Synthesis and characterization of substituted metal(II)-octa-methoxyphenylimino phthalocyanine pigments

Article abstract of DOI:10.13005/ojc/330548

The synthesis, spectral and magnetic susceptibility on symmetrically substituted metal (ΙΙ)-octa-methoxyphenyl imino phthalocyanine by condensing octa amino phthalocyanines with o-anisaldehyde are described. The dark green colour octa amino phthalocyanine

Full text of DOI:10.13005/ojc/330548

ISSN: 0970-020 X
CODEN: OJCHEG
2017, Vol. 33, No.(5):
Pg. 2530-2536
ORIENTAL JOURNAL OF CHEMISTRY
An International Open Free Access, Peer Reviewed Research Journal
www.orientjchem.org
Synthesis and Characterization of Substituted Metal(II)-octa-
MethoxyphenylImino Phthalocyanine Pigments
FASIULLA1* and M. P.YASHODA1
1Department of Chemistry, Manipal Institute of Technology, Manipal, Udupi district, Karnataka, India.
1Department of Chemistry, MIT, Manipal, Udupi District, Karnataka, India.
*Corresponding author E-mail: fasiulla1976@gmail.com
http://dx.doi.org/10.13005/ojc/330548
(Received: April 20, 2017; Accepted: June 28, 2017)
ABSTRACT
The synthesis, spectral and magnetic susceptibility on symmetrically substituted metal
(ΙΙ)-octa-methoxyphenyl imino phthalocyanine by condensing octa amino phthalocyanines with
o-anisaldehyde are described. The dark green colour octa amino phthalocyanine derivatives
were characterized by electronic, IR, elemental analysis, magnetic susceptibility, powder X-ray
diffraction and thermo gravimetric analysis (TGA) studies to structural integrity, check the purity
and crystalline properties of the pigments. The variation of magnetic moment as function of field
strength 2.20 to 4.01 kg indicated the presence of intermolecular co-operative effect
Keywords: Octamethoxy imino phathalocynaine, Electronic, IR, XRD, Magnetic
susceptibility, TGA.
INTRODUCTION
evaluated with regard to their electrochemical
suitability and structural suitability for a given
Phthalocyanines ( Pc) have been application such as an electronic material.
worldwide focused on attention to explore and
exploit the various versatile chromophores.
Phthalocyanines are blue or green in color have property for use as pigments for printing inks,
been widely exploited as colorants. plastics, rubbers, roofing granules, leather,
Phthalocyanines like high tinctorial
Phthalocyanines have a strong optical absorbance gasoline and photographic colour printing, fastness
in the red and near-IR portions of the to the light, chemical inertness etc.The electro-optic
electromagnetic spectrum and are stable under a behavior has led to their use in xerography.
wide range of thermal and electrochemical Phthalocyanines have also been investigated for
conditions. Besides the optical properties and potential use in a variety of other applications
stability of phthalocyanines, these dyes must be including nonlinear optical generation and

2531
FASIULLA & YASHODA., Orient. J. Chem., Vol. 33(5), 2530-2536 (2017)
limiting,photodynamic therapy, photovoltaics, calibrantmercury tetra thiocyanato cobalt (ΙΙ)
sensors, electrochromic displays and information complex was used. Shimadzu UV-Vis spectra
storage.Solubility and various physico-chemical recorded spectrophotometer. Infrared spectra were
properties associated with metal phthalocyanines measured using Nicolet MX-FTIR spectrometer
primarily depend upon the central metal atom and with KBr pellets. Philips analytical PW-1710 X-ray
nature as well as the position of the periphery of the diffractrometer was used to study the diffraction
molecule.
