Spectroscopic and electrochemical studies of transition metal complexes with N,N′-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7- trioxaheptane and structure effects on extractability of ligand towards some divalent cations

Article abstract of DOI:10.1007/s00706-007-0713-3

La(III), Cu(II), Ni(II), and Zn(II) metal complexes with a novel quadridentate Schiff base derived from 1,7-bis(2-formylphenyl)-1,4,7- trioxaheptane and 2-aminothiophenol were synthesized and characterized by microanalytical data, elemental analysis, magn

Full text of DOI:10.1007/s00706-007-0713-3

Monatshefte fu¨r Chemie 138, 1199–1209 (2007)
DOI 10.1007/s00706-007-0713-3
Printed in The Netherlands
Spectroscopic and Electrochemical Studies of Transition Metal
Complexes with N,N0-Bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-
1,4,7-trioxaheptane and Structure Effects on Extractability of Ligand
towards some Divalent Cations
1
1
2
3
Hamdi Temel1;ꢀ, Hu¨seyin Alp , Salih Ilhan , Berrin Ziyadanogulları , and Ismail Yılmaz
˙
˙
˘
1
Department of Chemistry, Faculty of Education, Dicle University, Diyarbakır, Turkey
2
Department of Chemistry, Faculty of Art and Sciences, Dicle University, Diyarbakır, Turkey
3
Department of Chemistry, Faculty of Art and Sciences, Istanbul Technical University, Istanbul, Turkey
Received April 5, 2007; accepted (revised) May 12, 2007; published online September 24, 2007
# Springer-Verlag 2007
Summary. La(III), Cu(II), Ni(II), and Zn(II) metal complexes
hydes and various amines have been widely inves-
tigated [6–14]. However, little attention has been
given to Schiff bases, which include the ONS donor
system [15, 16]. In addition, solvent extraction of
metal chelate complexes has been used as a separa-
tion method for a long time. Utilizing an apparatus
no more complicated than a separatory funnel, re-
quiring several minutes at the most to perform, and
applicable both to trace and macro levels of metals,
these extraction procedures offer much to the analy-
tical chemist [17]. The most widely used techniques
for the separation and preconcentration of trace
amounts are extraction [18], precipitation [19], and
chelating resins [20]. Very often, both separation and
preconcentration are required, and an advantage of
solvent extraction is that both can be obtained in the
same step [21]. Recovery of metals from an aqueous
phase by solvent extraction is achieved by contacting
the aqueous phase with an organic phase that con-
tains a metal selective chelating agent dissolved in a
diluent [22]. For extraction of metal ions, it is prefer-
able that the chelating agent used has high distri-
bution coefficient and pH dependence in the system
chosen [23].
with a novel quadridentate Schiff base derived from 1,7-bis(2-
formylphenyl)-1,4,7-trioxaheptane and 2-aminothiophenol
were synthesized and characterized by microanalytical data,
elemental analysis, magnetic measurements, 1H NMR, 13C
NMR, UV-Vis, IR, mass spectra, cyclic voltammetric and con-
ductance measurements. The extractability of divalent cations
was evaluated as a function of relationship between distri-
bution ratio of the metal and pH or ligand concentration.
The highest extraction percentage of Cu2þ and Ni2þ showed
pH 7.0 and 6.4. It was concluded that the ligand can effective-
ly be used in solvent extraction of copper(II) and nickel(II)
from the aqueous phase to the organic phase.
Keywords. Thio Schiff base; Transition metal complexes;
Extraction; Electrochemical studies.
Introduction
A large number of Schiff bases and their complexes
have been studied because of their interesting and
important properties, e.g., their ability to reversibly
bind oxygen [1], catalytic activity in hydrogenation
of olefins [2] and transfer of amino group [3], pho-
tochromic properties [4], and complexing ability to-
wards certain toxic metals [5]. Metal complexes
of Schiff bases derived from substituted salicylalde-
In the present work, we synthesized a new thio
Schiff base by the reaction of 2-aminothiophenol and
1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane. Then,
ꢀ
Corresponding author. E-mail: htemel@dicle.edu.tr

1200
H. Temel et al.
its La(III), Cu(II), Ni(II), and Zn(II) complexes
were synthesized using the template effect by reac-
tion of 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane
and 2-aminothiophenol with La(NO3)3 ꢁ 6H2O,
Cu(CH3COO)2 ꢁ H2O, Ni(CH3COO)2 ꢁ 4H2O, and
Zn(CH3COO)2 ꢁ 2H2O. Then the spectroscopic, mag-
netic, and electrochemical properties of all com-
pounds were studied in detail. The new complexes
with flexible structure and N and S donor atoms pos-
sibly offer the development of a novel extraction re-
agent having specific selectivity at various pH values.
