Manganese(II) coordination polymer having pyrazine and μ-phenolato bridging: Structure, magnetism and biological studies

Article abstract of DOI:10.1016/j.ica.2016.01.013

The manganese(II) coordination polymer, {[Mn(L)(pyz)]ClO₄·2(H₂O)}n. (1) has been synthesized from a mixture of Mn(ClO₄)₂·6H₂O, Schiff base HL (derived from the condensation of 4-aminoantipyrine and sa

Full text of DOI:10.1016/j.ica.2016.01.013

Inorganica Chimica Acta 443 (2016) 224–229
Contents lists available at ScienceDirect
Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Manganese(II) coordination polymer having pyrazine and
bridging: Structure, magnetism and biological studies
l-phenolato
Subrata K. Dey a, , Madhumita Hazra , Laurence K. Thompson , Animesh Patra
⇑
a
b
c
a
Department of Chemistry, Sidho-Kanho-Birsha University, Purulia 723 104, WB, India
Department of Chemistry, Memorial University, St. John’s, Newfoundland A1B 3X7, Canada
Department of Chemistry, Midnapore College, Midnapore 721101, WB, India
b
c
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 30 May 2015
Received in revised form 26 November 2015
Accepted 6 January 2016
Available online 12 January 2016
The manganese(II) coordination polymer, {[Mn(L)(pyz)]ClO Á2(H O)}n. (1) has been synthesized from a
4
2
mixture of Mn(ClO
4
2
) Á6H
2
O, Schiff base HL (derived from the condensation of 4-aminoantipyrine and sal-
icylaldehyde) and pyrazine (pyz). Its molecular structure was determined by single crystal X-ray diffrac-
tion, which reveals that the polymeric structure consists of simultaneous Mn–Pyz–Mn and Mn–O
(
phenoate)–Mn bridges between the metal centers. Variable temperature magnetic studies give
À1
g = 2.037(4), J = À1.90(4) cm , # = 0.5 K values, using a simple dinuclear Mn–Mn model, and indicates
that the major exchange pathway is via the two phenoxide bridges and the pyrazine has little influence.
The coordination polymer also shows enhanced antibacterial activity compared with the standard antibi-
otic levofloxacin.
Keywords:
Manganese (II) coordination polymer
Crystal structure
Magnetism
Antibacterial studies
Ó 2016 Elsevier B.V. All rights reserved.
1
. Introduction
The crystal engineering of solid-state materials is of ever
between metal centers to form 1-D chain and 2-D square-grid
polymers with a wide variety of structural types with transition
metals [17,18]. Crystal structure reports based on aminoantipyrine
Schiff bases are very limited. Instead of many compounds in the lit-
erature including two monomeric Cu(II) [19] structure with
aminoantipyrine based Schiff base ligand, our search on the CCDC
shows no crystal structure of Mn(II) has been reported so far and
the structures of those entire complexes are elucidated only with
spectroscopic evidence except the above mentioned Cu(II) com-
plexes. This report documents the first structurally characterized
Mn(II) coordination polymer with an antipyrine based ligand,
and also includes a discussion of its magnetic properties and
antibacterial studies.
increasing interest to chemists and material scientists alike [1].
The main goal has been to determine the topology (i. e. 1-, 2- or
3
-dimensional structure) formed by a given set of components
by the selection of metal nodes and multifunctional ligands [2–
]. Heterocyclic phenazones and their derivatives are known to
4
act as monodentate, bidentate or tridentate ligands when coordi-
nated to metal ions [5–7]. Transition metal complexes of Schiff
bases are of growing importance in co-ordination chemistry, attri-
butable to recent observations in antibacterial, antifungal and oxy-
gen carrier properties and of those aminopyrines are commonly
administered intravenously to detect liver disease [8] in clinical
treatment. Also, they are particularly interesting as promising
ligands for the building of polynuclear complexes as models to
bioinorganic systems [9] as well as some interesting catalytic
2. Experimental
2.1. Materials
[
10] and physicochemical properties [11], such as electrical con-
ductivity [10] and magnetism [12]. The ability of pyrazine (pyz)
to act as exo-bidentate ligands is well established [13–16]. It is a
good candidate for designing and synthesizing oligomeric and
polymeric complexes because of their good bridging ability [17].
