexes
of MII thiocyanate (M = Ni and Cu) containing a tridentate Schiff-base ligand: Synthesis,
structural diversity and magnetic properties. Eur. J. Inorg. Chem., 2005, 2376-2383.
[15] H. Adams, S. Clunas, L. R. Cummings, D. E. Fenton, P. E. McHugh. Copper(II) complexes
of unsymmetric compartmental ligands bearing adjacent {N2O}, {N,S,O} donor sets and {N2O},
{N,O} donor sets. Inorg. Chem. Commun., 2003, 6, 837-840.
[16] D.-M. Xian, Z.-L. You, M. Zhang, P. Hou, X.-H. Li. Dinuclear Schiff-base copper(II)
complexes with various bridging groups. J. Coord. Chem., 2011, 64, 3265-3272.
[17] SMART version 5.63 and SAINT-PLUS version 6.45, Bruker–Nonius Analytical X-ray
Systems Inc., Madison, WI, USA, 2003.
[18] G. M. Sheldrick. SADABS, Empirical Absorption Correction Program, University of
Göttingen, Göttingen, Germany, 1997.
[19] G. M. Sheldrick. SHELX-97, Structure Determination Software, University of Göttingen,
Göttingen, Germany, 1997.
[20] H. Elias, E. Hilms, H. Paulus. X-Ray structures and spectral properties of 4-coordinate
copper(II) and palladium(II) complexes with a tridentate ONN-Schiff base ligand. Z.
Naturforsch., Teil B., 1982, 37, 1266-1273.
[21] C.-Y. Wang. Bis{2-[2-(isopropylamino)ethyliminomethyl]-4-nitrophenolato}copper(II)
dinitrate. Acta Crystallogr., 2007, E63, m489-m491.
[22] J. R. Roper, H. Paulus, H. Elias. Square-planar copper(II) chelate complexes of the ONN-
monodentate ligand type - kinetics of ligand substitution as studied in acetone and the effect of
water. Inorg. Chem., 1989, 28, 2323-2329.
10
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
[23] W. J. Geary. Use of conductivity measurements in organic solvents for characterisation of
coordination compounds. Coord. Chem. Rev., 1971, 7, 81-122.
[24] S. Chattopadhyay, M. S. Ray, M. G. B. Drew, A. Figuerola, C. Diaz, A. Ghosh. Facile
synthesis of Cu(II) complexes of monocondensed N,N,N donor Schiff base ligands: Crystal
structure, spectroscopic and magnetic properties. Polyhedron, 2006, 25, 2241-2253.
[25] S. S. Massoud, F. A. Mautner. Synthesis and structure determination of two new dinuclear
end-to-end doubly bridged azido- and thiocyanato-copper(II) complexes derived from
diethyldiethylenetriamine. Inorg. Chim. Acta, 2005, 358, 3334-3340.
[26] Y.-M. Zhou, X.-R. Ye, F.-B. Xin, X.-Q. Xin. Solid state self-assembly synthesis of
cobalt(II), nickel(II), copper(II) and zinc(II) complexes with a bis-Schiff base. Transition Met.
Chem., 1999, 24, 118-120.
[27] Z.-L. You, L. Zhang, D.-H. Shi, X.-L. Wang, X.-F. Li, Y.-P. Ma. Synthesis, crystal
structures and urease inhibitory activity of copper(II) complexes with Schiff bases. Inorg. Chem.
Commun., 2010, 13, 996-998.
[28]
L.
Yuan.
Bis(2-{[2-(isopropylazaniumyl)ethyl]iminomethyl}-6-
methoxyphenolato)copper(II) bis(thiocyanate). Acta Crystallogr., 2011, E67, m201-m201.
[29] S.-N. Li, Q.-G. Zhai, M.-C. Hu, Y.-C. Jiang. Synthesis, crystal structures and
characterization of three novel complexes with N-[2-(2-hydroxybenzylideneamino)ethyl]-4-
methyl-benzene-sulfonamide as ligand. Inorg. Chim. Acta, 2009, 362, 2217-2221.
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Table 1
Crystal data and structure refinement parameters for complexes 1 and 2
1
2
Formula
C12H14BrCuN3OS
391.8
C22H30Br4CuN4O2
765.7
M
Temperature (K)
298(2)
298(2)
Radiation, wavelength (Å) Mo Kα, 0.71073
Mo Kα, 0.71073
Monoclinic
P21/n
Crystal system
Space group
a (Å)
Orthorhombic
Pca21
12.875(1)
6.788(1)
11.652(1)
8.699(1)
13.153(1)
102.660(2)
1300.8(2)
2
b (Å)
c (Å)
16.531(1)
β (°)
V (Å3)
1444.8(2)
4
Z
Dc( g/cm3)
µ (mm-1)
F(000)
1.801
4.416
780
1.955
7.010
750
Crystal colour
Blue
Blue
θ range for data collection 3.16-26.49
2.12-25.74
-14, 14; -8, 10; -16, 15
10758
Index ranges (h, k, l)
-16, 15; -8, 8; -20, 20
12900
Reflections collected
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Independent reflections
2978
2464
Rint
0.0448
0.0576
1936
Reflections with F2 > 2644
2σ(F2)
Absorption correction
Multi-scan
Multi-scan
Minimum and maximum 0.4299, 0.4721
transmission
0.2533, 0.3077
R1 [F2 > 2σ(F2)]
wR2 (all data)
0.0405
0.1020
1.082
0.0496
0.1206
1.077
Goodness-of-fit on F2
Table 2
Selected bond distances and angles for complexes 1 and 2 (Å and °)
1
Bond distances
Cu1-O1
1.912(4)
2.073(4)
Cu1-N1
Cu1-N3
1.929(4)
1.938(4)
Cu1-N2
Bond angles
O1-Cu1-N1
N1-Cu1-N3
N1-Cu1-N2
93.2(2)
167.1(2)
84.8(2)
O1-Cu1-N3
O1-Cu1-N2
N3-Cu1-N2
92.2(2)
172.5(2)
91.3(2)
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2
Bond distances
Cu1-O1
1.947(4)
Cu1-N1
2.019(5)
Bond angles
O1-Cu1-O1A
O1-Cu1-N1A
180
O1-Cu1-N1
90.4(2)
180
89.6(2)
N1-Cu1-N1A
Symmetry operation for A: – x, 2 – y, 2 – z.
Fig. 1. ORTEP diagram of complex 1 with thermal ellipsoids at 30% probability level. Selected
bond lengths and angles are given in Table 2.
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Fig. 2. ORTEP diagram of complex 2 with thermal ellipsoids at 30% probability level. Selected
bond lengths and angles are given in Table 2. Unlabeled atoms are related to the symmetry
operation – x, 2 – y, 2 – z.
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