Synthesis, spectral characterization, and fungicidal activity of transition metal complexes with benzimidazolyl-2-hydrazones of glyoxal, diacetyl, and benzil

Article abstract of DOI:10.1080/15533174.2013.776592

A series of complexes of the type [ML2].nH2O, where L = 2- (benzimidazolyl-2′-amino) imino ethanone (HBAIE), 2-(benzi midazolyl-2′-amino) imino-1,2-dimethyl ethanone (HBAIME), 2-(benzimidazolyl-2′-amino) imino-1,2-diphenyl ethanone (HBAIPE), M = Cu(II), Co(II), Ni(II), and Zn(II), have been synthesized and characterized. The results are in consistent with tridentate chelation of ligand with azo nitrogen, ring nitrogen, and oxygen atom of glyoxal, diacetyl, and benzil. The fungi toxicity of the ligands and their complexes against some fungal pathogen has been studied.

Full text of DOI:10.1080/15533174.2013.776592

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Synthesis, Spectral Characterization, and Fungicidal
Activity of Transition Metal Complexes With
Benzimidazolyl-2-hydrazones of Glyoxal, Diacetyl, and
Benzil
R. K. Mohapatra a , M. Dash a , U. K. Mishra b , A. Mahapatra b & D. C. Dash b
a Department of Chemistry , Govt. College of Engineering , Keonjhar , Odisha , India
b School of Chemistry , Sambalpur University , Jyoti Vihar, Burla, Sambalpur , Odisha , India
Accepted author version posted online: 12 Nov 2013.Published online: 16 Dec 2013.
To cite this article: R. K. Mohapatra , M. Dash , U. K. Mishra , A. Mahapatra & D. C. Dash (2014) Synthesis, Spectral
Characterization, and Fungicidal Activity of Transition Metal Complexes With Benzimidazolyl-2-hydrazones of Glyoxal,
Diacetyl, and Benzil, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 44:5, 642-648, DOI:
10.1080/15533174.2013.776592
To link to this article: http://dx.doi.org/10.1080/15533174.2013.776592
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Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 44:642–648, 2014
Copyright ꢀ Taylor & Francis Group, LLC
C
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2013.776592
Synthesis, Spectral Characterization, and Fungicidal Activity
of Transition Metal Complexes With
Benzimidazolyl-2-hydrazones of Glyoxal, Diacetyl,
and Benzil
R. K. Mohapatra,1 M. Dash,1 U. K. Mishra,2 A. Mahapatra,2 and D. C. Dash2
1Department of Chemistry, Govt. College of Engineering, Keonjhar, Odisha, India
2School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Sambalpur, Odisha, India
of DNA synthesis and cell growth.[9] This hydrazone also has
A series of complexes of the type [ML2].nH2O, where L = 2-
(benzimidazolyl-2ꢀ-amino) imino ethanone (HBAIE), 2-(benzi
midazolyl–2ꢀ-amino) imino-1,2-dimethyl ethanone (HBAIME),
mild bacteriostatic activity and a range of analogues has been
investigated as potential oral ion chelating drugs for genetic
disorders such as thalasemia.[10,11]
2-(benzimidazolyl-2ꢀ-amino)
imino-1,2-diphenyl
ethanone
Following all these observations and as a part of our con-
tinuing research on the coordination chemistry of multiden-
tate ligands,[12–19] we report here the synthesis and struc-
tural studies on the complexes of Cu(II), Co(II), Ni(II), and
Zn(II) with some hydrazone derivatives containing benzim-
idazole moiety such as 2-(benzimidazolyl-2ꢁ-amino) imino
ethanone (HBAIE), 2-(benzimidazolyl–2ꢁ-amino) imino-1,2-
dimethyl ethanone (HBAIME), and 2-(benzimidazolyl-2ꢁ-
amino) imino-1,2-diphenyl ethanone (HBAIPE).
