Synthesis of Schiff base 24-membered trivalent transition metal derivatives with their anti-inflammation and antimicrobial evaluation

Article abstract of DOI:10.1016/j.molstruc.2015.12.059

The paper presents the synthesis of macrocyclic complexes [{M(C₅₂H₃₆N₁₂O₄)X}X₂] of Cr(III), Mn(III) and Fe(III) with Schiff base ligand (C₅₂H₃₆N₁₂O₄) obtained through the condensation of 1,4-dicarbonyl phenyl dihydrazide with 1,2-di(1H-indol-1-yl)ethane-1,2-dione. The newly formed Schiff base and its complexes have been characterized with the help of elemental analysis, condensation measurements, magnetic measurements and their structure configuration have been determined by various spectroscopic (electronic, IR, ¹H NMR, ¹³C NMR, GCMS) techniques. The electronic spectra of the complexes indicate a five coordinate square pyramidal geometry of the center metal ion. These metal complexes and ligand were tested for their anti-inflammation and antimicrobial inhibiting potential and compared with standard drugs Phenyl butazone (anti-inflammation), Imipenem (antibacterial) and Miconazole (antifungal).

Full text of DOI:10.1016/j.molstruc.2015.12.059

Journal of Molecular Structure 1108 (2016) 680e688
Contents lists available at ScienceDirect
Journal of Molecular Structure
journal homepage: http://www.elsevier.com/locate/molstruc
Synthesis of Schiff base 24-membered trivalent transition metal
derivatives with their anti-inflammation and antimicrobial evaluation
,
Gajendra Kumar a *, Shoma Devi b, Dharmendra Kumar c
a Chemical Science Laboratory, Bhagwant Institute of Technology, Muzaffarnagar 251315 (UP), India
b Department of Zoology, Krishna College of Science, Bijnor 246701 (UP), India
c Department of Chemistry, Sahu Jain College, Najibabad 246763 (UP), India
a r t i c l e i n f o
a b s t r a c t
Article history:
The paper presents the synthesis of macrocyclic complexes [{M(C52H36N12O4)X}X2] of Cr(III), Mn(III) and
Fe(III) with Schiff base ligand (C52H36N12O4) obtained through the condensation of 1,4-dicarbonyl phenyl
dihydrazide with 1,2-di(1H-indol-1-yl)ethane-1,2-dione. The newly formed Schiff base and its complexes
have been characterized with the help of elemental analysis, condensation measurements, magnetic
measurements and their structure configuration have been determined by various spectroscopic (elec-
tronic, IR, 1H NMR, 13C NMR, GCMS) techniques. The electronic spectra of the complexes indicate a five
coordinate square pyramidal geometry of the center metal ion. These metal complexes and ligand were
tested for their anti-inflammation and antimicrobial inhibiting potential and compared with standard
drugs Phenyl butazone (anti-inflammation), Imipenem (antibacterial) and Miconazole (antifungal).
© 2015 Elsevier B.V. All rights reserved.
Received 11 October 2015
Accepted 19 December 2015
Available online 22 December 2015
Keywords:
Schiff base
Macrocyclic complexes
Antimicrobial activity
Anti-inflammation
Spectroscopic study
1. Introduction
shows less or no biological activity as comparison to their com-
plexes [9,10]. Important characteristics that can be correlated with
Schiff base macrocyclic mononuclear complexes have a rapid
development in recent years because of its important role in
pharmacological, biological and natural science [1e3]. Macrocyclic
Schiff base and the relevant transition metal complexes are
considered to be among the most important stereochemical models
in transition metal coordination chemistry due to their preparative
accessibility and structural variety [4,5]. Reaction of aldehydes and
ketones with semicarbazide/thiosemicarbazide leads to conden-
sation products named semicarbazones/thiosemicarbazones,
which may also be considered as Schiff bases, they can act as li-
gands in reaction with various metal ions. It is necessary for a
macrocyclic ligand to have an enough cavity to hold more metal
ions. The popular method to synthesize the macrocyclic ligand is
cyclo-condensation, such as (2þ2), (3þ3), (4þ4) [6,7]. Mckee et al.;
(1988) prepared a (2þ2) Schiff base tetranuclear copper complex
through template condensation reaction of 2,6-diformyl-4-methyl
phenyl and 1,5-diamino-3-hydroxy pentane. In this complex, the
alcohol groups coordinate with copper ion as endogenous bridge
ligand [8]. Literature reports reveal that free Schiff base ligands
good antimicrobial activities are as follows: (i) Lipophilicity and
penetration of the complexes through the lipid membrane [11], (ii)
the ability to form hydrogen bond with solvent molecule [12,13],
(iii) a stereochemistry that allows a favorable tridimensional
interaction with biomolecules and a high kinetic and thermody-
namic stability in order to control the dissociation in the acidic
medium [14,15], (iv) the presence of uncoordinated groups that
permit the recognition by living organism and enhances the solu-
bility [14].
Macrocyclic compounds containing oxalamide moiety have
been synthesized and showed a variety of catalyst and biological
activities [16e21]. The amide groups can bind with different metal
ions via nitrogen and/or oxygen atoms. Compounds incorporating
metal atoms are known as antitumor drugs such as cisplatin [22].
In the present paper we report the structure and biological ac-
tivity of the macrocyclic ligand was synthesized by reacting 1,2-di
(1H-indol-1-yl) ethane and 1,4 dicarbonyl phenyl dihydrazide and
its Cr (III), Mn (III) and Fe (III) complexes. Results are reported on
the bases of elemental analysis, conductance measurements,
magnetic measurements and various spectroscopic studies. The
newly synthesized compounds were tested for their antimicrobial
inhibiting potential against some pathogenic strain.
* Corresponding author.
E-mail address: gaj.chem@gmail.com (G. Kumar).
http://dx.doi.org/10.1016/j.molstruc.2015.12.059
0022-2860/© 2015 Elsevier B.V. All rights reserved.

G. Kumar et al. / Journal of Molecular Structure 1108 (2016) 680e688
681
2. Experimental
2.5.2. Synthesis of the metal complex (2)
Synthesis of [Cr(C52H36N12O4)NO3](NO3)2 complex (2). A solu-
tion of Cr(NO3)3$9H2O (0.624 g, 1.562 mmol) in methanol (8 mL)
was added to a hot solution (75 ꢀC) of HL (1) (1.394 g, 1.562 mmol)
in ethanol (25 mL), and the reaction mixture was refluxed for 7 h.
