Synthesis, crystal structure and biological activity of the Schiff base organotin(IV) complexes based on salicylaldehyde-o-aminophenol

Article abstract of DOI:10.1016/j.molstruc.2017.08.058

Schiff base organotin(IV) complexes C1 ～ C5b have been synthesized via the reaction of the substituted salicylaldehyde-o-aminophenol Schiff base ligands (L1 ～ L3) with the dibenzyltin dichloride, n-butyltin trichloride or dibutyltin oxide, respectively. T

Full text of DOI:10.1016/j.molstruc.2017.08.058

Accepted Manuscript
Synthesis, crystal structure and biological activity of the Schiff base organotin(IV)
complexes based on salicylaldehyde-o-aminophenol
Yu-Xing Tan, Zhi-Jian Zhang, Yang Liu, Jiang-Xi Yu, Xiao-Ming Zhu, Dai-Zhi Kuang,
Wu-Jiu Jiang
PII:
S0022-2860(17)31125-0
10.1016/j.molstruc.2017.08.058
MOLSTR 24196
DOI:
Reference:
To appear in: Journal of Molecular Structure
Received Date: 11 May 2017
Revised Date: 6 August 2017
Accepted Date: 16 August 2017
Please cite this article as: Y.-X. Tan, Z.-J. Zhang, Y. Liu, J.-X. Yu, X.-M. Zhu, D.-Z. Kuang, W.-J.
Jiang, Synthesis, crystal structure and biological activity of the Schiff base organotin(IV) complexes
based on salicylaldehyde-o-aminophenol, Journal of Molecular Structure (2017), doi: 10.1016/
j.molstruc.2017.08.058.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please
note that during the production process errors may be discovered which could affect the content, and all
legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT
Graphical abstract
A series of Schiff base organotin(IV) complexes have been synthesized. The crystal structures of
complexes exhibit dimer structure, one-dimensional chain or 2D network structure. The newly
synthesized compounds exhibited good anticancer activity and may be better potential candidates
for further chemical optimization and cancer therapy.

ACCEPTED MANUSCRIPT
Synthesis, crystal structure and biological activity of
the Schiff base organotin(IV) complexes based on
Salicylaldehyde-o-aminophenol
Yu-Xing Tan, Zhi-Jian Zhang, Yang Liu, Jiang-Xi Yu, Xiao-Ming Zhu, Dai-Zhi
Kuang, Wu-Jiu Jiang*
(Key Laboratory of Functional Organometallic Materials of Hengyang Normal University,
College of Hunan Province, College of Chemistry and Material Science, Hengyang Normal
University,Hengyang, Hunan , 421008, China)
ABSTRACT Schiff base organotin(IV) complexes C1 ~ C5b have been synthesized via the
reaction of the substituted salicylaldehyde-o-aminophenol Schiff base ligands (L1 ~ L3) with the
dibenzyltin dichloride, n-butyltin trichloride or dibutyltin oxide, respectively. The complexes have
been characterized by IR, UV-Vis, 1H NMR, 13C NMR spectra, elemental analysis and the crystal
structures have been determined by X-ray diffraction. The anticancer activity of the Schiff base
ligand and complexes C1 ~ C5b against five species of cancer cell which are Hela, MCF7, HepG2,
Colo205, NCI-H460 were tested respectively, the tests showed that C1 ~ C5b exhibited
significant anticancer activity for the cancer cells in comparison with the ligand, and the activity
was greater than carboplatin.
Keywords: organotin, Schiff base, synthesis, crystal structure, biological activity
1. Introduction
Schiff base is a kind of organic compounds containing C=N group, it is the condensation
product of aldehyde (or ketone) and amine (or hydrazine) [1, 2]. Among those, the
salicylaldehyde-o-aminophenol Schiff base has strong coordination ability and diverse
coordination mode [3-8], because of containing many oxygen and nitrogen atoms coordination site.
* Corresponding author.
E-mail address: jwj_china@163.com (W.-J. Jiang).

