Synthesis, characterization, thermal degradation, X-Ray and DNA binding studies on Metal(II) and Mixed metal hydrazone glyoxylate dihydrates: A typical one Step Aqueous Condensation Reaction

Article abstract of DOI:10.14233/ajchem.2017.20609

Glyoxylic acid condenses with hydrazine hydrate in the presence of transition metal(II) ions viz., Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺ or Zn²⁺ resulting in the formation of metal(II) hydrazoneglyoxylate dihydrates. The compositions of these complexes, [M(OOCCH=NNH2)2(H2O)2] were assigned on the basis of hydrazine and metal analyses and further characterized by magnetic susceptibility measurements, UV-visible, infrared, ¹H and ¹³C NMR and D2O exchange spectra, simultaneous TG-DTA analyses and X-ray powder diffraction techniques. The magnetic moments and UV-visible spectra indicate that these complexes are of high-spin octahedral geometry. The infrared spectra reveal the monodentate coordination of carboxylate ions and coordination of water molecules. The TG-DTA traces are in accordance with the formation of respective metal oxide as the end product after initial dehydration and further pyrolyses of the anhydrous complexes. The X-ray powder diffraction patterns indicate the isomorphism among the series of complexes. In these complexes the metal ions are octahedrally surrounded by two bidentate hydrazoneglyoxylate ions and two water molecules. The isomorphism among the series of complexes has been exploited in the preparation of mixed metal complexes. The mixed metal complex when heated to 300 °C in a pre-heated silica crucible undergoes autocatalytic decomposition to yield respective metal cobaltite, MCo2O4 as the final residue. The formation of the mixed metal complexes and metal cobaltites are confirmed by their infrared spectra and X-ray powder diffraction patterns. TG-DTA of the complexes also supports the formation of metal cobaltites. The particle size and SEM analyses of simple oxides and mixed metal oxides were carried out for further application of these metal cobaltites as catalysts. The interaction of Zn(II) complex with calf thymus DNA was investigated by absorption spectra. The DNA binding affinity of Zn(II) complex is 2.60 × 10⁴ M^-1 which reveals the strong binding affinity.

Full text of DOI:10.14233/ajchem.2017.20609

Asian Journal of Chemistry; Vol. 29, No. 8 (2017), 1746-1752
ASIAN JOURNAL OF CHEMISTRY
https://doi.org/10.14233/ajchem.2017.20609
Synthesis, Characterization, Thermal degradation, X-Ray and DNA Binding Studies on Metal(II) and
Mixed Metal Hydrazone Glyoxylate Dihydrates: A Typical One Step Aqueous Condensation Reaction
*
R. PRADEEP and B.N. SIVASANKAR
Department of Chemistry, Government Arts College, Udhagamandalam, The Nilgiris-643 002, India
*
Corresponding author: E-mail: sivabickol@yahoo.com
Received: 27 February 2017; Accepted: 27 April 2017;
Published online: 12 June 2017;
AJC-18435
2+
2+
2+
2+
2+
Glyoxylic acid condenses with hydrazine hydrate in the presence of transition metal(II) ions viz., Mn , Co , Ni , Cu or Zn resulting
in the formation of metal(II) hydrazoneglyoxylate dihydrates. The compositions of these complexes, [M(OOCCH=NNH
2
)
2
(H
2
2
O) ] were
assigned on the basis of hydrazine and metal analyses and further characterized by magnetic susceptibility measurements, UV-visible,
1
13
infrared, H and C NMR and D O exchange spectra, simultaneous TG-DTA analyses and X-ray powder diffraction techniques. The
2
magnetic moments and UV-visible spectra indicate that these complexes are of high-spin octahedral geometry. The infrared spectra reveal
the monodentate coordination of carboxylate ions and coordination of water molecules. The TG-DTA traces are in accordance with the
formation of respective metal oxide as the end product after initial dehydration and further pyrolyses of the anhydrous complexes. The X-
ray powder diffraction patterns indicate the isomorphism among the series of complexes. In these complexes the metal ions are octahedrally
surrounded by two bidentate hydrazoneglyoxylate ions and two water molecules. The isomorphism among the series of complexes has
been exploited in the preparation of mixed metal complexes. The mixed metal complex when heated to 300 °C in a pre-heated silica
crucible undergoes autocatalytic decomposition to yield respective metal cobaltite, MCo
2
4
O as the final residue. The formation of the
mixed metal complexes and metal cobaltites are confirmed by their infrared spectra and X-ray powder diffraction patterns. TG-DTA of the
complexes also supports the formation of metal cobaltites. The particle size and SEM analyses of simple oxides and mixed metal oxides
were carried out for further application of these metal cobaltites as catalysts. The interaction of Zn(II) complex with calf thymus DNA was
4
-1
investigated by absorption spectra. The DNA binding affinity of Zn(II) complex is 2.60 × 10 M which reveals the strong binding
affinity.
