Syntheses and crystal structures of [Ni(IIP)2] and [Cu 2(PMP)2(μ1,1-N3)2] · MeOH (IIP = 2-iminomethyl-4,6-diiodophenolate, PMP = 2-[(2-phenylaminoethylimino)methyl]phenolate)

Article abstract of DOI:10.1134/S1070328413090066

A new centrosymmetric mononuclear nickel(II) complex, [Ni(IIP)₂] (I), and a new end-on azido-bridged dinuclear copper(II) complex, [Cu ₂(PMP)₂(μ_1,1-N₃)₂] · MeOH (II) (IIP = 2-iminomethyl-4,

Full text of DOI:10.1134/S1070328413090066

ISSN 1070ꢀ3284, Russian Journal of Coordination Chemistry, 2013, Vol. 39, No. 10, pp. 704–709. © Pleiades Publishing, Ltd., 2013.
Syntheses and Crystal Structures of [Ni(IIP)2]
and [Cu2(PMP)2(µ1,1ꢀN3)2] · MeOH
(IIP = 2ꢀIminomethylꢀ4,6ꢀDiiodophenolate,
PMP = 2ꢀ[(2ꢀPhenylaminoethylimino)methyl]phenolate)1
S. S. Qiana, X. S. Chengb, Z. L. Youb, and H. L. Zhua, *
a School of Life Sciences, Shandong University of Technology, ZiBo, 255049 P.R. China
b Department of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian, 116029 P.R. China
*eꢀmail: hailiang_zhu@163.com
Received February 20, 2012
Abstract
—
A new centrosymmetric mononuclear nickel(II) complex, [Ni(IIP)2] (
·
I), and a new endꢀon
MeOH (II) (IIP = 2ꢀiminomethylꢀ
azidoꢀbridged dinuclear copper(II) complex, [Cu2(PMP)2(μ1,1ꢀN3)2]
4,6ꢀdiiodophenolate, PMP = 2ꢀ[(2ꢀphenylaminoethylimino)methyl]phenolate), have been prepared from
similar tridentate Schiff bases derived from Nꢀphenylethaneꢀ1,2ꢀdiamine with 3,5ꢀdiiodosalicylaldehyde
and salicylaldehyde, respectively. The complexes were characterized by elemental analysis, infrared spectra,
and singleꢀcrystal Xꢀray diffraction. Complex
dimensions = 4.936(1), = 11.779(3), = 15.789(4)
and wR2 = 0.0546. Complex II crystallizes in the orthorhombic space group Pna21 with unit cell dimensions
= 23.370(2), = 12.210(1), = 11.438(1) = 4, 1 = 0.0461, and wR2 = 0.0891. The
= 3263.8(5) Å3
Ni atom in is in a square planar coordination, and the Cu atoms in II are in square pyramidal coordination.
I
crystallizes in the monoclinic space group
P
21/
c
with unit cell
a
b
c
Å,
β
= 90.722(3)
°
,
V
= 918.0(4) Å3
,
Z
= 2,
R1 = 0.0267,
a
b
c
Å,
V
,
Z
R
I
DOI: 10.1134/S1070328413090066
1
INTRODUCTION
I
H
NH
OH
N
N
Metal complexes with Schiff bases have been reꢀ
ceived considerable attention for their importance in
the fields of coordination chemistry related to catalysis
and enzymatic reactions, magnetism and molecular
architectures [1–5]. Nickel and copper complexes
with Schiff base ligands been proved to possess interꢀ
esting biological, catalytic, and magnetic properties
[6–10]. During the search of literature, we found that
a large number of complexes with the tridentate Schiff
bases derived from salicylaldehyde and its derivatives
with versatile organic amines had been reported. Yet,
to the best of our knowledge, no complexes have been
reported for the tridentate Schiff bases 2,4ꢀdiiodoꢀ6ꢀ
[(2ꢀphenylaminoethylimino)methyl]phenol (HIMP)
OH
(HPMP)
I
(HIMP)
EXPERIMENTAL
Materials and measurements. Commercially availꢀ
able 3,5ꢀdiiodosalicylaldehyde, salicylaldehyde, and
Nꢀphenylethaneꢀ1,2ꢀdiamine were purchased from
Aldrich and used without further purification. Other
solvents and reagents were made in China and
used as received. C, H, and N elemental analyses
were performed with a PerkinElmer elemental analyꢀ
ser. The infrared spectra were recorded on a Nicolet
AVATAR 360 spectrometer as KBr pellets in the 4000–
400 cm–1 region. Thermal stability analysis was perꢀ
formed on a PerkinElmer Pyris Diamond TGꢀDTA
thermal analyses system.