The solution was concentrated under vacuum. The precipitate was
filtered off, washed with methanol and dried under vacuum over
anhydrous CaCl2 (1.16 g, 78% yield). Conductance Lm:
2.1. Reagents
The entire chemicals used, were of the analytical grade, diethyl
oxalate, Indole, Diethyl terephthalate and hydrazinhydrate pro-
cured from s.d.-fine. Metal salts were purchased from Merck.
2.2. Synthesis of 1,2-di(1H-indol-1-yl)ethane-1,2-dione
169 Uꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
525, 720 and 1155. IR (KBr): (H2O) 3429,
(N2H) 3272,
1720, (C]N) 1644, (CeC) 770, (C]C, aromatic) 1544,
(NH, hydrazide) 3140, (NeN) 1120,
(MꢂN) 422,
l
¼ 255, 275, 320,
(C]O)
(CeH,
n
n
n
1 H-indol (3.6 g, 0.030 mol) was dissolved in ethanol and this
solution was added diethyl oxalate (2.26 g, 0.015 mol) in a 2:1 M
ratio containing few drop of concentrated HCl. The solution was
refluxed for 3 h. The cream crystalline product which formed was
filtered off under vacuum and recrystallized from ethanol [23].
n
n
n
n
aromatic) 3030,
n
n
n
n
(MꢂO) 485 cmꢂ1
.
2.5.3. Synthesis of the metal complex (3)
Synthesis of [Cr(C52H36N12O4)OAc](OAc)2 complex (3). A solu-
tion of Cr(OAc)3$2H2O (0.472 g, 1.781 mmol) in methanol (7 mL)
was added to a hot solution (75 ꢀC) of HL (1) (1.590 g, 1.781 mmol)
in ethanol (30 mL), and the reaction mixture was refluxed for 7 h.
The solution was concentrated under vacuum. The precipitate was
filtered off, washed with methanol and dried under vacuum over
anhydrous CaCl2 (1.30 g, 75% yield). Conductance Lm:
2.3. Synthesis of 1,4-dicarbonyl phenyl dihydrazide
A mixture of diethyl ester of terephthalic acid (2.22 g) and hy-
drazine hydrate (98% 2 mL) in ethanol was refluxed for 4e5 h. The
reaction mixture was allowed to cool at room temperature then,
the cooled solution was poured onto ice cold water. The dihy-
drazide of terephthalic acid was thus obtained, filtered and
recrystallized from ethanol [24].
161
U
ꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
(H2O) 3340,
(N2H) 3260,
(NeN) 1123, (CeC) 766, (C]C, aromatic) 1543,
l
¼ 260, 272, 325, 520,
724 and 1150. IR (KBr):
n
n
n
(C]O) 1780,
n
n
n
(C]N) 1651,
n
n
n
2.4. Synthesis of Schiff base macrocyclic ligand
(CeH, aromatic) 3033,
n
(NH, hydrazide) 3150,
n
(MꢂN) 420,
(MꢂO) 500 cmꢂ1 nsym(OC(O)CH3) 1559 (m), nasym(OC(O)CH3)
1,2-di(1H-indol-1-yl) ethane-1, 2-dione (0.58 g, 2 mmol) in
ethanol (20 mL) was added to an ethanolic solution of 1,4-dicar-
bonyl phenyl dihydrazide (0.388 g, 2 mmol, 30 mL) containing a
few drops of concentrated HCl. The reaction mixture was refluxed
for 8 h. The mixture was cooled to room temperature and the sol-
vent removed under reduced pressure by rotavapour until a solid
product was formed and it was washed with cold ethanol and dried
under vacuum. Melting point 151 ꢀC and Yield 70e75% (Scheme
1368 cmꢂ1, (Dn ¼ 191 cmꢂ1).
2.5.4. Synthesis of the metal complex (4)
Synthesis of [Mn(C52H36N12O4)Cl]Cl2 complex (4). A solution of
MnCl3$6H2O (0.476 g, 1.771 mmol) in methanol (15 mL) was added
to a hot solution (75 ꢀC) of HL (1) (1.581 g, 1.771 mmol) in ethanol
(18 mL), the reaction mixture was refluxed for 7 h. The precipitate
was filtered off, washed with methanol and dried under vacuum
over anhydrous CaCl2 (1.37 g, 73% yield). Conductance Lm:
1).1 H NMR (300 MHz, DMSO-d6)
Indol), 8.13 (s, AreH, Carbonyl Phenyl), 10.15 (s, 4x1H, NH of Hy-
drazide). 13C NMR (300 MHz, DMSO-d6)
¼ 154.2 (C ] N), 170.6
(C]O),147.6,145.9,138.1,137.6,135.5,132.2,130.1,128.3,121.1,112.4
d
¼ 6.45e7.65 (m, 24H, AreH
141 Uꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
450, 700, 1150. IR (KBr): (H2O) 3380,
(N2H) 3260,
(C]N) 1680, (NeN) 1146, (CeC) 755,
(MꢂN) 440,
(CeH, aromatic) 3040, (NH, hydrazide) 3145,
l
¼ 260, 280, 320,
(C]O) 1735,
(C]C, ar-
d
n
n
n
n
n
n
n
n
(AreC). UV/vis (Nujol mul (nm)):
l
¼ 370, 420, 480. UV/vis
¼ 360, 390, 445. IR (KBr):
(N2H) 3245,
(NeN) 1115, (CeC) 760, (C]C, ar-
(NH, hydrazide) 3155 cmꢂ1
omatic) 1540,
n
n
n
(1 ꢁ 10ꢂ4 mol, DMSO):
l
n
(MꢂCl) 330 cmꢂ1
.
n
(C]O) 1720,
n
(C]N) 1610,
n
n
n
omatic) 1540,
n(CeH, aromatic) 3040,
n
.
2.5.5. Synthesis of the metal complex (5)
Synthesis of [Mn(C52H36N12O4)NO3](NO3)2 complex (5). A so-
lution of Mn(NO3)3$9H2O (0.631 g, 1.578 mmol) in methanol (8 mL)
was added to a hot solution (75 ꢀC) of HL (1) (1.409 g, 1.578 mmol)
in ethanol (25 mL), and the reaction mixture was refluxed for 7 h.
