Synthesis and characterization of new schiff bases 2-(2-(2-(aryl) methyleneamino)phenylthio) ethylthio)-N-((aryl)methylene)benzeneamine

Article abstract of DOI:10.1080/10426500903107930

A series of Schiff bases containing four to six coordination sites N2S2 X2(X = O,N) 2-(2-(2-(aryl)methyleneamino)phenylthio)ethylthio)-N-((aryl) methylene)benzeneamine (2c-f) were prepared from the reaction of 1,2-di(2-aminophenylthio)ethane (1) with aromatic aldehydes. All compounds were characterized by means IR, mass, 1H and 13C NMR spectroscopy, and elemental analysis, and in the case of 2b with a single crystal X-ray diffraction. The X-ray crystal structure of 2b showed that the resonance occurs between aromatic rings, through the C=N bonds of the molecule. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/10426500903107930

This article was downloaded by: [University of Newcastle, Australia]
On: 08 January 2015, At: 08:45
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
Phosphorus, Sulfur, and Silicon and the
Related Elements
Publication details, including instructions for authors and
subscription information:
http://www.tandfonline.com/loi/gpss20
Synthesis and Characterization
of New Schiff Bases 2-(2-(2-
(Aryl)Methyleneamino)Phenylthio)
Ethylthio)-N-
((aryl)Methylene)Benzeneamine
Ali Kakanejadifard a , Toraj Hayati a & Azam Rezayat a
a Department of Chemistry , Faculty of Science, Lorestan
University , Khorramabad, Iran
Published online: 02 Jul 2010.
To cite this article: Ali Kakanejadifard , Toraj Hayati & Azam Rezayat (2010) Synthesis and
Characterization of New Schiff Bases 2-(2-(2-(Aryl)Methyleneamino)Phenylthio) Ethylthio)-N-
((aryl)Methylene)Benzeneamine, Phosphorus, Sulfur, and Silicon and the Related Elements, 185:7,
1511-1515, DOI: 10.1080/10426500903107930
To link to this article: http://dx.doi.org/10.1080/10426500903107930
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

Phosphorus, Sulfur, and Silicon, 185:1511–1515, 2010
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500903107930
SYNTHESIS AND CHARACTERIZATION OF NEW SCHIFF
BASES 2-(2-(2-(ARYL)METHYLENEAMINO)PHENYLTHIO)
ETHYLTHIO)-N-((ARYL)METHYLENE)BENZENEAMINE
Ali Kakanejadifard, Toraj Hayati, and Azam Rezayat
Department of Chemistry, Faculty of Science, Lorestan University, Khorramabad,
Iran
A series of Schiff bases containing four to six coordination sites N2S2 X2(X = O,N) 2-(2-(2-
(aryl)methyleneamino)phenylthio)ethylthio)-N-((aryl)methylene)benzeneamine (2c–f) were
prepared from the reaction of 1,2-di(2-aminophenylthio)ethane (1) with aromatic aldehydes.
All compounds were characterized by means IR, mass, 1H and 13C NMR spectroscopy, and
elemental analysis, and in the case of 2b with a single crystal X-ray diffraction. The X-ray
crystal structure of 2b showed that the resonance occurs between aromatic rings, through
the C N bonds of the molecule.
Supplemental materials are available for this article. Go to the publisher’s online edition of
Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental
file.
Keywords
2-(2-(2-(Aryl)methyleneamino)phenylthio)ethylthio)-N-((aryl)methylene)ben-
zeneamine; 1,2-di(2-aminophenylthio)ethane; Schiff base; X-ray
INTRODUCTION
The coordination chemistry of transition metal ions with the N2S2 donor sets has
received considerable interest in recent years.1–5 Quadridentate ligands with the donor sets
N2S2 are very important for nuclear medicine, because their technetium and rhenium com-
plexes are sufficiently stable in vivo to function as effective radioimaging and therapeutic
agents.6,7
The N, S donor ligand and Pd(II), Pt(II) complexes, used to prepare antiviral, anti-
fungal, antimicrobial, antitumor8,9 products, and their mechanism of action most probably
involves the inhibition of ribonucleotide reductase, converting ribonucleotides to deoxyri-
bonucleotides.10,11 Recently, new N2S2 Schiff bases 2a–b were prepared from the reaction
of 1,2-di(2-amino phenylthio)ethane (1) with aromatic aldehydes.12–14 These Schiff bases
are suitable for preparation of coordination polymers and oxidative cleavage of the ligand
when it was reacted with transition metal ions, rather than forming a simple complex.15–17
Considering these properties, we have prepared some new Schiff bases, N4S2, N2O4, N2S4,
Received 9 March 2009; accepted 6 June 2009.