and
2ꢀ[(2ꢀphenylaminoethylimino)methyl]phenol
(HPMP). As an extension of the work on the Schiff
base complexes [11–13], we report in this paper the
syntheses and crystal structures of two new nickel(II)
and copper(II) complexes, [Ni(IIP)2] (
I) and
[Cu2(PMP)2(μ1,1ꢀN3)2] MeOH (II) (IIP = 2ꢀimiꢀ
nomethylꢀ4,6ꢀdiiodophenolate, PMP = 2ꢀ[(2ꢀpheꢀ
nylaminoethylimino)methyl]phenolate.
·
Synthesis of the Schiff base HIMP. 3,5ꢀDiiodosalꢀ
icylaldehyde (1.0 mmol, 0.374 g) and Nꢀphenylꢀ
ethaneꢀ1,2ꢀdiamine (1.0 mmol, 0.136 g) were disꢀ
solved in EtOH (20 mL) with stirring. The mixture was
stirred for about 30 min at room temperature to give a
1
The article is published in the original.
704

SYNTHESES AND CRYSTAL STRUCTURES
705
yellow solution. The solvent was evaporated to give tion. The resulting solution was allowed to stand in air
yellow gummy product of HIMP. The yield was 98%.
for a few days. Blue blockꢀshaped crystals suitable for
Xꢀray single crystal analysis were formed at the bottom
of the vessel. The isolated product was washed three
times with cold EtOH, and dried in a vacuum over anꢀ
hydrous CaCl2. The yield was 16.0 mg (44% on the baꢀ
sis of HPMP).
For C15H14N2OI2
anal. calcd., %: C, 36.6;
Found, %: C, 36.5;
H, 2.9;
H, 2.9;
N, 5.7.
N, 5.6.
Synthesis of the Schiff base HPMP. Salicylaldeꢀ
hyde (1.0 mmol, 0.122 g) and Nꢀphenylethaneꢀ1,2ꢀ
diamine (1.0 mmol, 0.136 g) were dissolved in EtOH
(20 mL) with stirring. The mixture was stirred for
about 30 min at room temperature to give a yellow soꢀ
lution. The solvent was evaporated to give yellow gumꢀ
my product of HPMP. The yield was 95%.
For C31H34N10O3Cu2
anal. calcd., %: C, 51.6;
Found, %: C, 51.7;
H, 4.7;
H, 4.8;
N, 19.4.
N, 19.2.
Xꢀray structure determination. Diffraction intensiꢀ
ties for the complexes were collected at 298(2) K
using a Bruker SMART 1K areaꢀdetector with Mo
K
α
For C15H16N2O
radiation ( = 0.71073 Å). The collected data were reꢀ
λ
duced using the SAINT program [14], and multiꢀscan
absorption corrections were performed using the
SADABS program [15]. The structures of the comꢀ
plexes were solved by direct methods and refined
against F2 by fullꢀmatrix leastꢀsquares methods using
the SHELXTL [16]. All of the nonꢀhydrogen atoms
anal. calcd., %: C, 75.0;
Found, %: C, 74.8;
H, 6.7;
H, 6.8;
N, 11.7.
N, 11.5.
