Synthesis, crystal structure, and electrochemical properties of two new manganese complexes with a ligand derived from 1,2-propanediamine and 2-hydroxy-5-methoxybenzaldehyde

Article abstract of DOI:10.1080/15533174.2012.740740

Two new homo binuclear manganese(III) complexes, [Mn(L)(H ₂O)]₂(PF₆)₂, where [H₂ L = N,N′-Bis(2-hydroxy-5-methoxybenzylidene)-propane-1,2-diamine] have been prepared by reaction of N,N′-bis(2-hydroxy-

Full text of DOI:10.1080/15533174.2012.740740

This article was downloaded by: [Florida State University]
On: 21 June 2013, At: 00:39
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, Crystal Structure, and Electrochemical
Properties of Two New Manganese Complexes With
a Ligand Derived From 1,2-Propanediamine and 2-
Hydroxy-5-Methoxybenzaldehyde
Mohammad Hossein Habibi a & Elham Askari a
a Department of Chemistry, University of Isfahan, Isfahan, I. R. Iran
Accepted author version posted online: 04 Dec 2012.Published online: 26 Feb 2013.
To cite this article: Mohammad Hossein Habibi & Elham Askari (2013): Synthesis, Crystal Structure, and Electrochemical
Properties of Two New Manganese Complexes With a Ligand Derived From 1,2-Propanediamine and 2-Hydroxy-5-
Methoxybenzaldehyde, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 43:4, 400-405
To link to this article: http://dx.doi.org/10.1080/15533174.2012.740740
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions
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.
The publisher does not give any warranty express or implied or make any representation that the contents
will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should
be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims,
proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in
connection with or arising out of the use of this material.

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 43:400–405, 2013
Copyright ꢀ Taylor & Francis Group, LLC
C
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2012.740740
Synthesis, Crystal Structure, and Electrochemical
Properties of Two New Manganese Complexes
With a Ligand Derived From 1,2-Propanediamine
and 2-Hydroxy-5-Methoxybenzaldehyde
Mohammad Hossein Habibi and Elham Askari
Department of Chemistry, University of Isfahan, Isfahan, I. R. Iran
catalyst in oxidative addition reactions.[1–6] A bimetallic core is
Two new homo binuclear manganese(III) complexes, [Mn
(L)(H2O)]2(PF6)2, where [H2L = N,Nꢀ-Bis(2-hydroxy-5-methox-
ybenzylidene)-propane-1,2-diamine] have been prepared by
reaction of N,Nꢀ-bis(2-hydroxy-5-methoxybenzylidene)propane-
1,2-diamine as a Schiff-base ligand, manganese(II) acetate and
ammonium hexafluorophosphate. The complexes were charac-
terized by spectral, structural and electrochemical studies. X-ray
structural analysis shows the presence of dimanganese core in the
complexes and the binding of the ligands to the manganese(III)
is through N2O2. The dimeric unit is formed by a double Mn–O
bridge of one molecule with its centrosymmetric homologue.
The crystal structure of the complexes indicates that in the
solid state the complex adopts an octahedral environment of the
imine N and hydroxo O with the one axial H2O ligand around
manganese. There are two coordination/chelation environments
present around two manganese centers of each binuclear complex.
The electronic spectra of the complex show red shift in the d–d
transition. The electrochemical reduction of these complex at
a glassy carbon electrode in acetonitrile solution indicates that
the first reduction process corresponding to Mn(III)–Mn(II)
used as an active site for metalloenzymes in biological systems.