We thank Lorestan University for financial support of this work.
Address correspondence to Ali Kakanejadifard, Department of Chemistry, Lorestan University, Khorram-
abad, Iran. E-mail: kakanejadi.a@lu.ac.ir
1511

1512
A. KAKANEJADIFARD ET AL.
and N2O2S2, from the reaction of 1,2-di(2-aminophenylthio)ethane (1) with aromatic alde-
hydes. The Schiff bases 2 contain four to six coordination sites; they are therefore suitable
for the preparation of catalysts or coordination polymers.
RESULTS AND DISCUSSION
The condensation reaction of 1,2-di(2-aminophenylthio)ethane (1) with various sub-
stituted aromatic aldehydes in absolute ethanol gave the acyclic Schiff base products
(Scheme 1). All prepared compounds 2c–f are air-stable solids and soluble in acetone,
CDCl3, and THF. The structure of the prepared compounds 2c–f was confirmed by means
of 1H NMR, 13C NMR, IR, mass spectroscopy, and elemental analysis. The compound 2b
was further characterized by single crystal X-ray crystallography (Figure 1).
2a, Ar =
2b, Ar =
2c, Ar =
2d, Ar =
Ar
N
Ar
N
N
HO
H
H
H
EtOH
S
S
+ ArCHO
2e, Ar =
2f, Ar=
S
N
H2N
NH2
S
S
N
O
1
2
Scheme 1
The infrared spectra of all products, recorded in the region of 4000–500 cm−1, similar to the
total absence of NH2 in the IR spectra of 1, together with the appearance of new absorption
(C N) in the range of 1605–1627 cm−1, clearly indicated that a new Schiff base had formed
in each case. A band observed in the spectra of 2c–f in the region of 2835–2923 cm−1
can be assigned to the CH N group. The IR spectra of 2c–f show bands at 740–778 cm−1
1
1
assigned to the C–S stretching mode. The H NMR spectrum of 2c–f shows a single H
imine resonance at ca. 8.18–8.71 ppm, demonstrating the equivalence of the two imine en-
vironments. The absorption signals of aromatic protons appeared in the region of 6.54–7.81
ppm, and the CH2 group of all Schiff bases appeared in 3.19–3.27 ppm. The 13C NMR
spectra include imine and methylene carbons, which appeared at 152.21–154.58 ppm and
31.51–31.92 ppm, respectively. The molecular structure of 2b, which is shown in Figure 1,
possesses a center of symmetry and exhibits a helical structure.18
The bond lengths, angle, and torsion of 2b show that a resonance occurs between
aromatic rings, through the C N bonds of the molecule. The thiophene ring is a rather
planar relative to the aminothiphenole ring, and the imine groups have the anti conformation
in agreement with the NMR spectra. However, the C(1)–C(1A) bond has a single bond
characteristic (Table I).
EXPERIMENTAL
All chemical reagents were obtained from Merck and Fluka and used without further
purification. The diamine 1,2-di(2-aminophenylthio)ethane (1) was prepared by the method
in the literature.8 Melting points were measured with Electrothermal 9200 apparatus and are
uncorrected. Elemental analyses were performed on an Elementar Vario EL III elemental
analyzer. The FT-IR spectra (potassium bromide) were recorded with a Shimadzu 8400
1
S spectrometer. Mass spectra were recorded on a Shimadzu QD 5050. H and 13C NMR
spectra were measured with a Bruker DRX-500 Avance Spectrometer in CDCl3 as solvent.

SYNTHESIS AND CHARACTERIZATION OF NEW SCHIFF BASES
1513
Figure 1 ORTEP drawing of 2-(2-(-2-((thiophen-2-yl)methyleneamino)phenylthio) ethylthio)-N-((thiophen-2-
yl) methylene)benzenamine (2b).