(HBAIPE), M = Cu(II), Co(II), Ni(II), and Zn(II), have been
synthesized and characterized. The results are in consistent with
tridentate chelation of ligand with azo nitrogen, ring nitrogen, and
oxygen atom of glyoxal, diacetyl, and benzil. The fungi toxicity of
the ligands and their complexes against some fungal pathogen has
been studied.
Keywords benzil, benzimidazolyl-2-hydrazones, diacetyl, glyoxal,
transition metal complexes
INTRODUCTION
Schiff bases are an important class of ligands in coordina-
tion chemistry and their complexing ability containing different
donor atoms are widely reported.[1,2] In this way, the synthesis,
structural investigation, and reaction of transition metal Schiff
bases have received a special attention, because of their bio-
logical activities as antitumoral, antifungal, and antiviral activ-
ities.[3] Thus, Schiff base hydrazones are also interesting from
the point of view of pharmacology. Hydrazone derivatives are
found to possess antimicrobial,[4] antitubercular,[5] anticonvul-
sant,[6] and anti-inflammatory[7] activities. Particularly, the an-
tibacterial and antifungal properties of hydrazones and their
complexes with some transition metal ions were studied and
reported by Carcelli et al.[8] In addition, complexes of salicy-
laldehyde benzoylhydrazone were shown to be a potent inhibitor
EXPERIMENTAL
Material and Method
All the chemicals used of AR grade. The solvents were pu-
rified before use by standard procedures. The starting material
such as 2-hydrazinobenzimidazole was synthesized according
to literature method.[20]
Preparation of Ligands
The ligands used in the present investigation were
benzimidazolyl-2-hydrazones of aldehydes and ketones such
as glyoxal, diacetyl, and benzil have been synthesized by con-
densing 2-hydrazinobenzimidazole with respective aldehydes
and ketone in the following manner.
Ethanolic solution of 2-hydrazinobenzimidazole (0.01 mol
in 20 mL) was added to ethanolic solution of gly-
oxal/diacetyl/benzil (0.01 mol in 20 mL) and the resulting solu-
tion was refluxed on a water bath for 6–8 h. It was concentrated
and allowed to stand overnight when colored precipitate was
separated out. It was filtered, washed, and recrystallized from
ethanol. The sample was dried in vacuo over fused calcium
chloride and then analyzed.
Received 20 February 2012; accepted 10 February 2013.
The authors gratefully acknowledge the services rendered by Di-
rector, Regional Sophisticated Instrumentation Center, I. I. T., Madras,
for recording the spectra.
Address correspondence to R. K. Mohapatra, Department of Chem-
istry, Govt. College of Engineering, Keonjhar-758002, Odisha, India.
E-mail: ranjank mohapatra@yahoo.com
642

TRANSITION METAL COMPLEXES WITH BENZIMIDAZOLYL-2-HYDRAZONES
643
SCH. 1.
SCH. 2.
SCH. 3.
electronic spectra of the complexes in DMSO were recorded on
a Perkin-Elmer spectrophotometer. Thermo gravimetric anal-
ysis was done by Netzch-429 thermo analyzer. The H-NMR
spectra of the complexes were recorded in DMSO-d6 medium
on JEOL, GSX-400 model equipment.
Preparation of the Complexes
The complexes were synthesized by refluxing ethanolic so-
lution of the ligand HBAIE/HBAIME/HBAIPE (0.02 mol in
20 mL) with a hot ethanolic solution of corresponding hydrated
metal (II) chloride (0.01 mol in 20 mL) for about 4 h when col-
ored complexes precipitated out in each case. The complexes
were filtered, washed with ethanol followed by ether and finally
dried in vacuo over fused CaCl2.
1
RESULTS AND DISCUSSION
The complexes were formulated from the analytical data and
molar conductance data support the suggested formulae (Ta-
ble 1). The complexes are highly colored and insoluble in water
and common organic solvent but soluble in highly coordinating
solvents such as dioxane, DMF, and DMSO. They are non hy-
groscopic, highly stable under normal conditions, and all of them
decompose above 250◦C. The molar conductance data values in
DMSO for the complexes indicate them to be nonelectrolyte in
nature.