Bimetallic Schiff-base complexes of different structural types
have new applications and biological activities.[7–10] Design and
synthesis of multidentate Schiff-base ligands and their dinuclear
complexes have been an interesting area of research because of
their importance in basic and applied chemistry. Particular inter-
est has developed in dinuclear complexes as models for metallo-
proteins.[11,12] Schiff-base complexes offer numerous attractive
properties, such as electron transport, high thermal stability,
and light emission. Organic light emitting diodes have received
enormous attention and become an active field of research be-
cause of their potential applications in flat panel displays.[13–19]
The multidenate binucleating Schiff-bases can take up two same
or different metal ions. Multidentate binucleating Schiff-bases
are reported to form binuclear transition metal complexes.[20–28]
There are only a limited number of dinuclear manganese com-
plexes.[29,30] Differential thermal gravimetry (DTG) and ther-
mogravimetry (TG) are useful to study the modes of thermal
decompositions as well as the composition of some metal com-
plexes of Schiff-bases.[31] Several researches have proposed that
the redox potential in Schiff-base complexes is directly related
to chemical characteristics of the entire complex. Thus, there has
been a strong interest in determining thermodynamically mean-
ingful redox potentials of manganese Schiff-base complexes and
in understanding the relationship between these potentials and
the detailed structure of the Schiff-base ligand.[32–34] We have
focused part of our research program on design of new transi-
tion metal complexes,[35–38] which constitute one of the more
versatile systems in order to mimic biological and industrial
catalyses.
is electrochemically quasireversible in the range of
0 to
−1.0 V.
Keywords binuclear complexes, crystal structure, electrochemical
study, manganese(III), homo-dinuclear complexes, N2O2
donors thermal study, UV–vis spectroscopy
INTRODUCTION
Multidentate Schiff-base ligands played vital role as chelat-
ing in the transition metal coordination chemistry. Transition
metal complexes of multidentate Schiff-base ligands find appli-
cations as model analogues of certain metal enzymes, modifier
for selective electrodes, applications in material chemistry, and
In the present research article, we wish to report the
structural and electrochemical investigations of two new
tetradentate binuclear Schiff-base complex of manganese.
The ligand was prepared by the condensation of 2-hydroxy-
5-methoxybenzaldehyde, as starting material, with propane-
1,2-diamine to afford the corresponding Schiff-base, H2L,
ligand. The newly prepared binuclear manganese complexes
were identified by different physicochemical and spectroscopic
Received 6 February 2012; accepted 13 October 2012.
The authors wish to thank the University of Isfahan for financially
supporting this work.
Address correspondence to Mohammad Hossein Habibi, Depart-
ment of Chemistry, University of Isfahan, Isfahan, 81746–73441, I. R.
Iran. E-mail: habibi@chem.ui.ac.ir
400

BINUCLEAR MANGANESE(II) COMPLEX
401
techniques. The H2L ligand acts as N2O2 tetradentate sites and
+
can coordinate with two metal ions to form binuclear complexes.
N
N
EXPERIMENTAL
N
H2N
OH2
_
Materials and Methods
NH2
PF6
All solvents and chemicals (Sigma-Aldrich, Germany) were
used as received, except for the amines which were distilled un-
der reduced pressure prior to use. UV–vis spectra were recorded
on a Varian Cary 500 Scan spectrophotometer (Germany). In-
frared spectra (KBr pellets) were obtained on a Bruker FT-IR
(Tensor 27) spectrophotometer. Cyclic voltammograms (CV)
were recorded by using a SAMA Research Analyzer M-500
(Isfahan, Iran). Three electrodes were utilized in this system, a
glassy carbon working electrode, a platinum disk auxiliary elec-
trode, and Ag/Ag+ as reference electrode. The glassy carbon
working electrode (Metrohm 6.1204.110, Germany) with 2.0
0.1 mm diameter was manually cleaned with 1 μm alumina
polish prior to each scan. Tetrabutylammonium tetrafluorobo-
rate (n-Bu)4NBF4, was used as supporting electrolyte. Acetoni-
trile was dried over CaH2. The solutions were deoxygenated
by purging with Ar for 5 min. All electrochemical potentials
were calibrated versus internal Fc+/o (E0 = 0.40 V versus SCE)
couple under the same conditions.
N
N
Mn
H3CO
H3CO
O
O
OCH3
OCH3
O
N
O
Mn
N
OH2
FIG. 1. Chemical formula of Mn(III) complex, [Mn(L)(H2O)]2(PF6)2.TZ (1).