Keywords: Hydrazoneglyoxylate, Transition metal(II) complexes, Metal cobaltites, DNA binding.
coordination mode without the participation of the nitrogen
INTRODUCTION
atoms from the -C=N- groups. However, if a base is added
Condensation of aldehydes with simple and higher
into the reaction solution, the acidic hydrogen atoms are
neutralized, forming -1 charged ligand, which are able to
coordinate with transition and rare earth metal ions using the
naked nitrogen atom(s). Depending on the reaction conditions
employed (acidic or alkaline) complexes were formed with
different compositions.
Hydrazine is a versatile and simplest diamine provides
access to the syntheses of innumerable organic and inorganic
compounds including coordination complexes and coordi-
nation polymers. Besides its applications in organic synthesis,
hydrazine and its derivatives have been exhaustively exploited
in the preparation of number of coordination compounds with
several varieties such as mono, bis-, tris-hydrazine and hydrazi-
nium metal complexes.Among the anions used [1], carboxylate
ions are specific in the sense that their complexes undergo
complete pyrolyses resulting in the formation of pure metal
molecular weight amines conducted in non-aqueous medium
to extract hydrazides. Imines and substituted imines type
Schiff’s base ligands have been revealed to possess stronger
coordination ability resulting in an emerging interest. It is well
known that imines are not very stable compounds and are easy
to hydrolyze. Hence, synthesis of free imine type Schiff”s base
ligands in the metal free environment with high yield becomes
more difficult due to their side polymerization reactions. One
effective method to fix this problem involves an ‘in situ’reaction.
In other words, the metal ion acts as a templating agent, direc-
ting the condensation without polymerization.
Research and review of literature show that the pH values
play a vital role in determining the type of complexes formed
during the course of the reaction. When the pH is between 5
and 6, the ligand does not ionize and mostly adopts the neutral

Vol. 29, No. 8 (2017)
Studies on Metal(II) and Mixed Metal Hydrazone Glyoxylate Dihydrates 1747
oxides and mixed metal oxides like chromites, manganites,
ferrites and cobaltites [2-5].
contained in the filtrate after the separations were estimated
by titration with standard Na EDTA solution. Room tempe-
rature magnetic susceptibility measurements were carried out
by Gouy balance using Hg[Co(NCS) ] as a calibrant. The
H
2 2
The need and role of hydrazine in their complexes are
due to the presence of N–N bond which is endothermic and
hence undergoes violent exothermic degradation during
pyrolyses. This liberates enormous amount of heat energy
which in turn utilized naturally to decompose the organic part
of the complexes.
In spite of a number of acid hydrazides prepared and utilized
as neutral ligands in the preparation of metal complexes, the
hydrazone carboxylic acids and their complexes are less in
the literature. Among the carboxylic acids, glyoxylic acid is
the simplest carboxylic acid possessing an aldehyde group
shows interesting chemical behaviour. In the present investi-
gation it is observed that glyoxylic acid has the ability to undergo
condensation with hydrazine in aqueous medium at room
temperature. In the presence of metal ion the above product,
hydrazoneglyoxylate generated in situ form insoluble comp-
lexes in aqueous solution. These complexes are expected to
show interesting structural and thermal properties.
The aqueous condensation reaction and the metal hydra-
zoneglyoxylates are new to the literature except the cadmium
complex for which the crystal structure has been reported [6].
Furthermore, these hydrazonecarboxylate complexes have not
been prepared and utilized so far in the preparation of mixed
metal oxides though hydrazine complexes were used as
precursors for metal oxides and mixed metal oxides such as
cobaltites and ferrites [7-10]. The difficulty with hydrazine
based mixed metal complexes in the synthesis of metal
cobaltites is mainly due to their violent decomposition and
explosion when heated. However, the present series of complexes
show smooth, self sustaining and autocatalytic degradation
behaviour. Hence, in this paper we wish to report the synthesis,
spectral, thermal and X-ray diffraction studies on metal and
mixed metal hydrazoneglyoxylate hydrates.
