Properties and synthesis of the Cr(III)-salen/salophen complexes containing triphenylamine core

Article abstract of DOI:10.1080/15533174.2011.609517

Two triphenylamine derivatives bearing 4-aminobenzoic acid and 5-aminoisophthalic acid were synthesized. Then, the prepared triphenylamine derivatives were reacted with two new Cr(III) complexes involving tetradenta Schiff bases N,N-bis(salicylidene)ethyl

Full text of DOI:10.1080/15533174.2011.609517

This article was downloaded by: [Monash University Library]
On: 05 October 2013, At: 11:20
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
Synthesis and Reactivity in Inorganic, Metal-Organic,
and Nano-Metal Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/lsrt20
Properties and Synthesis of the Cr(III)-Salen/Salophen
Complexes Containing Triphenylamine Core
Ozcan Kocyigit a
a Selcuk University, Department of Chemistry, Konya, Turkey
Published online: 23 Mar 2012.
To cite this article: Ozcan Kocyigit (2012) Properties and Synthesis of the Cr(III)-Salen/Salophen Complexes Containing
Triphenylamine Core, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 42:2, 196-204, DOI:
10.1080/15533174.2011.609517
To link to this article: http://dx.doi.org/10.1080/15533174.2011.609517
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained
in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the
Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and
should be independently verified with primary sources of information. Taylor and Francis shall not be liable for
any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever
or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of
the Content.
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any
form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://
www.tandfonline.com/page/terms-and-conditions

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 42:196–204, 2012
Copyright ꢀ Taylor & Francis Group, LLC
C
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2011.609517
Properties and Synthesis of the Cr(III)-Salen/Salophen
Complexes Containing Triphenylamine Core
Ozcan Kocyigit
Selcuk University, Department of Chemistry, Konya, Turkey
Condensation of salicylaldehydes or salicylaldehyde deriva-
tives with 1,2-diamines leads to the formation of one extremely
important class of ligands, generally known as Salens (ac-
cordingly with o-phenylenediamine, Salophen). Salen-type and
Salophen-type ligands with N and O donor atoms are important
because their metal complexes find widespread applications as
homogeneous and heterogeneous catalysts in various organic
transformation reactions.[9] For example, a Schiff base com-
plex of chromium(III), [Cr(Salen)(OH2)2]+, was found to en-
hance insulin activity and insulin derivatized with the same was
found to exhibit higher activity in glucose metabolism in animal
models when compared to either free insulin or other deriva-
tives.[10,11] The bridged complexes of Salen-Salophen are espe-
cially attractive by lastest studies in inorganic chemistry.[12–14]
Triphenylamine (TPA) has been known as a hole-transporting
as well as thermally and photolytically stable material.[15] TPA
and its derivatives have been widely utilized as a functional
building block in the fabrication of the organic photoconduc-
Two triphenylamine derivatives bearing 4-aminobenzoic
acid and 5-aminoisophthalic acid were synthesized. Then,
the prepared triphenylamine derivatives were reacted with
two new Cr(III) complexes involving tetradenta Schiff
bases N,N-bis(salicylidene)ethylenediamine or bis(salicylidene)-o-
phenylenediamine. The structures of these compounds were char-
1
acterized by elemental analysis, FT-IR, TG, H NMR, and 13C
NMR techniques and magnetic susceptibility measurement. The
complexes can also be characterized as low-spin distorted octa-
hedral Cr(III) bridged by carboxylic acids. The carboxylic acids
play a role as bridges for weak antiferromagnetic intramolecular
exchange. Also, the UV spectra of these derivatives revealed that
the maximum wavelengths of the complexes are shifted, compared
with the ligands.
