1
6
M. Mitra et al. / Polyhedron 61 (2013) 15–19
2
h, the reaction solution was evaporated under reduced pressure
Table 1
Crystal data and structure refinement parameters for 1 and 2.
to yield a gummy mass, which was dried under vacuum and stored
over CaCl
2
for subsequent use.
Formula
Formula weight
T (K)
C22H28N O Cu (1)
C26H32N O10Mn2 (2)
642.42
100.0(2)
0.71073
monoclinic
2
6
2
ꢁ4
ꢁ3
For catecholase activity study, 1 ꢀ 10 mol dm solutions of 1
480.00
295(2)
0.71073
tetragonal
I41/a
ꢁ2
ꢁ3
(
(
0.0004 g) and 2 (0.0006 g) were treated with 1 ꢀ 10 mol dm
100 equivalents) of 3,5-DTBC (0.0222 g) under aerobic conditions.
k (Å)
Crystal system
Space group
Unit cell dimensions
a (Å)
b (Å)
c (Å)
1
P2 /c
2.2. Physical measurements
30.5151(6)
30.5151(6)
4.55220(10)
90°
90°
90°
4238.88(15)
8
1.504
1.073
11.7101(14)
15.7540(16)
7.5998(8)
90.00
108.905(7)
90.00
1326.4(3)
2
1.609
Elemental analyses (carbon, hydrogen and nitrogen) were per-
formed on a Perkin-Elmer 2400 CHNS/O elemental analyzer. UV–
Vis and IR spectra (KBr discs, 4000–300 cm ) were recorded using
a Shimadzu UV–Vis 2450 spectrophotometer and Perkin–Elmer FT-
IR model RX1 spectrometer, respectively. The H NMR spectral data
were collected in CDCl
netic measurements were carried out in the ‘‘Servei de Magnet-
oquímica (Universitat de Barcelona)’’ on polycrystalline samples
a
(°)
b (°)
(°)
ꢁ1
c
3
1
V (Å )
Z
D
3
on a Bruker 400 MHz spectrometer. Mag-
calc (Mg/m3)
Absorption coefficient
1.014
ꢁ
1
(mm
)
F(000)
2008
664
(
30 mg) with a Quantum Design SQUID MPMS-XL magnetometer
3
Crystal size (mm )
Theta range for data
collection (°)
0.25 ꢀ 0.15 ꢀ 0.10
0.1 ꢀ 0.1 ꢀ 0.1
working in the 2–300 K range. The magnetic field was 0.1 T. The
diamagnetic corrections were evaluated from Pascal’s constants.
1.89–28.29
2.248–32.694
Index ranges
ꢁ40 6 h 6 39,
ꢁ37 6 k 6 40,
ꢁ16 6 h 6 17,
ꢁ23 6 k 6 16,
ꢁ11 6 l 6 7
2.3. Preparation of 1 and 2
ꢁ
6 6 l 6 6
Reflections collected
Independent reflections
Completeness to theta
Absorption correction
19278
12002
Compound
(OAc) O (0.0249 g, 0.125 mmol) into a stirring solution of
ꢂ2H
L (0.0262 g, 0.125 mmol) in a methanol–acetonitrile mixture
15 ml). The resulting light green colored solution was kept in
1 was prepared by the addition of solid
2624 (Rint = 0.0411)
99.9% (h = 28.29°)
multi-scan
0.9003 and 0.7753
full-matrix least-
squares on F2
2624/0/142
4592 (Rint = 0.0367)
99.3% (h = 32.03°)
multi-scan SADABS [17]
0.7469 and 0.6789
full-matrix least-
squares on F2
4592/0/183
Cu
2
4
2
H
2
Tmax and Tmin
(
Refinement method
the open air for slow evaporation. After 2–3 days, green crystals
of 1 were collected, washed with hexane and dried in vacuo over
silica gel indicator.
Data/restraints/
parameters
Yield: (based on metal salt) 0.0723 g (74.31%). Anal. Calc. for
Goodness-of-fit (GOF) on 1.029
F
1.029
2
C
5
1
4
22 28 2 6
H N O Cu (1): C, 54.80; H, 5.85; N, 5.81. Found: C, 54.69; H,
ꢁ1
Final R indices [I > 2
r
(I)]
R
1
= 0.0361,
wR = 0.0901
= 0.0537,
wR = 0.0987
0.492 and ꢁ0.418
R
1
= 0.0408,
wR = 0.0814
= 0.0646,
wR = 0.0894
0.641 and ꢁ0.558
.76; N, 5.88%. Selected IR bands (KBr pellet, cm ): 3283 (s),
625 (s), 1603 (s), 1545 (s). UV–Vis (k, nm, MeOH): 235, 290,
11, 601.