pattern.The spectra were recorded using Cu Ka as
target material, a current of 20 mA, at the voltage of
In the present paper discussesthe 40 kV, a channel width of 7mm,A time constant of 4,
synthesis and spectral and magnetic susceptibility and chart speed of 10 mm/min. Thermo-gravimetric
on substituted metal (ΙΙ) 1, 3, 8, 10, 15, 17, 22, analyses were carried out by using a Shimadzu
24- ocat methoxyphenyl imino phthalocyanines.The DTG/DTA-60.TheTGA and DTA is thermal analyzer
lite- rature survey revealed about the reports on at a heating rate of 100C/min. in a nitrogen
synthesis spectral and magnetic susceptibility on atmosphere and air.
substituted (ΙΙ) octaamino phthalocyanines.The
available procedure in the literature was suitably
modified and used for the synthetic route. The
substituted metal(ΙΙ)octa-methoxyphenyl imino
EXPERIMENTAL
The 3,5-dintrophthalic acid was prepared
phthalocyanines pigments is given as per the as reported elsewhere. All necessary chemicals
scheme-1.
used in the experiment were of analytical grade
obtained from commercial supplier. The substituted
metal (ΙΙ) 1, 3, 8, 10, 15, 17, 22, 24-octa amino
phthalocyanines complexe sprepared by the
reported procedure. These octa amino
phthalocyanines complexes converted into imino
phthalocyanines complexes by using 2-methoxy
aldehyde compounds with suitable modification as
per scheme-1
NO 2
O2
N
NO 2
N
Metal Salt
O2
N
CO(NH
PhNO 2
)
2
2
N
O2
N
COOH
COOH
N
N
N
M
N
N
4
NH 4Cl
N
(NH 4
)
6Mo 7O24
NO 2
NO 2
O2
N
a
NO 2
NO 2
b
Reduction
NH 2
H
CO
3
H
H
N
H2
N
N
H
CO
H
NH 2
3
N
PreparationofCopper(ΙΙ)octa-methoxyphenylimino
phthalocyanines complex.
H2
N
OCH
3
N
N
N
N
Condensation
H
N
N
N
N
N
N
N
M
N
N
N
M
H
CO
N
N
3
OCH
Copper (ΙΙ), 1, 3, 8, 10, 15, 17, 22, 24- octa-
3
N
NH2
H
N
N
N
H2
N
nitro phthalocyanine complex was synthesized
according to reported elsewhere. The nitro
derivative of the aforesaid complex was converted
into amino derivative quantitatively by reduction
using sodium sulphide nonahydrate (Na2S 9H2O)
in aqueous medium. The finely grounded metal
(ΙΙ) -octa amino phthalocyanine (6.30g / 0.1mole)
was added in stiochiometric quantity of 15 M
sulphuric acid, to this (13.6g/0.1mole) 2-methoxy
benzaldehyde is dissolved in ethyl alcohol and
catalytic amount of con. H2SO4 was added, and the
contents were refluxed with stirring for about
5 hours.
NH2
H
NH 2
H
OCH
OCH
3
3
N
H
OCH
3
c
d
Scheme.1. Synthesis of metal (ll) - octa-methoxy
phenyl iminophthalocyanine.a. 3, 5-dinitrophthalic
acid, b. M-PcONc. M-PcOAand d. M-MePhImPcO
The elemental analysis Carbon,
Hydrogen, and Nitrogen were performed at Cochin
University, Sophisticated Test & Instrumentation
Center, Kochi, Kerala, India. The metal content was
determined by incinerating them to the oxides. The
magnetic susceptibility is carried out at room
temperature (3 supply unit and a digital semi-
microbalance. The diamagnetic corrections to be
calculate using Pascal’s constant. The
The settled green solid condensed
octa-methoxyphenylimino phthalocyanine complex
was washed alternatively twice with alcohol free
from aldehyde and finally it was washed with

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FASIULLA & YASHODA., Orient. J. Chem., Vol. 33(5), 2530-2536 (2017)
distilled water. The complexes dried at 1000C for
40 min. and finally in a vacuum over anhydrous
phosphorous pentoxide. CoMePhlmPcO , NiMe
RESULTS AND DISCUSSION
The synthesis of M-MePhImPcO yield pure
PhlmPcO, ZnMePhlmPcO, were synthesized complexes and it shows that dark green in color
similarly by using the respective substituted metal except for that of zinc, green with brown tinge.These
aminophthalocyanines.