In addition, the electrochemical behavior of the Zn(II)
complex has also been studied by cyclic voltammetry.
band was previously assigned to be due to the stretch-
ing frequency of NþH group, which is expected in
these regions assigned to the stretching vibration of
the intramolecular hydrogen bonded N ꢁ ꢁ ꢁ HS in the
molecule.
This band disappeared in the IR spectra of the
complex. The bands at 752 and 696 cmꢂ1 in the IR
spectrum of the ligand are ascribed to the phenolic
C–S [27, 28]. This band is found at ca. 754, 746,
727, 695, 694, 687, 668, 661, and 660 cmꢂ1 in the IR
spectra of the complexes. These changes suggest that
the o-SH group of this Schiff base moiety has taken
part in complex formation. The solid state IR spectra
of the complexes compared with those of the ligand
indicate that the C¼N band 1599 cmꢂ1 is shifted to
lower values for complexes [6–14]. Conclusive evi-
dence of the bonding is also shown by the obser-
vation that new bands in the spectra of the metal
complexes appear at 475–458 cmꢂ1 assigned to
(M–N) stretching vibrations that are not observed
in the spectra of the ligand [6–14]. The IR spectra
of the Zn(II) complex clearly demonstrated that the
COC and CCO stretching vibrations are altered com-
pared to the ligand due to conformational changes.
The C–O–C absorption is shifted to lower wave
Results and Discussion
The ligand and complexes were synthesized
(Schemes 1 and 2) and characterized. The ligand
and its complexes were identified by elemental anal-
1
ysis, IR, H, and 13C NMR data, electronic spectra,
magnetic susceptibility measurements, molar con-
ductivity, mass spectra and cyclic voltammetry. The
crystals were unsuitable for single-crystal X-ray
structure determination.
IR Spectra
The important features for the Schiff base and its
complexes may be summarized as follows:
The IR spectrum of the thio Schiff base ligand
exhibited a strong sharp band at 3331 cmꢂ1. This
Scheme 1

Spectroscopic and Electrochemical Studies
1201
Scheme 2
numbers in complexes providing another evidence of
complexing [29, 30]. The La(III) complex shows six
absorption bands near 1497, 1317, 1028, 923, 727,
and 693 cmꢂ1 assigned to ꢀꢀ4, ꢀꢀ1, ꢀꢀ2, ꢀꢀ6, ꢀꢀ3, and ꢀꢀ5
vibrations, respectively. The magnitudes of ꢀꢀ4–ꢀꢀ1
and ꢀꢀ3–ꢀꢀ5 are in the range of 210–220 and 41–
47 cmꢂ1. This confirms the coordination of the
nitrate group in a bidentate fashion [31, 32]. In ad-
dition, conclusive evidence of the bonding is also
shown by the observation that new bands in the

1202
H. Temel et al.
spectra of the metal complexes appear at 1582,
1497 cmꢂ1 assigned to (–ONO2) stretching vibra-
tions that are not observed in the spectra of the li-
gand [31, 32].
the Ni(II) complex shows an absorption band at
1
1
479.00 nm attributed to the A1g ! B1g transition,
which is compatible with this complex having a
square-planar structure [36] and according to a dis-
cussion based on group theory [37] (approximately,
in D2h symmetry), ligand field bands consist of
UV-Vis Studies
1
3
a spin-forbidden transition A1g ! B1g related to
The electronic spectrum of the ligand (L) in C2H5OH
shows absorption bands at 228 nm (" ¼ 48720),
297 nm (" ¼ 17440), and 322 nm (" ¼ 23520), in
CHCl3 shows absorption bands at 251 nm (" ¼
13500), 286 nm (" ¼ 21680), and 323 nm (" ¼
13500), and in DMF shows absorption bands at
295 nm (" ¼ 27680) and 321 nm (" ¼ 38540). The
bands are indicative of benzene and other chromo-
phore moieties present in the ligand. The absorption
bands of the complexes are shifted to longer wave
length compared to that of the ligand [33–35]. The
bands are indicative of phenyl and other chromo-
phore moieties present in the ligand. A moderately
intensive band observed in the range of 320–325 nm
dxy!dx2 ꢂ y2 orbital excitation at around 858 nm, a
1
1
spin-allowed A1g! B1g transition related to dxy!