Keywords complexation, Schiff base, synthesis, triphenylamin
INTRODUCTION
Investigation on metal organic complexes represents one of tors, nonlinear optical materials, and photorefractive materials
the most active areas of materials science and chemical research. in OLEDs owing to their excellent solubility, stability and the ex-
Major advances have been made in these materials due to their cellent hole-transporting capability (the electron-donating prop-
interesting properties and potential in various applications (e.g., erties).[16–22] Triarylamines (TAAs) having various substituents
electrical conductivity, magnetism, hostguest chemistry, ion ex- at their para positions have been widely known to give the cor-
change, catalysis, nonlinear optics).[1–3] Synthesis of new Schiff responding very stable cation radicals upon chemical or elec-
bases and their metal complexes still the aim of many recent trochemical one electron oxidation,[23] serving as stable posi-
investigations. Schiff bases have played an important role in tive charge and spin bearing units. During the past decade, this
the development of coordination chemistry as they readily form salient feature has been utilized for the synthesis of a num-
stable complexes with most of the transition metals. They show ber of p-extended TAA-based oligomers as models for posi-
interesting properties such as their ability to reversibly bind tively charged purely organic high-spin entities[24] as well as
oxygen,[4] catalytic activity in hydrogenation of olefins[5] and for organic mixed-valence molecular systems.[25] Very recently,
transfer of an amino group,[6] photochromic properties,[7] and Bushby et al. reported a triarylamine-based ligand with a 4-
complexing ability towards toxic metals.[8]
pyridyl unit and its manganese complex.[26] Yano and cowork-
ers[27] designed and prepared a starburst-shaped ligand, 4,4’4”-
tris[N, N-bis(2-pyridylmethyl) aminomethyl] triphenylamine,
and its palladium and copper trinuclear complexes.
Received 6 July 2011; accepted 28 July 2011.
In the present article, we report the synthesis of novel triph-
enylamine derivatives containing mono- and dicarboxylic acid
groups by using 4-aminobenzoic acid and 5-aminoisophthalic
acid reagents and the preparation of their mono- and dinu-
clear Cr(III)(Salen/Salophen) complexes. The structure of the
compounds was characterized using elemental analysis, FT-
The author would like to thank the Scientific Research Projects
Foundation of Selcuk University (SUBAP) and Technical Research
Council of Turkey (TUBITAK) for financial support of this work. He
also thanks Serkan Erdemir for assistance in the preparation of the
manuscript.
Address correspondence to Ozcan Kocyigit, Selcuk Uni-
versity, Department of Chemistry 42075, Konya, Turkey. E-mail:
okocyigit40@gmail.com
1
IR, TGA, H NMR, and 13C NMR techniques and magnetic
196

CR(III)-SALEN/SALOPHEN COMPLEXES
197
susceptibility measurement. Also, the magnetic and physical synthesized by using phosphorus oxychloride and DMF ac-
properties of the synthesized complexes are reported and their cording to a literature procedure.[31] For compound 1, 1H NMR
ultraviolet visible spectrum (UV-vis) was recorded.
(CDCl3 δ, ppm): 9.82 (s, 1H, CHO), 7.70 (d, 2H, J = 8.7 Hz,
ArH), 7.36 (t, 4H, J = 7.7–8.2 Hz, ArH), 7.21–7.17 (m, 6H,
ArH), 7.04 (d, 2H, J = 8.7 Hz, ArH).
EXPERIMENTAL
General Procedure for the Synthesis of Triphenylamine
Derivatives Bearing Carboxylic Acid Groups (2a and 2b)
A solution of triphenylamine monoaldehyde (1) (1.0 mmol)
in absolute EtOH (20 mL) was added 4-aminobenzoic acid or
5-aminoisophthalic acid (1.0 mmol) and refluxed for 24 h. Then,
the reaction mixture was allowed to cool to room temperature,
and filtered. The precipitate was washed with cool EtOH.