4
diamagnetic corrections were applied by summing up the
Pascal’s constants for the diamagnetic contributions of various
atoms of the molecule. Due to the insoluble nature of the
complexes in water and most of the organic solvents, the solid
state absorption spectra of the complexes in nujol mull were
recorded on aVarian 5000 UV-visible spectrophotometer. The
infrared spectra of the complexes were recorded on a Perkin-
-1
Elmer 597 spectrophotometer in the range 4000-400 cm using
KBr pellets of the samples. The simultaneous TG-DTA of the
samples in air and nitrogen atmosphere were recorded using a
SWI TG/DTA 6200 thermal analyzer using about 5 mg of the
sample with the heating rate of 10 °C per min and platinum
cups as sample holders. The NMR spectra of zinc complex was
recorded on a Bruker FT- NMR 500 spectrometer operating at
1
13
500.13 MHz for both H NMR spectra and C NMR spectra
using DMSO as solvent and tetramethyl silane as internal
standard.
The X-ray powder diffraction patterns of the complexes
and metal oxides and mixed metal oxides were recorded on a
Philips PW 1050/70 employing Cu-K radiation of wavelength
α
λ = 1.5406 Å and recorded between the 2θ values 80° and 20°
at the scan rate of 2° per min. The SEM photographs of the
oxides and nickel cobaltite were recorded using a Cambridge
Stereoscan model S-150 scanning electron microscope. The
particle size distribution and polydipersity index (PDI) measu-
rements of the metal oxides and metal cobaltites were carried
out using a Horiba ZS-100-Green laser source (532 nm). All
measurements reported were made at a temperature of 25 °C
and performed at a scattering angle of 90°. Polydipersity index
(PDI) values were calculated from the cumulants analysis [14].
DNA binding studies
Electronic absorption titration: Electronic absorption
experiment was performed at room temperature to determine
the binding affinity between CT-DNA and Zn(II) complex.
Interaction of CT-DNA were carried out in buffer containing
EXPERIMENTAL
Glyoxylic acid monohydrate, hydrazine hydrate (99 %),
metal nitrate hydrates and other chemicals used were ofAnalaR
grade. The solvents were distilled before use and double distilled
water was used for the preparation and analyses of the comp-
lexes. Calf thymus DNA (CT-DNA) was purchased from Merck
and stored at 4 °C. Double distilled water was used throughout
the experiment.
5
mM Tris(hydroxyl-methyl)aminomethane and 50 mM NaCl
adjusted to pH 7.2 with hydrochloric acid. A solution of CT-
DNA gave a ratio of absorbance at 260 and 280 nm of about
1
.8 -1.9, indicating that CT-DNA was sufficiently free protein
15]. The CT-DNA concentration per nucleotide was deter-
mined by UV spectrophotometer employing molar absorption
[
The hydrazine contents were determined by volumetric
analysis using a 0.025 M KIO
3
solution underAndrew’s condi-
-1
-1
coefficient 6000 M cm at 260 nm [16].An appropriate amount
of Zn(II) complex is dissolved in a solvent mixture of 1 %
DMSO and 99 % Tris-HCl buffer.Absorption titration experi-
ments were performed with fixed concentration of the Zn(II)
complex while gradually increasing the concentration of CT-
DNA. From the absorption titration data, the binding constant
tion [11]. When concentrated HCl is added to the aqueous
suspension of complexes, the complexes decompose to give
hydrazine hydrochloride from which the quantity of hydrazine
was determined volumetrically. The metal contents in the
complexes were determined by EDTA complexometric titrations
after completely decomposing a known amount of complexes
with concentrated nitric acid for several times to eliminate the
organic portion of the molecule to obtain exclusively the respec-
tive metal nitrate hydrate [12]. The cobalt and metal ions
present in the mixed metal complex and metal cobaltites were
(
K
b
) of the complex was determined from eqn. 1, through a
plot of [DNA]/(ε – ε ) vs. [DNA].
DNA]/(ε – ε ) = [DNA]/(ε
where, [DNA] is the concentration of DNA and ε
a
f
[
a
f
b
– ε
f
b
) + 1/K (ε
b
– ε
f
)
(1)
and ε
a
, ε
f
b
determined by separating cobalt as Co(C10
using α-nitroso β-naphthol [13]. The divalent metal ions
H
6
ONO)
3
complex
the apparent extinction coefficient (Aobs/[M]), the extinction
coefficient for free metal complex (M) and the extinction

1
748 Pradeep et al.
Asian J. Chem.
coefficient for the free metal complex (M) in the fully bound
form, respectively. In plots of [DNA]/(ε – ε ) vs. [DNA], K is
given by the ratio of slope to intercept [17].
Preparation of complexes: To an aqueous solution (30
mL) respective metal nitrate hydrate (0.01 mol), an aqueous
solution (10 mL) of glyoxylic acid monohydrate (1.84 g, 0.02
mol) was added slowly with constant stirring. The resulting
clear solution was heated on a water bath in a round bottom
flask for about 2 h. To the hot solution, hydrazine monohydrate
qualitative tests confirmed the presence of hydrazine and
glyoxylic acid in the above solution.