dx2 ꢂ y2 orbital excitation at around 478 [38]. The
high absorption by the ligand as compared to the
La(III) ions masks any splitting of the band and only
slight wavelength and intensity variations are seen in
the complex. The spectra of the La(III) complex is
dominated by the ligand absorption bands [38].
1H NMR and 13C NMR
The NMR spectra of the Cu(II) and La(III) com-
plexes could not be taken since the Cu(II) complex
is paramagnetic and La(III) complex is little soluble
1
is attributable to the n–ꢁ transitions and the strong
band observed in the range of 270–282 nm is due to
in DMSO-d6. The H NMR and 13C NMR spec-
ꢀ
tral data of ligand and complexes are given in
the Experimental. The 1H NMR values of the
CH2OCH2, CH2OC6H4, and HC¼N protons are
changed in the complexes indicating that the metals
are coordinated by the ligands. The 13C NMR spec-
trum of the ligand is shown in Fig. 1.
ꢀ
Cu(II) complex shows an absorption band at 478 nm
the ꢁ–ꢁ transitions [23] of the complexes. The
2
2
attributed to the T2g! Eg (G) transition, which is
compatible with these complexes having a square-
planar structure [34]. The electronic spectrum of
13
Fig. 1. C NMR spectrum of N,N0-bis(2-aminothiophenol)-1,7-bis(2-formylpenyl)-1,4,7-trioxaheptane

Spectroscopic and Electrochemical Studies
1203
Fig. 2. The mass spectrum of the Zn(II) complex
Magnetic and Conductivity Studies
containing 1.1ꢂ03ꢂ4 mol dmꢂ3 of M2þ (M ¼ Cu, Ni),
1.10ꢂ1 mol dm
of potassium nitrate, and
The Cu(II) complex is paramagnetic and its magnet-
ic moment is 1.93 ꢂB. Since the Cu(II) complex is
1.10ꢂ1 mol dmꢂ3 of the buffer (acetic acid, acetate
and sodium carbonate, bicarbonate) were introduced
into a stoppered flask and shaken for 60 min at
25 ꢃ 0.1ꢄC. This period of shaking was enough to
establish an equilibrium between the phases. The
ionic strength of the aqueous phase was kept as
I ¼ 0.1 M by adding an appropriate amount of potas-
sium nitrate. The two phases were separated by cen-
trifugation and then, the pH of the aqueous phase
after extraction was measured and metal concentra-
tions were determined by AAS.
The percentage extraction (% E) of some divalent
metals into chloroform with Schiff base were plotted
as a function of the aqueous phase pH equilibrated with
the organic phase in Fig. 4. The results are also ex-
pressed as distribution ratio (Table 1). The distribution
ratio of divalent cation may be represented by Eq. (1).
1
paramagnetic [1–6], its H NMR spectra could not
be obtained. The Ni(II) and Zn(II) complex is dia-
magnetic. Their 1H NMR spectra could be obtained.
All complexes are nonelectrolytes [6–14].
Mass Spectra
The peaks of the mass spectra of the ligand and
its metal complexes are attributable to the molecular
ions: m=z: 527.1 [L–H]þ (MA: 528 g=mol), m=z: 553
[[La(L)(NO3)]–[O(CH2)2O(CH2)2O]–(NO3)]þ (MA:
727 g=mol), m=z: 523 [Cu(L)–(CH2)2O(CH2)2 þ
5H]þ (MA: 590 g=mol), m=z: 592 [Zn(L)]þ (MA:
592 g=mol). The mass spectrum of the Zn(II) com-
plex is shown in Fig. 2.