Materials and Methods
All starting materials and reagents used were of standard
analytical grade from Fluka, Merck as well as from Aldrich
and used without further purification. [{Cr(Salen)2}O] and
[{Cr(Salophen)2}O] were prepared according to previously
published methods.[28–30] Melting points were measured using
a Buchi B-540 melting point apparatus. 1H NMR and 13C NMR
spectra were recorded on a Varian 400 MHz spectrometer at
room temperature. Thermal gravimetric analysis (TG) was car-
ried out with Seteram thermogravimetric analyzer. The sample
weight was 12–15 mg. Analysis was performed from room tem-
perature to 900◦C at heating rate of 15◦C/min in argon atmo-
sphere with a gas flow rate of 20 mL/min. The elemental analysis
for the ligand and the bridged complexes were carried out at on a
Hewlett-Packard 185 analyzer. UV-vis spectra were obtained on
a PerkinElmer Lambda 25 UV/Vis System. FT-IR spectra were
recorded on a PerkinElmer Spectrum 100 as KBr pellets. Mag-
netic susceptibilities of metal complexes were determined using
a Sherwood Scientific MX Gouy magnetic susceptibility appa-
ratus carried out using the Gouy method with Hg[Co(SCN)4]
as calibrant. The effective magnetic moments, µeff, per metal
Compound 2a
1H NMR (CDCl3 δ, ppm): 8.33 (s, 1H, CHN), 8.13 (d, 2H,
J = 8.6 Hz, ArH), 7.74 (d, 2H, J = 8.0 Hz, ArH), 7.28–7.33 (m,
4H, ArH), 7.22 (d, 2H, J = 8.0 Hz, ArH), 7.06–7.17 (m, 8H,
ArH); 13C NMR (CDCl3): δ 122.3, 125.1, 125.8, 126.7, 128.1,
128.3, 129.5, 130.6, 131.5, 145.6, 148.3, 157.1, 159.9, 169.1.
Compound 2b
1H NMR (CDCl3): δ 8.89 (t, 1H, J = 1.56 Hz, CHN), 8.48
(s, 1H, ArH), 8.04 (d, 2H, J = 1.56 Hz, ArH), 7.71 (d, 2H,
J = 8.8 Hz, ArH), 7.25–7.30 (m, 4H, ArH), 7.03–7.14 (m, 8H,
ArH); 13C NMR (CDCl3): δ 125.2, 125.7, 126.6, 128.1, 128.5,
129.2, 129.4, 130.6, 130.4, 145.2, 147.3, 153.1, 159.8, 168.3.
atom was calculated from the expression: µeff. = 2.84.(χM)1/2
where χM is the molar susceptibility.
,
Preparation of [Compound 2a-{Cr(III)(Salen/Salophen)
(3a-b)}] and [Compound 2b- {Cr(III)(Salen/Salophen)
(4a-b)}] Complexes
Synthesis
The target compounds 2a-b were prepared via a three-
A solution of compound 2a or 2b (1 mmol) and
step procedure which is shown in Figure 1. Compound 1 was [{Cr(Salen)}2O] (1.5 mmol) or [{Cr(Salophen)}2O] (1.5 mmol)
FIG. 1. Synthesis of triphenylamine derivatives bearing carboxylic acid groups (2a) and (2b); (i) POCl3, DMF; (ii) 4-aminobenzoic acid, ethanol reflux for 24
h; (iii) 5-aminoisophthalic acid, ethanol reflux for 24 h.

198
O. KOCYIGIT
TABLE 1
Elemental analysis, magnetic and physical properties of the compounds
Compound
Formula
Color
µeff (B.M.) m.p (◦C) Yield (%)
Found (Anal. Calcd.) (%)
C
N
H
Cr
1
C19H15NO
Pale yellow
-
-
130
203
80
78
83.47
(83.49)
78.34
5.15
(5.13)
7.22
5.57
(5.53)
5.12
—
—
—
2a
C26H20N2O2
Light
yellow
(79.50)
73.91
(7.14)
6.85
(5.14)
4.43
—
—
2b
C27H20N2O4
Light
-
175
80
yellow
(74.30)
70.65
(70.98)
72.67
(72.81)
65.96
(66.04)
68.19
(6.42)
7.96
(7.88)
7.40
(7.38)
7.92
(7.83)
7.39
(4.62)
4.76
(4.82)
4.50
(4.52)
4.40
(4.51)
4.01
—
7.12
(7.32)
6.46
(6.85)
9.28
3a
3b
4a
4b
C42H34N4O4Cr
C46H34N4O4Cr
C59H48N6O8Cr2
C67H48N6O8Cr2
Light green
Green
3.60
3.72
3.65
3.70
215
220∗
350a
350a
60
65
65
70
Dark green
Dark green
(9.69)
8.83
(68.83)
(7.19)
(4.14)
(8.89)
∗Decomposition.
in 40 mL of absolute ethanol was refluxed for 3 h. The mixture appearance of carbon signals at 169.1 and 168.3 ppm belong to
was allowed to cool to room temperature. Then the mixture was CH N groups in 13C-NMR. From the FT-IR results, the band
filtered and the residue was washed with ethanol and dried in of CH O vibration of 1 observed at 1690 cm−1 was disap-
vacuum. Elemental analysis and magnetic and physical proper- peared and imine C = N bands for 2a and 2b were observed at
ties of the synthesized complexes are given in Table 1.