Many examples exist where pyz acts as a linear rod-like spacer
All chemicals and solvents used for the synthesis were of ana-
lytical grade, and were purchased from E. Merck, India and used
as received without further purification.
2.2. Synthesis of the ligand (HL) and the coordination polymer {[Mn(L)
(
4
pyz)]ClO Á2(H
2
O)}n (1)
⇑
Corresponding author. Tel.: +91 0947455 7873; fax: +91 3252 202419.
E-mail address: skdusask@yahoo.ca (S.K. Dey).
1:1 equimolar methanolic solution (40 ml) of 4-aminoan-
tipyrine (0.406 g, 2 mmol) and salicyaldehyde (0.19 ml, 2 mmol)
http://dx.doi.org/10.1016/j.ica.2016.01.013
020-1693/Ó 2016 Elsevier B.V. All rights reserved.
0

S.K. Dey et al. / Inorganica Chimica Acta 443 (2016) 224–229
225
were mixed and refluxed at 45 °C for 2 h with constant stirring. The
characteristic yellow precipitate obtained by Schiff base (Scheme 1)
condensation was filtered out and kept for crystallization by dis-
solving in dichloromethane/methanol (1:1) mixture. Fine yellow
crystals were obtained upon slow evaporation at room tempera-
thermal parameters. Molecular graphics, crystallographic illustra-
tions, and publication materials were prepared using ORTEP [23],
CAMERON [24], WinGX [25], software. Further crystallographic data
and structure refinement parameters of the coordination polymer
are summarized in Table 1. Selected bond distances and bond
angles for the coordination polymer are given in Table 2. Powder
X-ray data was recorded using a XRD, PW 1710, Philips, Holland
ture after 12 h. Yield: 85%, ES [MSI] Calc for C18
) = 308.34. Found = 309.46. Anal. Calc. for C18
H, 5.57; N, 13.67. Found: C, 70.06; H, 5.59; N, 13.56%. A methanolic
solution of Mn(ClO O (1 mmol, 0.33 g, 30 ml) was slowly
H
17
N
3
O
2
(m/z + H
+
H
17
3
N O
2
: C, 70.34;
(
Cu Ka radiation, k = 1.5406 Å) diffractometer.
4
)
2
Á4H
2
added to a methanolic solution of HL (1 mmol, 0.308 g, 20 ml).
2.5. Biological studies
The pH of the solution was adjusted to ꢀ6 by adding a few drops
4 4
of NH OH/HClO (2/1). After stirring for 25 min in air, the mixture
The antibacterial activities of the Mn (II) coordination polymer
have been studied by agar disc diffusion method. The antibacterial
activities were done at 100 and 200 g/mL concentrations of com-
was placed into a round bottom flask containing pyrazine (1 mmol,
0
.09 g, 10 ml) and refluxed in a temperature controlled oil bath at
l
8
0 °C for 24 h. The reaction mixture was cooled to room tempera-
pound in DMF solvent by using two pathogenic gram negative bac-
teria (Shigella flexneri and Proteus mirabilis) and two gram positive
pathogenic bacteria (Bacillus cereus and Bacillus subtilis). The bacte-
ria were cultured for 24 h at 37 °C in an incubator. The agar med-
ium was prepared and autoclaved at 121 °C for 15 min. The
autoclaved medium was mixed well and poured onto a pre-
sterilized Petridis. Petri dishes containing nutrient Muller Hinton
medium were seeded with 24 h culture of bacterial strains using
sterile L-rod. Wells were punched using a sterile cork borer and
the solution of Mn (II) coordination polymer was added from stock
ture, and filtered. Rectangle shaped light brown colored crystals of
1
suitable for X-ray diffraction were obtained after 10 days by slow
evaporation of the filtrate and washed by dry methanol and air
dried. Yield: 0.260 g (30%). Crystallinity of the bulk product was
confirmed from the comparisons with powder X-ray data
(Figs. S7–S9). Anal. Calc. for [C22
8 5
H25MnClO N ]: C, 45.72; H, 4.36;
N, 12.12. Found: C, 46.12; H, 4.23; N, 13.11 (%).
2.3. Physical studies
Elemental analyses (carbon, hydrogen, nitrogen) were per-
formed using a Perkin-Elmer 240 C elemental analyzer. FT-IR spec-
trum in KBr (4000–400 cm ) was recorded using a Perkin-Elmer
Table 1
À1
Crystal Structure parameters for 1.