Analysis and Physical Measurements
A weighed quantity of the compound (0.2–0.3 g) was treated
with a few drops of concentrated H2SO4 and 1 cc. of concen-
trated HNO3. It was heated till all the organic matter decom-
posed and sulfur trioxide fumes came out. The same process
was repeated 2–3 times to decompose the substance completely.
Then it was dissolved in water and the resulting solution was
used for analysis of metal ions. The metal contents in the com-
plexes were determined gravimetrically following standard pro-
cedure.[21] The molar conductance measurements were carried
IR Spectra
In the high frequency region, 2-hydrazinobenzimidazole ex-
out at room temperature with a Toshniwal conductivity Bridge hibits a pair of strong bands precisely located at ∼3310 and
(model CL-01–06, cell constant 0.5 cm−1) using 1 × 10−3M ∼3275 cm−l which may be assigned to asymmetric and sym-
solution of the complexes in DMSO. Carbon, hydrogen, and metric stretching modes of vibrations of the -NH2 group. Apart
nitrogen contents of the complexes were determined by using a from these bands a multiple band system of medium intensity is
MLW-CHN micro analyzer. FTIR spectra in KBr pallets were observed at ∼3150 and ∼3100 cm−1, which may be attributed
recorded on a Varian FTIR spectrophotometer, Australia. The to v (N H) benzimidazolyl group and v (N H) exocyclic,

644
R. K. MOHAPATRA ET AL.
TABLE 1
Analytical and physical data of the compounds
C Found
(Calcd.)
H Found
(Calcd.)
N Found
(Calcd.)
M Found
(Calcd.)
Sl no
1
Compound
HBAIE
Color
Yield (%)
80
ꢀa
m
Brick red
—
—
37.82
(37.89)
36.11
(36.16)
46.55
(46.58)
47.85
(47.89)
47.91
(47.94)
45.58
(45.61)
47.21
(47.26)
52.04
(52.07)
52.09
(52.12)
49.81
(49.85)
51.43
(51.46)
66.71
(66.75)
66.76
(66.79)
64.78
(64.82)
66.19
0.32
(0.35)
0.24
(0.27)
0.16
(0.18)
3.51
(3.54)
3.52
(3.55)
3.76
(3.80)
3.48
(3.50)
4.69
(4.73)
4.69
(4.73)
4.88
(4.91)
4.64
(4.67)
4.18
(4.23)
4.19
(4.24)
4.34
(4.37)
4.16
39.26
(39.30)
46.00
(46.03)
41.35
(41.40)
24.79
(24.83)
24.82
(24.86)
23.61
(23.65)
24.47
(24.50)
22.05
(22.09)
22.07
(22.11)
21.11
(21.15)
21.79
(21.83)
14.79
(14.83)
14.81
(14.84)
14.35
(14.40)
14.66
—
—
—
2
3
HBAIME
HBAIPE
Light brown
Light brown
Brown
75
80
62
63
65
62
62
65
58
61
63
60
60
64
—
4
[Co(BAIE)2]H2O
7.9
13.05
(13.08)
12.93
(12.98)
13.38
(13.41)
14.18
(14.22)
11.58
(11.63)
11.51
(11.54)
11.95
(11.99)
12.63
(12.67)
7.78
5
[Ni(BAIE)2]H2O Dark yellow
14.3
12.6
10.6
8.4
6
[Cu(BAIE)2] 2H2O
[Zn(BAIE)2] H2O
Yellow
Green
7
8
[Co(BAIME)2]
H2O
[Ni(BAIME)2] H2O
Light Green
Red
9
7.2
10
11
12
13
14
15
[Cu(BAIME)2]
2H2O
[Zn(BAIME)2]
H2O
Brown
13.4
10.4
11.2
5.7
Yellow
Brown
[Co(BAIPE)2] H2O
(7.81)
7.71
(7.75)
8.12
(8.16)
8.50
[Ni(BAIPE)2] H2O Dark Green
[Cu(BAIPE)2]
2H2O
[Zn(BAIPE)2] H2O Pale yellow
Yellowish
green
7.8
10.2
(66.22)
(4.20)
(14.71)
(8.54)
aOhm−1 cm2 mol−1
.