Synthesis of [Ni(IIP)2] (I). A MeOH solution
(5 mL) of nickel acetate (0.1 mmol, 24.9 mg) was addꢀ
ed to a MeOH solution (10 mL) of HIMP (0.1 mmol,
49.2 mg) with stirring. The mixture was stirred for
30 min to give a red solution. The resulting solution
was allowed to stand in air for a few days. Red blockꢀ
shaped crystals suitable for Xꢀray single crystal analysis
were formed at the bottom of the vessel. The isolated
product was washed three times with cold EtOH, and
dried in a vacuum over anhydrous CaCl2. The yield
was 21.0 mg (52% on the basis of HIMP).
were refined anisotropically. The imino H atoms in
and the amino H atoms in II were located from differꢀ
ence Fourier maps and refined isotropically, with
H distances restrained to 0.90(1) . The remaining
I
N
⎯
Å
H atoms were placed in idealized positions and conꢀ
strained to ride on their parent atoms. The crystalloꢀ
graphic data for the complexes are summarized in Taꢀ
ble 1. Selected bond lengths and angles are given in Taꢀ
ble 2. Supplementary material has been deposited with
the Cambridge Crystallographic Data Centre
For C14H8N2O2I4Ni
(nos. 825216 (I) and 867494 (II); deposit@
ccdc.cam.ac.uk or http://www.ccdc.cam. ac.uk).
anal. calcd., %: C, 21.0;
Found, %: C, 20.8;
H, 1.0;
H, 1.1;
N, 3.5.
N, 3.5.
RESULTS AND DISCUSSION
Synthesis of [Cu2(PMP)2(µ1,1ꢀN3)2]
·
MeOH (II).
The complexes
the similar synthetic procedure, as shown in Scheme.
It is interesting that for the preparation of , the startꢀ
ing material HIMP was changed to HUP during the
I and II were readily prepared by
A MeOH solution (5 mL) of copper acetate
(0.1 mmol, 19.9 mg) was added to the mixture of a
MeOH solution (10 mL) of HPMP (0.1 mmol, 24.0 mg)
and sodium azide (0.1 mmol, 6.5 mg) with stirring.
I
The mixture was stirred for 30 min to give a blue soluꢀ coordination.
H
H
I
I
N
N
H
I
N
+ Ni(MeCOO)2
O
Ni
O
OH
I
N
I
I
(I)
N
N
H
Cu
O
H
N
N
NNN
MeOH
+ Cu(MeCOO)2 + NaN3
NNN
H
N
OH
O
Cu
N
(II)
Scheme.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
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706
QIAN et al.
Table 1. Crystallographic and experimental data for the complexes I and II
Value
Parameter
I
II
Fw
802.5
721.8
Crystal shape/color
Crystal size, mm
Crystal system
Space group
Block/red
Block/blue
0.20
Monoclinic
21/
×
0.20
×
0.18
0.23
×
0.21 × 0.21
Orthorhombic
Pna21
P
c
a
, Å
, Å
4.936(1)
11.779(3)
15.789(4)
90.722(3)
918.0(4)
2
23.370(2)
12.210(1)
11.438(1)
90
b
c
, Å
β
V
Z
μ
, deg
, Å3
3263.8(5)
4
(Mo
K
), mm–1
7.791
1.352
α
ρcalcd, g cm–3
(000)
Tmin Tmax
2.903
1.469
F
724
1488
,
0.3048, 0.3345
7095
0.7462, 0.7644
13865
Reflections measured
Unique reflections (Rint
)
1981
6857
Observed reflections (
I
≥
2σ(I
))
1559
4778
Parameters
109
425
Restraints
1
4
Goodness of fit on F 2
1.079
1.000
R1
,
wR2
(
I
≥
2
σ
(
I
))*
0.0267, 0.0546
0.0402, 0.0609
1.150 and –0.768
0.0461, 0.0891
0.0800, 0.1022
0.343 and –0.279
R1,
wR2 (all data)*
Largest diff. peak and hole, e
Å–3
2
/
2
(F2o – F2c)
∑
w
(F2o)
]
.