RX I FT-IR spectrophotometer. Thermogravimetric analyses were
1
carried out with a heating rate of 10 °C/min with a Mettler-Toledo
e
Empirical formula
Formula weight
Crystal system
Space group
a (Å)
C22H21MnClN O6
541.83
triclinic
P1
8.465(3)
9.980(4)
15.786(6)
82.440(10)
74.735(9)
65.166(9)
1167.3(7)
2
293(2)
0.71073
1.542
0.729
556
11299
4100
2081
0.0989
1.005
R
R
5
Star TGA/SDTA-851 thermal analyzer system in a dynamic atmo-
À1
sphere of N
2
(flow rate 80 mL min ), the sample was in an alu-
mina crucible, and the temperature range was 25–550 °C.
Variable-temperature magnetic data (2–300°K) were obtained
using a Quantum Design MPMS5S SQUID magnetometer using a
field strength of 0.1 T. Background corrections for the sample
holder assembly and diamagnetic components of the complexes
were applied.
ꢀ
b (Å)
c (Å)
a
(°)
b (°)
(°)
c
3
V(Å )
Z
2.4. X-ray data collection and structure refinement
T (K)
k
D
l
Mo Ka
(Å)
À3
c
(g cm )
Diffraction quality single crystal of compound 1 with dimension
À1
(mm
)
(
0.18 Â 0.15 Â 0.12 mm) was mounted on a ‘‘Oxford Xcalibur”
diffractometer equipped with a graphite monochromated fine
focus Mo sealed tube (kMo K = 0.71073 Å). Data collection was per-
formed at 293(2) K temperature using scan technique. Data col-
lection and unit cell refinement were carried out using CrysAlisPro
20] while data reduction was performed using CrysAlis Red [21]
F(000)
Total data
Unique data
Observed data [I > 2
a
x
r
(I)]
R
int
Goodness-of-fit (GOF) on F2
[
= 0.0719, wR2 = 0.2284
= 0.1462, wR2 = 0.1783
Final R indices [I > 2
R indices (all data)
r
(I)]
1
programs. Multiscan absorption corrections were applied empiri-
cally to the intensity values (Tmax = 0.877, Tmin = 0.916) using
CrysAlis RED [21]. The molecular structure was solved by direct
methods using program SHELXS-97 [22] combined to Fourier differ-
ence synthesis and refined with full matrix least square technique
1
(a)R =
|, (b)
w
2
|2]}½.
R
(|F
o
À F
c
|)/
R
|F
o
R
= {
R
[w(|F
o
À F
c
|) ]/R[w|F
o
2
based on F using program SHELXL-97 [22]. Non-hydrogen atoms
Table 2
Bond lengths (Å) and bond angles (°) of 1.
were refined with anisotropic thermal parameters. Water hydro-
gen atoms were geometrically fixed and refined with isotropic
Mn(1)–O(6) 2.159(5) Mn(1)–O(5) 2.089(5) Mn(1)–N(1)
2.344(5)
Mn(1)–N(5) 2.278(6) Mn(1)–N(3) 2.236(6) Mn(1)–O(5)c 2.173(4)
O(6)–Mn(1)–O(5)
O(6)–Mn(1)–N(5)
O(6)–Mn(1)–O(5)c
O(5)–Mn(1)–N(5)
O(5)–Mn(1)–O(5)c
N(1)–Mn(1)–N(3)
N(5)–Mn(1)–N(3)
N(3)–Mn(1)–O(5)c
161.0(2)
92.1(2)
O(6)–Mn(1)–N(1)
O(6)–Mn(1)–N(3)
O(5)–Mn(1)–N(1)
O(5)–Mn(1)–N(3)
N(1)–Mn(1)–N(5)
N(1)–Mn(1)–O(5)c
N(5)–Mn(1)–O(5)c
88.9(2)
79.4(2)
CH3
N
99.32(18)
106.9(2)
80.87(16)
90.45(19)
169.11(19)
98.10(18)
93.76(19)
81.75(18)
82.53(18)
169.1(2)
89.92(17)
N
N
O
HO
Scheme 1.
Symmetry operations: x, y, z and Àx, Ày, Àz.