1668 and 1654 cm−1, respectively. The results of the elemental
analyses, given in Table 1, are in a good agreement with the
structures suggested for the ligands and their complexes. In ad-
dition, the synthesized Salen and Salophen capped complexes
were characterized with thermal gravimetric analysis, magnetic
susceptibility and FT-IR.
RESULTS AND DISCUSSION
Synthesis
In order to evaluate the complexation with [{Cr(Salen)}2O]
and [{Cr(Salophen)}2O] of triphenylamine derivatives contain-
ing mono- and dicarboxylic acid groups as ligand (2a and
2b), first we synthesized triphenylamin monoaldehyde (1) using
FT-IR Spectra
The characteristic FT-IR bands for compound 2a -2b and
phosphorus oxychloride and DMF according to literature pro- their Cr(III)-Salen/Salophen complexes (3a, 3b, 4a and 4b)
cedure.[31] Then, compound 1 was reacted with 4-aminobenzoic were given Table 2. The FT-IR spectra of the complexes have
acid and 5-aminoisophthalic acid in ethanol medium to ob- different absorption peaks, compared with that of the ligands.
tain compound 2a and 2b, respectively (Figure 1).. Then, the As seen in Table 2, the vibrations of the carboxylic acid
obtained compounds 2a and 2b were converted to complexes
C
O and imine C
N of 2a and 2b have been observed
bridged by carboxylate anions to the chromium center with at 1683, 1668 cm−1 for 2a and 1684, 1654 cm−1 for 2b, re-
[{Cr(Salen)}2O] and [{Cr(Salophen)}2O] as ligand complex spectively. In the complexes, these bands are, however, shifted
because it can coordinate to another ligand (Figure 2). Char- to lower or higher frequencies indicating that the nitrogen and
acterization of these compounds was made with 1H NMR, 13
C
oxygen atoms of compound 2a and 2b are coordinated to the
NMR, FT-IR, and elemental analysis. Figures 3 and 4 show ligand complexes [12]. The C O band in complexes 3a and
1H-NMR spectrums of 2a and 2b, respectively. The formation 3b shifted from 1683 to 1688 and 1689 cm−1, the C = N band
of 2a and 2b was confirmed by the disappearance of the alde- shifted from 1668 to 1645 and 1658 cm−1, respectively. Also,
hyde protons in triphenylamine monoaldehyde at 9.82 ppm and the C O band in complexes 4a and 4b shifted from 1684 to
the appearance of imine protons (CH
N) at 8.33 and 8.89 1616 and 1604 cm−1, the C
N band shifted from 1654 to
ppm belong to 2a and 2b compounds, respectively (Figures 3 1601 and 1581 cm−1, respectively. In the FT-IR analysis of the
and 4). Also, the synthesis of 2a and 2b was supported by the complexes (3a, 3b, 4a, and 4b), the bands in the 556–533 and

CR(III)-SALEN/SALOPHEN COMPLEXES
199
FIG. 2. Synthetic routes for complexation between compound 2a-2b and Cr (III) (color figure available online).
FIG. 3. 1H NMR spectrum of compound 2a (color figure available online).

200
O. KOCYIGIT
FIG. 4. 1H NMR spectrum of compound 2b (color figure available online).