General Procedure for Preparation of Schiff Base from the Reaction
of 2-(2-(2-Amino phenylthio)benzeneamine with Aldehyde
To a stirring solution of 1,2-di(2-aminophenylthio)ethane (1) (2.76 g, 10 mmol) in
absolute ethanol (25 mL), a solution of aldehyde (20 mmol) was added dropwise for 10 min
at room temperature. The mixture was stirred and heated to reflux for 5 h. Then the solvent
was evaporated under reduced pressure, and the product was crystallized from acetonitrile.
2-(2-(2-(Furan-2-yl)methyleneamino)phenylthio)ethylthio)-N-((furan-2-
yl)methylene) benzeneamine (2c). Yield: 2.12 g (49%), mp 122–123◦C; Color:
Table I Selected bond lengths (Å), bond angles (◦), and torsion angles (◦) for 2b
Bond lengths
Å
Bond angles
(◦)
Torsion angles
(◦)
C(1)–C(1)#1
S(1)–C(1)
S(1)–C(2)
C(2)–C(7)
N(1)–C(7)
N(1)–C(8)
C(8)–C(9)
S(2)–C(9)
C(9)–C(10)
C(8)–H(8A)
C(1)–H(1A)
1.524
1.811
1.763
1.412
1.411
1.282
1.439
1.726
1.3757
0.9500
0.9900
C(1)#1–C(1)–S(1)
C(2)–S(1)–C(1)
S(1)–C(1)–H(1A)
C(7)–C(2)–S(1)
C(3)–C(2)–S(1)
N(1)–C(7)–C(2)
C(8)–N(1)–C(7)
N(1)–C(8)–C(9)
N(1)–C(8)–H(8A)
C(8)–C(9)–S(2)
C(12)–S(2)–C(9)
107.55
102.36
110.20
115.42
125.63
117.03
118.94
121.68
119.20
121.50
91.53
C(2)–S(1)–C(1)–C(1)#1
C(1)–S(1)–C(2)–C(3)
C(1)–S(1)–C(2)–C(7)
C(8)–N(1)–C(7)–C(6)
S(1)–C(2)–C(7)–N(1)
C(8)–N(1)–C(7)–C(2)
C(7)–N(1)–C(8)–C(9)
N(1)–C(8)–C(9)–C(10)
N(1)–C(8)–C(9)–S(2)
C(8)–C(9)–C(10)–C(11)
S(2)–C(9)–C(10)–C(11)
−166.07
−4.13
174.52
53.92
2.73
−130.73
−177.31
−174.31
8.43
−177.69
−0.20

1514
A. KAKANEJADIFARD ET AL.
yellow; FT-IR: 3124–3095 (Ar H), 2923, 2880 (CH N), 1623 (C N), 1571–1436
(C C), 1022 (C O), 783 (C S), 744 (C S) cm−1; 1H NMR: δ = 8.18 (s, 2H, CH N),
7.62 (d, 2H, Ar H, J = 3.7 Hz), 7.29 (d, 2H, Ar H, J = 3.4 Hz), 7.20–7.18 (d, 2H,
Ph H, J = 5.2 Hz), 7.15–7.12 (t, 2H, Ar H), 7.00–6.95(m, 4H, Ph H), 6.55–6.54 (d,
2H, Ph H, J = 4.7 Hz), 3.19 (s, 4H, CH2); 13C NMR: δ 152.21, 150.73, 145.88, 130.59,
128.11, 126.72, 126.38, 118.46, 118.26, 118.14, 116.20, 112.24, 31.51. The EI-MS: m/z
432(M)+, 429, 355, 271; Anal. Calcd. For C24H20N2O2S2: C, 66.64; H, 4.66; N, 6.48; S,
