Synthesis and
Investigation of Formazane compounds (Azo – Imine) and their complexes
Dr. Nagham Mahmood Ajamali
Assist. Professor, Chem. Dept., Kufa
Univ., Iraq.
*Corresponding
Author E-mail: Dr.Nagham_mj@yahoo.com
Novel formazane ligands and
their complexes with cadmium ion have been synthesized by the coupling reaction
of azo or di azo compounds with imine compounds , the resulting compounds named
(formazane), which included (azo group linked with imine group at same carbon
atom of Schiff base .The structures of five ligands and complexes with Cd(II)
were confirmed by several method like [FTIR–spectra , H.NMR–spectra
,(C.H.N)–analysis (UV–Vis)-spectra, Atomic absorption, molar conductance
melting points).
KEY WORDS: imine–azo, formazane, azomethine–azo ) complexes, Cd.
INTRODUCTION:
Imine compounds (Schiff bases )consider starting material
to synthesis several organic compounds like hetero cycles macro cycles,
reagents in analytical chemistry, it also have biological importance in the
metabolism and biosynthesis of amino acids, as a ligands in inorganic
chemistry, their complexes have biological properties, like antifungal, antitumor,
antibacterial., in other fields(1-6)Azo compounds and their
complexes also have a wide range of applications(7, 8) that stretch
from their use in analytical and inorganic chemistry with transition metals.
In the present work, we have synthesized five formazane(9)
ligands and their complexes with cadmium ion (II) the presence of azo–group
(-N=N-) linked with imine (-CH=N) group at same carbon atom of Schiff base
makes them poly dentate ligands which gave them importance properties in the
complexation.
EXPERIMENTAL:
All measurement were carried out by : melting points in
electro thermal 9300, LTD, U.K., FTIR in four ever transform infrared shimadzu
8300, KBr–disc., H.NMR–spectra in DMSO–solvent and (C.H.N)–analysis with Atomic
absorption in Malaysia, molar conductance in DMSO –solvent, (UV–Vis)
–spectrophotometer .
Synthesis of ligand ( BAI) :
2-(5-benzothiadiazol azo )-2- (amine benzene )-phenyl
imine .
A mixture of benzoic acid (0.01mole) and thiosemicarbazide
(0.01mole) were reacted in refluxing for (8hrs), the resulting precipitate was
amino compound, which dissolved in (2ml) of hydrochloric acid with (0.5gm)
solution of sodium nitrite at (0-5)C̊,
ethanolicsolution of 2- amine benzene phenyl imine added to mixture to give 89%
of ligand (BAI).
Synthesis of ligand (HAD) :
1, 1 –bis [(2- hydroxyl phenyl (azo) -2- (phenyl)] methylene
di imine .
According to procedure(9, 10), ethanolic
mixture of (0.01mole) of methylene di amine with (0.02mole) from benzaldehyde
were refluxed for (5hrs) in presence of drops from glacial acetic acid to
produce precipitate of di imine compound, which (0.01mole) reacted with
(0.02mole) of 2- hydroxyl benzene azo at (0-5)C̊, the
precipitate was filtered and dried then re crystallized to yield 87% of ligand
(HAD) .
Synthesis of ligand (HAP) :
2- (2- hydroxyl phenyl azo )-2- (amino phenyl )- phenyl
imine .
Equimolar mixture (0.01mole) of 0- phenylene di amine and
benzaldehyde were refluxed in presence of absolute ethanol for (2hrs), the
resulting compound reacted with mixture of diazonium salt (0-5)C̊, to
produce fromazane compound 87% of ligand (HAP).
Synthesis of ligand (DIA) :
1, 4 –bis (di phenyl imine–azo) phenylene .
P-phenylene di amine (0.01mole) dissolved in (3ml) of
hydrochloric acid, sodium nitrite solution added at (0-5)C̊, diazonium
salt was formed, then ethanolic solution of di phenyl imine added to
diazononium salt to produce other formazane compound 89% of ligand (DIA).
Synthesis of ligand (HMD) :
According to procedure(9, 10), ethanolic
mixture of 0- phenylene di amine (0.01mole) with (0.02mole) of 4-
methoxybenzaldehyde were refluxed in presence of absolute ethanol for (4hrs),
the resulting precipitate was di imine compound, which (0.01mole) dissolved in
ethanol, then added to mixture of dizonium salt (0- hydroxyl benzene azo) to
yield 88% of ligand (HMD) .
Synthesis of Complexes with Cd (II) :
These complexes were prepared according to procedure(11).,
the hot solution of ligand [(HMD), (HAD), (BAI), (DIA), (HAP)] respectively
were added to solution of cadmium salt (CdCl2 .2H2O ) in
mole ratio (metal :ligand) (1:1) for four complexes with [(HMD), (HAD), (BAI),
(DIA), (HAP)] accept with ligand (DIA) was (metal: ligand) (2:1) ., after
stirring (1hrs), precipitates formed, dried and re crystallized to yield (82,
85, 80, 82, 80)% respectively from complexes of[(HMD), (HAD), (BAI), (DIA),
(HAP)] .