3a complex, at 200–475◦C, ligand and CO2 leave the com-
plex structure. Moreover, the loss of C6H6 was observed within
475–650◦C. For the 3b complex, the first step (40–350◦C) is
due to the loss of moisture and CO2. At the second decompo-
465–478 cm−1 range can be attributed to the M–N and M–O
stretching modes.[32]
Thermal Properties
The thermal analysis of ligands and their complexes were sition step, the ligand and C6H6 groups leave from structure at
recorded in argon atmosphere from 40 to 900◦C. The corre- 350–800◦C.
lations between the different decomposition steps of the com-
As seen in Table 3, ligand 2b shows three decomposition
pounds with the corresponding weight losses are discussed in steps within the 175–700◦C temperature range. The decom-
terms of the proposed formula of the compounds. The thermal position within the 175–325◦C, 325–460◦C, and 460–700◦C
behaviors of the obtained complexes are summarized in Table 3. temperature ranges is due to the loss of CO2, triphenylamine,
An exemplary TG curve of complex 3b is depicted in Figure 5. and C6H6N from main structure, respectively. The ligand 2a’s
The results show good agreement with the formula suggested Cr(III)-Salen/Salophen complexes (4a, 4b) have different de-
from the analytical data (Table 1).
composition steps. While the complex 4a thermally decomposed
The ligand 2a is thermally decomposed in only two suc- only three decomposition step, the complex 4b decomposed
cessive decomposition steps. The mass loss of within the tem- four decomposition steps. The first decomposition step for 4a
perature range 250–425◦C may be attributed to the loss of the (40–140◦C) is due to the loss of moisture. At 175–325◦C, the
CO2 and triphenylamine groups. At the second decomposition CO2 left from the residue structure. Also, the loss of ligand and
step, C6H6N groups lefts from the main structure at 425–650◦C. C6H6 groups in 4a was observed within 325–800◦C. The de-
The TG results of 3a and 3b complexes show two decomposi- composition of the complex 4b proceeds with four main degra-
tion steps within the temperature range of 40–900◦C. For the dation steps. The first decomposition within the temperature
TABLE 2
Characteristic FT-IR bands (cm−1) of ligand and complexes
Compounds
C = N
C = O
C-N
C-Car
C-Haliph
2a
3a
3b
2b
4a
4b
1668 s
1645 m
1658 m
1654 s
1601 s
1581 s
1683 s
1688 s
1689 s
1684 s
1616 m
1604 m
1163 s
1155 s
1164 s
1157 s
1050 m
1048 m
1585 s
1578 s
1584 s
1579 s
1541 m
1548 m
2865 w
2829 w
3059 w
2978 m
2969 w
3063 m

CR(III)-SALEN/SALOPHEN COMPLEXES
201
TABLE 3
TG results of the ligands and complexes
Weight loss found
(Anal. Calcd.) (%)
Compounds
TG range (◦C)
Fragments
2a
250–425◦C
425–650oC
200–475◦C
475-650◦C
67.50(68.38)
28.65(29.86)
54.50(55.49)
22.10(21.97)
CO2, triphenylenamine group
loss of C6H6N
loss of ligand, CO2
loss of C6H6
Metal oxide and R(CN)2 residue
moisture, CO2
loss of ligand and C6H6
Metal oxide and R(CN)2 residue
CO2
3a
3b
2b
4a
40–350◦C
7.21(5.80)
65.31(66.49)
350–800oC
175-325◦C
325–460◦C
460–700oC
40-140◦C
19.77(20.18)
55.78(56.19)
22.13(24.08)
3.28
9.07(8.20)
59.45(61.50)
triphenylenamine group
Loss of C6H6N group
moisture
175–325◦C
325–800◦C
CO2
loss of ligand and C6H6 groups
Metal oxide and R(CN)2 residue
Moisture
CO2
loss of ligand
loss of C6H6 groups
Metal oxide and R(CN)2 residue
4b
40–120◦C
200–350◦C
325–650◦C
650–900◦C
2.23
8.12(7.52)
27.29(29.76)
25.71(26.68)
FIG. 5. TG and dTG curve of complex 3b (color figure available online).

202
O. KOCYIGIT
FIG. 6. Absorption spectra of the ligands and complexes (1 × 10−5 mol L−1 in DMSO). (a) 2a, 3a, and 3b; (b) 2b, 4a, and 4b.