respectively. Apart from these bands, a multiple band system in case of (HBAIPE) methyl, v(C O) carbonyl, and v(C N)
of medium intensity is observed at ∼1540 v (C N) cyclic and azomethine vibration, respectively, and suggesting thereby the
–1340 v (C N) cyclic, which may be due to ring stretching condensation of 2-hydrazinobenzimidazole with glyoxal, di-
vibrations mode of benzimidazole moiety. The N H bending acetyl, and benzil occurs in 1:1 proportion with conversion of
vibrations for primary amine occur at 1600–1575 cm−1. The NH2 group to azomethine group. The previous spectral data
band occurring at 1620 cm−1 may be assigned due to N H thus provide a logical and self consistent picture to indicate the
bending vibrational mode. The band observed at 1230 cm−l and structural feature of the ligands.
at ∼1000 cm−l may be due to the C N (exocyclic) stretching
The position of bands due to v (C N) cyclic, and v (C N)
cyclic remains practically unaltered in the present complexes
vibrations and N N stretching vibrations respectively.
Reaction of 2-hydrazinobenzimidazole with glyoxal, di- indicating non–coordination of ring nitrogen atom to the metal
acetyl, and benzil brings about significant changes in the IR ions. Whereas, the position of benzimidazole v (N H) band
spectra of the product, which has been used as ligand in the occurring at 3150 cm−l is shifted by 20–25 cm−l to lower fre-
present investigation. The most notable feature of the spectrum quency region indicating involvement of NH group of benz-
is the disappearance of band at ∼3310 cm−l and at 3275 cm−l imidazole in coordination to Co(II), Ni(II), Cu(II), and Zn(II)
and appearance of additional band systems at ∼2900 cm−1
,
ions. In the spectra of the complexes the band due to v(C O)
∼1710 cm−l, and ∼1590 cm−1 due to v(C H) phenyl ring was found to be absent and two new bands of medium intensity

TRANSITION METAL COMPLEXES WITH BENZIMIDAZOLYL-2-HYDRAZONES
645
are observed at ∼1550 cm−l and ∼1450 cm−l, which may be
assigned to v(C C) and v(C O), respectively, indicating that
Thermal Analysis
Thermal characteristics of the metal complexes are recorded
the ligands coordinate to the metal ions through deprotonation in Table 2. These complexes follow the same pattern of ther-
of enolic OH after enolization via tautomerization.[22,23] The mal decomposition. The complexes remain almost unaffected
bands observed at 1610 cm−l due to v(C N) azomethine and up to ∼40◦C. After this a slight depression up to ∼120◦C is ob-
at ∼1050 cm−l due to v(N N) of the ligand is also found to served. The weight loss at this temperature range is equivalent
be absent and a new band due to N N (azo group) appears to two water molecules in case of copper(II) complexes and one
at ∼1630 cm−1, indicating thereby coordination of one of the molecule in case of other complexes indicating them to be lattice
nitrogen atom of the azo group with metal ion. A pair of sharp water[26] in conformity with our earlier observations from ana-
bands of moderate intensity is observed in the IR spectra of all lytical and IR spectral investigations. The anhydrous complexes
the metal complexes, the first band appears at ∼530 cm−1 and remain stable up to 240–340◦C and thereafter the complexes
the second one at ∼450 cm−1. These bands are distinctly absent show rapid degradation presumably due to decomposition of
in the spectra of ligands. Considering the sharpness and inten- organic constituents of the complex molecules as indicated by
sity, higher band is attributed to v(M N) and lower band is at- the steep fall in the percentage weight loss. The decomposition
tributed to v(M O) vibrations.[24,25] These observations clearly continues up to ∼500◦C and reaches to a stable product in each
support our assumptions that oxygen (enolized), nitrogen (azo complex as indicated by the consistency in weight in the plateau
group), and ring nitrogen (benzimidazole moiety) atoms are of the thermogram. This corresponds to the composition of their
coordinated to the metal ions. This is supported by the dis- stable oxides. The decomposition temperature varies for differ-
appearance of band at ∼3100 cm−I due to v (N H) vibration. ent complexes. Thermal stability of the complexes is found to
Thus IR spectral investigation of ligand as well as its metal com- be in the following order:
plexes provides unequivocal evidence of coordination of ligand
to the metal center through conversion of keto form to the enolic
form.