Extraction Studies
½MLꢅo
D ¼
ð1Þ
½Mþꢅw
Distribution of the Metals
Equal volumes (10 cm3) of chloroform contain-
ing 1.10ꢂ3 mol dmꢂ3 of a ligand, an aqueous phase
As seen in Fig. 5, the effect of time on the degree of
the extraction of Cu(II) and Ni(II) was studied at con-

Fig. 3. The fragments observed in the mass spectrum of the Zn(II) complex

H. Temel et al.: Spectroscopic and Electrochemical Studies
1205
where H2L represents the extractant reagent and sub-
scripts w and o denote the aqueous and organic
phases.
In this case, extraction constant (Kex) can be ex-
pressed as follows:
2
½MLꢅo½Hþꢅ
Kex
¼
ð3Þ
½M2þꢅ½H2Lꢅo
The values of log Kex can be calculated by using the
following equation:
Fig. 4. The plot of % E vs. pH (Ni: &, Cu: ^)
log Kex ¼ log D ꢂ log½H2Lꢅo ꢂ 2pH
ð4Þ
Table 1. Distribution ratio of cation between the organic and
aqueous phases
According to Eq. (2), plots of log D against log
½H2Lꢅo at constant pH 7 for Cu(II) and pH 6.4
for Ni(II) will give straight lines of slopes, one
and intercept, log Kex þ 2pH. Hence, from the graphs
(shown in Figs. 6 and 7) the extraction constants
(ꢂlog Kex) have been calculated as 8.63 and 6.29.
From the results, the extraction equilibrium was
found as shown in Eq. (2). Both from quantitative
evaluation of the extraction equilibrium data (Figs. 6
and 8) and Job’s method (Figs. 7 and 9) it has been
deduced that the complexes extracted are the simple
1:1 chelates, [CuL], [NiL].
pH
Distribution ratio (D)a
Cu2þ
Ni2þ
0.0
3.7
4
0.21
0.74
0.08
4.5
5
1.98
3.00
0.77
2.67
5.5
5.9
6.4
7
7.5
8
4.15
7.06
26.84
454
65.17
51.90
14.90
12.52
3.62
21.67
1607
749
44.64
23.47
15.16
13.5
8.5
9
a
Averages calculated for data obtained from three indepen-
dent extraction experiments
Fig. 6. Graphical calculation of the extraction constant of
Cu(II)
Fig. 5. The plot of % E vs. time (Ni: &, Cu: ^)
stant pH 7.0 and 6.4. Shaking time was determined
as 45 and 60 min.
The extraction process may be represented by the
equation:
Fig. 7. The metal and ligand mole ratio (1:1) determined by
Job’s method (l ¼ 478 nm)
M2þw þ H2Lo ! MLo þ 2Hþ
ð2Þ
w

1206
H. Temel et al.
Fig. 8. Graphical calculation of the extraction constant of
Ni(II)
Fig. 11. Cyclic voltammogram of the Zn complex contain-
ing 0.1 M TBAP (anodic scan). Scan rates ¼ 0.100 V ꢁ sꢂ1
TBAP. The Fig. 10 shows the CV of the Zn(II) com-
plex which displays a cathodic wave without corre-
sponding anodic wave and its cathodic peak potential
(Epc) was found to be ꢂ1.25 V vs. Ag=AgCl. As
seen, the reduction process is irreversible and as-
signed to metal-based character since the ligand
did not exhibit any process in the same scale upon
cathodic scan. The complex also exhibited one ir-
reversible oxidation peak without corresponding
anodic wave (Fig. 11). The anodic peak potential
corresponding to the oxidation wave is located at
0.767 V, which is assigned to the ligand-based pro-
cess because the ligand exhibits the anodic wave at
0.746 V. Cathodic peak potential of the complex is
anodically shifted by 0.021 V compared with that of
the ligand. The nickel and copper complexes did not
give any voltammetric response in the same experi-
mental condition, probably due to highly unstable
identity of their oxidized or reduced species in the
time scale of the CV measurements.