CR(III)-SALEN/SALOPHEN COMPLEXES
203
range 40–120◦C could be attributed to the loss of moisture. The π–π∗ transition of the conjugated backbone (Salen and Sa-
second step occurs within the temperature range 200–350◦C, lophen). The λmax of 3a and 3b was hypsochromically shifted
which is reasonably accounted for loss of CO2 groups. The by about 15 nm and 21 nm, respectively when compared with
third and fourth decomposition within the temperature ranges 2a. Spectra of 2b and its complexes (4a-4b) given in Figure 6
of 325–650◦C and 650–900◦C corresponds to the liberation of showed a maximum absorption peak at 364, 372, and 358 nm,
ligand and C6H6 groups, respectively.
respectively. The characteristic absorption peaks of tripheny-
The total weigh losses were theoretically calculated and com- lamine unit in complex 4a and 4b are unapparent by reason of
pared with experimentally. The estimated mass losses for all the enhancing π-conjugated structure.
complexes were presented in Table 3 and observed to good
agreement with the formulae suggested from the analytical data.
CONCLUSIONS
In conclusion, two novel Cr(III) Salen/Salophen complexes
containing a triphenylamine unit have been efficiently synthe-
sized. These complexes are the examples of mono- and dinuclear
complexes bridged by carboxyl to the chromium centers. The
UV-vis absorption spectra of these complexes in DMSO were
investigated. Also, their structures were characterized by means
Magnetic Moments Studies
As is known, magnetic susceptibility measurements provide
information regarding the geometric structure of the complexes.
Magnetic susceptibility was determined using a magnetic sus-
ceptibility balance. The magnetic moment data of the solid-
state complexes at room temperature are reported in Table 1.
The magnetic susceptibility measurements show that the 3a-3b
and 4a-4b complexes have paramagnetic property with a mag-
netic susceptibility value per atom: 3.60, 3.72 B.M. and 3.65,
3.70 B.M., respectively. These values for Cr(III) Salen/Salophen
complexes (3a-4b) are consistent with expected spin-only mag-
netic moment of an S = 3/2 (3.87 BM). It is seen that
the [{Cr(Salen)}2O] and [{Cr(Salophen)}2O] containing com-
1
of elemental analysis, H NMR, FT-IR spectroscopy, thermal
analyses, and magnetic susceptibility measurements. The pre-
pared complexes exhibit good thermal stability with a decom-
position temperature range from 200 to 900◦C. Moreover, the
magnetic data for the mono- and dinuclear complexes show
good agreement with the d3 metal ion in an octahedral structure.
pounds are represented by the electronic structure of t32geg . The
0
REFERENCES
magnetic data for the [{Cr(Salen)}2O] and [{Cr(Salophen)}2O]
complexes demonstrate well agreement with the d3 metal ion in
an octahedral structure. This consequence is supported by the re-
sults of the elemental analyses suggesting that these complexes
have also an octahedral structure.[12 28]
1. Gatteschi, D.; Kahn, O.; Miller, J. (Eds.). Molecular Magnetic Materials,
Nato ASI Series E198; Kluwer: Dordrecht, The Netherlands, 1991.
2. Yaghi, O.M.; Li, G.; Li, H. Selective binding and removal of guests in
amicroporous metal-organic framework. Nature 1995, 378, 703–706.
3. Chen, C.T.; Suslick, K.S. One-dimensional coordination polymers-
applications to material science. Coord. Chem. Rev. 1993, 128, 293–322.
4. Jones, R.D.; Summerville, D.A.; Basolo, F. Synthetic oxygen carriers re-
lated to biological systems. Chem. Rev. 1979, 79, 139–179.
5. Henrici-Olive, G.; Olive, S. The Chemistry of the Catalyzed Hydrogenation
of Carbo Monoxide; Springer: Berlin, 1984, p. 152.
The UV-Vis Spectra
The UV-Vis absorption spectra of ligands (2a-2b) and com-
plexes (3a, 3b, 4a, and 4b) in DMSO are shown in Figure 6
and their absorption peaks are summarized in Table 4. Figure
6 shows the UV-absorption spectra of 2a and their complexes
(3a-3b). The ligand (2a) has two absorption bands at around 294
and 375 nm, which originated from π–π∗ transition of tripheny-
lamine unit and intraligand π–π∗ transition of the conjugated
backbone (2a).[33] In the absorption spectra of the complexes 3a
and 3b, the maximum absorptions of the complexes 3a and 3b
are 360 and 354 nm, which can be assigned to intramolecular
6. Dugas, H.; Penney, V. Bioorganic Chemistry; Springer: New York, 1981.
7. Margerum, J.D.; Miller, L.J. Photochromism; Wiley Interscience: New
York, 1971.