[Mn(L)(H2O)]2(PF6)2 (2), complex
To a stirring solution of Mn(CH3COO)2. 2H2O (0.0662 g,
0.500 mmol) in methanol (25 mL) was added an equimo-
lar of N,Nꢁ-bis(2-hydroxy-5-methoxybenzylidene)-propane-
1,2-diamine (0.500 mmol), and the reaction mixture was stirred
for 2 h. To this solution was added 0.500 mmol of NH4PF6.
The resulting dark brown solution was then stirred for 5 min
(Figure 2). A dark brown microcrystalline solid was produced
by slow evaporation of methanol at room temperature. The prod-
uct was then recrystallized from methanol-propanol (2:1v/v) and
dark brown crystals suitable for X-ray crystallography were ob-
tained. Yield: 70%, m.p = 264◦C. IR (KBr cm−1): 840 (PF6−),
1609 (C=N), 2900 (C-H sp3). UV–vis (Methanol, λmax, nm):
237, 360.
Synthesis
N,Nꢁ-Bis(2-hydroxy-5-methoxybenzylidene)-propane-1,2-
diamine, ligand
N,Nꢁ-Bis(2-hydroxy-5-methoxybenzylidene)-propane-1,2-
diamine was prepared by the condensation of 1,2-propan-
ediamine with 2-hydroxy-5-methoxybenzaldehyde (1:2 mol
stoichiometric ratio) in MeOH at room temperature and was
recrystallized from methanl. Yield: 73%, m.p: 135◦C, IR (KBr
cm−1): 1627 υ(C=N), 2865 υ (C–H sp3). UV-vis (Methanol :
λmax, nm): 260, 335.
X-Ray crystallography for [Mn(L)(H2O)]2(PF6)2.TZ (1) and
[Mn(L)(H2O)]2(PF6)2 (2)
Dark brown crystal of complex 1 and 2 was mounted with
a cryoloop and flash-cooled by cold nitrogen stream. All
measurements were made at 193(2) K on a Rigaku RAXIS
RAPID imaging plate area detector (Japan) with graphite
[Mn(L)(H2O)]2(PF6)2.TZ, TZ=(5-phenyl-1,3,5-triazine-2,6-
diamine) (1)
To a stirring solution of Mn(CH3COO)2. 2H2O (0.0662 g,
0.500 mmol) in ethanol (25 mL) was added an equimo-
lar of N,Nꢁ-Bis(2-hydroxy-5-methoxybenzylidene)-propane-
1,2-diamine (0.5 mmol) and 2 mmol of 5-phenyl-1,3,5-triazine-
2,6-diamine and the mixture was stirred for 3 h (Figure 1). The
pink solution turned dark brown immediately upon the forma-
tion of Mn(III) complex and then 0.500 mmol of NH4PF6 was
added. A dark brown microcrystalline solid was produced by
slow evaporation of ethanol at room temperature. The product
was then recrystallized from methanol-propanol (2:1 v/v) and
dark brown crystals suitable for X-ray crystallography were ob-
tained. Yield: 80%, m.p = 269◦C. IR (KBr cm−1): 850 (PF4−),
1610, 1550 (C=N), 2900 (C-H sp3), 3450, 3500 (NH2). UV–vis
(Ethanol: λmax, nm): 238, 345.
FIG. 2. Chemical formula of Mn(III) complex, [Mn(L)(H2O)]2(PF6)2 (2).