The mixed metal complexes were prepared in the similar
fashion when aqueous mixtures of metal nitrates were used in
appropriate ratio. The chemical reactions for the formation of
the complexes may be represented as follows:
a
f
b
M(NO
3
)
2
.xH
2
O + 2HOOCCHO.H
2
O
M(OOCCHO) .yH
2
2
O + (x+2-y)H
2
O
M(OOCCHO) .yH
2
2
O + 2N
2
H
4
.H
2
O
M(OOCCH=NNH
2
)(H O) + (y+2)H O
2
2
2
(1 mL, 0.02 mol) in 10 mL of distilled water was added in drops
Where M = Mn, Co, Ni, Cu or Zn
with constant stirring. The mixture was further heated on
a boiling water bath for about 1 h. The resulting solution was
allowed to stand at room temperature. The complexes preci-
pitated after 8 to 12 h were filtered and washed with water,
then with alcohol and dried in air.
The complexes are stable in air except cobalt complex
which undergo decomposition on long standing. They are
insoluble in water and organic solvents and decompose in dilute
hydrochloric acid. However, the zinc complex is soluble in
DMSO. Higher yields of the complexes were obtained when
excess hydrazine hydrate (0.03 to 0.04 mol) was used though,
in the case of copper, addition of excess hydrazine resulted in
the precipitating copper metal.
Preparation of mixed metal complexes: The mixed metal
complex were prepared by the method described above by
using a mixture of cobalt nitrate hexahydrate (0.02 mol) and
nickel nitrate hexahydrate (0.01 mol), glyoxylic acid mono-
hydrate (0.02 mol) and hydrazine monohydrate (0.02 mol).
The complexes formed were homogeneous and stable in air.
Preparation of metal cobaltites: Metal cobaltites were
prepared by heating the metal-cobalt mixed metal complex in
a pre-heated silica crucible at 250 °C. Large amount of gases
2
/3Co(NO
3
)
2
.6H
2
O + 1/3M(NO
3
)
2
.6H
2
O + 2HOOCCHO.H
2
O
Co2/3
M
1/3(OOCCHO)
2 2
.yH O
+
(x+2-y) H O
2
Co2/3
M
1/3(OOCCHO)
2
.yH
2
O + 2N
2
H
4
.H
2
O
2 2 2 2
Co1/3M2/3(OOCCH=NNH )(H O) + (y+2)H O
Where M = Mn, Ni or Zn
The compositions of the metal complexes were assigned
on the basis of the metal and hydrazine analyses. The chemical
analyses data is summarized in Table-1.
Magnetic moments and electronic spectra:The magnetic
moments of the complexes are given in Table-1. These values
indicate that the complexes are of high-spin variety. The zinc
complex is diamagnetic as expected from its completely filled
3
d orbital [18]. The electronic spectrum of cobalt complex
-1
shows a broad band as a doublet at 20,250 and 19,200 cm
which are assigned to the T1g(F) → T1g(P) transition in which
the splitting is attributed to the spin-orbit coupling in the T1g(P)
state. The nickel complex shows two strong bands at 26,600
4
4
4
-1
3
3
and 17,400 cm which are assigned to the A2g → T1g(F) and
3
3
A
2g → T1g(P) transitions, respectively. The copper complex
-1
2
2
shows a band at 16,700 cm due to the E2g → T2g transition.
All these observation suggest octahedral geometry around the
metal ions [19].
Infrared spectra: The infrared spectrum of glyoxylic acid
such as CO
2
, H O, etc., are evolved during decomposition and
2
-1
shows two important bands at 1740 and 1628 cm for the carbonyl
stretching of free carboxylic acid and aldehyde groups,
respectively. These two bands disappeared in the complexes
and a new band appeared at 1643 cm which is attributed to
the –CH=N– stretching which supports the condensation
between glyoxylic acid and hydrazine. The monodentate
coordination behaviour of carboxylate ions are supported by
two bands in the range 1600-1590 cm and 1370-1360 cm
which are assigned for νasy and νsym stretchings of carboxylate
ions.A sharp band observed at 3400 cm revealed the presence
of coordinated water molecules in the complexes [20,21]. The
infrared spectrum of nickel and cobalt-nickel mixed metal
complexes are shown in Figs. 1 and 2, respectively.
swelling was observed during the process.
RESULTS AND DISCUSSION
-1
Metal nitrate hydrates in aqueous medium react with glyo-
xylic acid to yield metal glyoxylate hydrates. When hydrazine
hydrate was added to the metal glyoxylate hydrates the free
aldehydic groups present undergo condensation with the
elimination of water to yield hydrazoneglyoxylate complexes.