2
2
R indices (all data)
R
1
R
1
2
2
Largest difference in
peak and hole (e Åꢁ3)
To synthesize compound 2, a methanolic solution (5 ml) of
manganese(II) acetate tetrahydrate (0.0306 g, 0.125 mmol) was
added dropwise into a solution of H L (0.0262 g, 0.125 mmol) in
2
acetonitrile (10 ml) with constant stirring. The yellow solution of
the ligand turned dark brown and the supernatant liquid was kept
in the open air for slow evaporation. After 3–4 days, the dark
brown fine microcrystalline compound 2 separated out, was
washed with hexane and dried in vacuo over silica gel indicator.
Yield: (based on metal salt) 0.0328 g (81.79%). Anal. Calc. for
3
. Results and discussion
.1. Synthesis and formulation
The self-assembly of Cu(II) acetate dihydrate and the ligand H
3
2
L
26 32 2 2
C H N O10Mn (2): C, 48.61; H, 5.02; N, 4.36. Found: C, 48.52;
in methanol–acetonitrile afforded the tetracoordinated mononu-
clear complex 1. On changing the metal ion from copper(II) to
manganese(II), the hexacoordinated diacetato bridged dinuclear
manganese complex 2 was obtained using reaction between Mn(II)
ꢁ1
H, 4.98; N, 4.30%. Selected IR bands (KBr pellet, cm ): 3449 (s),
618 (s), 1599 (s), 1560 (s), 1440 (s), 1426 (m), 1401 (s). UV–Vis
k, nm, MeOH): 234, 277, 405.
1
(
2
acetate tetrahydrate and H L in methanol–acetonitrile medium,
where aerial oxidation converts Mn(II) to Mn(III).
The reactions are summarized as follows:
2
.4. X-ray diffraction study
Single crystals of 1 and 2 suitable for X-ray crystallographic
analysis were selected following examination under a microscope.
Diffraction data at 295(2) and 100 K for 1 and 2, respectively were
collected on Bruker SMART APEX II CCD and Bruker AXS Kappa
II
Cu
2
ðOAcÞ ꢂ2H
2
Oþ4H
2
Lꢁ! 2½Cu ðHLÞ ꢃþ4CH
2
3
COOHþ2H
2
O
4
2
III
2
2MnðOAcÞ ꢂ4H
2
Oþ2H
Lꢁ! ½ Mn ðl1;3-OAcÞ2L
2
ꢃþ2CH COOHþ8H
3
2
O
2
APEX II CCD diffractometers using Mo
k = 0.71073 Å). The crystal data and refinement details are listed
in Table 1. 1 and 2 were identified as crystallizing in the I 4 /a
and P2 /c space groups, respectively. The structures were solved
K
a
radiation
(
The new complexes were characterized by microanalytical (C, H
and N), spectroscopic and other physicochemical results. The
microanalytical data are in good conformity with the formulations
of 1 and 2. The moisture insensitive complexes are stable over long
periods of time in powdery and crystalline states, and are soluble
in methanol, ethanol, dimethyl formamide and dimethyl sulfoxide,
but are insoluble in water. In the IR spectra, relatively intense
1
1
by direct methods, and the structure solution and refinement were
2
based on |F| . The final differences Fourier map showed the maxi-
ꢁ3
mum and minimum peak heights at 0.492 and ꢁ0.418 eÅ for 1
and 0.641 and ꢁ0.558 for 2, with no chemical significance. All cal-
culations were carried out using SHELXL-97 [11] and were refined
using SHELSL-97 [11], available within the OLEX-2 [12] suite of pro-
grams. All the figures were generated using ORTEP-32 [13].
ꢁ
1
peaks around 1590–1600 cm
due to the C@N stretching fre-
ꢁ
1
quency and weak bands in the range 2980–2900 cm due to the
aliphatic C–H stretching frequency appear in both the complexes.