HBAIEComplexes : Co(II) < Zn(II) < Cu(II) < Ni(II)
HBAIMEComplexes : Ni(II) < Co(II) < Cu(II) < Zn(II)
HBAIPEComplexes : Ni(II) < Cu(II) < Zn(II) < Co(II)
Besides the previous bands, a broad band at ∼3400 cm−1
is observed in the IR spectra of all the complexes indicating
the presence of coordinated or lattice water due to vOH vibra-
tion. However, all the complexes lose water when heated to
∼100◦C as indicated by thermal analysis conforms presence
of lattice water molecules. The representative spectrum of the
[Cu(BAIPE)2] 2H2O complex is shown in Figure 1.
Electronic Spectra and Magnetic Properties
The electronic spectral data of Co(II) complexes in DMSO
exhibit a band system at ∼10,000 cm−1 (1000 nm) and
FIG. 1. IR spectrum of [Cu(BAIPE)2] 2H2O.

646
R. K. MOHAPATRA ET AL.
TABLE 2
Important features of thermo gravimetric analysis (TGA)
% of water loss
% of residue
Total wt. for
TG (mg)
Temp. range of
Decomposition
Composition of
the residue
Compound
water loss (◦C)
Found
Calcd.
temperature (◦C)
Found Calcd.
4
5
6
7
8
22.2
18.8
20.1
10.9
20.0
17.6
22.3
14.6
20.3
9.9
50–110
56–125
50–118
50–119
55–125
50–120
55–118
50–120
50–115
50–115
50–122
50–125
3.66
3.64
7.15
3.79
3.37
3.22
6.47
3.20
2.36
2.34
4.35
2.33
3.70
3.71
7.08
3.65
3.33
3.34
6.38
3.29
2.28
2.29
4.42
2.25
250
295
285
275
285
276
294
320
325
268
282
308
16.59
16.51
16.74
17.68
14.74
14.68
14.96
15.75
9.89
16.63
16.54
16.79
17.72
14.79
14.71
15.01
15.79
9.93
CoO
NiO
CuO
ZnO
CoO
NiO
CuO
ZnO
CoO
NiO
CuO
ZnO
9
10
11
12
13
14
15
9.82
10.18
10.61
9.87
10.22
10.64
11.6
24.8
4
∼23,000 cm−1 (434 nm) corresponding to 4T1g(F)→ T2g(F) (v1)
range 1.75–2.20 B.M. and is temperature independent in nature
and dose not indicate major interaction between unpaired elec-
trons of neighboring Cu(II) ions. The representative spectrum
of the [Cu(BAIME)2].2H2O complex is shown in Figure 2.