The solution was concentrated under vacuum. The precipitate was
filtered off, washed with methanol and dried under vacuum over
anhydrous CaCl2 (1.06 g, 72% yield). Conductance Lm:
2.5. Synthesis of the Cr(III), Mn(III) and Fe(III) complexes
A solution of trivalent metal salt (1.0 mmol) in methanol (8 mL)
was added to a hot solution (75 ꢀC) of macrocyclic ligand
(1.0 mmol) in ethanol (25 mL), and the reaction mixture was
refluxed for 8 h. The solution was concentrated under vacuum. The
precipitate was filtered off, washed with methanol and dried under
vacuum over anhydrous CaCl2 (68e75% yield) Scheme 2.
158 Uꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
525, 720 and 1155. IR (KBr): (H2O) 3429,
(N2H) 3272,
(NeN) 1122, (CeC) 754, (C]C, aromatic)
(NH, hydrazide) 3144,
(MꢂN) 425,
l
¼ 255, 275, 320,
n
n
n
(C]O)
1732,
1544,
n
n
(C]N) 1644,
n
n
n
2.5.1. Synthesis of the metal complex (1)
n
(CeH, aromatic) 3044,
n
n
Synthesis of [Cr(C52H36N12O4)Cl]Cl2 complex (1). A solution of
CrCl3$6H2O (0.443 g, 1.674 mmol) in methanol (8 mL) was added to
a hot solution (75 ꢀC) of HL (1) (1.494 g, 1.674 mmol) in ethanol
(25 mL), and the reaction mixture was refluxed for 7 h. The solution
was concentrated under vacuum. The precipitate was filtered off,
washed with methanol and dried under vacuum over anhydrous
(MꢂO) 490 cmꢂ1
.
2.5.6. Synthesis of the metal complex (6)
Synthesis of [Mn(C52H36N12O4)OAc](OAc)2 complex (6). A solu-
tion of Mn(OAc)3$2H2O (0.523 g, 1.953 mmol) in methanol (10 mL)
was added to a hot solution (75 ꢀC) of HL (1) (1.743 g, 1.953 mmol)
in ethanol (20 mL), and the reaction mixture was refluxed for 7 h.
The precipitate was filtered off, washed with methanol and dried
under vacuum over anhydrous CaCl2 (1.54 g, 77% yield). Conduc-
CaCl2 (1.06 g, 71% yield). Conductance Lm: 147
vis (Nujol mul (nm)):
¼ 355, 375, 420, 525, 720 and 1155. IR (KBr):
(N2H) 3272,
(C]N) 1644, (C]O) 1720, (NeN) 1122, (CeC)
760, (C]C, aromatic) 1540, (NH, hydra-
zide) 3144,
U
ꢂ1 cm2 molꢂ1. UV/
l
n
n
n
n
n
n
n
(CeH, aromatic) 3040,
n
tance Lm: 143 Uꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
280, 330, 451, 680 and 1140. IR (KBr): (H2O) 3311,
(N2H) 3260,
l
¼ 255,
n(MꢂN) 425,
n
(MꢂCl) 310 cmꢂ1
.
n
n

682
G. Kumar et al. / Journal of Molecular Structure 1108 (2016) 680e688
Scheme 1. Formation of Schiff base ligand.
n
(C]O) 1722,
n
(C]N) 1657,
n(CeH, aromatic) 3043, n
n
(NeN) 1123,
n
(CeC) 750,
(NH, hydrazide) 3140,
, nsym(OC(O)CH3) 1549, nasym(OC(O)
n
(C]C, ar-
The solution was concentrated under vacuum. The precipitate was
filtered off, washed with methanol and dried under vacuum over
anhydrous CaCl2 (1.06 g, 74% yield). Conductance Lm:
omatic) 1539,
n
(MꢂN) 470,
n
(MꢂO) 510 cmꢂ1
CH3) 1366 cmꢂ1, (Dn ¼ 190 cmꢂ1).
152 Uꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
l
¼ 255, 275, 320,
(N2H) 3272,
(C]O)
(CeC) 760, (C]C, aromatic)
(NH, hydrazide) 3133,
(MꢂN) 425,
525, 720 and 1155. IR (KBr):
n
(H2O) 3429 (br),
n
n
1690,
1533,
n
(C]N) 1633,
n
(NeN) 1132,
n
n
2.5.7. Synthesis of the metal complex (7)
n
(CeH, aromatic) 3053,
n
n
Synthesis of [Fe(C52H36N12O4)Cl]Cl2 complex (7). A solution of
FeCl3$6H2O (0.465 g, 1.723 mmol) in methanol (11 mL) was added
to a hot solution (75 ꢀC) of HL (1) (1.538 g, 1.723 mmol) in ethanol
(28 mL), the reaction mixture was refluxed for 7 h. The precipitate
was filtered off, washed with methanol and dried under vacuum
over anhydrous CaCl2 (1.28 g, 75% yield). Conductance Lm:
131
and 1061. IR (KBr):
N) 1650, (NeN) 1145,
aromatic) 3044, (NH, hydrazide) 3145,
333 cmꢂ1
n
(MꢂO) 490 cmꢂ1
.
2.5.9. Synthesis of the metal complex (9)
Synthesis of [Fe(C52H36N12O4)OAc](OAc)2complex (9). A solu-
tion of Fe(OAc)3$2H2O (0.496 g, 1.847 mmol) in methanol (12 mL)
was added to a hot solution (75 ꢀC) of HL (1) (1.350 mg,1.649 mmol)
in ethanol (25 mL), the reaction mixture was refluxed for 7 h. The
precipitate was filtered off, washed with methanol and dried under
vacuum over anhydrous CaCl2 (1.35 g, 76% yield). Conductance Lm:
U
ꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
(H2O) 3406,
(N2H) 3286,
(CeC) 745, (C]C, aromatic) 1533,
(MꢂN) 455,
l
¼ 260, 331, 467, 652
(C]O) 1735, (C]
(CeH,
(MꢂCl)
n
n
n
n
n
n
n
n
n
n
n
.