8. Sawodny, W.J.; Riederer, M. Addition compounds with polymeric
chromium(II)–Schiff base complexes. Angew. Chem. Int. Ed. Engl. 1977,
6, 859–860.
9. Adam, W.; Saha-Moeller, C.R.; Ganeshpure P.A. A convenient synthesis
of nickel(II) and cobalt(II) complexes of unsymmetrical salen-type ligands
and their application as catalysts for the oxidation of 2,6-dimethylphenol
and 1,5-dihydroxynaphthalene by molecular oxygen. Ind. J. Chem. 2004,
43A, 56–62.
10. Govindaraju, K.; Ramasami, T.; Ramaswamy, D. Chymotrypsincatalyzed
hydrolysis of chromium(III) derivatives of insulin: evidence for stabilization
of the protein through interactions with metal ions. J. Inorg. Biochem. 1989,
35, 127.
11. Shrivastava, H.Y.; Devaraj, S.N.; Nair, B.U. A Schiff base complex of
chromium(III): an efficient inhibitor for the pathogenic and invasive poten-
tial of Shigella dysenteriae. J. Inorg. Biochem. 2004, 98, 387–392.
12. Kocyigit, O.; Guler, E. The investigation of complexation properties and
synthesis of the (salen and salophen)-bridged Fe/Cr(III) capped complexes
of novel Schiff bases. J. Incl. Phenom. Macro. 2010, 67, 29–37.
13. Silva, A.R.; Freire, C.; Castro, B. Modulation of the catalytic activity of
manganese (III) salen complexes in the epoxidation of styrene: influence of
the oxygen source. New J. Chem. 2004, 28, 253–260.
TABLE 4
Absorption peaks of the ligands and complexes
Compounds
Absorption peaks (nm)
2a
2b
3a
3b
4a
4b
294
376
364
360
354
372
358
292
289
290
277
289

204
O. KOCYIGIT
14. Wang, S.H.; Li, Y.T.; Yan C.W. Synthesis, characterization and antiferro-
magnetic interaction in oxalato-bridged chromium(III)-chromium(III) bin-
uclear complexes, Pol. J. Chem. 2006, 80, 865–872.
15. Nomura, M.; Fukukawa, K.; Shibasaki, Y.; Ueda, M. New
amorphous hole-transporting molecular materials: 1,1,1-Tris(4-(4-
diarylaminobenzoyloxy)phenyl)ethane. Synthetic Met. 2002, 132, 9–13.
16. Sonntag, M.; Kreger, K.; Hanft, D.; Strohriegl, P. Novel star-shaped triph-
(c) Yano, M.; Ishida, Y.; Tatsumi, M.; Sato, K.; Shiomi, D.; Oyama, M.;
Takui, T. Organic high-spin systems: synthesis, electrochemical and ETSF
studies of a series of tetraaryl-meta-phenylenediamines. J. Phys. Chem.
Solids. 2004, 65, 733–736. (d) Yano, M.; Nakanishi, Y.; Matsushita, K.;
Tatsumi, M.; Oyama, M.; Sato, K.; Takui, T. Properties of tetraaryl-m-
phenylendiamine oligocations as examined by electron transfer stopped-
flow method. Polyhedron 2005, 24, 2116–2120.
enylaminebased molecular glasses and their use in OFETs. Chem. Mater. 25. Lambert, C.; No¨ll, G.; The class II/III transition in triarylamine redox
2005, 17, 3031–3039.
systems. J. Am. Chem. Soc. 1999, 121, 8434–8442.
17. Koene, B.E.; Loy, D.E.; Thompson, M.E. Asymmetric triaryldiamines as
thermally stable hole transporting layers for organic light-emitting. Chem.
Mater. 1998, 10, 2235–2250.
18. Roquet, S.; Cravino, A.; Leriche, P.; Aleveque, O.; Frere, P.; Roncali, J.
Triphenylamine–thienylenevinylene hybrid systems with internal charge
transfer as donor materials for heterojunction solar cells. J. Am. Chem. Soc.