402
M. H. HABIBI AND E. ASKARI
TABLE 1
TABLE 2
Crystal data and structure refinement for
[Mn(L)(H2O)]2(PF6)2.TZ (1)
Crystal data and structure refinement for [Mn(L)(H2O)]2(PF6)2
(2)
Chemical formula (moiety)
Chemical formula (total)
Formula weight
C38H44Mn2N4O102+·2(F6P1−)·2(H2O)
C38H44Mn2N4O102+·2(F6P1−)·2(H2O)
1132.62
Chemical formula (moiety)
Chemical formula (total)
Formula weight
C28H35F6MnN7O8P
C28H35F6MnN7O8P
797.54
Temperature
193(2) K
Temperature
193(2) K
Radiation, wavelength
Crystal system, space group
Unit cell parameters
MoKα, 0.71075 Å
monoclinic, P21/n
a = 11.9845(7) Å α = 90◦
b = 13.0588(9) Å β = 107.709(4)◦
c = 15.8540(10) Å γ = 90◦
2363.6(3) Å3
Radiation, wavelength
Crystal system, space group
Unit cell parameters
MoKα, 0.71075 Å
monoclinic, P21/n
a = 10.6103(17) Å α = 90◦
b = 20.372(4) Å β = 105.349(4)◦
c = 16.087(3) Å
3353.2(10) Å3
4
γ = 90◦
Cell volume
Z
Cell volume
Z
2
1.620 Mg/m−3
Calculated density
Absorption coefficient μ
F(000)
Crystal color and size
Reflections for cell refinement
Data collection method
1.580 Mg/ m−3
0.53 mm−1
1640
Calculated density
Absorption coefficient μ
F(000)
Crystal color and size
Reflections for cell
refinement
0.71 mm−1
1176
Block, brown, 0.3 × 0.2 × 0.2 mm3
dark brown, 0.2 × 0.2 × 0.2 mm3
28 (θ range 3.09–27.48◦)
Rigaku RAXIS-RAPID
28 (θ range 3.09–27.48◦)
Data collection method
Rigaku RAXIS-RAPID diffractometer
ω scans
diffractometer ω scans
θ range for data collection
Index ranges
3.09–27.48.0◦
θ range for data collection
Index ranges
3.09–27.48.0◦
h −17 to 16, k −17 to 17, l −18
h −17 to 16, k −17 to 17, l −18 to 17
to 17
Completeness to θ = 24.0◦
99.4%
Completeness to θ = 24.0◦
Reflections collected
Independent reflections
Reflections with F2 > 2σ
Absorption correction
Min. and max. transmission
Structure solution
99.4%
4940
Reflections collected
4940
Independent reflections
Reflections with F2 > 2σ
Absorption correction
Min. and max. transmission
Structure solution
2854 (Rint = 0.042)
2854 (Rint = 0.042)
2015
2015
multi-scan Higashi.t(1995)
0.892 and 0.892
direct methods
multi-scan Higashi.t(1995)
0.892 and 0.892
direct methods
Refinement method
Full-matrix least-squares on F2
0.0611, 1.1171
Refinement method
Full-matrix least-squares on F2
0.0611, 1.1171
2854/2/237
Weighting parameters a, b
Data/restraints/parameters
Final R indices [F2 > 2σ]
R indices (all data)
Weighting parameters a, b
Data/restraints/parameters
Final R indices [F2 > 2σ]
R indices (all data)
2854/2/237
R1 = 0.0659, wR2 = 0.1450
R1 = 0.1043, wR2 = 0.1605
1.167
R1 = 0.0659, wR2 = 0.1450
R1 = 0.1043, wR2 = 0.1605
1.167
Goodness-of-fit on F2
Extinction coefficient
Largest and mean shift/su
Largest diff. peak and hole
Goodness-of-fit on F2
Extinction coefficient
Largest and mean shift/su
Largest diff. peak and hole
0.012(2)
0.012(2)
0.000 and 0.000
0.34 and −0.24 e Å−3
0.000 and 0.000
0.34 and −0.24 e Å−3
(n-Bu)4NBF4 as supporting electrolyte and complex concentra-
tions of about 3 × 10−3 mol dm−3. The ligands are electroinac-
tive over a range of +2.0 to –2.0 V.
monochromated Mo-Kα radiation. Absorption corrections
were applied by the numerical method.[39] Crystal data, together
with other relevant information on structure determination,
are listed in Tables 1 and 2. The structure was solved by the
direct method using SIR2004[40] and refined on F2 with all in-
dependent reflections by full-matrix least-square method using
SHELXL97 program.[41] The non-hydrogen atoms were refined
anisotropically. Hydrogen atoms were introduced at the posi-
tions calculated theoretically and treated with riding models.