Fig. 9. The metal and ligand mole ratio (1:1) determined by
Job’s method (l ¼ 841 nm)
Electrochemistry
The electrochemical behaviour of the new zinc
complex was investigated using cyclic voltammetric
(CV) technique in DMSO solution containing 0.1 M
The spectroelectrochemical behavior of the zinc
complex was investigated using an in situ spectro-
electrochemical technique including chronoampero-
metry and UV-Vis spectroscopy in DMSO solution
containing 0.2 M TBAP. The UV-Vis spectral changes
for the reduced complex were obtained in a thin-
layer cell during applied potentials. The absorption
spectra of the neutral complex and its electrochemi-
cally generated species are given in Fig. 12. The
convenient applied potential value for in situ spec-
troelectrochemical experiment was determined for
the reduction process by performing a CV measure-
ment of the complex in the thin-layer cell.
Fig. 10. Cyclic voltammogram of the Zn complex contain-
ing 0.1 M TBAP (cathodic scan). Scan rates ¼ 0.100 V ꢁ sꢂ1

Spectroscopic and Electrochemical Studies
1207
electrode, and an Ag=AgCl reference electrode. The reference
electrode was separated from the bulk solution by a fritted-
glass bridge filled with the solvent=supporting electrolyte mix-
ture. The ferrocene=ferrocenium couple (Fc=Fcþ) was used as
an internal standard but all potentials in the paper are refer-
enced to the Ag=AgCl reference electrode. Solutions contain-
ing the complex were deoxygenated by a stream of high purity
nitrogen for at least 5 min before running the experiment and
the solution was protected from air by a blanket of nitrogen
during the experiment. Controlled potential electrolysis (CPE)
was performed with Princeton Applied Research Model 2263
potentiostat=galvanostat. A BAS model electrolysis cell with a
fritted glass to separate the cathodic and anodic portions of the
cell was used for bulk electrolysis. The sample and solvent
were placed into the electrolysis cell under nitrogen. UV-Vis
spectroelectrochemical experiments were performed with a
home-built thin-layer cell that utilized a light transparent
platinum gauze working electrode. Potentials were applied
and monitored with a Princeton Applied Research Model
2263 potentiostat. Time- and potential-resolved UV-Vis spec-
tra were recorded on Agilent Model 8453 diode array spec-
trophotometer. A Unicam model 929 atomic absorption
spectrophotometer was used for the determination of the con-
centration of a metal in aqueous solution. A Toledo model pH
meter equipped with a Toledo 413 combined glass electrode
was used to determine the pH values. Magnetic moments were
determined on a Sherwood Scientific magnetic moment bal-
ance (Model No: MK1) at room temperature (23ꢄC) using
Hg[Co(SCN)4] as a calibrant: diamagnetic corrections were
calculated from Pascal’s constants [24].
Fig. 12. Time-resolved UV-Vis spectral changes of the Zn
complex during the reduction at Eapp ¼ ꢂ1.45 V in DMSO
solution containing 0.2 M TBAP
Figure 12 shows the changes of the electronic
spectrum of the zinc complex during the reduction
process in a thin-layer cell. The isosbestic points are
observed at 350 confirming that the electrode reac-
tion proceeds in a quantitative fashion and therefore
the absence of any coupled chemistry [39–44]. The
intensity of the band at 324 nm increased and a new
broad band in low intensity formed at about 438 nm
Materials
1,7-Bis(2-formylphenyl)-1,4,7-trioxaheptane was prepared by
the literature method [25, 26]. All the other chemicals and
solvents were of analytical grade and used as received.
in the time scale of applied potential at Eapp
ꢂ1.45 V (this process completed in about 300 s).
¼
Synthesis and Spectral Characterization of N,N0-Bis(2-
aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-
Experimental
Physical Measurements
Elemental analysis was carried out on a LECO CHNS model
932 elemental analyzer. The results agreed favorably with
trioxaheptane (C30H30N2O3S2)
A solution of 2-aminothiophenol (20.00 mmol, 2.5 g) in
50 cm3 absolute ethanol was added dropwise over 2 h to a
stirred solution of 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane
(10.00mmol, 3.14g) dissolved in 50cm3 warm absolute etha-
nol. A solid mass separated out on cooling, which was kept
in a refrigerator for better crystallization. It was then filtered
off and recrystallized from a mixture of absolute ethanol-
DMF. Yield 3.43g (65%), light yellow, mp 132–135ꢄC; IR:
ꢀꢀ¼ 3331 (NþH), 3053 (Ar–CH), 2926, 2872 (Aliph–CH),
1599 (C¼N), 1485, 1452 (Ar–C¼C), 1290, 1250 (Ar–O),
1
the calculated values. H NMR and 13C NMR spectra were
recorded using a model Brucker Avance DPX-400 NMR spec-
trometer. IR spectra were recorded on a Perkin Elmer
Spectrum RX1 FTIR spectrometer on KBr discs in the wave-
number range of 4000–400 cmꢂ1. The electronic spectra of
the complexes in UV-Vis region were recorded in DMF solu-
tions using a Shimadzu Model 160 UV-Vis spectrophotometer.