1/2
*
R
=
∑
||F
| – |F
||/
∑
|F
|, wR = [
∑
w
1
o
c
o
2
The molecular structure of the complex
in Fig. 1. The compound is a centrosymmetric monoꢀ parallel to the yz plane, as shown in Fig. 2.
I
is shown
⎯
1/2 +
y
, 1/2 –
z
) hydrogen bonds, forming layers
nuclear nickel(II) complex, with the Ni atom located
at the inversion center. The Ni atom in the complex is
The molecular structure of the complex II is shown
in Fig. 3. The compound contains an endꢀon azidoꢀ
coordinated by two phenolate O and two imine N atꢀ
bridged dinuclear copper(II) complex molecule and a
oms from two IIP ligands, forming a square planar geꢀ
methanol molecule of crystallization. The intramolecꢀ
ometry. The Ni–O and Ni–N bond lengths in the
ular Cu···Cu distance is 3.339(1) Å, indicating there
complex are comparable to the corresponding values
observed in other Schiff base nickel(II) complexes
with square planar geometies [17, 18]. In the crystal
structure of the complex, molecules are linked
through intermolecular N(1)–H(1)···I2i (N(1)–H(1)
exists strong metallophilic interaction. Each Cu atom
in the complex is in a squareꢀpyramidal coordination,
with the phenolate O, imine N, and amine N atoms of
the PMP ligand and one azide N atom defining the
basal plane, and with the other azide N atom occupyꢀ
ing the apical position. The deviations of the Cu(1)
and Cu(2) atoms from the leastꢀsquares planes defined
0.90(1), H(1)···I(2) 3.07(5), N(1)···I(2) 3.775(4)
Å
x
,
,
i
N(1)–H(1)···I(2) 137(5)°; symmetry code: 1 –
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
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SYNTHESES AND CRYSTAL STRUCTURES
707
Table 2. Selected bond lengths (Å) and angles (deg) for
structures and II
by the basal donor atoms are 0.101(2) and 0.140(2) Å,
I
respectively. The azide ligands adopt endꢀon bridging
mode. Significant distortion of the square pyramid is reꢀ
vealed by bond lengths and angles among the apical and
basal donor atoms. The apical Cu–N bond lengths are
much longer than usual; the other bond lengths are withꢀ
in normal ranges and comparable to the corresponding
values observed in other Schiff base copper(II) complexꢀ
es with azide bridges [19–21]. The bridging azide
groups are nearly linear and show bent coordination
Bond
d, Å
Bond
d, Å
I
Ni(1)–O(1)
1.833(3) Ni(1)–N(1)
II
1.847(4)
Cu(1)–O(1)
Cu(1)–N(2)
Cu(1)–N(8)
Cu(2)–N(3)
Cu(2)–N(4)
1.919(3) Cu(1)–N(1)
2.034(4) Cu(1)–N(5)
2.507(4) Cu(2)–O(2)
1.930(4) Cu(2)–N(8)
2.083(4) Cu(2)–N(5)
1.956(4)
2.004(4)
1.916(3)
2.000(4)
2.435(4)
with Cu atoms (N(5)N(6)N(7) 178.0(6)
Cu(1)N(5)N(6) 128.2(3) , N(8)N(9)N(10) 175.8(6)
Cu(2)N(8)N(9) 124.3(4) ).
In the crystal structure of the complex (Fig. 4), the
methanol molecule is linked to the dinuclear copper
complex molecule through intermolecular
N(2) H(2)···O(3) (N(2)–H(2) 0.90(1), H(2)···O(3)
1.98(2), N(2)···O(3) 2.871(6) , N(2)–H(2)···O(3)
174(6) ) hydrogen bond. In addition, the two
[Cu(PMP)] units are further linked via intramolecular
N(4)–H(4)···O(1) (N(4)–H(4) 0.90(1), H(4)···O(1)
1.97(2), N(4)···O(1) 2.849(5) , N(4)–H(4)···O(1)
164(5) ) hydrogen bond.