These complexes are stable in air and insoluble in water and
other organic solvents except zinc complex which is partially
soluble in DMSO. When dissolved in dilute hydrochloric acid
they undergo decomposition to give respective metal chloride
along with hydrazine hydrochloride and glyoxylic acid. The
-
1
-1
-
1
TABLE-1
ANALYTICAL DATA OF THE COMPLEXES
Complex (empirical
formula)
Physical
appearance
Elemental analysis (%): Found (calcd.)
Magnetic moment
m.w.
(µ , BM)
eff
M
Co
N H
2
4
MnX Y2
265.08
269.07
268.84
273.69
275.54
267.72
268.97
271.21
Colourless
Pink
Green
Blue
Colourless
Light pink
Greenish pink
Red
19.81 (20.72)
21.06 (21.90)
22.54 (21.83)
22.78 (23.21)
23.34 (23.73)
6.58 (6.84)
7.51 (7.27)
7.80 (8.04)
-
-
-
-
23.67 (24.14)
24.60 (23.78)
23.19 (23.80)
22.86 (23.38)
23.92 (23.22)
23.70 (23.90)
23.08 (23.79)
23.20 (23.59)
5.64
4.76
2.9
1.8
2
CoX Y2
2
NiX Y2
2
CuX Y
2 2
ZnX Y2
-
Diamagnetic
2
Mn Co X Y
14.20 (14.67)
14.05 (14.60)
14.00 (14.48)
-
–
–
1/3
2/3
2
2
Ni Co X Y
2
1/3
2/3
2
Zn Co X Y
2
1/3
2/3
2
X = (OOCCH=NNH ); Y = (H O)
2
2

Vol. 29, No. 8 (2017)
Studies on Metal(II) and Mixed Metal Hydrazone Glyoxylate Dihydrates 1749
100
50
9.5
9.0
8.5
8.0
7.5
7.0
δ
(ppm)
1
Fig. 3. H NMR spectrum of Zn(OOCCH=NNH ) (H O)
2 2 2 2
0
4000
3000
2000 –1
Wavenumber (cm )
1000
O)
400
Fig. 1. IR spectrum of Ni(OOCCH=NNH
2
2
) (H
2
2
100
50
7
.5 7.4 7.3 7.2 7.1 7.0 6.9 6.8 6.7 6.6 6.5 6.4 6.3 6.2
(ppm)
O exchange spectrum of Zn(OOCCH=NNH
δ
Fig. 4. D
2
2 2 2 2
) (H O)
continued to yield respective metal oxide as the final residue.
However, manganese and zinc complexes resulted in the
formation of respective metal carbonate as the end residue.
In air also the present series of complexes show similar
degradation trend, dehydration and ligand pyrolysis resulting
in the formation of metal oxides in all the cases. The mixed
metal complex was also subjected to thermal degradation in
air and the end residue was found to be the respective metal
cobaltite. The thermal degradation data for the complexes in
nitrogen and air are summarized in Tables 2 and 3, respectively.
The simultaneous TG-DTA traces of manganese and cobalt
complexes in nitrogen atmosphere are shown in Figs. 5 and 6,
respectively. The simultaneous TG-DTA curves for cobalt-
nickel mixed metal complex in air are also shown in Fig. 7.
0
4
000
3000
2000
Wavenumber (cm )
1000
400
–1
Fig. 2. IR spectrum of Ni1/3Co2/3(OOCCH=NNH ) (H O)
2 2 2 2
1
13
1
H NMR and C NMR spectrum:The H NMR spectrum
of the zinc complex was recorded in DMSO. The signal for
the azomethine proton was observed at δ 6.98 ppm. The signals
for NH
and δ 7.30 ppm, respectively. The D
the complex clearly shows the disappearance of the signals
2
protons and OH
2
protons are observed at δ 7.04 ppm
2
O exchange spectrum of
1
for NH
2
protons and OH
2
protons. The H NMR spectrum and
D
3
2
O exchange spectrum of the zinc complex are shown in Figs.
13
and 4, respectively. In C NMR two signals are observed
166.87 ppm and
196.90 ppm, respectively. These peaks are slightly shifted
TABLE-2
THERMAL DATA IN NITROGEN ATMOSPHERE
for azomethine and carboxylate carbon at δ
C
δ
C
DTA peak
temp. (°C)
TG temp.
range (°C)
TG weight loss
Found Calcd.
Compd.
Residue
MnX
to downfield region (compared with ligand) indicating the
azomethine nitrogen and carboxylate oxygen atoms are strongly
coordinated with metal(II) ion.