RESULTS AND DISCUSSION
Synthesis
Two Mn(III) complexes have been prepared by the reaction of
an equimolar of N,Nꢁ-Bis(2-hydroxy-5-methoxybenzylidene)-
propane-1,2-diamine and manganese(II) acetate in the presence
of the appropriate axial ligand (water) in aerobic conditions
Electrochemical studies
The CV of complex was conducted at 25◦C under an argon at- (Figures 1 and 2). The air oxidation was continued for a period
mosphere using acetonitrile solutions containing 0.05 mol dm−3 of 3 h, which the dark brown color solution resulted. Dark

BINUCLEAR MANGANESE(II) COMPLEX
403
FIG. 3. ORTEP drawing of [Mn(L)(H2O)]2(PF6)2.TZ, TZ=(5-phenyl-1,3,5-triazine-2,6-diamine) (1) with the atom numbering scheme. The displacement
ellipsoids are drawn at the 50% probability level (color figure available online).
brown crystals of these complexes were obtained in good yield the ligands to the manganese(III) is through N2O2. The equato-
(70–80%).
rial plane of MnIII has two nitrogen and two oxygen atoms of
the N2O2 ligand with the bond distances of Mn1–O1 1.84(9),
Mn1–O3 1.91(2), Mn1–N1 1.99(1), and Mn1–N2 1.97(1) Å.
The dimeric unit is formed by a double Mn–O bridge of
one molecule with its centrosymmetric homologue. The crys-
tal structures of the complexes indicate that in the solid state
Structural Studies
X-ray structural analysis of 1 and 2 are shown in Figures 3
and 4, respectively. X-ray structural analysis shows the pres-
ence of dimanganese core in the complexes and the binding of
FIG. 4. ORTEP drawing of [Mn(L)(H2O)]2(PF6)2 (2) with the atom numbering scheme. The displacement ellipsoids are drawn at the 50% probability level
(color figure available online).

404
M. H. HABIBI AND E. ASKARI
fact that the tetradentate N2O2 ligands are coordinated as dian-
ions. The (C=N) band appearing at 1620 cm−1 in the ligands is
shifted to lower frequencies by 13–25 cm−1 in the correspond-
ing Mn complexes, indicating that the ligands are coordinated
to the metal ions through the imino groups.
CONCLUSION
We have prepared two new homo binuclear manganese(III)
complexes. X-ray structural analysis of complexes showed the
presence of dimanganese core in the complexes and the binding
of the ligands to the manganese(III) through N2O2. The dimeric
unit is formed by a double Mn–O bridge of one molecule. The
CV of complex demonstrate that complex present only a single
species in acetonitrile solution and the redox processes may be
described as Mn(III)/Mn(II) and Mn(II)/Mn(III).
REFERENCES
1. Emara, A.A. A. Spectrochim. Acta A 2010, 77, 117–125.
2. Shebl, M. Spectrochim. Acta A 2008, 70, 850.
3. Cerchiaro, G.; Ferreira, A.M. D. C. J. Brazil. Chem. Soc. 2006, 17, 1473.
4. Cozzi, P.G. Chem. Soc. Rev. 2004, 33, 410.
FIG. 5. Cyclic voltammogram of [Mn(L)(H2O)]2(PF6)2 in acetonitrile solu-
tion stored for 48 h at 293 K. Scan rate: 100 mV/s. c = 3.0 × 10−3
.
the complex adopts an octahedral environment of the imine
N and hydroxo O with the one axial H2O ligand around
manganese. There are two coordination/chelation environments
present around two manganese centers of each binuclear com-
plex. One axial position around each Mn is occupied by one
oxygen atom and another axial position by water. Manganese
oxygen bond distances in axial positions, Mn1–O5 2.21(9),
Mn1–O3(axi) 2.42(1) Å, are significantly longer than those in
the equatorial planes, consistent with the Jahn–Teller elongation
of high-spin d4 MnIII in the axial direction and the difference in
ligand type. For complex 1 the bond distances of N2O2 in equa-
torial positions are as followings: Mn1–O1 1.85(2), Mn1–O2
1.89(6), Mn1–N1 1.98(3), and Mn1–N2 1.97(6) Å.