14.83. Found: C, 66.47; H, 4.53; N, 6.34; S, 14.03.
2-(2-(2-(1H-Pyrrol-2-yl)methylene)-2-(2-(1H-pyrrol-2-yl)methyleneamino)
phenylthio) ethylthio)benzeneamine (2d). Yield: 2.2 g (51%), FT-IR: 3329 (N-H),
3132–3095 (Ar H), 2912, 2877 (CH N), 1650 (C N), 1606–1477 (C C), 748 (C S)
1
cm−1; H NMR: δ 8.17 (s, 2H, CH N), 7.44 (d, 2H, Ar H, J = 4.1 Hz), 7.38 (d, 2H,
Ar H, J = 3.3 Hz), 7.23(d, 2H, Ph H, J = 5.4 Hz), 7.17–7.14 (t, 2H, Ar H), 7.03 (d, 2H,
Ph H, J = 4.9 Hz), 6.76–6.71 (m, 4H, Ph H), 6.30 (bs, 2H, NH), 3.18 (s, 4H, CH2); 13
C
NMR: δ 150.73, 150.18, 136.17, 130.48, 129.91, 126.83, 126.30, 118.49, 117.02, 116.26,
114.88, 31.50. The EI-MS: m/z 430(M)+, 429(M-1)+, 271; Anal. Calcd. For C24H22N4S2:
C, 66.94; H, 5.15; N, 13.01; S, 14.89. Found: C, 66.62; H, 4.91; N, 12.89; S, 15.02.
2-(2-(2-(Pyridin-2-yl)methyleneamino)phenylthio)ethylthio)-N-((pyridin-
2-yl)methyl ene)benzeneamine (2e). Yield: 2.22 g (51%), mp 127–128◦C, Color:
red; FT-IR: 3153–3062 (Ar H), 2975, 2877 (N CH), 1627 (C N), 1588–1471 (C C),
777 (C S), 740 (C S) cm−1; 1H NMR: δ 8.53 (s, 2H, CH N), 8.70 (d, 2H, Py H, J =
5.3 Hz), 8.28 (d, 2H, Py H, J = 4.9 Hz), 7.81–7.77 (t, 2H, Py H, J = 2.8 Hz), 7.38–7.35
(t, 2H, Py H, J = 3.05 Hz), 7.31–7.19(m, 8H, Ar H), 3.23 (s, 4H, CH2); 13C NMR: δ
160.73, 154.58, 149.87, 149.62, 136.69, 130.97, 128.25, 127.06, 126.96, 125.27, 122.00,
118.21, 31.53; The EI-MS: m/z 454(M)+, 452(M-2)+ 431, 429, 355, 271. Anal. Calcd. For
C26H22N4S2: C, 68.69; H, 4.88; N, 12.32; S, 14.11. Found: C, 68.84; H, 4.71; N, 12.14; S,
14.38.
2-(2-(2-(Pyridin-4-yl)methyleneamino)phenylthio)ethylthio)-N-((pyridin-
4-yl)methyl ene)benzeneamine (2f). Yield: 2.80 g (60%), mp 162–162.5◦C, Color:
yellow; FT-IR: 3058–3018 (Ar H), 2993, 2887 (CH N), 1623 (C N), 1596–1460
1
(C C), 817 (C S), 746 (C S) cm−1; H NMR: δ 8.37 (s, 2H, N CH), 8.76 (d, 2H,
Py H, J = 5.6 Hz), 7.77, 7.75 (d, 2H, Py H, J = 5.6 Hz), 7.32–7.01 (m, 8H, Ar H),
3.21 (s, 4H, CH2). 13C NMR: δ 158.07, 150.65, 149.74, 142.48, 130.93, 128.12, 127.36,
126.90, 122.39, 118.06, 31.25. The EI-MS: m/z 454(M)+, 452(M-2)+ 431, 429, 355, 271.
Anal. Calcd. For C26H22N4S2: C, 68.69; H, 4.88; N, 12.32; S, 14.11. Found: C, 68.41; H,
4.68; N, 12.11; S, 14.29.