The middle and sharp band at 3298 cm–1 for
°,
°,
°
°
Angle
ω
, deg
Angle
ω
, deg
⎯
I
Å
O(1)Ni(1)N(1) 93.6(2)
°
II
O(1)Cu(1)N(1) 92.25(15) O(1)Cu(1)N(5) 89.03(15)
N(1)Cu(1)N(5) 173.96(18) O(1)Cu(1)N(2) 173.29(15)
N(1)Cu(1)N(2) 84.32(15) N(5)Cu(1)N(2) 93.80(16)
N(8)Cu(1)N(1) 103.63(16) N(8)Cu(1)N(2) 96.31(16)
N(8)Cu(1)N(5) 82.26(16) N(8)Cu(1)O(1) 90.09(16)
O(2)Cu(2)N(3) 92.86(16) O(2)Cu(2)N(8) 93.26(15)
N(3)Cu(2)N(8) 173.60(17) O(2)Cu(2)N(4) 164.13(16)
N(3)Cu(2)N(4) 82.14(17) N(8)Cu(2)N(4) 91.46(16)
O(2)Cu(2)N(5) 108.53(14) N(3)Cu(2)N(5) 95.62(16)
N(8)Cu(2)N(5) 84.23(16) N(4)Cu(2)N(5) 87.01(15)
Å
°
I
is asꢀ
signed to the N–H streching vibration. The weak and
broad band at 3435 cm–1 for II is assigned to the O–H
streching vibration of the methanol molecule. The
strong absorption bands at 1612 cm–1 for
I
and
1633 cm–1 for II are assigned to the azomethine
groups, (C=N). The phenolate (Ar–O) in the comꢀ
and
ν
ν
plexes exhibit middle bands at 1206 cm–1 for
1197 cm–1 for II. The intense band at 2038 cm–1 for II
is assigned to the stretching vibrations of the azide
ligands. The weak bands located at the low numbers
I
responding to the loss of the methanol molecule. The
observed weight loss of 4.1% is close to the calculated
may be assigned to the
ν
(M–O) and (M–N).
ν
Differential thermal (DT) and thermal gravimetric
analyses (TGA) were conducted to examine the stabilꢀ
ity of the azidoꢀbridged complex II (Fig. 5). The first
value of 4.4%. The second step, from 185 to 285
corresponds to the loss of the terminal benzene groups
C and was completed at 185°C, corꢀ of the Schiff base ligands and the azide ligands. The
°C,
step started at 91
°
I(1A)
C(7)
C(3A)
C(6)
N(1)
O(1A)
C(4A)
C(5)
C(4)
C(1)
C(2)
I(2)
C(2A)
C(5A)
Ni(1)
I(2A)
C(1A)
C(6A)
O(1)
C(3)
C(7A)
N(1A)
I(1)
Fig. 1. Molecular structure of
, 1 – , –
I at 30% probability displacement. Atoms labeled with the suffix A are at the symmetry position
⎯x
y
z.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39
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708
QIAN et al.
x
z
0
y
Fig. 2. Molecular packing structure of
I
, viewed along the
x
axis. Hydrogen bonds are shown as dashed lines.
C(5)
C(4)
C(28)
C(6)
C(29)
C(3)
C(30)
C(1)
C(7)
C(2)
C(27)
N(10)
N(9)
C(25)
N(1)
O(1)
C(26)
N(4)
C(8)
N(8)
C(24)
Cu(1)
Cu(2)
C(9)
N(2)
C(23)
C(22)
C(16)
N(3)
N(5)
O(2)
C(15)
C(31)
C(17)
C(10)
O(3)
N(6)
C(18)
C(14)
C(21)
C(19)
C(11)
N(7)
C(20)
C(13)
C(12)
Fig. 3. Molecular structure of II at 30% probability displacement. Hydrogen bonds are shown as dashed lines.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 39 No. 10
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SYNTHESES AND CRYSTAL STRUCTURES
709
of the Schiff base ligands, and the formation of the fiꢀ
nal product (CuO). The observed weight loss of 42.0%
in this step is close to the calculated value of 40.4%.
The total weight loss of 79.5% is close to the calculated
value of 78.0%.
x
z
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°
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