complexes are sparingly inDimethyl sulfoxide,
Dimethylformamide, pyridine and completely
soluble in con.H2SO4.The elemental analysis results
are given in Table.1 and the calculated values and
are consistent with the suggested structure given
below in Fig.1. The reduction of nitro derivatives to
the corresponding amino derivatives and the
conversion of later into M-MePhImPcO’s were almost
quantitative with good yield.
H3CO
H
H
N
N
H3CO
H
OCH3
H
N
N
N
N
N
N
N
M
N
H3CO
N
OCH3
N
H
Electronic Spectra
N
N
H
The synthesized complexes were
N
H
recorded DMSO in the concentration range of
1.00 -1.40 X 10-4 M and data are summarized in
Table 2. All the absorption peaks are interpreted in
terms of Q- band, B-band, L-band and C-band
characteristic of phthalocyanine molecule.
M-Me Phlm PcO complexes a peak were observed
in the wave length 726-749 nm, which was assigned
to Q-band, a1u→eg transition and 327-337 nm
assigned to B-band due to a2u→eg transition. The
OCH3
OCH3
N
H
OCH3
Fig.1. Suggested structure of symmetrically
substituted octa-methoxyphenylimino
phthalocyanines, where M= Co, Cu, Ni, and Zn.
Table.1: Elemental analysis and magnetic susceptibility data of metal (II) -octa-
methoxyphenyliminophthalocyanines.
Complex
(Yield)
Colour
Empirical
formulae.
(Formula
weight)
Field strength
KGauss
Magnetic Magnetic Elemental analysis (%)
susceptibility moments
(cm 10-6cgs meff (B.M)
units)
found (calcd)
CoMePhImPcO
(86%)
Dark green
C H N16O8Co
96 -(76234.9)
2.2
2.66
3.1
3.58
4.01
2.2
2.66
3.1
3.58
4.01
+2642.28
+2439.08
+2103.52
+1937.02
+1804.08
+2610.1
+2471.16
+2125.54
+1939.46
+1825.62
2.85
2.75
2.64
2.51
2.4
2.78
2.65
2.57
2.47
2.42
C, 70.28; (70.46)
H, 4.35; (4.40)
N, 13.65; (13.70)
Co, 3.56; (3.60)
CuMePhImPcO
(85%)
Dark green
C H72N16O8Cu
96(1639.5)
C, 70.13; (70.26)
H, 4.24; (4.39)
N, 13.51; (13.60)
Co, 3.72; (3.87)
NiMePhImPcO
(79%)
Dark Green
C96H N16O Ni
(176234.7)8
C, 70.25; (70.47)
H, 4.23; (4.40)
2.66
-766.81
—-
N, 13.62; (13.70)
Co, 3.49; (3.59)
C, 70.04; (70.18)
H, 4.13; (4.38)
N, 13.42; (13.6)
Zn, 4.72; (4.98)
ZnMePhImPcO
(74%)
Green with brown ting
C H N16O8Zn
96(176241.4)
2.66
-849
—-

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FASIULLA & YASHODA., Orient. J. Chem., Vol. 33(5), 2530-2536 (2017)
Q-band is due to M-MePhImPcO’s was observed
to be shifted to higher wavelength range. The peaks
are observed in the wavelength range 577-593 nm
for Cu-MePhImPcO, Co-MePhImPcO, Ni-
MePhImPcO, and Zn-MePhImPcO which is
accounted for aggregation of complexes in the
solvent. For all M-MePhImPcO’s a band was
observed in the wavelength range of 214-226 nm
suggested C-band of the phthalocyanine complexes.
sharp peak at 1628-1634 cm-1 is assigned to C=N
of imine group and the peaks in the 1380-1387
cm-1 is due to C-N aromatic stretching frequency.