Molar conductivity was measured with a WTW LF model 330
conductivity meter, using prepared solutions of the complex
in DMF:DMSO (1:1). LC=MS-API-ES mass spectra were
recorded using an Agilent model 1100 MSD mass spectropho-
tometer. Cyclic voltammograms were carried out using CV
measurements with Princeton Applied Research Model 2263
potentiostat controlled by an external PC. A three electrode
system (BAS model solid cell stand) was used for CV mea-
surements in DMSO and consisted of a 2 mm sized platinum
disc electrode as working electrode, a platinum wire counter
1162, 1114, 1050 (R–O), 752, 696 (C–S) cmꢂ1 13C NMR:
;
ꢃ ¼ 68.64 (CH2–OCH2), 69.82 (CH2–OC6H4), 163.03
(CH¼N), 112.73, 121.17, 121.48, 122.61, 122.8, 124.61,
125.89, 129.72, 131.74, 136.09, 152.12, 156.42 (Ar–Cs)
1
ppm; H NMR: ꢃ ¼ 4.24 (t, 4H, J ¼ 4 Hz, CH2–OCH2), 4.4
(d, 4H, J ¼ 4 Hz, CH2–OC6H4), 7–8.1 (m, 16H, J ¼ 8 Hz, Ar–
H), 8.5 (s, CH¼N) ppm; MS: m=z ¼ 527.1 [Lꢂ H]þ (MA:
528 g=mol); UV-Vis ("): l ¼ 228 (48270), 297 (17440), 322
(23520) nm (Mꢂ1 cmꢂ1) (in ethanol); l ¼ 251 (13500), 286

1208
H. Temel et al.
(21680), 323 (13500) nm (Mꢂ1 cmꢂ1) (in chloroform);
l ¼ 295 (27680), 322 (38540) nm (Mꢂ1 cmꢂ1) (in DMF).
Acknowledgement
We are grateful to Dicle University Research Found (DUAPK-
06-EF-11) for the support of this research.
Synthesis of La(III), Cu(II), Ni(II), and Zn(II) Complexes
To a stirred solution of 1,7-bis(2-formylphenyl)-1,4,7-trioxa-
heptane (1.5mmol, 0.47g) and 2-aminothiophenol (3mmol,
0.38g) in 40 cm3 methanol was added dropwise metal acetate
(1.5mmol) in 40 cm3 methanol. After the addition was com-
pleted, the stirring was continued for 2 h. A colored precipita-
tion was filtered off, washed with CH3COOH and diethyl
ether, and then dried in air.
References
[1] Jones RD, Summerville DA, Basolo F (1979) Chem Rev
79: 139
[2] Henrici-Olive G, Olive S (1984) The Chemistry of
the Catalyzed Hydrogenation of Carbon Monoxide,
Springer, Berlin, p 152
Spectral Characterization of La(III) Complex
[3] Dugas H, Penney C (1981) Bioorganic Chemistry,
Springer, New York, p 435
(C30H28LaN3O6S2)
Yield 0.55 g (55%), dark yellow, mp 163–165ꢄC; IR: ꢀꢀ¼
3058 (Ar–CH), 2923, 2866 (Aliph–CH), 1582 (C¼N), 1497,
1446 (Ar–C¼C), 1291, 1246, (Ar–O), 1143, 1115, 1051
(R–O), 751, 727, 694, 660 (C–S), 446 (La–N) cmꢂ1; MS:
m=z ¼ 553 [[La(L)(NO3)]–[O(CH2)2O(CH2)2O]–(NO3)]þ
(MA: 727 g=mol); UV-Vis ("): l ¼ 298 (27400), 323 (36280)
nm (Mꢂ1 cmꢂ1); LM ¼ 1.6 Oꢂ1 ꢁ molꢂ1 ꢁ cm2; ꢂeff ¼ Dia.