RESULTS AND DISCUSSION :
The synthesized ligands and their complexes with Cd (II)
have been studied by several methods and techniques :
Study of optimal conditions of complexes :
This work involved, the optimal conditions for formation
of complexes with (Cd+2 ) like calibration curves of optimal
concentration of Cd+2 (0.95X10-4 ), while concentration
of ligands [1X10-3M of ligand (DIA) ., 0.5X10-3M of
ligand (HAD), 0.4X10-3M of ligand (BAI) ., 0.5X10-3M of
ligand (HMD) ., 0.25X10-3M of ligand (HAP)] ., while optimal (PH=7)
for complexes of [ligand (BAI) and ligand (DIA), but (PH=8) for complexes of
[(HAD), (HMD), and (HAP) ]., mole ratio (M:L) was determined from relationship
between the absorption of observed light and mole ratio through series of
solutions were prepared having a constant concentration (1X10-3M) of
cadmium salt (CdCl2. 2H2O) and ligand ., (M:L) found to
be (1:1) for four complexes except complex with (DIA) was (2:1) other studies
of these complexes in table (1) and figs (1-7). Other measurements :
The elemental analysis (C.H.N) and atomic absorption shown in
table (1) indicate that the Cd- complexes [(HAD), (HMD), (HAP), (BAI) ] have
stoichiometry (metal: ligand) (1:1) except Cd- complex (DIA) (2:1) from results
of mole ratio method.
The molar conductance values (0.82- 1.92) ohm-1.mol-1.cm2
of (10-3M) solution in DMSO indicate that the Cd –complexes are non-
electrolytic in nature.
FT.IR spectra shown absorption bands in all
ligand at [(1489-1498) and )1630-1642)cm-1 ] due to [(-N=N-) –azo
group and (C=N)(12-14) imine group ] respectively which shifted
towards frequencies at [(1464-1476) and (1615-1630)] cm-1
respectively as a result of coordination with cd (II) ., absorption bands (3450
and 3455)cm-1 due to phenolic hydroxyl groups in ligands [(HAP) and
(HMD)] respectively which disappeared in spectra of their complexes and other
bands appeared [(460-475)] and (560-580) cm-1 ]respectively due to
[(M-N) and (M-O)] in complexes, other data in table (2).
H.NMR spectra of three ligands and their
complexes showed peaks at 
(10.83 and 10.92) due to (OH) hydroxyl group(15,
16) of phenol in free ligands [(HAP) and (HMD) ] respectively, which
disappeared in their complexes as a result of coordination with cadmium ion .,
other peaks are shown in table (3).
CONCLUSION:
The coordination in these complexes through nitrogen of
imine group (C=N) and nitrogen of (-N=N-) azo group and oxygen of hydroxyl of
phenol and through (-NH) in ligand (HAP).
Fig.(1) : Mole ratio of
Complex [Cd(HMD)]
Fig.(2): Mole ratio of
Complex [Cd(HAD)]
Fig.(3) : Mole ratio of
Complex [Cd(HAP)]
Fig. (4) : Mole ratio of
Complex [Cd (BAI) Cl2]
Fig. (5) : Mole ratio of
Complex [Cd2(DIA)Cl4]
Fig. (6) : Variation of PH
of Complexes
Fig. (7) : Variation of PH
of Complexes
Table (1): physical properties and Elemental Analysis:
|
Ligands
and Complexes
|
M.P
(C)0
|
λmax
|
Ω-1.Cm2.mole-1 (Conductance)
|
Calc./Found
|
|
|
C%
|
H%
|
N%
|
Cd%
|
Cl%
|
|
(BAI)
C21H16N6S
|
176
|
375
|
/
|
65.62
65.54
|
4.16
4.06
|
21.87
21.79
|
/
/
|
/
/
|
|
(HAP)
C19H16N4O
|
160
|
395
|
/
|
72.15
72.03
|
5.06
4.98
|
17.72
17.66
|
/
/
|
/
/
|
|
(HMD)
C34H28N6O4
|
205
|
390
|
/
|
69.86
69.72
|
4.79
4.65
|
14.38
14.29
|
/
/
|
/
/
|
|
(HAD)
C27H22N6O2
|
184
|
382
|
/
|
70.12
70.04
|
4.76
4.65
|
18.18
18.10
|
/
/
|
/
/
|
|
(DIA)
C32H24N6
|
192
|
360
|
/
|
78.04
77.91
|
4.87
4.78
|
17.07
17.00
|
/
|
/
|
|
[Cd(BAI)Cl2]
|
>250
|
455
|
1.92
|
44.41
44.32
|
2.81
2.71
|
14.80
14.73
|
19.81
19.70
|
12.51
12.45
|
|
[Cd(HAP)]
|
236
|
440
|
0.82
|
53.46
53.33
|
3.28
3.17
|
13.13
13.05
|
26.36
26.27
|
/
|
|
[Cd(HMD)]
|
>250
|
472
|
0.98
|
58.75
58.63
|
3.74
3.67
|
12.09
12.01
|
16.18
16.10
|
/
|
|
[Cd(HAD)]
|
>250
|
460
|
1.30
|
56.60
56.48
|
3.49
3.41
|
14.67
14.58
|
19.63
19.57
|
/
|
|
[Cd2(DIA)Cl4]
|
>250
|
435
|
1.72
|
44.75
44.64
|
2.79
2.67
|
9.79
9.65
|
26.20
26.13
|
16.55
16.40
|
|
|
|
|
|
|
|
|
|
|
Table (2) :FT.IR data (cm-1) of ligands with
complexes .