154 Uꢂ1 cm2 molꢂ1. UV/vis (Nujol mul (nm)):
489, 636, 1051. IR (KBr): (H2O) 3419,
(N2H) 3277,
(NeN) 1120, (CeC) 750, (C]C, aromatic) 1539,
l
¼ 265, 280, 340,
2.5.8. Synthesis of the metal complex (8)
n
n
n
(C]O) 1710,
Synthesis of [Fe(C52H36N12O4)NO3](NO3)2 complex (8). A solu-
tion of Fe(NO3)3$9H2O (0.677 g, 1.678 mmol) in methanol (8 mL)
was added to a hot solution (75 ꢀC) of HL (1) (1.498 g, 1.678 mmol)
in ethanol (25 mL), and the reaction mixture was refluxed for 7 h.
n
n
n
(C]N) 1621,
n
n
n
(CeH, aromatic) 3044,
n
(NH, hydrazide) 3144,
n
(MꢂN) 460,
(MꢂO) 525 cmꢂ1 nsym(OC(O)CH3) 1561 (m), nasym(OC(O)CH3)
1370 cmꢂ1 (m) (Dn ¼ 192 cmꢂ1).

G. Kumar et al. / Journal of Molecular Structure 1108 (2016) 680e688
683
culture containing approximately 104 CFU (colony forming unit)
per mL were spread on the surface of Muller Hinton Agar media
plates. Wells with 6 mm diameter made, then solution of test
compound was filled to the wells. The plates were incubated at
30 ꢀC for 24 h. The activity of the compounds was determined by
measuring diameter of the inhibition zone (in mm) each test was
carried in triplicate [25,26].
3.2. Anti-inflammation activity
The inflammation activity of the test compounds was evaluated
in albino rats of either sex weighing (100e125 g) were divided into
groups of 5 animals each. A freshly prepared suspension of carra-
geenin (0.9% saline) 0.05 mL, was injected under the planter
aponeurosis of right paw of the rat by the method of Winter et al.
[27]. One group was kept as control and the animals of other group
were pretreated with the test drugs suspended in gum acacia, given
1 h before the carrageenin injection. The volumes of foot were
measured before 1 h and after 3 h treatment of carrageenin using
digital plethsmometer apparatus. The present inhibition of paw
volume for each rat in treated group was calculated by comparing
with mean paw volume of control group according to the formula
given below.
% anti-inflammation activity ¼ (1ꢂVt/Vc) x 100
Where Vt and Vc are paw volumes of oedema in drug treated and
control group. Phenyl butazone was used as a standard drug for
comparison.
4. Results and discussion
4.1. Mass spectra
The FAB mass spectra of Schiff base ligand, its M(III) metal
complexes have been recorded (Table 1). The molecular ion (Mþ)
peaks obtained from various complexes are as follows: (1) m/
z
¼
891.92C52H36N12O4 (Ligand), (2) m/z
¼
1050.27
1129.93
1121.04
1053.21
1132.87
[Cr(C52H36N12O4)Cl]Cl2 (complex 1), (3) m/z
[Cr(C52H36N12O4)NO3](NO3)2 (complex 2), (4) m/z
[Cr(C52H36N12O4)OAc](OAc)2 (complex 3), (5) m/z
[Mn(C52H36N12O4)Cl]Cl2 (complex 4), (6) m/z
¼
¼
¼
¼
[Mn(C52H36N12O4)NO3](NO3)2 (complex 5), (7) m/z ¼ 1123.99
[Mn(C52H36N12O4)OAc](OAc)2 (complex 6), (8) m/z ¼ 1054.12
Scheme 2. Formation of Schiff base metal complex cation.
[Fe(C52H36N12O4)Cl]Cl2 (complex 7), (9) m/z
¼
1133.78
[Fe(C52H36N12O4)NO3](NO3)2 (complex 8), (10) m/z ¼ 1124.89
[Fe(C52H36N12O4)OAc](OAc)2 (complex 9). This data is in good
agreement with the proposed molecular formula for these com-
plexes. In addition to the peaks due to the molecular ion, the
spectra exhibit peaks assignable to various fragments arising from
the thermal cleavage of the complexes. The peak intensity gives an
idea of the stability of the fragments.
3. Pharmacology
3.1. Antimicrobial activity
Antimicrobial screening of the newly synthesized compound
were evaluated using agar well diffusion method [25]. The bio-
logical activity of the free ligand, its metal complexes and standard
drug (antibacterial lmipenem and antifungal miconazol) were
studied against the Staphylococcus aureus, Bacillus subtilis (as gram
positive bacteria) and Pseudomonas aeruginosa, Escherichia coli,
Salmonella typhi (as gram negative bacteria) and fungi Rizoctonia
sp., Aspergillus sp., Penicillium sp. All strains were obtained from
Microbial Type Collection and Gene Bank, Institute of Microbial
Technology (IMTECH) Chandigarh, India. The solution of different
concentration 1, 1.5 and 2 mg/mL of each compound (free ligand, its
metal complexes and standard drug lmipenem and miconazol) in
DMSO was prepared for testing against spore germination of fungi
and bacteria. Centrifuged pellets of microorganism from a 24 h old
4.2. IR spectra
The IR spectral of the Schiff base ligand show a ѵ(C]N) peak at
1610 cmꢂ1 and a medium intensity absorption band at 3180 cmꢂ1
which is attributed to the ѵ(NeH) stretching vibration. The high
intensity band at 1613e1632 cmꢂ1 which is attributed to the ѵ(C]
N) vibration. The bands present in the range ~3020e3060 cmꢂ1
may be assigned due to ѵ(CeH) stretching vibrations of aromatic
moiety [28]. The various absorption band in the range
~1455e1570 cmꢂ1 may be assigned due to ѵ(C]C) aromatic
stretching vibrations of the aromatic ring [29]. Another strong band
at 1690e1735 cmꢂ1 indicate the presence of ѵ(C]O). The presence

684
G. Kumar et al. / Journal of Molecular Structure 1108 (2016) 680e688
Table 1
FAB mass spectral data of the trivalent chromium, manganese and iron complexes derived from macrocyclic ligand.
þ
Complexes
Mol. wt.