2
26
S.K. Dey et al. / Inorganica Chimica Acta 443 (2016) 224–229
solution. The inoculated plates were incubated for 24 h at 37 °C.
After incubation, the diameter of the inhibition zone was measured
and the results were recorded in millimeters (mm). The DMF sol-
vent was used as a negative control whereas media with levoflox-
acin (standard antibiotic) was used as the positive controls. The
experiments were performed in triplicate.
non-coordinated perchlorate. The
m
C–O (phenolic) stretching fre-
À1
quency of the ligand is observed around 1329 cm and is shifted
À1
to lower frequency by ꢀ35 cm in the complex indicating coordi-
À1
nation of phenolic oxygen. A band at 1654 cm in the free ligand
is due to mC@O stretching, which is shifted to lower frequency by
À1
ꢀ43 cm in the coordination polymer, suggesting the coordina-
tion of the ligand to the metal ion via the phenolic C–O group
[
5
[
27]. The two bands appearing in the low frequency range around
3
. Result and discussion
À1
À1
70 cm and 500 cm are due to
m
Mn–O and
mMn–N respectively
À1
28]. The peaks observed at 475–490 cm , are particularly diag-
3.1. Infrared studies
nostic of bridging bidentate pyrazine ligand.
IR spectrum of the ligand displayed a medium intensity band
3
.2. Thermal studies
À1
around 1600 cm due to
m
C@N. The characteristic shifting to lower
À1
frequency region to the extent ꢀ25 cm in the coordination poly-
mer, indicates that the nitrogen of the azomethine group is coordi-
nated to the metal ion. The broad bands of coordination polymer in
It is observed from the TGA curve (Fig. S6) that on heating under
non-isothermal conditions complex 1 loses two molecules of water
in the temperature range 90–110 °C. Then it undergoes decompo-
sition and loses one molecule of pyrazine in the temperature range
À1
the range of 3150–3600 cm indicate the presence of lattice water
À1
molecules [26]. A major band at 1095 cm is in agreement with
1
45–210 °C. Upon further heating it was observed that the coordi-
nation polymer 1 is decomposed within the temperature range
50–515 °C. The decomposition residue (black) is identified as
MnO , which is confirmed by a qualitative test (see Supplementary
file, Fig. S5).
2
2
3.3. Crystal structure
Suitable crystals of compound 1 were grown from methanolic
solution at room temperature. Single crystal X-ray diffraction
ꢀ
showed that the compound 1 crystallizes in P1 space group. Crystal
structure determination of 1 shows that asymmetric unit (Fig. 1)
altogether consists of a Mn(II) center possesses distorted octahe-
dral geometry with N O donor atoms coordinating from two Schiff
3 3
base ligands and two different bridging pyrazine molecules (Fig. 2).
The ligand binds to the Mn(II) ion in a tridentate fashion through
one deprotonated phenolic oxygen, one coordinated oxygen from
the antipyrine exocyclic five membered ring and one nitrogen of
the azomethine group. The fourth coordination site of each Mn
(
II) ions is occupied by another deprotonated phenolic moiety
coming from a second Schiff base ligand acting as a bridging phe-
nolate group. The fifth and sixth coordination sites of each Mn(II)
Fig. 1. Asymmetric unit of 1.
Fig. 2. Coordination modes of ligands to manganese(II) atoms in 1.

S.K. Dey et al. / Inorganica Chimica Acta 443 (2016) 224–229
227
Fig. 3. Packing diagram of 1 viewed along b axis.
ions are occupied by two different bridging pyrazine molecules.
One interesting point to be noted is that despite the rigidity and
the steric strain imposed by the methyl substitution on the anti-
pyrine moiety the ligand acts in a tridentate fashion. The extended
structure of complex shows a rectangularly ordered hexa-man-
ganese core bridged by two different types of bridging moiety, phe-
nolate oxygen and pyrazine nitrogen atoms, with two arms
0
.5
9
8
7
6
5
4
3
2
0.4
0
0
.3
.2
(
MnÁ Á ÁMn separation) of 7.325 and 10.015 Å respectively and a
Mn–Pyz–Mn and Mn–Mn–Mn angle of 176.99 and 134.29° respec-
tively. In such manner it produces a polymeric grid like projection
(Fig. 3), which shows the rigidity of the system. In the longest arm
0.1
of the rectangular arrangement there are two different types of
bridging, one with pyrazine and another with two phenolate
groups from two different ligand moieties giving rise two different
types of Mn–Mn distances, 3.244 Å and 7.245 Å respectively, a sum
of 10.489 Å. The bridging phenolate oxygen produces the Mn–Mn
distance of 3.244 Å and Mn–O–Mn angles of 99.12°, which are
0
.0
0
50 100 150 200 250 300 350
Temp (K)
+
4
Fig. 4. Magnetic data of compound 1 recorded in the temperature range 2–300 K.