|
Ligand and Complexes
|
(-N=N-) azo
|
(-C=N-) imine
|
(NH2)
|
OH
|
(M-N)
|
(M-O)
|
|
(BAI)
|
1489
|
1635
|
3320
3360
|
/
|
/
|
/
|
|
(HAP)
|
1492
|
1630
|
3340
3365
|
3450
|
/
|
/
|
|
(HMD)
|
1498
|
1642
|
/
|
3455
|
/
|
/
|
|
(DIA)
|
1495
|
1639
|
/
|
/
|
/
|
/
|
|
(HAD)
|
1490
|
1637
|
/
|
3450
|
/
|
/
|
|
[Cd(BAI)Cl2]
|
1465
|
1624
|
3310
3360
|
/
|
580
|
580
|
|
[Cd(HAP)]
|
1476
|
1615
|
3310
|
/
|
562
|
562
|
|
[Cd(HMD)]
|
1464
|
1630
|
/
|
/
|
575
|
575
|
|
[Cd2(DIA)Cl4]
|
1466
|
1622
|
/
|
/
|
560
|
560
|
|
[Cd(HAD)]
|
1472
|
1618
|
/
|
/
|
468
|
570
|
Table (3) :H.NMR –data (ɓ ppm )of some compounds .
|
Ligandandcomplexes
|
H.NMR(DMSO) (only important peaks)
|
|
(BAI) ligand
|
8.25(-NH2)protons
of ligand ., 6.93-7.87(ph-)protons of phenyl rings .
|
|
[Cd(BAI)Cl2]
Complex
|
8.32(-NH2)
protons of complex ., 6.95-7.88 (ph-) protons of phenyl rings .
|
|
(HAP) ligand
|
10.83(-OH)
proton of phenol ., 8.45(-NH2) protons of amine in ligand .,
6.92-7.65 (ph-)protons of phenyl rings .
|
|
[Cd(HAP) ] Complex
|
8.12(-NH)
proton of amine in complex ., 6.96-7.66(ph-)protons of phenyl rings .
|
|
(HMD) ligand
|
10.92(-OH)proton
of phenol ., 3.25(-OCH3) protons of methoxy group .,
6.95-7.84(ph-)protons of phenyl rings .
|
|
[Cd(HMD)] Complex
|
3.22(-OCH3)
protons of methoxy group ., 6.95-7.88 (ph-) protons of phenyl rings .
|
REFERENCES :
1. Shaikh.M., Mele.J., Kalam.A and Ronok. Z.,
(2012)., Asian. Pacific.J. Trop Bio., S 1036 –S 1039., Cited byIVSL of
Iraq *.
2. Hament.K and Ram. P., (2010)., Der chemical
Sinica., 1, 2, 55 -61.
3. Gehad. G, Mohamed. M and Ahmed. M.,
(2006)., Turk.J. chem., 30, 361-382.
4. Atmaram. K and Kiran. V., (2011)., Int. J.chem Tech.
Res., 3, 2, 636 -641.
5. Sultan. J., (2012)., Ibn. Haitham.J. App.
Sci., 3, 25, 264 -275.
6. Maheshk. G., Ajay. M and Kushal. R.,
(2013)., Int. J. Pharm.. Sci., 5, 3, 421-426.
7. Reda. M, Fabio.B, Zahraa. M, Angela. T and
, Antonio. R., (2013)., Dyes and Pigments., 96, 45-51, Cited by IVSLof
Iraq *.
8. Patel. D and Prajapati. N., (2012)., Asi.
J. Bio.Pharm Res., 1, 2, 255-261.
9. Nagham. M.Aljamali., (2013)., J.Chem.
andCheml. Sci., 3, 3 147 -154.
10. Nagham. M. Aljamali., (2013)., Asian. J. Res.
Chem., 6, 4, 377 -383
11. Nagham. M. Aljamali, Rajaa. A and Afaaq. K.,
(2013)., Iraqi. Nat. J. Chem., 50, 128-140.
12. Wanale. S, Pachlings. S and Hangirgekar. S.,
(2012)., J. Chem. Pharm..Res., 4, 5, 2458 -2462.
13. Irfan. A., (2011)., Der. Pharmacia. Sinica.,
2, 6, 102-106.
14. Nagham. M.Aljamali., (2013)., J.Sci.
INNOV.Res., 2, 1, 53 -60.
15. Pramili. A and Chandra. A., (2012).,
J.Current Pharm. Res., 9, 1, 44-48.
16. Muhammad.A, Wajid. A and Karamat. M.,
(2011)., Int.Conf.Chem. Proce., IPCBEE., 10, 1-7.