Molecular ion peak [M]
Important peak due to complex fragmentation
C52H36N12O4
[Cr(C52H36N12O4)Cl]Cl2
892.92
1051.27
1130.93
1122.04
1054.21
1133.87
1124.99
1055.12
1134.78
1125.89
891.9
1050.2
1129.9
1121.0
1053.2
1132.8
1123.9
1054.1
1133.7
1124.8
27.0, 43.0, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.6, 730.7, 887.7
27.1, 43.1, 116.1, 142.1, 162.1, 284.3, 428.7, 446.7, 608.7, 730.7, 887.7, 891.7, 942.7, 978.2
27.1, 43.1, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.6, 730.7, 887.7, 891.8, 943.9, 1005.8
27.0, 43.0, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.7, 730.7, 887.7, 891.8, 943.8, 1002.9
27.0, 43.0, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.6, 730.7, 887.7, 891.8, 945.7, 981.2
27.1, 43.1, 116.1, 142.1, 162.1, 284.3, 428.8, 446.8, 608.8, 730.8, 887.8, 891.8, 945.7, 1008.7
27.0, 43.0, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.8, 730.7, 887.7, 891.8, 945.7, 1005.8
27.1, 43.1, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.7, 730.7, 887.7, 891.8, 946.6, 982.1
27.1, 43.1, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.7, 730.7, 887.7, 891.8, 946.5, 1009.5
27.1, 43.1, 116.1, 142.1, 162.1, 284.3, 428.3, 446.4, 608.9, 730.9, 887.9, 891.8, 946.6, 1006.7
[Cr(C52H36N12O4)NO3](NO3)2
[Cr(C52H36N12O4)OAc](OAc)2
[Mn(C52H36N12O4)Cl]Cl2
[Mn(C52H36N12O4)NO3](NO3)2
[Mn(C52H36N12O4)OAc](OAc)2
[Fe(C52H36N12O4)Cl]Cl2
[Fe(C52H36N12O4)NO3](NO3)2
[Fe(C52H36N12O4)OAc](OAc)2
of the absorption bands at 1400e1445, 1280e1315 and
1020e1045 cmꢂ1 in the IR spectra of the nitrato complexes sug-
gests that the nitrate groups are coordinated to the central metal
ion in a unidentate fashion [30]. In IR spectra of the acetate com-
plexes the appearance of three characteristic bands in the ranges
1555e1575 cmꢂ1, 1377e1395 cmꢂ1 and 1795e1810 cmꢂ1 in the
case of complexes was attributed to nasym(COOꢂ), nsym(COOꢂ) and
uncoordinated (COOe), respectively, indicating the participation of
the carboxylate oxygen in the complexes formation. The mode of
coordination of carboxylate group has often been deduced from the
magnitude of the observed separation between the nasym(COOꢂ)
and nsym(COOꢂ). The separation value, Dn(COOꢂ), between
nasym(COOꢂ) and nsym(COOꢂ), in these complexes were more than
190 cmꢂ1 (191e193 cmꢂ1) suggesting the coordination of carbox-
ylate group in a monodentate fashion [31]. The IR spectra of nitrato
complexes exhibits bands at 1290e1310 cmꢂ1, 1050e1065 cmꢂ1
and 1435e1450 cmꢂ1 which can be assigned to NO2 symmetric
stretching (n1); NeO stretching (n2); NO2 asymmetric stretching
27,480e27,880 cmꢂ1 attributed to 4B1g/4E1g
,
4B1g/4B2g
,
4B1g/4A2g and 4B1g/4Eg. The spectral bands are consistent with
that of five coordinated Cr (III) complexes [41]. On the bases of
spectral studies of these complexes, a five coordinated square py-
ramidal geometry may be assigned for these complexes. Thus we
assume the C4v symmetry for these complexes [42,43]. The mag-
netic moment values for this complexes were found to be
3.68e4.93 B.M. at room temperature which is close to the predicted
values for three unpaired electrons in the metal ions [44].
The absorption spectral bands of manganese (III) complexes
showed three spin allowed transitions: 5B1g/5A1g 5B1g/5B2g
, ,
5B1g/5Eg appearing in the ranges 12,240e12,540, 16,140e18,860
and 35,460e35,730 cmꢂ1, respectively consistent with a five co-
ordinated square pyramidal geometry of Mn (III) complexes [42,43]
and Assuming C4v symmetry for these complexes. The magnetic
moment values for these complexes were found in the range
4.92e5.74 B.M expected for square pyramidal manganese com-
plexes [44].
(
n5); and out of plane rocking, respectively. These frequencies are
The electronic spectra of the iron (III) complexes gave two bands
at 9840e9970, and 27,640e27,750 cmꢂ1, which could be assigned
to the transitions 6A1g/4T1g and 6A1g/4T2g, respectively, sug-
gesting a five coordinated square pyramidal geometry of Fe (III)
complexes [43,45] and Assuming C4v symmetry for these com-
plexes. The complexes show magnetic moment values in the range
5.20e5.45 B.M [45].
compatible with monodentately coordinated nitro group [32], IR
absorption band ~1355e1360 cmꢂ1 assigned the uncoordinated
nitro group. The far infrared spectra show bands in the region
420e450 cmꢂ1 corresponding to ѵ(MꢂN) vibration [33e35]. The
presence of bands in all complexes in the region 420e450 cmꢂ1
originate from (MꢂN) azomethine vibrational mode and identify
coordination of azomethine nitrogen [36]. The band present in the
range 310e330 cmꢂ1 may be assigned due to ѵ(MꢂCl) vibration
[33e35]. The bands present in the region 235e260 cmꢂ1 in all the
nitrato complexes are assignable to ѵ(MꢂO) stretching vibration
[33,34].
The spectral characterization shows the formula for macrocyclic
complexes as [M(C52H36N12O4)X]X2] where M ¼ Cr(III), Mn(III),
Fe(III) and X ¼ Clꢂ, NO3ꢂ and CH3COOꢂ. The measurements of molar
conductance in DMSO are 130e170
U
ꢂ1. All complexes give satis-
factory elemental analyses results as shown in Table 2. Various
attempts such as crystallization using mixtures of solvents, low
temperature crystallization were unsuccessful to obtain a single
crystal for X-ray crystallography. However, the analytical, spectro-
scopic and magnetic data enable us to predict the possible structure
of the synthesized complexes.
4.3. 1H NMR
A survey of literature reveals that Schiff base have characterized
by 1H NMR and 13C NMR spectra to ensure ligand structure and
purity in d6-dimethylsulfoxide (DMSO-d6) solution using Me4Si
(TMS) as internal standard. The 1H NMR spectra of Schiff base
ligand (HL) was recorded. The 1H NMR spectra of the ligand shows
broad signal at 9.4e12.1 ppm due to the presence of eNH [37]. The
multiplets in the region 6.54e8.76 ppm may be assigned to aro-
matic proton [38,39].