higher than normally seen in planar [Mn
2
(l-O)
2
]
species, which
À1
The solid line corresponds to a fit with g = 2.037(4), J = À1.90(4) cm
, q = 0.005,
usually have values of >2.7 Å and >97° respectively [29,30]. Bond
valence sum calculations indicate that the oxidation states of all
manganese atoms are Mn(II) [31]. The Mn–N distances (Mn1–N1,
2
h = 0.5 K, 10 R = 1.62 (Hex = ÀJ{S
1
ÁS
2
}; S = 5/2).
the slight shoulder in the susceptibility profile at low temperature.
Examining the structure the dominant feature which would lead to
such behavior is the repeating dinuclear Mn (l -O) subunit, with
2 2 2
a short Mn–Mn distance and a Mn–O–Mn angle of 99.1°. Such phe-
nolate bridge angles typically lead to antiferromagnetic exchange
2
.334 Å, Mn1–N5, 2.278 Å, Mn1–N3, 2.237 Å) and Mn–O (Mn1–
O6, 2.159 Å, Mn1–O5(c), 2.173 Å, Mn1–O5, 2.089 Å) are well
within the range reported for related Schiff base complexes of
Mn(II) [32].
[
33]. Further bridging connections in the 2D structure from the
pyrazine groups are expected to lead to weak, and perhaps
insignificant exchange. Consequently the magnetic data were fit-
ted to a simple model based on a dinuclear exchange Hamiltonian
3.4. Magnetic studies
Variable temperature magnetic data were obtained for 1 in the
(Hex = ÀJ{S
1
ÁS
2
}; S = 5/2). A good fit was obtained with g = 2.037(4),
À1
2
range 2–300 K, and are shown in Fig. 4 as plots of molar suscepti-
bility and moment as a function of temperature. The characteristic
drop in moment on lowering the temperature indicates
intramolecular antiferromagnetic exchange. This is mirrored by
J = À1.90(4) cm
,
;
q
q
= 0.005, # = 0.5 K, 10 R = 1.62 (R = [
= fraction paramagnetic impurity, # = Weiss
r (v
obs
P
2
2
1/2
À
v
calc) /
v
obs
]
correction). Given the good fit extracting further exchange
information from more elaborate models including longer range

2
28
S.K. Dey et al. / Inorganica Chimica Acta 443 (2016) 224–229
Fig. 5. Antibacterial activity of coordination polymer 1 at 100 and 200
lg/mL concentrations DMF solvent by using two pathogenic gram negative bacteria (Shigella flexneri
and Proteus mirabilis) and two gram positive pathogenic bacteria (Bacillus cereus and Bacillus subtilis).
connections was not attempted. The Weiss correction (h) implies
possible weak ferromagnetic inter-dinuclear exchange behavior,
presumably occurring via the long pyrazine connections.
may also be extended to UGC, New Delhi, India for financial
assistance.
Appendix A. Supplementary material
3.5. Antibacterial activity
CCDC 1059136 contains 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.
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.ica.2016.01.013.
Antibacterial activity of the coordination polymer is given in
Fig. 5. Antibacterial activity of Mn(II) polymer with respect to stan-
dard levofloxacin antibiotic against gram-positive (B. cereus and B.
subtilis) and gram-negative (S. flexneri and P. mirabilis) bacteria
were studied. The obtained results evidently showed that the coor-
dination polymer have good antibacterial effects against the stud-
ied bacterial strains except B. subtilis. The activity of the metal
chelates can be explained by overtone concept and the Tweedy
chelation theory. The variation in the activity of coordination poly-
mer against some different organisms depend either on the imper-
meability of the cells of the microbes or difference in ribosome of
microbial cells. The lipid membrane surrounding the cell favors
the passage of any lipid soluble materials and it is known that
liposolubility is an important factor controlling antimicrobial
activity. On chelation, the polarity of the metal ion will be reduced
to a greater extent due to the overlap of the ligand orbital and par-
tial sharing of the positive charge of the metal ion with donor
References
[
1] (a) D. Braga, F. Grepioni, G.R. Desiraju, Chem. Rev. (1998) 1375;
b) D. Braga, Acc. Chem. Res. 33 (2000) 601.