147 (+)
110-165
190-400
125-170
200-250
130-190
190-250
160-190
200-250
110-180
185-400
14.00
56.00
14.00
70.00
14.00
73.00
13.00
69.00
14.00
54.00
13.59
56.63
13.39
69.18
13.40
72.21
13.16
70.93
13.08
54.48
2
MnX Y2
2
2
1
2
1
2
1
14 (-)
61 (+)
39 (-)
77 (+)
36 (-)
85 (+)
MnCO3
CoX2
Thermal degradation studies: The presence of water
molecule and their nature (coordinated of lattice water) could
be determined byTG/DTA studies. In the present case, in nitrogen
atmosphere all the complexes show a sharp endotherm in the
temperature range 145-190 °C which is strong evidence for
the presence of coordination water molecules. The TG-weight
losses are well in accordance with the elimination of two water
molecules. After dehydration, pyrolysis of the organic ligand
CoX Y2
2
Co O3
2
NiX
2
2
NiX Y2
NiO
CuX2
CuO
CuX Y2
2
210 (-)
146 (+)
ZnX
ZnCO3
2
ZnX Y2
2
206 (-)
X = (OOCCH=NNH ; Y = (H O); (+): endotherm; (-): exotherm
2
)
2

1
750 Pradeep et al.
Asian J. Chem.
TABLE-3
THERMAL DATA IN AIR
DTA peak
temperature (°C)
TG temperature
range (°C)
TG weight loss
Compd.
MnX Y
Residue
MnX2
Found
Calcd.
1
60 (+)
30 (-)
70 (+)
40 (-)
50 (+)
71 (-)
60 (+)
20 (-)
80 (+)
220 (-)
00 (-)
70 (+)
140-200
220-320
160-210
200-250
200-240
250-320
180-200
200-230
160-180
180-250
250-420
160-180
180-230
180-200
200-240
170-200
200-260
13.00
70.00
12.00
62.00
13.00
72.00
13.50
70.00
12.50
55.00
71.00
11.90
69.80
12.50
69.00
11.30
69.00
13.59
70.22
13.39
61.64
13.40
72.21
13.16
70.93
13.08
54.48
70.45
11.97
70.52
13.45
70.19
11.82
69.62
2
2
2
1
Mn O3
2
CoX2
CoX Y
2
2
2
1
Co O3
2
NiX2
NiO
CuX2
CuO
ZnX2
NiX Y
2
2
2
1
CuX Y
2
2
2
1
ZnX Y
ZnCO3
ZnO
2
2
4
1
Mn Co X
1
/3
2/3
2
Mn Co X Y
2
1
/3
2/3
2
221(-)
MnCo O4
2
190 (+)
Ni Co X
1
/3
2/3
2
Ni Co X Y
2
1
/3
2/3
2
2
1
2
30 (-)
80 (+)
50 (-)
NiCo O4
2
Zn Co X
1/3 2/3 2
Zn Co X Y
2
1
/3
2/3
2
ZnCo O4
2
X = (OOCCH=NNH ); Y = (H O); (+): endotherm; (-): exotherm.
2
2
8
4
0
60
40
1
8
6
4
2
0
00
1
8
6
4
2
00
0
0
20
0
-
2
0
0
0
-
6
0
-20
0
-
10
0
0
200
400
600
800
Temperature (°C)
Fig. 7. Simultaneous TG-DTA of Ni1/3Co2/3(OOCCH=NNH
)
2 2
(H
2
O) in air
2
-
14
0
200
400
Temperature (°C)
600
800
Fig. 5. Simultaneous TG-DTA of Mn(OOCCH=NNH
)
2 2
(H
2
O)
2
in nitrogen
1
2
8
4
100
(a)
8
0
0
6
0
2
-
40
20
0
(b)
-6
-
10
(c)
0
200
400
Temperature (°C)
600
800
1
0
20
30
40
50
60
O)
Fig. 6. Simultaneous TG-DTA of Co(OOCCH=NNH ) (H O) in nitrogen
2 2 2 2
2
θ
(°)
Fig. 8. X-ray powder diffraction patterns of (a) Co(OOCCH=NNH
b) Ni(OOCCH=NNH (H O) and
(c) Ni1/3Co2/3(OOCCH=NNH (H O)
)
2 2
(H
2
2
XRD: The present set of complexes shows almost super
imposable powder pattern which reveal the isomorphism
among the complexes. The mixed metal complex also shows
a similar pattern with sharp lines indicating the formation of
solid solutions. X-ray powder diffraction patterns of Co, Ni
and Ni-Co complexes are shown in Fig. 8.