5. Denmark, S.E.; Heemstra, J.R.; Beutner, G.L. Angew. Chem. Int. Ed. Engl.
2005, 44, 4682.
6. Huang, W.; Gou, S.; Hu, D.; Chantrapromma, S.; Fun, H.-K.; Meng, Q.
Inorg. Chem. 2001, 40, 1712.
7. Kaim, W.; Schwederski, B. Bioinorganic Chemistry: Inorganic Elements
in the Chemistry of Life; Wiley, New York, 1994.
8. Atakol, O.; Nazir, H.; Arici, C.; Durmus, S.; Svoboda, I.; Fuess, H. Inorg.
Chim. Acta 2003, 342, 295.
9. Ramadan, A.M.; Sawadny, W.; Issa, R.M.; El-Baradie, H.Y. F. Egypt J.
Chem. 2000, 43, 285.
10. Chohan, Z.H.; Pervez, H.; Rauf, A.; Scozzafava, A.; Supuran, C.T. J. En-
zyme Inhib. Med. Chem. 2002, 17, 122.
11. Serbest, K.; Colak, A.; Gu¨ner, S.; Karabo¨cek, S.; Kormalı, F. Transition
Met. Chem. 2001, 26, 625–629.
12. Serbest, K.; Karaoglu, K.; Erman, M.; Er, M.; Degirmencioglu, I. Spec-
trochim. Acta A 2010, 77, 643–651
13. Eltayeba, N.E.; Teoha, S.G.; Kusrinib, E.; Adnan, R.; Func, H.K. Spec-
trochim. Acta A 2010, 75, 453–457
14. Hung, L.S.; Chen, C.H. Mater. Sci. Eng. R: Rep. 2002, 39, 143.
15. Wang, P.; Xie, Z.; Hong, Z.; Tang, J.; Wong, O.; Lee, C.-S.; Wong, N.; Lee,
S.J. Mater. Chem. 2003, 13, 1894.
16. Tao, X.T.; Miyata, S.; Sasabe, H.; Zhang, G.J. Appl. Phys. Lett. 2001, 78,
279.
17. Yu, T.; Su, W.; Li, W.; Hong, Z.; Hua, R.; Li, B. Thin Solid Films 2007,
515, 4080.
Voltammetric Characterization
The CV of complex was measured in acetonitrile solution.
The CV exhibits irreversible mechanism (Figure 5). In cathodic
and anodic voltamogram, two peaks were observed which indi-
cates of reduction of Mn(III) to Mn(II) and oxidation of Mn(II)
to Mn(III). These results demonstrate that complex is dimmer in
solution phase and consistent with dimmer solid state structure.
Spectroscopic Properties
18. Shen, Y.-Z.; Gu, H.; Pan, Y.; Dong, G.; Wu, T.; Jin, X.-P.; Huang, X.-Y.;
Hu, H. J. Organomet. Chem. 2000, 605, 234.
19. Chen, T.-R. J. Mol. Struct. 2005, 737, 35.
20. B. Geeta, K. Shravankumar, Reddy, P.M.; Ravikrishna, E.; Sarangapani, M.;
Krishna Reddy, K.; Ravinder, V. Spectrochim. Acta A 2010, 77, 911–915.
21. Trujillo, A.; Sinbandhit, S.; Toupet, L.; Carrillo, D.; Manzur, C.; Hamon,
J.R. J. Inorg. Organomet. Polym. 2008, 18, 81–99.
22. Lozan, V.; Loose, C.; Kortus, J.; Kersting, B. Coord. Chem. Rev. 2009, 253,
2244–2260.
23. Sallam, S.A. Transit. Met. Chem. 2006, 31, 46–55.
24. Ali, M.A.; Mirza, A.H.; Nazimuddin, M.; Karim, F.; Bernhardt, P.V.
Inorg. Chim. Acta 2005, 358, 4548–4554.