(
[
2] (a) N.S. Persky, J.M. Chow, K.A. Poschmann, N.N. Lacuesta, S.L. Stoll, S.G. Bott, S.
Obrey, Inorg. Chem. 40 (2001) 29;
(
b) S. Subramanian, M.J. Zaworotko, Angew. Chem., Int. Ed. Engl. 34 (1995)
127;
c) M. Ward, Nature 374 (1995) 764.
[3] (a) D. Venkataraman, S. Lee, J. Moore, P. Zhang, Chem. Mater. 8 (1996) 2030;
b) H. Li, M. Eddaoudi, M. O’Keeffe, O.M. Yaghi, Nature (London) 402 (1999)
76.
2
(
(
2
[
4] (a) Y. Dong, M. Smith, R. Layland, H. Loye, Chem. Mater. 12 (2000) 1156;
(b) G. Guilera, J.W. Steed, Chem. Commun. (1999) 1563;
groups. Further, it increases the delocalization of p-electrons over
(
c) O.H.S.L. Al-Obaidi, Bioinorg. Chem. Appl. (2012) 1.
the whole polymer and enhances the lipophilicity of the coordina-
tion polymer. This increased lipophilicity helps the penetration of
the bacterial cell membranes and blocks the metal binding sites
in enzymes of microorganisms and restricts further growth of the
microorganisms. The Mn (II) coordination polymer shows no anti
bacterial activity against B. subtilis due to lower impermeability
of the bacterial cells.
[
5] M. Sönmez, I. Berber, E. Akbas, Eur. J. Med. Chem. 41 (2006) 101.
[
6] S.M.E. Khalil, H.S. Seleem, B.A. El-Shetary, M. Shebl, J. Coord. Chem. 55 (2002)
883.
[7] M. Weitzer, S. Brooker, Dalton Trans. 14 (2005) 2448.
8] (a) I. Costova, L. Saso, Curr. Med. Chem. 20 (2013) 4609;
b) D. Chiaramonte, J.M. Steiner, J.D. Broussard, K. Baer, S. Gumminger, E.M.
Moeller, D.A. Williams, R. Shumway, Can. J. Vet. Res. 67 (2003) 183.
[9] (a) S. Kawata, H. Kumagai, K. Adachi, S. Kitagawa, J. Chem. Soc., Dalton Trans.
[
(
(
(
2000) 2409;
b) A.N. Evstopov, V.E. Yavorovskaya, E.S. Vorobev, Z.P. Kudonogova, L.N.
Gritsenko, E.N. Schmidt, S.G. Medevedeva, D.V. Filimonov, T.P. Prishchep, A.S.
Saratikov, Pharm. Chem. J. 26 (1992) 426.
4
. Conclusion
[
[
10] (a) A. Togni, L.M. Venanzi, Angew. Chem., Int. Ed. Engl. 33 (1994) 497;
(b) R.A. Heinz, H. Zhao, X. Ouyang, G. Grandinetti, J. Cowen, K.R. Dunbar, Inorg.
Chem. 38 (1999) 144.
Here, we present the synthesis, crystal structure, low-tempera-
ture magnetic study and antibacterial activity of one doubly
bridged Mn(II) coordination polymer. From the forgoing discus-
sion, it is found that the two phenoxo groups of two Schiff bases
and two pyrazine groups coordinate to two manganese(II) centers.
The coordination polymer shows moderate antiferromagnetic
behavior and the magnetic interaction is dependent predominantly
on the phenoxo bridges between the two manganese(II) centers.
The coordination polymer also shows enhanced antibacterial activ-
ity compared with standard antibiotic levofloxacin.
11] (a) M. Fujita, Y.J. Kwon, S. Washizu, K. Ogura, J. Am. Chem. Soc. 116 (1994)
1151;
(b) T.N. Sorrell, V.A. Vankai, M.L. Garrity, Inorg. Chem. 30 (1991) 207.