[4] Margerum JD, Miller LJ (1971) Photochromism, Inter-
science, Wiley, p 569
[5] Sawony WJ, Riederer M (1977) Angew Chem Int Edn
Engl 16: 859
[6] Temel H (2004) J Coord Chem 57(9): 723
˙
˘
[7] Temel H, Ilhan S, S¸ekerci M, Ziyadanogulları R (2002)
Spectrosc Lett 35: 219
¨ ˙
˘
°akır U, Tolan V, Otludil B, Ugras¸ H-I (2004)
[8] Temel H, C
J Coord Chem 57(7): 571
Spectral Characterization of Cu(II) Complex
˙
[9] Temel H, Ilhan S, S¸ekerci M (2002) Synth React Inorg
(C30H28CuN2O3S2)
Yield 0.73 g (82%), black, mp 201–202ꢄC; IR: ꢀꢀ¼ 3058, (Ar–
CH), 2938, 2873 (Aliph–CH), 1598, 1559 (C¼N), 1482,
1452, (Ar–C¼C), 1290, 1250 (Ar–O), 1160, 1116, 1055
(R–O), 754, 695, 668 (C–S), 475, 458 (Cu–N) cmꢂ1; MS:
m=z ¼ 523 [Cu(L)–(CH2)2O(CH2)2 þ 5H]þ (MA: 590 g=mol);
UV-Vis ("): l ¼ 277 (1684), 321 (18020), 478 (3020) nm
(Mꢂ1 cmꢂ1); LM ¼ 6.8 Oꢂ1 ꢁ molꢂ1 ꢁ cm2; ꢂeff ¼ 1.93ꢂB.
Met-Org Chem 32: 162
¨ ˙
˘
°akır U, Ugras¸ H-I, S¸ekerci M (2003) J Coord
[10] Temel H, C
Chem 56(11): 943
˘
[11] Tas¸ E, Aslanoglu M, Ulusoy M, Temel H (2004) J Coord
Chem 57(8): 77
˘
[12] Temel H, Ziyadanogulları B, Aydın I, Aydın F (2005)
J Coord Chem 58(14): 1177
[13] Temel H, S¸ekerci M (2001) Synth React Inorg Met-Org
Chem 31: 849
¨ ˙
˘
[14] Temel H, C°akır U, Ugras¸ H-I (2004) Synt React Inorg
Met-Org Chem 34(4): 819
[15] Soliman AA, Linert W (1999) Thermochimica Acta
338: 67
Spectral Characterization of Ni(II) Complex
(C30H28N2NiO3S2)
Yield 0.66g (75%), brown, mp 172–174ꢄC; IR: ꢀꢀ¼ 3072
(Ar–CH), 2867 (Aliph–CH), 1596, 1582 (C¼N), 1497, 1446,
1431 (Ar–C¼C), 1291, 1257 (Ar–O), 1162, 1116, 1052 (R–
[16] Soliman AA, Linert W (2007) Monatsh Chem=Chem-
ical Monthly 138: 175
1
O), 752, 727, 695, 661 (C–S), 456 (Ni–N) cmꢂ1; H NMR:
ꢃ ¼ 4.0 (t, 4H, J ¼ 4 Hz, CH2–O–CH2), 4.50 (t, 4H, J ¼
5.2 Hz, CH2–OC6H4), 6.2–7.6 (m, 16H, J ¼ 8 Hz, Ar–H),
8.17 (s, HC¼N) ppm; MS: m=z ¼ 571 [Ni(L)–(CH2)]þ (MA:
587.4 g=mol); UV-Vis ("): l ¼ 275 (25940), 841 (14380) nm
(Mꢂ1 cmꢂ1); LM ¼ 4.1 Oꢂ1 ꢁ molꢂ1 ꢁ cm2; ꢂeff ¼ Dia.