4.5. Thermal gravimetric analysis
With the help of thermal analysis nature of decomposition of
the compound can be obtained. TG analysis data of the ligand and
its complexes that recorded in the temperature range from 40 to
550 ꢀC. The complex decomposed about 550 ꢀC. The absence of any
decomposition step in the range 125e180 ꢀC indicate the absence of
any water moiety in the coordination sphere. In the case of chloride
complex the loss of coordinated chloride ion in the temperature
ranges 190e260 ꢀC. The decomposition step corresponds to esti-
mated mass loss 15.78% in the range 300e420 ꢀC may corre-
sponded to (OAc)3 moiety (Fig.1). After the loss of coordination ions
all complexes rapidly degrade in the temperature range
450e550 ꢀC due to the decomposition of organic part of the com-
plex [46].
13C NMR of the Schiff base ligand, the signal appeared in the
region 113e158 are assigned to aromatic carbon. The signal at
172.8e165.6 and 144.3e142.3 ppm are due to C]N, and C]O
respectively [40].
4.4. Electronic spectral studies, magnetic measurements and molar
conductance
The electronic spectra of Cr (III) complexes showed absorption
band in the region 8960e9320,13,145e13,510,17,490e1,84,395 and

G. Kumar et al. / Journal of Molecular Structure 1108 (2016) 680e688
685
Table 2
Analytical data of the trivalent chromium, manganese and iron complexes derived from macrocyclic ligand.
Complex
Mol. wt
C
H
N
M
Color
Yield
Conductance LM
C52H36N12O4
[Cr(C52H36N12O4)Cl]Cl2
892.92
1051.27
1130.93
1122.04
1054.21
1133.87
1124.99
1055.12
1134.78
1125.89
69.95 (69.87)
59.41 (59.39)
55.22 (55.25)
62.08 (62.05)
59.24 (59.20)
55.08 (55.06)
61.92 (61.94)
59.19 (59.17)
55.04 (55.00)
61.87 (61.77)
4.06 (4.04)
3.45 (3.48)
3.21 (3.25)
4.04 (4.06)
3.44 (3.42)
3.20 (3.18)
4.03 (4.03)
3.44 (3.41)
3.20 (3.24)
4.03 (4.02)
18.82 (18.78)
15.99 (16.02)
18.58 (18.62)
14.98 (14.95)
15.94 (15.94)
18.53 (18.54)
14.94 (14.96)
15.93 (15.90)
18.51 (18.55)
14.93 (14.92)
4.95 (4.92)
4.60 (4.60)
4.63 (4.61)
5.21 (5.25)
4.85 (4.86)
4.88 (4.88)
5.29 (5.30)
4.92 (4.95)
4.96 (4.95)
Orange
Orange
Light Yellow
Brown
Gray
Light gray
Light Yellow
Reddish
71%
78%
75%
73%
72%
77%
75%
74%
76%
147 Uꢂ1
169 Uꢂ1
161 Uꢂ1
141 Uꢂ1
158 Uꢂ1
143 Uꢂ1
131 Uꢂ1
152 Uꢂ1
154 Uꢂ1
[Cr(C52H36N12O4)NO3](NO3)2
[Cr(C52H36N12O4)OAc](OAc)2
[Mn(C52H36N12O4)Cl]Cl2
[Mn(C52H36N12O4)NO3](NO3)2
[Mn(C52H36N12O4)OAc](OAc)2
[Fe(C52H36N12O4)Cl]Cl2
[Fe(C52H36N12O4)NO3](NO3)2
[Fe(C52H36N12O4)OAc](OAc)2
Light Yellow
Fig. 1. T.G Curve of [Cr(C52H36N12O4)OAc](OAc)2 complex.
4.6. X-ray diffraction analysis
4.7. Antifungal activity
The power X-ray diffraction patterns of the metal complexes
were used for the determination of structure and lattice
dimension of unit cell. The X ray pattern of metal complexes was
The antifungal activity of newly synthesized compounds Schiff
base ligand, its Cr(III), Mn(III) and Fe(III) metal ion complexes
exhibited a considerable enhancement against Aspergillus sp.,
Rizoctonia sp. and Penicillium sp. at 1, 1.5 and 2 mg/ml concentra-
tion. The activity is greatly enhanced at the higher concentration.
DMSO (control) has showed a negligible activity as compare to
ligand and M(III) Schiff base metal complexes. However, the metal
complexes show better activity than the ligand [48,49]. The anti-
fungal experimental results of the compounds were compared with
the standard antifungal drugs Miconazole. From the data (Table 3)it
has been also observed that the activity depends upon the type of
metal ion and varies in the following order of the metal ion:
Cr > Fe > Mn. The complexes are highly effective against Aspergillus
sp. at 2 mg/ml concentration. [Cr(C52H36N12O4)OAc](OAc)2 is the
only complex to show 93% activity against Aspergillus sp. The effect
is susceptible to the concentration of the compound used for
inhibition.
recorded at the wave length
l
¼ 1.5406 Å and 2
q value between
5ꢀ to 65ꢀ. The diffractogram revel the crystalline nature of the
complex, system has been worked by trial and error method for
finding the best fit between observed and calculated values [47].
The pattern of Cr(III) complex shows 24 reflections with maxima
at 2
q
¼ 50.573 and d ¼ 1.84 Å. The observed unit cell parameters
are as follows a ¼ 8.54 Å, b ¼ 8.47 Å, c ¼ 9.35 Å and
a
¼ 92.527ꢀ,
b
¼ 108.364ꢀ,
g
¼ 97.856ꢀ. The complex satisfies the condition a
s b s c and
a s b s g
. s 90ꢀ and the compound to be triclinic.