X-Ray Structure Analysis of 2-(2-(-2-((Thiophen-2-yl)methyleneamino)
phenylthio)ethylthio)-N-((thiophen-2-yl)ethylene)benzenamine (2b)
The clear colorless crystal with dimension 0.30 × 0.20 × 0.15 mm3 crystallized
from MeCN/MeOH was used for data collection on a Bruker SMART 1000 CCD diffrac-
tommeter with graphite monochromated MoKα (λ = 0.71073 Å). C24H20N2S4, FW =
464.66. Monoclinic crystals in a P 21/c Space group, a = 11.179(5) Å, b = 7.730(4) Å,
c = 12.608(6) Å, α = 90◦, β = 91.899(12)◦, γ = 90◦, V = 1088.9(9) Å−3. Z = 2, Dcalc
=
1.417 g/cm3. µ = 0.451 mm−1, F (000) = 484, T = 100 (2) K. Of the 12,880 total reflec-
tions, 2899 were unique ([R(int) = 0.0294]). The structure was solved by direct methods
(SHELEXTL)19 and refined by full-matrix least-squares on F2 (isotropic refinement of the

SYNTHESIS AND CHARACTERIZATION OF NEW SCHIFF BASES
1515
molecule and location of remaining non-hydrogen atoms from a difference Fourier map
and subsequent anisotropy refinement on all atoms; H atoms were found after high-angle
refinement in a difference Fourier map and their positions included in the final stages of
refinement), factors of = 0.0288, wR2 = 0.0751 for 2569 reflections with I < 2σ (I). No
significant features, only ripples from 0.337 to −0.257 e Å−3, were observed in the final
difference map. The nonhydrogen atoms were refined anisotropically.
Complete bond lengths and angles, coordinates, and displacement parameters have
been deposited at Cambridge Crystallography Data Center. Supplementary data are avail-
able from the CCDC, 12 Union Road, Cambridge CB2 IEZ, UK on request, quoting
the deposition numbers 730627 for 2-(2-(-2-((thiophen-2-yl)methyleneamino)phenylthio)
ethylthio)-N-((thiophen-2-yl) methylene)benzenamine (K5).
REFERENCES
1. P. Chattopadhyay and C. Sinha, Indian J. Chem. Sect. A, 76, 34 (1995).
2. P. Chakraborty, S. Chandra, and A. Chakravorty, Inorg. Chim. Acta, 229, 477 (1995).
3. J. R. Dilworth and S. Parrot, J. Chem. Soc. Rev, 27, 43 (1998).
4. H. Zhang, M. Dai, C. Qi, B. Li, and X. Guo, Appl. Rad. Isotopes, 60, 643 (2004).
5. R. K. Home and J. A. Katzenellenbogen, Nucl. Med. Biol., 24, 485 (1997).
6. M. Glaser, M. J. Howard, K. Howland, A. K. Powell, M. T. Rae, S. Wocadlo, R. A. Williamson,
and P. J. Blower, J. Chem. Soc., Dalton Trans., 3087 (1998).
7. P. K. Dhara, B. Dasa, J. M. Lob, and P. Chattopadhyay, Appl. Rad. Isotopes, 62, 729 (2005).
8. A. Garoufis, S. K. Hadjikakou, and N. Hadjiliadis, Coord. Chem. Rev., 253, 1384 (2009).
9. C. Lodeiro and F. Pina, Coord. Chem. Rev., 253, 1353 (2009).
10. E. Bermejo, R. Carballa, A. Castineiras, R. Dominguez, A. E. Liberta, C. Maichelle-Mo¨ssmer,
M. M. Salberg, and D. X.West, Eur. J. Inorg. Chem., 965 (1999).
11. A. G. Quiroga, J. M. Perez, I. Lopez-Solera, J. R. Masaguer, A. Luque, P. Roman, A.Edwaeds,
C. Alonso, and C. Navarro-Ranninger, J. Med. Chem., 41, 1399 (1998).
12. S. K. Hadjikakou and N. Hadjiliadis, Coord. Chem. Rev., 253, 235 (2009).
13. W. X. Zhang, C. Ma, and S. Si, Trans. Met. Chem., 26, 38 (2001).
14. S. Chandra and R. Kumar, Trans. Metal. Chem., 29, 269 (2004).
15. G. Rajsekhar, C. P. Rao, P. K. Saarenketo, E. Kolehmainen, and K. Rissanen, Inorg. Chem.
Commun., 5, 649 (2002).
16. G. Rajsekhara, C. P. Rao, P. Saarenketo, N. Nattinenb, and K. Rissanen, New J. Chem., 28, 75
(2004).
17. M. Morshedi, M. Amirnasr, S. Triki, and A. D. Khalaji, Inorg. Chim. Acta, 362, 1637 (2009).
18. E. Borisova, M. D. Reshetova, and Y. A. Ustrynyuk, Chem. Rev., 107, 46 (2007).
19. G. M. Sheldrick, SHELXTL v. 5.10 “Structure Determination Software Suite,” Bruker AXS,
Madison, Wisconsin, USA (1998).