4
4
transition and T1g(F)→ T1g(P) (v3) transition, respectively,
under octahedral symmetry. The electronic spectra of Ni(II)
complexes show three well-resolved bands at ∼9,800 cm−1
(1020 nm), ∼16,400 cm−1 (609 nm), and ∼25,800 cm−1
1H-NMR Spectra
(387nm) assignableto 3A2g(F)→ T2g(F) (v1), 3A2g(F)→ T1g(F)
3
3
1
(v2), and 3A2g(F)→ T1g(P) (v3) transitions, respectively, under
3
The H NMR spectrum of the ligand HBAIPE displays a
complex multiplet in the region δ 8.0–8.7 ppm pertaining to
14 aromatic protons of the three phenyl groups only, while the
signals due to ring NH proton and exocyclic NH proton ap-
pear at δ 7.0 and δ 9.0 ppm, respectively. On the other hand,
the ligand HBAIME shows a complex broad multiplet in the
region δ 8.0–8.5 ppm corresponding to four aromatic protons
while the singlet due to ring NH proton and ring exocyclic NH
proton appear at δ 7.1 and δ 9.1 ppm, respectively, and a sin-
glet at δ 9.1 ppm for ring NH proton and exocyclic NH proton,
respectively. It is to be noted that, instead of getting two peaks
as observed in case of ligand HBAIME due to –CH3 protons,
only one 1H NMR peak at δ 2.5 ppm is observed in the ligand
HBAIME. But in case of HBAIE complexes a new signal at ∼δ
6.5 ppm ( CH CH ) is observed, conforms the coordination
of ligand to the metal center through conversion of keto form
to the enolic form. The signal due to ring NH proton shows a
downfield shifts appearing at δ 7.5 ppm indicating coordination
through ring NH group of benzimidazolyl moiety in the com-
plexes. The proton signals due to exocyclic NH proton is absent
octahedral field. The electronic spectra of Cu(II) complexes
show two main bands at ∼14,600 cm−1 (684 nm) (v2) and
∼16,340 cm−1 (611 nm) (v3) assignable to B1g→ B2g and
2
2
2B1g→ Eg transitions, respectively, under D4h symmetry.
2
The magnetic moment values of octahedral Co(II) com-
plexes, specially in weak and medium field strength, generally
lie in the range 4.7–5.2 B.M., indicating much higher value
than expected spin only value for three unpaired electrons. The
higher value can be attributed to large orbital contribution, which
is reinforced by spin orbit coupling. The magnetic moment
values of tetrahedral Ni(II) complexes usually lie in the range
3.7–4.0 B.M. that are higher than those of octahedral complexes.
Magnetic moment of mononuclear Cu(II) complexes lie in the
1
in the H NMR spectra of the complexes indicating deproto-
nation of enolic OH via tautomerization after complexation in
conformity with the results of IR investigations, while the po-
sitions of other 1H NMR peak of the ligands remain practically
unaltered in the present complexes.
Based on the foregoing observations the following tentative
structures (Figure 3) have been proposed for the present com-
plexes.
FIG. 2. Electronic spectrum of [Cu(BAIME)2].2H2O.

TRANSITION METAL COMPLEXES WITH BENZIMIDAZOLYL-2-HYDRAZONES
647
Gentamycin as a standard drug. At concentration 1000 μmg
mL−1 compounds show better antifungal screening (i.e., inhi-
bition was found to increase with increasing concentration of
metal complex).[28]
It has been observed that on comparison with reference to
fungicides the complexes were found to be more effective than
ligands. It is suggested that complexation tends to make the
ligand to act as more potent fungal agent than the free ligand.
Moreover, coordination reduces the polarity[29,30] of the metal
ion mainly because of the partial sharing of its positive charge
within the chelate ring formed during coordination. This pro-
cess increases the lipophilic nature of the central metal atom,
which favors its permeation more efficiently through the lipid
layer of the microorganism[31–33] thus destroying them more
aggressively. In addition to this, many other factors, such as sol-
ubility, dipole moment, and conductivity, which are influenced
by the metal ion may be the possible reasons for the antifungal
activities of these metal complexes.[34]
FIG. 3.
Electrochemical Study
Antifungal Activity
The cyclic voltammogram of copper complexes was recorded
The antifungal activities of the compounds were determined in DMSO solution (1.1 to –1.5 V potential range). The na-
against two fungal strains (i.e., A. niger and A. flavus) by potato ture of cyclic voltammogram is similar for all the complexes.