12] J.S. Miller, A.J. Epstein, Angew. Chem., Int. Ed. Engl. 33 (1994) 385.
13] (a) L. Carlucci, G. Liani, D.M. Proserpie, A. Sironi, J. Am. Chem. Soc. 117 (1995)
[
[
4562;
(b) C.R. Choudhury, S.K. Dey, S. Sen, B. Bag, S. Mitra, V. Gramlich, Z.
Naturforsch. 57b (2002) 1191.
[
14] L. Carlucci, G. Ciani, D.M. Proserpio, A. Sironi, Angew. Chem., Int. Ed. Engl. 34
(
1995) 1895.
[15] I.G. Filippova, I.L. Malaestean, S.G. Baca, Z. Anorg, Allg. Chem. 640 (2014).
[
16] (a) A. Das, I. Todorov, S.K. Dey, S. Mitra, Inorg. Chim. Acta 359 (2006) 2041;
c) A.J. Blake, N.R. Chanpress, A.N. Khlobystov, S. Parsons, M. Schröder, Angew.
(
Acknowledgements
Chem., Int. Ed. Engl. 39 (2000) 2317.
[
[
17] B.Q. Ma, S. Gao, J. Yi, G.X. Xu, Polyhedron 20 (2001) 1255.
18] K. Adachi, Y. Sugiyama, H. Kumagai, K. Inoue, S. Kitagawa, S. Kawata,
Polyhedron 20 (2001) 1411.
We thank the CSIR, New Delhi, India for financial assistance to
Dr. S. K. Dey (Ref. No. 01(2458)/EMR-II dt 16.05.2011). Thanks
[19] P.M. Selvakumar, E. Suresh, P.S. Subramanian, Polyhedron 26 (2007) 749.

S.K. Dey et al. / Inorganica Chimica Acta 443 (2016) 224–229
229
[
[
20] Agilent Technologies, CrysAlisPro Software System, Version 1.171.33.31.
Aglient Technologies UK Ltd., Oxford, UK (2012).
21] Agilent Technologies, Crysalis CCD and Crysalis RED Software System, Aglient
Technologies UK Ltd., Oxford, UK (2012).
[28] (a) K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination
Compounds, third ed., Interscience-Wiley, New York, 1978. p. 233;
(b) S.K. Dey, M.S. El. Fallah, J. Ribas, T. Matsushita, V. Gramlich, S. Mitra, Inorg.
Chim. Acta 357 (2004) 1517;
[
[
[
22] G.M. Sheldrick, Acta Crystallogr. 64A (2008) 112.
23] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565.
24] D.J. Watkin, C.K. Prout, L.J. Pearce, CAMERON, Chemical Crystallography
Laboratory, University of Oxford, UK, 1996.
(c) K.A. Kumar, K.L. Reddy, S. Satyanaryana, Spectrosc. Lett. 44 (2011) 27.
[29] L. Que, A.E. True, Prog. Inorg. Chem. 38 (1990) 97.
[30] N.A. Law, J.W. Kampf, V.L. Pecoraro, Inorg. Chim. Acta 297 (2000) 252.
[31] G.J. Palenik, Inorg. Chem. 36 (1997) 122.
[
[
25] L.J. Farrugia, J. Appl. Crystallogr. 32 (1999) 837.
26] (a) A.A. Soliman, G.G. Mohamed, Thermochim. Acta 421 (2004) 151;
[32] (a) B. Mabad, P. Casuoux, J.P. Tuchagues, D.N. Hendrickson, Inorg. Chem. 25
(1986) 1420;
(
b) L. Lindoy, W.E. Moody, D. Taylor, Inorg. Chem. 16 (1977) 1962.
(b) S.K. Dey, L.K. Thompson, L.N. Dawe, Chem. Commun. (2006) 4967.
[33] L.K. Thompson, S.K. Mandal, S.S. Tandon, J.N. Bridson, M.K. Park, Inorg. Chem.
35 (1996) 3117.
[
27] (a) T. Radmakrishnan, P.T. Joseph, C.P. Prabhakaran, J. Inorg. Nucl. Chem. 38
(
(
1976) 2217;
b) G. Shankar, R.R. Premkumar, S.K. Ramalingam, Polyhedron 5 (1986) 991.