The pattern of Mn(III) complex shows 19 reflections with max-
ima at 2
¼ 21.253 and d ¼ 2.81 Å. The observed unit cell pa-
q
rameters are as follows a ¼ 10.25 Å, b ¼ 10.25 Å, c ¼ 11.82 Å and
a
¼ 90ꢀ,
b
¼ 90ꢀ,
g
¼ 90ꢀ. The complex satisfies the condition a
s b s c and
a s b s g
. s 90ꢀ and the compound to be
tetragonal. The pattern of Fe(III) complex shows 20 reflections
with maxima at 2
¼ 32.524 and d ¼ 2.16 Å. The observed unit
q
4.8. Minimum inhibitory concentration (MIC) and minimum
bacterial concentration (MBC) of synthesized compounds
cell parameters are as follows a ¼ 7.25 Å, b ¼ 7.25 Å, c ¼ 8.47 Å
and
a
¼ 90ꢀ,
b
¼ 90ꢀ,
g
s
¼ 90ꢀ. The complex satisfies the condition
a s b s c and
a
b
s
g
. s 90ꢀ and the compound to be
The antibacterial screening concentrations of the compounds to
be used were estimated from the minimum inhibitory
tetragonal.

686
G. Kumar et al. / Journal of Molecular Structure 1108 (2016) 680e688
Table 3
complexes, standard drug Imipenem (C12H17N3O4S) and DMSO
solution control were screened for their antibacterial activity
against the bacteria S. aureus and B. subtilis (as gram positive
bacteria) and P. aeruginosa, E. coli and S. typhi (as gram negative
bacteria). From the bactericidal activity, it is apparent that the
complexes were more toxic towards gram positive strains than
gram negative strains. The reason is the difference in the structure
of the cell walls. The walls of gram negative cells are more complex
than those of gram positive cells. Antibacterial activity of all the
complexes towards gram positive and gram negative bacteria is
quite significant. Further to it, the ligand showed moderate, and
the complexes moderate to high activities as compared to stan-
dard drug towards the all organism. This may be due to the
presence of eNH group playing an important role in the biological
activity; this group is believed to impart the transformation re-
action in biological system. Coordination reduced polarity of the
metal ion [51], mainly because of the partial sharing of its positive
charge with the donor group within the chelate ring system
formed during coordination, this process, in turn increases the
lipophilic nature of the central metal atom, which subsequently
favors it's permeability through the lipid layer of the cell mem-
brane and blocking the metal binding sites on enzymes of
microorganism [52e54].
Fungicidal screening data of the ligand and their corresponding metal complexes.
Compound
% Inhibition of spore germination
Aspergillus sp. Penicillium
Rizoctonia sp.
(mg/ml)
sp. (mg/ml)
(mg/ml)
1.0 1.5 2.0 1.0 1.5 2.0 1.0 1.5 2.0
C52H36N12O4
48 56
75 85
63 69
82 86
73 78
61 29 37 42 50 56 59
87 65 70 82 59 64 66
80 56 61 73 52 55 62
93 72 77 86 68 72 79
82 66 68 74 59 63 66
71 55 59 67 56 58 60
89 66 70 74 58 48 65
84 61 68 75 54 59 71
78 54 59 71 48 51 60
89 66 69 79 59 62 75
[Cr(C52H36N12O4)Cl]Cl2
[Cr(C52H36N12O4)NO3](NO3)2
[Cr(C52H36N12O4)OAc](OAc)2
[Mn(C52H36N12O4)Cl]Cl2
[Mn(C52H36N12O4)NO3](NO3)2 62 66
[Mn(C52H36N12O4)OAc](OAc)2 79 81
[Fe(C52H36N12O4)Cl]Cl2
68 78
51 61
80 85
[Fe(C52H36N12O4)NO3](NO3)2
[Fe(C52H36N12O4)OAc](OAc)2
Miconazole (standard)
57 69 100 65 78 83 76 82 94
concentration (MIC). Minimum inhibitory concentration is the
lowest concentration of an antimicrobial complex that will inhibit
the visible growth of microorganisms after overnight incubation.
The MIC of the newly synthesized compounds were tested against
bacterial strains through a macrodilution tube method [50]. The
MIC values for ligand against B. subtilis, S. aureus, E. coli, S. typhi and
P. aeruginosa were 128, 128, 68, 68 and 66
(ligand) 18, 21, 18, 16 and 22 g/ml for the [Cr(C52H36N12O4)Cl]Cl2,
12, 12, 14, 14 and 10 g/ml for [Cr(C52H36N12O4)NO3](NO3)2, 15, 15,
16, 16 and 14 g/ml for [Cr(C52H36N12O4)OAc](OAc)2, 70, 70, 52, 52
and 48 g/ml for [Mn(C52H36N12O4)Cl]Cl2, 58, 58, 38, 35 and 35 g/
In the present study, low activity of the some metal complexes is
due to their low lipophilicity, because of which penetration of the
complex through the lipid membrane was decreased and hence,
they could neither block nor inhibit the growth of the microor-
ganism. HPLC was used to analyze the lipophilicity of the com-
pounds (linear regression analysis) [28]. RP-HPLC method flow rate
mg/ml for C52H36N12O4
m
m
m
m
m
ml for [Mn(C52H36N12O4)NO3](NO3)2, 50, 50, 38, 38 and 32
for [Mn(C52H36N12O4)OAc](OAc)2, 35, 48, 30, 30 and 28
[Fe(C52H36N12O4)Cl]Cl2, 25, 35, 25, 30 and 30
[Fe(C52H36N12O4)NO3](NO3)2, 22, 20, 15, 15 and 18
m
m
m
m
g/ml
g/ml
g/ml
g/ml
of 1 mL/min, an injection volume of 5 mL, a column temperature of
25 ꢀC, the UV detection at 254 nm and a 25 min isocratic mobile
phase methanol, 25 mmol KH2PO4, pH3 (20:80) was used to
determine the lipophilicity of the compounds [55].
[Fe(C52H36N12O4)OAc](OAc)2, 12, 12, 10, 10 and 10 mg/ml for stan-
dard drug Imipenem. The values of MIC showed that the Cr com-
plexes were found more potent as compared to the other studied
complexes.
4.10. Anti-inflammation activity against carrageenin induced
oedema
Minimum bacterial concentration (MBC) is the lowest concen-
tration of antimicrobial compounds that will prevent the growth of
microorganism after subculture on the antibiotic free media [50].
Minimum bacterial concentration (MBCs) was determined by
All the newly synthesized compounds (1e9) were evaluated
for their anti-inflammatory activity. Due to their potentiality
these compound and reference drug were tested at the three
grade does (25, 50 and 100 g/kg p.o). Compound [Fe(C52H36N12O4)
OAc](OAc)2 have shown better activity at 25, 50, and 100 mg/kg
p.o (31.1%, 46.7% and 64.9%, respectively) than reference drug
(18.2%, 32.4% and 61.0%, respectively) compound FeHL have
shown better ant inflammation activity at the low doses 25 and
50 mg/kg p.o and almost at the 100 mg/kg p.o as compare to
standard drug. The anti inflammation activity of all the compound
are given in Table 5.
spreading the 100 ml compound from one below MIC and MIC itself.