[17] Morrison GH, Freiser H (1957) Solvent Extraction
in Analytical Chemistry, John & Wiley Sons Inc.,
pp 3–4
[18] Franson MAH (1995) Standard Methods for Examina-
tion of Water and Waste Water, American Publication
Health Associations, pp 3–68
Spectral Characterization of Zn(II) Complex
(C30H28N2O3S2Zn)
[19] Eidecker R, Jackwerth E (1987) Fresenius Z Anal Chem
328: 469
Yield 0.8g (90%), orange, mp 108–110ꢄC; IR: ꢀꢀ¼ 3088, 3038
(Ar–CH), 1589, 1573, 1549 (C¼N), 1466, 1436 (Ar–C¼C),
1297, 1261 (Ar–O), 1155, 1065 (R–O), 746, 724, 702, 687
[20] Sung YH, Liu ZS, Huang SD (1997) Spectrochim Acta
Part B 52: 755
[21] Rydberg J, Musikas C, Choppin GR (1992) Principles
and Practices of Solvent Extraction, Marcel Dekker Inc.,
New York
[22] Pazos C, Diaz MR, Coca J (1986) J Chem Tech Bio-
technol 36: 79
[23] Shimizu K, Furuhashi A (1984) Bull Chem Soc Jpn 57:
3593
(C–S) cmꢂ1
;
13C NMR: ꢃ ¼ 68.65 (CH2–OCH2), 69.83 (CH2–
OC6H4), 163.42 (CH¼N), 112.74, 121.16, 121.49, 122.62,
122.79, 124.60, 125.88, 129.73, 131.74, 136.08, 152.12, 156.42
1
(Ar–Cs) ppm; H NMR: ꢃ ¼ 4.2 (t, 4H, J ¼ 4.8 Hz, CH2–O–
CH2), 4.4 (t, 4H, J ¼ 5.2 Hz, CH2–OC6H4), 7.0–8.1 (m, 16H,
J ¼ 7.3 Hz, Ar–H), 8.59 (s, 2H, HC¼N) ppm; MS: m=z ¼ 592
[Zn(L)]þ (MA: 594.07 g=mol); UV-Vis ("): l ¼ 324 (30100)
nm (Mꢂ1 cmꢂ1); L ¼ 0.7 Oꢂ1 ꢁ molꢂ1 ꢁ cm2; ꢂeff ¼ Dia.
[24] Earnshaw A (1968) Introduction to Magnetochemistry,
Academic Press, London, p 4

Spectroscopic and Electrochemical Studies
1209
[25] Adam KR, Leong AJ, Lindoy LF, Lip HC, Skelton BW,
White AH (1983) J Am Chem Soc 105: 4645
[26] Lindy LF, Armstrong LG (1975) Inorg Chem 14(6): 1322
[27] Khalil MMH, Aboaly MM, Ramadan RM (2005) Spec-
trochimica Acta A 61: 157
[28] Aboaly MM, Khalil MMH (2001) Spectrosc Lett 34:
495
[29] Lodeiro C, Bastıda R, Bertolo E, Rodriguez A (2004)
Can J Chem 82: 437
[34] Tas E, Aslanoglu M, Kilic A, Kaplan O, Temel H (2006)
J Chem Research 242
[35] Ben-saber SM, Mailub AA, Hudere SS, El-ajaily MM
(2005) Microchem J 81: 191
[36] Nishida Y, Kida S (1979) Coord Chem Rev 27: 275
[37] Bosnich B (1968) J Am Chem Soc 90: 627
[38] Akitsu T, Einaga Y (2005) Polyhedron 24: 1869
[39] Yilmaz I, Gurek AG, Ahsen V (2005) Polyhedron 24: 791
[40] Yilmaz I, Kocak M (2004) Polyhedron 23: 1279
[41] Kadish KM, Nakanishi T, Ahsen V, Yilmaz I (2001)
J Phys Chem B 105: 9817
¨
[30] Temel H, Hos¸goren H, Boybay M (2001) Spectrosc Lett
34(5): 1
[31] Krishnapriya KR, Kandaswamy M (2005) Polyhedron
24: 113
[42] Yilmaz I, Nakanishi T, Gu¨rek A, Kadish KM (2003)
J Porhyrins Phthalocyanines 7: 227
[32] Maravalli PB, Dhumwad SD, Goudar TR (1999) Synth
React Inorg Met-Org Chem 29(3): 525
[33] Curtis MF, Curtis YM (1965) Inorg Chem 4: 804
[43] Nakanishi T, Yilmaz I, Nakashima N, Kadish KM (2003)
J Phys Chem B 107: 12789
[44] Arslan S, Yilmaz I (2007) Inorg Chem Commun 10: 385