dextrose agar diffusion method.[27] The ligands and its com- Hence the representative Cu(II) (6) is discussed here. A cyclic
plexes were mixed directly at different concentrations as 100, voltammogram of [Cu(BAIE)2] 2H2O (6) (Figure 5) displays
200, 400, 800, and 1000 μmg mL−1. All the newly synthe- a well defined redox process corresponding to the formation
sized compounds show considerable inhibition capacity against of Cu(II)/Cu(III) couple at Epa = 0.53 V and the associated
all the species screened. The results of the antifungal screen- anodic peak at Epc = 0.46 V. This couple is found to be re-
ing are presented in Table 3. DMSO was used as a control and versible with ꢁEp = 0.07 V and the ratio of anodic to cathodic
TABLE 3
Antifungal activities of the ligands and their metal complexes
Representation zone of inhibition (μmg mL−1
)
Aspergillus niger
Aspergillus flavus
Compound
100
200
400
800
1000
100
200
400
800
1000
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
9.2
11.6
14.2
16.5
13.2
15.2
11.3
18.6
16.7
15.7
14.2
19.4
18.2
17.4
16.5
57.4
13.1
15.4
18.5
21.6
17.6
19.6
14.8
23.1
20.3
19.3
18.4
26.2
24.6
23.5
21.6
62.1
16.2
19.8
23.4
27.3
22.4
23.4
18.3
33.2
27.1
27.2
25.7
34.3
32.7
30.4
26.4
73.6
28.7
34.3
40.6
35.2
33.7
32.5
30.4
46.6
42.3
40.1
38.6
66.3
60.2
54.7
48.4
82.4
53.6
50.7
58.1
64.1
58.6
57.6
55.5
64.2
61.0
59.3
55.3
78.5
74.6
70.3
64.2
90.3
7.3
12.4
15.2
13.6
13.3
14.6
12.2
17.1
16.3
17.5
18.3
18.5
16.5
16.3
16.7
51.8
11.9
17.5
19.1
18.3
17.2
17.2
16.7
25.3
23.4
21.2
23.2
26.6
23.6
22.5
21.3
58.3
15.7
24.3
24.3
24.8
22.3
22.4
20.3
31.5
32.4
31.2
28.3
36.1
34.7
31.8
28.3
76.2
25.4
33.5
34.4
32.6
31.6
33.2
31.2
43.4
44.3
42.5
35.6
68.5
62.7
53.7
45.2
85.7
49.6
53.6
56.2
60.3
57.8
56.8
55.7
67.3
65.2
64.4
58.2
76.7
72.3
70.2
65.3
94.4
Gentamycin (std.)

648
R. K. MOHAPATRA ET AL.
12. Dash, D. C.; Mahapatra, A.; Pathjoshi, S. B.; Mishra, U. K.; Naik, S. K. J.
Ind. Chem. Soc. 2006, 83, 782.
13. Dash, D. C.; Mahapatra, A.; Jena, P.; Naik, S. K.; Mishra, U. K. J. Ind.
Chem. Soc. 2007, 84, 1092.
14. Dash, D. C.; Mahapatra, A.; Mohapatra, R. K.; Ghosh, S.; Naik, P. Ind. J.
Chem. 2008, 47A, 1009.
15. Dash, D. C.; Mohapatra, R. K.; Ghosh, S.; Naik, P. J. Kor. Chem. Soc. 2008,
52, 468.
16. Dash, D. C.; Mohapatra, R. K.; Ghosh, S.; Naik, P. J. Ind. Chem. Soc. 2009,
86, 121.
17. Mohapatra, R. K. J. Ind. Chem. Soc. 2010, 87, 1251.
18. Mohapatra, R. K.; Dash, D. C. J. Kor. Chem. Soc. 2010, 54, 395.
19. Dash, D. C.; Mahapatra, A.; Naik, P.; Mohapatra, R. K.; Naik, S. K. J. Kor.
Chem. Soc. 2011, 55, 412.
20. Katz, L. J. Am. Chem. Soc. 1951, 73, 4007.
21. Vogel, A. I. A Text Book of Quantitative Inorganic Analysis, 3rd edn. Long-
mans, New York, 1969.
FIG. 4. Cyclic voltammogram of [Cu(BAIE)2] .2H2O.
22. Rao, C. N. R. Chemical Applications of Infrared Spectroscopy; Academic
peak currents corresponding to a simple one electron process.
The complexes also show a reversible peak in the negative re-
gion, characteristic of the Cu(II)/Cu(I) couple at Epc = –0.92 V,
with the associated anodic peak at Epa = –0.35 V and ꢁEp
= 0.57 V for Cu(I)→Cu(II) oxidation.[35–37] The representative
cyclic voltammogram of [Cu(BAIE)2] 2H2O complex is shown
in Figure 4.