25. Jeragh, B.J. A.; El-Dissouky, A. J. Coord. Chem. 2005, 58, 1029–1038.
26. Vigato, P.A.; Tamburini, S. Coord. Chem. Rev. 2004, 248, 1717–2128.
The electronic spectra of complexes 1 and 2 have maxima
at 238 and 345 nm for 1 and 237 and 360 nm for 2. The ab-
sorptions at 232 and 238 nm can be related to the spin allowed
π –π∗ azomethane intraligand transition.[42] The band at 360 nm
in the UV region can be assigned to spin-allowed metal-to-
ligand charge transfer transition.[43–45] FT-IR spectral data of the
complexes were compared with those of the uncomplexed lig-
and. N,Nꢁ-bis(2-hydroxy-5-methoxybenzylidene)propane-1,2-
diamine ligand show a broad band characteristic of the OH
group in the 3300–3500 cm−1 region. The disappearance of this
band in the FT-IR spectra of the complexes is indicative of the

BINUCLEAR MANGANESE(II) COMPLEX
405
27. Khalil, S.M. E.; Bashir, K.A. J. Coord. Chem. 2002, 55, 681–696.
28. Al-Kubaisi, A.H. Bull. Korean Chem. Soc. 2004, 25, 37–41.
38. Jamialahmadi, M.; Tayyari, S.F.; Habibi, M.H.; Yazdanbakhsh, M.;
Kadkhodaei, S.; Sammelson, R.E. J. Mol. Struct. 2011, 985, 139–147
29. Siddiqi, Z.A.; Noor, S.; Shahid, M.; Khalid, M. Spectrochim. Acta A 2011, 39. Higashi, T. Shape Program for Absorption; Rigaku Corporation, Tokyo,
78, 1386–1391. 2005.
30. Eltayeb, N.E.; Teoh, S.G.; Kusrini, E.; Adnan, R.; Fun, H.K. Spectrochim. 40. Burla, M.C.; Caliandro, R.; Camalli, M.; Carrozzini, B.; Cascarano, G.L.;
Acta A 2010, 75, 453–457
31. Issa, R.M.; Amer, S.A.; Mansour, I.A.; Abdel-Monsef, A.I. J. Therm. Anal.
Calorim. 2007, 90, 261.
32. Carter, M.J.; Rillema, D.P.; Basolo, F. J. Am. Chem. Soc. 1974, 96, 392.
33. Donald, F.; Averill, F.; Broman, R. Inorg. Chem. 1978, 17, 3389.
34. Patterson, G.S.; Holm, R.H. Bioinorg. Chem. 1975, 4, 257.
35. Schenk, K.J.; Meghdadi, S.; Amirnasr, M.; Habibi, M.H.; Amiri, A.; Salehi,
M.; Kashi, A. Polyhedron 2007, 26, 5448–5457.
36. Dabbagh, H.A.; Zamani, M.; Farrokhpour, H.; Habibi, M.H.; Barati, K. J.
Mol. Struct. 2010, 983, 169–185.
37. Meghdadi, S.; Amirnasr, M.; Habibi, M.H.; Amiri, A.; Ahmadi, F.; Kihara,
K.; Suzuki, T.; Bijanzadeh, H.R. Transition Met. Chem. 2008, 33, 879–886.
De Caro, L.; Giacovazzo, C.; Polidori, G.; Spagna, R. J. Appl. Cryst. 2005,
38, 381.
41. Sheldrich, G.M. SHELXL97; University of Go¨ttingen, Germany, 1997.
42. Naskar, S.; Biswas, S.; Mishr, D.; Adhikary, B.; Falvello, L.R.; Soler,
T.; Schwalb, C.H.; Chattopadhyay, S.K. Inorg. Chim. Acta 2004, 357,
4257.
43. Hwang, F.M.; Chen, H.Y.; Chen, P.S.; Liu, C.S.; Chi, Y.C.; Shu, C.F.;
Wu, F.L.; Chou, P.T.; Peng, S.M.; Lee, G.H. Inorg. Chem. 2005, 44,
1344.
44. Baldo, M.A.; Thompson, M.E.; Forest, S.R. Nature 2000, 403, 750.
45. Biswas, S.; Mitra, K.; Schwalbe, C.H.; Lucas, C.R.; Chattopadhyay, S.K.;
Adhikary, B. Inorg. Chim. Acta 2005, 358, 2473.