The bands at 1045-1119, and 741-772 cm-1 may
be observed to the various phthalocyanines skeletal
vibration.
Magnetic Susceptibility
The magnetic susceptibility and magnetic
moments values of square planner M-MePhImPcO’s
were investigated in the solid state over a range of
2.20-4.45K Gauss and summary of the results were in
Table. 1. The values reported are the average of three
independent determinations.The magnetic susceptibility
were studies revealed that CuMePhImPcO and
CoMePhImPcO are paramagnetic and NiMePhImPcO
and ZnMePhImPcO are diamagnetic complexes.
Infrared absorption spectra
Infrared spectra were data recorded the
substituted metal (ΙΙ) octa-methoxyphenylimino
phthalocyaninesa complex was recorded in KBr
pellets and the reported results were presented in
Table 2. In the range at 3424-3451 cm-1a broad
absorption band were observed for all complexes
and assigned to the H- bonding formed between
nitrogen atom of the phthalocyanine molecules,
hydrogen atom of moisture absorbed on KBr pellets
during pelletization.The peak observed in the range
2362-2364 cm-1 is due to C-H stretching vibration
on the periphery of the phthalocyanine moiety. The
The observed magnetic moments for
CuMePhImPcO and CoMePhImPcO are higher
than the expected only spin value corresponding
to one unpaired electron (1.73BM),mixing of higher
energy degenerate states with ground state orbital
Table. 2: Electronic, IR and powder XRD data of metal (II) octamethoxyphenylimino
phthalocyanines
Complex
UV-visible absorption
l nm (logÎ)
IR-Spectral
Data (cm-1)
Powder. XRD data
2q angle (d Å)
Relative
intensity (%)
218 (4.82)
260 (4.80)
335 (5.42)
593 (5.07)
749 (5.20)
214 (4.92).
265 (4.79)
337 (5.43)
584 (5.02)
747 (5.14)
226 (4.90)
257 (4.63)
328 (5.06)
582 (4.44)
726 (4.61)
219 (5.58)
251 (5.46)
327 (5.41)
577 (5.39)
728 (5.04)
741, 1045, 1170,
1382, 1634, 1711,
2362, 3451.
27.77, (3.49)
28.93, (3.11)
24.53, (3.40)
31.30, (2.72)
100
CoMePhImPcO
CuMePhImPcO
79.36
49.25
31.46
772,1090, 1387,
1634, 1718, 2362, .
3442.
45.52, (2.82)
31.72, (2.84)
43.77, (2.73)
25.96, (3.45)
100
80.28
52.44
34.27
NiMePhImPcO
ZnMePhImPcO
759, 1119, 1363,
1401, 1628, 2223,
2362, 3424.
27.93, (3.74)
28.82, (3.11)
23.25, (3.45)
42.76, (2.83)
100
79.24
44.32
29.54
769, 1121, 1380,
1632 ,2325, 2364,
3441.
27.94, (3.57)
28.88, (3.03)
42.96, (2.75)
20.52, (4.37)
100
80.81
50.24
35.91

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FASIULLA & YASHODA., Orient. J. Chem., Vol. 33(5), 2530-2536 (2017)
and intermolecular co-operative effects.The higher
magnetic moment then spin only value is due to
the orbital contribution to µeffwhich may arise as a
result of mixing of ground state orbitals (b2g)2, (eg)4,
and (a1g)1 with higher orbitally degenerate states
( b2g )2, (eg)3 and (a1g)2. The orbital contributes is
consists of higher at magnetic field then that of
higher one evidenced by higher µeff values at lower
field strength attributed to intermolecular magnetic
interaction coupled with magnetic anisotropy of
phthalocynaninesπ electronic current as reported
in the literature.The crystallographic studies that
the metal phthalocyanines of Cu, Co, Ni and Zn
has square planar structure with D4h symmetry and
are isomerphous.