All tubes were incubated for 24 h at 37 ꢀC. The growth was observed
on each plate.
4.9. Antibacterial activity
The results of the bactericidal study of the synthesized com-
pounds are summarized in Table 4. The Schiff base ligand, its metal
Table 4
Bactericidal screening data of the ligand and their corresponding metal complexes (inhibition zone in mm).
Microorganism
Ligand
Complexes
1
Imipenem
2
3
4
5
6
7
8
9
Gram-positive
Staphylococcus aureus
Bacillus subtilis
36
35
61
58
70
67
92
90
12
43
22
28
41
40
30
38
24
29
62
60
100
100
Gram-negative
Escherichia coli
Salmonella typhi
Pseudomonas aeruginosa
10
10
08
12
61
40
45
39
28
69
64
61
10
15
11
19
28
21
36
38
32
41
42
36
22
28
25
33
35
65
100
100
100
Excellent activity (90e100% inhibition), Good activity (60e70% inhibition), Significant activity (30e50% inhibition), negligible activity (08e20% inhibition).
Complex 1 ¼ [Cr(HL)Cl]Cl2, 2 ¼ [Cr(HL)NO3](NO3)2, 3 ¼ [Cr(HL)OAc](OAc)2, 4 ¼ [Mn(HL)Cl]Cl2, 5 ¼ [Mn(HL)NO3](NO3)2, 6 ¼ [Mn(HL)OAc](OAc)2, 7 ¼ [Fe(HL)Cl]Cl2, 8 ¼ [Fe(HL)
NO3](NO3)2, 9 ¼ [Fe(HL)OAc](OAc)2.
Imipenem ¼ Standard drug.

G. Kumar et al. / Journal of Molecular Structure 1108 (2016) 680e688
687
Table 5
Anti-inflammatory screening data of the ligand and their corresponding metal complexes.
Compound
Control
Dose of compound mg/kg p.o
Mean increas in paw vol SE
Anti-inflammatory activity %
0.77 0.011
0.70 0.009
0.68 0.009
0.66 0.010
0.65 0.011
0.59 0.009
0.53 0.012
0.63 0.015
0.61 0.012
0.55 0.011
0.61 0.008
0.54 0.010
0.49 0.014
0.58 0.010
0.56 0.008
0.43 0.011
0.61 0.011
0.57 0.011
0.45 0.012
0.55 0.011
0.46 0.011
0.30 0.010
0.55 0.009
0.48 0.010
0.35 0.010
0.56 0.011
0.51 0.011
0.38 0.011
0.53 0.012
0.41 0.011
0.27 0.012
0.63 0.010
0.52 0.010
0.30 0.011
C
52H36N12O4
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
25
09.0
11.6
14.2
15.5
23.3
31.1
18.1
20.7
28.5
20.7
29.8
36.3
24.6
27.2
44.1
20.7
25.9
41.5
28.5
40.2
60.1
28.5
37.6
54.5
27.2
33.7
50.6
31.1
46.7
64.9
18.2
32.4
61.0
[Cr(C52H36N12O4)Cl]Cl2
[Cr(C52H36N12O4)NO3](NO3)2
[Cr(C52H36N12O4)OAc](OAc)2
[Mn(C52H36N12O4)Cl]Cl2
[Mn(C52H36N12O4)NO3](NO3)2
[Mn(C52H36N12O4)OAc](OAc)2
[Fe(C52H36N12O4)Cl]Cl2
[Fe(C52H36N12O4)NO3](NO3)2
[Fe(C52H36N12O4)OAc](OAc)2
Phenyl butazone (standard)
50
100
25
50
100
25
50
100
Phenyl butazone ¼ standard.
5. Experimental protocols
inflammation and Antimicrobial study reveals that, metal com-
plexes have more biological activity than free ligand. Complex
[Cr(C52H36N12O4)OAc](OAc)2 shows best antimicrobial activity
against the given microorganism and complex [Fe(C52H36N12O4)
OAc](OAc)2 shows the best Anti-inflammation activity against
carrageenin. than standard drug phenyl butazone.
The microanalysis of C, H and N were estimated by elemental
analyzer (Perkin Elmer 2400) and the metal contents of Cr (III), Mn
(III) and Fe (III) were determined by atomic absorption spectro-
photometer (Perkin Elmer 5000). IR spectra was recorded on a FT-
IR spectrophotometer (Perkin Elmer) in the range 4000e200 cmꢂ1
using Nujol Mull. 1H NMR and 13C NMR spectra (at room temper-
ature) (in DMSO-d6) were recorded on a Bruker AVANCE II 300 DRX
or average 400 DRX spectrometer with reference to Me4Si
(0.0 ppm). The FAB mass spectra (at room temperature) were
recorded on JEUL JMS-AX-500 mass spectrometer, GCeMS analysis
was performed on a Shimadzu GCMS- QP5050A instrument, Indian
Institute of Petroleum Dehradun, India. Magnetic susceptibility
measurements were carried out at SAIF, IIT Roorkee, on vibrating
sample magnetometer (Model PAR 155). Electronic spectra in
Acknowledgment
We wish to express our cordial thanks to Dr. A.K. Bhatanagar,
(Retired scientist ‘G’) Indian Institute of Petroleum, (CSIR) Dehra-
dun, India, for fruitful discussion and suggestion for performing this
research work.
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864e869.
DMSO were recorded on
a Hitachi 330 spectrophotometer
(1300e200 nm) at room temperature. The conductivity was
measured on digital conductivity meter (HPG system, G-3001). The
chromatographic apparatus consisted of a model waters 600 pump
with waters 600 controller, waters 2996 photodiode array detector,
a non polar C18 column, 15 cm ꢁ 4.6 mm I.D., 5
mm particles (all
from waters, Milford MA, USA).
6. Conclusion
The electronic spectral data is in the favor of a five coordinate
square pyramidal geometry of the complexes. New synthesized
compounds were tested for biological evaluation against some
pathogenic strains and compared with standard drug. Anti-
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