Press, New York, 1963.
23. Pinchas, S.; Silver, B. L.; Laulicht, I. J. Chem. Phys. 1967, 46, 1506.
24. Ferraro, J. R. Low Frequency Vibrations of Inorganic and Coordination
Compounds; Plenum Press, New York, 1971.
25. Singh, H. R.; Agarwala, B. V. J. Ind. Chem. Soc. 1988, 35, 591.
26. Nikolaev, A. V.; Lagvienko, V. A.; Myachina, I. Thermal Analysis; Aca-
demic Press, New York, 1969.
27. Kannan, N. Laboratory Manual in Microbiology; Palani Paramount, Palani,
India, 1996.
28. Mohanan, K.; Devi, S. N. Russian J. Coord. Chem. 2006, 32, 600.
29. Lever, A. B. P. Inorganic Electronic Spectroscopy; Elsevier, New York,
1968.
REFERENCES
1. Samy, C. R.; Radhey, S. Ind. J. Chem. 1996, 35A, 1.
2. Shen, X.; Yang, Q. L. C. Synth. React. Inorg. Met.-Org. Chem. 1996, 26,
1135.
30. Balhausen, C. J. An Introduction to Ligand Field; McGraw Hill, New York,
1962.
3. Sridhar, S. K.; Pandeya, S. N.; Stables, J. P.; Ramesh, A. Eur. J. Pharm. Sci.
2002, 16, 129.
4. Vicini, P.; Zani, F.; Cozzini, P.; Doytchinova, I. Eur. J. Med. Chem. 2002,
37, 553.
5. Kocyigit-Kaymakcioglu, B.; Rollas, S. Farmaco 2002, 57, 595.
6. Ragavendran, J. V.; Sriram, D.; Patel, S. K.; Reddy, I. V.; Bharathwajan,
N.; Stables, J.; Yogeeswari, P. Eur. J. Med. Chem. 2007, 42, 146.
7. Rollas, S.; Gulerman, N.; Erdeniz, H. Farmaco 2002, 57, 171.
8. Carcelli, M.; Mazza, P.; Pelizi, C.; Zani, F. J. Inorg. Biochem. 1995,
57, 43.
31. Chohan, Z. H.; Pervez, H.; Kausar, S.; Supuran, C. T. Synth. React. Inorg.
Met.-Org. Chem. 2002, 3, 529.
32. Chohan, Z. H.; Pervez, H.; Rauf, A.; Supuran, C. T. Met.-Based Drugs
2002, 8, 42.
33. Chohan, Z. H.; Scozzafava, A.; Supuran, C. T. J. Enzym. Inhib. Med. Chem.
2003, 18, 259.
34. Chohan, Z. H.; Hassan, M. U.; Khan, K. M.; Supuran, C. T. J. Enzym. Inhib.
Med. Chem. 2005, 20, 181.
35. Zanello, P.; Seeber, R.; Cinquantini, A.; Mazzocchin, G. A.; Fabbrizzi, L.
J. Chem. Soc., Dalton Trans. 1982, 893.
9. Johnson, D. K.; Murphy, T. B.; Rose, N. J.; Goodwin, W. H.; Pickart, L.
36. Jeyasubramanian, K.; Samath, S. A.; Thambidurai, S.; Murugesan, R.; Ra-
malingam, S. K. Transition Met. Chem. 1996, 20, 76.
37. Pilo, M. I.; Manca, G.; Zoroddu, M. A.; Seeber, R. Inorg. Chem. 1991, 30,
225.
Inorg. Chim. Acta 1982, 67, 159.
10. Ranford, J. D.; Vittal, J. J.; Wang, Y. M. Inorg. Chem. 1998, 37, 1226.
11. Buss, J. L.; Greene, B. T.; Turner, J.; Torti, F. M.; Torti, S. V. Curr. Top.
Med. Chem. 2004, 4, 1623.