2006, 128, 3459–3466.
26. Bushby, R.J.; Kilner, C.; Taylor, N.; Williams, R.A. Antiferromagnetic
spin-coupling between MnII and amminium radical cation ligands: models
for coordination polymer magnets. Polyhedron 2008, 27, 383–392.
27. Yano, M.; Manabe, M.; Tatsumi, M.; Oyama, M.; Sato, K.; Takui, T. Syn-
thesis and properties of a redox active starburst ligand with three bispi-
corylamino groups and its trinuclear complexes. Polyhedron. 2009, 28,
1935–1939.
19. Leriche, P.; Frere, P.; Cravino, A.; Aleveque, O.; Roncali, J. Molecular
engineering of the internal charge transfer in thiophene–triphenylamine
hybrid p-conjugated systems. J. Org. Chem. 2007, 72, 8332–8336.
20. Wei, P.; Bi, X.; Wu, Z.; Xu, Z. Synthesis of triphenylamine-cored dendritic
twophoton absorbing chromophores. Org. Lett. 2005, 7, 3199–3202.
21. Chen, L.; Cui, Y.; Mei, X.; Qian, G.; Wang, M. Synthesis and character-
ization of triphenylamino-substituted chromophores for nonlinear optical
applications. Dyes Pigments 2007, 72, 293–298.
22. Zhang, Q.; Ning, Z.; Tian, H. Click synthesis of starburst triphenylamine
as potential emitting material. Dyes Pigments 2009, 81, 80–84.
23. (a) Seo, E.T.; Nelson, R.F.; Fritsch, J.M.; Marcoux, L.S.; Leedy, D.W.;
Adams, R.N. Anodic oxidation pathways of aromatic amines. Electrochem-
ical and electron paramagnetic resonance studies. J. Am. Chem. Soc. 1966,
88, 3498–3503. (b) Nelson, R.F.; Adams, R.N. Anodic oxidation pathways
of substituted triphenylamines. II. Quantitative studies of benzidine forma-
tion. J. Am. Chem. Soc. 1968, 90, 3925–3930.
28. Kopel, P.; Sindelar, Z.; Klicka, R. Complexes of iron(III) salen and salophen
Schiff bases with bridging dicarboxylic and tricarboxylic acids. Transit.
Metal. Chem. 1998, 23, 139–142.
29. Kopel, P.; Sindelar, Z.; Biler, M.; Klicka, R. Complexes of iron(III) salen
and salophen Schiff bases bridged by dicarboxylicacids. Pol. J. Chem. 1998,
72, 2060–2066.
30. Gembicky, M.; Boca, R.; Renz, F. A heptanuclear Fe(II)–Fe(III) system
with twelve unpaired electrons. Inorg. Chem. Commun. 2000, 3, 662–665.
31. Sengupta, S.; Sadhukhan, S.K.; Muhuri, S. A tetraphenylmethane based
starburst triarylamine cluster:spectroscopy, electrochemistry and morpho-
logical studies. Tetrahedron Lett. 2002, 43, 3521–3524.
32. Guler, E.; Kocyigit, O. Synthesis and characterization of Ni(II)
and Co(II) complexes of Schiff bases derived from 3,4-dimethyl-
Delta(3)-tetrahydrobenzaldehyde
and
4,6-dimethyl-Delta(3)-
tetrahydrobenzaldehyde and glycene. Russ. J. Coord. Chem. 2007,
33, 607–610.
24. (a) Itoh, K.; Kinoshita, M. (Eds.). Molecular Magnetism, New Magnetic 33. Bao, L.; Qian, L.; Bin, L.; Youfeng, Y.; Mingxin, Y. The synthesis and pho-
Materials; Gordon & Breach, Inc.: Amsterdam, The Netherlands (Kodansha
as copublisher, Tokyo), 2000. (b) Lahti, P.M. (Ed.). Magnetic Properties
of Organic Materials; Marcel Dekker Inc.: New York, 1999, Chapter 9.
toluminescence characteristics of novel α,β-diarylacrylonitrile derivatives
containing both a biphenyl group and a triphenylamine unit. Dyes Pigments
2011, 88, 301–306.