Powder XRD
The spectra of M-MePhImPcO’s in the
range of 2θ angles 6-70o showed are not identical
peaks Table -2. It is observed two peaks. One of the
sharp peak at lower angle with maximum intensity
and the other peak at higher angle with higher
intensity. The inter- planar spacings on these angle
gave the following values. Co-MePhImPcO 3.49,
27.97 Å; Cu-MePhImPcO 2.82, 45.52 Å; Ni-
MePhImPcO 3.74, 27.93 Å and Zn-MePhImPcO
3.57, 27.94 Å, clearly indicating the crystanilline
nature of the complex. The observed patterns are
very much similar to those of the unsubstituted
parent phthalocyanines except the broadening of
the peaks in the case of M-MePhImPcO’s which
may be due to the presence of substituents and
which seems to play an significant role in the
stacking of the substituted metal (ΙΙ)phthalocyanine
derivatives. X-ray diffraction patterns are used only
to explain crystallinity qualitatively.
N
N
M
N
N
Thermogravimatric and Kinetic Studies
N
N
Thermogravimatric analytical data of octa-
M
methoxyphenyliminophthalocyanine complexes
both in air and nitrogen atmosphere are summarized
in the Table 3 and 4. It is observed that the
decomposition of the above complexes occurs
generally in two steps, revealed that the initial
weight loss of 2-3% corresponding to moisture.The
first step degradation in air, which takes place in
the temperature range of 250-350oC, may be
accounted for the loss of four substituted imine
groups. The major weight loss is observed for all
the complexes in the second step in the
temperature ranges of 350-600oC corresponds to
the oxidative degradation of remaining four
N
N
N
N
M
N
N
Fig. 2. Probable molecular stacking of metal
phthalocyanine crystal, (M = Cu, Co, Ni, Zn.)
N= azamethanic atom of phthalocyanine.
The molecular plan is approximate normal
to a-b plane and molecules were stacked along
the short b-axis. The molecular planes are inclined
to the a-c axis at an angle of 45o .Thus the complexes
stacked in column with N-atoms above and below
on every metal atom (Fig.2) Hence the nearest
neighbouring molecule along the b-axis contributes
N-atom at the interplanar distance 3.8 Ao.
The overlapping of two neighboring
molecules depends on the crystal modification.The
XRD data reveals that the M-MePhImPcO's as in β-
form. The substituted metal (ΙΙ) of one of the
phthalocyanine overlaps with N-atom of
azamethine atom of the other metal phthalocyanine
molecule.
Fig. 3. Plots of ln(ln 1/y) versus 1/T for thermal
(• •d•eg•r)adCaotMioenPohfIm( P•c•O•,(• ) CuMe) PNhiMImePPchOIm, PcO
and ( „ „ „ „ ) ZnMePhImPcO in air.

2535
Table. 3: TGA data of Cu(II), Co(II), Ni(II) and Zn(II)-octa-methoxyphenylimino phthalocyanines.