(
2
)
2
2
2
2
)
2
2
2
DNA binding studies
Electronic absorption titration: The electronic absor-
ption spectroscopy is most common and useful technique to

Vol. 29, No. 8 (2017)
Studies on Metal(II) and Mixed Metal Hydrazone Glyoxylate Dihydrates 1751
determine interaction of complexes with DNA [22]. The Zn(II)
complex in DMSO-buffer mixture exhibit intense band at 261
nm and also show hyperchromic effect with blue shift (about
which were assigned to the M–O stretching of tetrahedral and
octahedral sites, respectively (Table-4). The X-ray powder
pattern of NiCo
2
O is in agreement with the standard pattern
4
1
nm) indicate that complex bind to DNA by external contact
[26]. The SEM photograph of the nickel cobaltite shows lot of
voids and cracks indicating the large quantity of gases evolved
possibly via electrostatic binding [23,24]. The absorption
intensities of Zn(II) complex increased (hyperchromism) upon
increasing the concentration of CT-DNA preferably binding
to the DNA helix via groove binding interaction [25]. Thus
the conformation changes of CT-DNA occur due to damage
or unwinding of the double helix structure. The binding constant
during the decomposition. The SEM photograph of NiCo
O
2 4
is shown in Fig. 10. The SEM image shows irregularly shaped
agglomerated particles of sub micron size.
K
b
for Zn(II) complex is determined from plot of [DNA]/(ε
a
-ε )
f
4
-1
vs. [DNA] and found to be 2.60 × 10 M indicating strong
binding affinity. The absorption spectral trace of Zn(II) complex
is shown in Fig. 9.
Characterization of metal cobaltites: The infrared spec-
-1
trum of nickel cobaltite shows two bands at 660 and 555 cm
1
1
0
0
0
.663
.316
.698
.620
.272
1
1
0
0
0
.2
.0
.8
.6
.4
4
–1
Kb = 2.60 × 10
M
0
1
2
3
4
–5
[
DNA] × 10
M
2 4
Fig. 10. SEM photograph of NiCo O
Particle size distribution: The particle size distribution
values of the metal oxides were obtained from the light sca-
ttering measurements. The polydispersity index (PDI) values
were calculated from cumulant operation. The particle size
distribution and polydispersity index (PDI) of oxides are
summarized in Table-5. The mean intensity diameter of cobalt
and nickel oxides are shown in Fig. 11.
-
0.076
2
00
320
Wavelength (nm)
Fig. 9. Absorption trace of Zn(II) complex
400
70
60
50
40
30
20
10
0
60
218.6
(a)
(b)
246.9
50
40
30
20
10
0
0
500
1000 1500
Diameter (nm)
2000
2500
0
500
1000 1500
Diameter (nm)
2000
2500
50
40
30
20
10
0
50
40
30
20
10
0
356.2
279.4
(c)
(d)
0
500
1000 1500
Diameter (nm)
2000
2500
0
500
1000 1500
Diameter (nm)
2000
2500
Fig. 11. Particle size distribution of (a) Co
2
O
3
and(b) NiO (c) NiCo
2
O
3
(d) MnCo
2
O
4

1
752 Pradeep et al.
Asian J. Chem.
TABLE-4
ANALYTICAL AND SPECTRAL DATA OF METAL COBALTITES
–
1
Cobalt (%)
Metal (%)
Co/M ratio
Found
IR spectra (cm )
Oxide
XRD (Å)
Found
Calcd.
Found
Calcd.
ν1
ν2
MnCo O4
50.00
49.30
47.00
49.78
49.00
47.67
23.00
24.00
26.00
23.20
24.40
26.45
2.01
1.99
1.98
658
663
660
562
560
558
8.193
8.132
8.154
2
NiCo O4
2
ZnCo O4
2
TABLE-5
PARTICLE SIZE ANALYSIS
8. P. Ravindranathan, G.V. Mahesh and K.C. Patil, J. Solid State Chem.,
66, 20 (1987);
https://doi.org/10.1016/0022-4596(87)90216-7.
9. K.C. Patil, D. Gajapathy and V.R.P. Verneker, Mater. Res. Bull., 17, 29
Particle size by
intensity (nm)
Polydipersity index
(PDI)
Metal oxides
(
1982);
MnO2
214.66
218.60
246.90
255.24
261.40
268.28
279.44
356.21
230.56
2.562
2.743
3.800
3.844
3.891
3.924
3.968
4.292
3.214
https://doi.org/10.1016/0025-5408(82)90179-9.
10. G.C. Ulmer and W.J. Smothers, J. Am. Ceram. Soc., 51, 315 (1968);
https://doi.org/10.1111/j.1151-2916.1968.tb15945.x.