FASIULLA & YASHODA., Orient. J. Chem., Vol. 33(5), 2530-2536 (2017)
Complex
Temperature of
Decomposition oC
Mass Loss
(%) Found
Probable mode of
(%)Calcd
Fragmentation
CuMePhImPcO
350-600
250-350
250-350
65.45
29.81
350-600
250-350
350-600
250-350
350-600
29.83
65.84
30.17
65.94
29.77
65.86
29.65
65.53
30.05
Pc moiety
8-Imino groups
65.04
8-Imino groups
CoMePhImPcO
Pc moiety
8-Imino groups
Pc moiety
8-Imino groups
Pc moiety
NiMePhImPcO
ZnMePhImPcO
30.16
65.18
30.14
65.14
Table. 4: Kinetic and thermodynamic parameters of octa-methoxyphenyliminophthalocyanines
of Cu, Co, Ni and Zn in air and inert atmosphere
Compounds
Activation energy E0
Frequency
ΔH
ΔS
ΔG
KJ/mole
5.86
factor. lnA min-1 KJ/mole
J/K
KJ/mole
62.41
-61.53
81.66
-79.54
74.94
-74.78
79.53
-77.26
72.87
-70.56
81.74
-80.23
75.26
-74.96
82.45
-80.92
CuMePhImPcO
I
II
I
6.16
-2.02
5.37
-5.46
6.36
-3.38
7.48
-4.65
5.22
-2.25
4.44
-4.83
3.49
-2.38
7.97
-6.45
2.72
(-1.28)
-0.74
-165.04
(-160.03)
-152.26
(-149.74)
-176.06
(-174.11)
-143.93
(-141.97)
-159.63
(-157.58)
-149.76
(-143.64)
-175.96
(-173.35)
-142.74
(-140.43)
-0.74
3.73
-1.52
0.88
(-2.42)
-1.37
CuMePhImPcO
NiMePhImPcO
NiMePhImPcO
-0.67
4.66
(-1.11)
2.87
II
I
-1.25
1.44
(-1.32)
-1.24
-0.71
5.85
(-0.78)
-0.86
II
-1.53
1.94
(-0.84)
-0.96
I
-0.67
8.55
(-1.48)
2.86
II
-5.53
(-1.52)
(I and II corresponds to the I and II stage of degradation and the values in the
parenthesis are for nitrogen atmosphere)
substituted imine groups and phthalocyanine
moiety. Analysis of the final charred residue
corresponds to the corresponding metal oxides.The
thermal decomposition of imino substituted metal
phthalocyanine complexes in the nitrogen
atmosphere appears to be very slow. For
Co-MePhImPcO, 69% of the complex was found to
be decomposed at 700oC. For Cu-MePhImPcO,
Ni-MePhImPcO about 55%, 54% and 43% loss of
the mass was observed for Zn-MePhImPcO. Above

2536
FASIULLA & YASHODA., Orient. J. Chem., Vol. 33(5), 2530-2536 (2017)
trend conforms the relatively stability of these methoxyphenylimino phthalocyanines of Cu (ΙΙ), Co (ΙΙ),
complexes in the order Co-MePhImPcO>Cu- Ni (ΙΙ)andZn (ΙΙ). Magneticsusceptibilitystudiesrevealed
MePhImPcO> Ni-MePhImPcO> Zn-MePhImPcO. the paramagnetic behavior of Cu (ΙΙ) and Co (ΙΙ)
DTA results revealed that all degradation steps are octamethoxyphenyliminophthalocyanine derivatives
exothermic in nature. Kinetic and thermodynamic and the variation of magnetic moments with magnetic
parameters of the title complexes have been field indicated the presence of intermolecular co-
evaluated by Boride’s method.
operative effect. Thermogravimatric analysis of the
complexes in an inert atmosphere revealed the stability
Plot of ln(ln1/y) versus 1/T (where y is the in the order CuMePhImPcO >CoMePhImPcO >
fraction of the complex not decomposed) were NiMePhImPcO > ZnMePhImPcO.
developed for the decomposition segment where
loss of functional groups occur. From the plots, the
energy ogactivation(Ea) and frequency factor (lnA)
were evaluated. Enthalpy(ΔH), Entropy(ΔS) and free
ACKNOWLEDGEMENTS
The authors are thankful to the HOD,
energy (Δ) have been computed using standard Department of Chemistry, MIT, Manipal for providing
equation in Table 4.
the basic laboratory facilities;thanks are also due to
Prof.A.M.A.Khader, MangaloreUniversity, Prof.M.A.
Pasha, Bangalore University, and Mr.Harikrishana
Bhatt from RRL, Trivandrum for recording
CONCLUSION
A simple and convenient method has been spectraldata.
optimized for the synthesis of pigments -octa
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