11. A.I. Vogel,A Text Book of Quantitative InorganicAnalysis, Longmans,
London, edn 3 (1962).
2
Co O3
NiO
CuO
ZnO
CdO
12. L. Erdey and I. Buzaz, GravimetricAnalysis, Part II, Pergamon, London,
(
1965).
NiCo O3
2
1
1
3. A.I. Vogel,A Text Book of Quantitative InorganicAnalysis, Longmans,
London, edn 2 (1951).
4. International Organization for Standardization, ISO: 13321, Methods
for Determination of Particle Size Distribution, part 8 (1996).
https://www.iso.org/obp/ui/iso:std:13321:en.
MnCo O4
2
ZnCo O4
2
ACKNOWLEDGEMENTS
The authors sincerely acknowledge University Grants
Commission-SERO, Hyderabad, India for the financial assistance
in the form of minor research project (Ref. No. F MRP-4964/
4 (SERO/UGC). One of the authors, R. Pradeep is highly
thankful to University Grants Commission, New Delhi, India
for RGNFD fellowship (Ref. No. F/2014-15/RGNF-2014-
1
1
1
5. J. Marmur, J. Mol. Biol., 3, 208 (1961);
https://doi.org/10.1016/S0022-2836(61)80047-8.
6. C.V. Kumar and E.H. Asuncion, J. Am. Chem. Soc., 115, 8547 (1993);
https://doi.org/10.1021/ja00072a004.
7. P.R. Reddy, K.S. Rao and B. Satyanarayana, Tetrahedron Lett., 47, 7311
(
2006);
1
https://doi.org/10.1016/j.tetlet.2006.08.033.
8. B.N. Figgis and J. Lewis, in eds.: J. Lewis and R.G. Wilkins, The Magneto-
chemistry of Complex Compounds in Morden Coordination Chemistry,
Interscience, New York (1996).
1
1
5D-OBC-TAM-84300).
1
2
9. A.P.B. Lever, Inorganic Electronic Spectroscopy, Elsevier, Amsterdam,
edn 2 (1984).
0. A. Braibanti, F. Dallavalle, M.A. Pellinghelli and E. Leporati, Inorg. Chem.,
7, 1430 (1968);
REFERENCES
1
.
E.W. Schmidt, Hydrazine and its Derivatives, John Wiley & Sons, New
York (1984).
https://doi.org/10.1021/ic50065a034.
2
3
.
.
B.N. Sivasankar and S. Govindrajan, Z. Naturforsch., 49b, 950 (1994).
P. Ravindranathan and K.C. Patil, Thermochim. Acta, 71, 53 (1983);
https://doi.org/10.1016/0040-6031(83)80354-2.
B.N. Sivasankar and S. Govindarajan, Synth. React. Inorg. Met.-Org.
Chem., 25, 127 (1995);
https://doi.org/10.1080/15533179508218208.
K.C. Patil, C. Nesamani and P.R. Paiverneker, Synth. React. Inorg. Met.-
Org. Chem., 12, 383 (1982);
21. K. Nakamoto, Infrared and Raman spectra of Inorganic and Coordination
Compounds, Wiley Interscience, New York, edn 3 (1978).
22. L. Chen, J. Liu, J. Chen, C. Tan, S. Shi, K. Zheng and L. Ji, J. Inorg.
Biochem., 102, 330 (2008);
https://doi.org/10.1016/j.jinorgbio.2007.09.006.
23. S. Arjmand and S. Parveen, RSC Adv., 2, 6354 (2012);
https://doi.org/10.1039/c2ra20660a.
24. M.S.S. Babu, K.H. Reddy and P.G. Krishna, Polyhedron, 26, 572 (2007);
https://doi.org/10.1016/j.poly.2006.08.026.
25. S. Rajalakshmi, T. Weyhermuller, A.J. Freddy, H.R. Vasanthi and B.U.
Nair, Eur. J. Med. Chem., 46, 608 (2011);
https://doi.org/10.1016/j.ejmech.2010.11.041.
26. B.N. Sivasankar and S. Govindarajan, Mater. Res. Bull., 31, 47 (1996);
https://doi.org/10.1016/0025-5408(95)00159-X.
4
5
6
7
.
.
.
.
https://doi.org/10.1080/00945718208063122.
S.Yasodhai, V. Gomathi, B. Vinobha and K.J. Saravanan, Coord. Chem.,
5
9, 1615 (2006);
https://doi.org/10.1080/00958970500537812.
K.C. Patil, Bull. Mater. Sci., 16, 533 (1993);
https://doi.org/10.1007/BF02757654.