ACCEPTED MANUSCRIPT
So other groups can be introduced to enrich their structure and improve their activity through the
chemical reaction. Organotin complexes have good anticancer activity [9-12], it is a research focus
in the field of anticancer drugs. Some studies have shown that the Schiff base organotin
complexes are similar to cisplatin in the anticancer mechanism, they also belong to the anticancer
drugs targeted to DNA, and the ligand has synergistic effect [13]. To fully understand the
mechanism and explore the potential of organotin as anticancer drugs, more experimental data and
studies are need. However, based on the previous work [14-17], we further study the antitumor
activity of salicylaldehyde-o-aminophenol Schiff base organotin complexes in vitro, three kinds of
substituted salicylaldehyde-o-aminophenol and their organotin complexes were synthesized and
characterized in this paper. The inhibitory activity of the complexes on cancer cells (MCF7,
Colo205, NCI-H460, Hela and HepG2) and the human normal cell (HL7702) in vitro was studied.
It provide theoretical basis for the application of this substance to anticancer drugs.
2. Experimental
2.1. Materials and physical measurements
All regants and solvents were available from commercial sources and used as received
without further purification. Dibenzyltin dichloride was prepared by us according to literatures
[18]. FT-IR spectrum was obtained for KBr pellets on Shimadzu Prestige-21 spectrophotometer in
1
the 4000-400 cm-1. H, 13C and 119Sn NMR analysis was performed on a Bruker AVANCE NMR
spectrometer. Elemental analyses for C, H, and N were determined on a PE-2400 (II) analyzer.
Crystal structure was determined on a CCD area detector X-ray diffractometer. UV-Vis absorption
spectra was measured by UV-2550 spectrometer. Melting point measurement was executed on an
X-4 binocular micromelting point apparatus with the temperature unadjusted.
2.2. Synthesis

ACCEPTED MANUSCRIPT
Scheme.1 Synthesis of complexes
2.2.1. Synthesis of ligands (L1 ~ L3)
According to literatures [16], a mixture of 3,5-dichlorosalicyaldehyde (10 mmol), absolute
ethanol (20 mL) and 2-amino-5-nitrophenol 10 mmol) or o-aminophenol 10 mmol) or
4-chloro-o-aminophenol 10 mmol) were added to microwave reactor, the reaction continued for
(
(
(
about 30 min at 100℃. After that, the solvent was removed by evaporation in vacuo and the
residual solution was filtered. It was recrystallized by absolute ethanol.
3,5-Cl2C6H2(OH)C=NC6H3(OH)-5-NO2 (L1): Yield: 72.9%。m.p.: 327 ~ 328 ℃。Anal. Calc.
for (C13H8Cl2N2O2)：C 47.73, H 2.47, N 8.56%. Found: C 47.80, H 2.45, N 8.58%. IR (KBr, cm-1):
1
3445 (w), 3086 (w), 2959 (w), 1627 (s), 1596 (s), 1340 (s), 1292 (s), 1020 (w), 747 (s). H
NMR(DMSO-d6, 400MHz, δ/ppm):14.68 (s, 1H), 11.69 (s, 1H), 9.21 (s, 1H), 8.40 (s, 1H), 8.14 (d,
J=8.8Hz, 1H), 7.75 (s, 1H), 7.15 (d, J=8.8Hz, 1H).
3,5-Cl2C6H2(OH)C=NC6H4(OH) (L2): Yield: 89.6%。m.p.: 243 ~ 245 ℃。Anal. Calc. for
(C13H9Cl2NO2): C 55.35, H 3.22, N 4.96%. Found: C 55.40, H 3.25, N 4.98%. IR (KBr, cm-1):
1
3432 (w), 3047 (w), 2700 (w), 1629 (s), 1499 (s), 1217(s), 1135 (w), 1032 (s), 747 (s). H
NMR(DMSO-d6, 400MHz, δ/ppm): 15.51 (s, 1H), 10.19 (s, 1H), 9.08 (s, 1H), 7.65 (d, J =12.8 Hz,
2H), 7.50 (d, J =7.6 Hz, 1H), 7.20 (t, J = 7.2 Hz, 1H), 7.01 (d, J = 7.6 Hz, 1H), 6.93 (t, J = 7.6 Hz,
1H).
3,5-Cl2C6H2(OH)C=NC6H3(OH)-5-Cl (L3): Yield: 81.6%。m.p.: 277 ~ 278℃。Anal. Calc. for
(C13H8Cl3NO2): C 49.32, H 2.55, N 4.42%. Found: C 49.30, H 2.55, N 4.48%. IR (KBr, cm-1)：
3440 (w), 3064 (w), 2689 (w), 1628 (s), 1610 (w), 1500 (s), 1437 (s), 1207 (s), 1086 (m), 856 (m),
815 (m). 1H NMR(DMSO-d6, 400MHz, δ/ppm): 14.96 (s, 1H), 10.34 (s, 1H), 9.05 (s, 1H), 7.67 (d,
J = 2.0 Hz, 1H), 7.55 (d, J = 2.0 Hz, 1H), 7.18 (dd, J1 = 8.4 Hz, J2 = 1.6 Hz, 1H), 6.96 (d, J = 8.4
Hz, 1H), 5.59 (d, J =2.0 Hz, 1H).
2.2.2. Synthesis of complexes (C1 ~ C5b)
According to literatures [16], a mixture of Schiff base ligands (L1, L2 or L3 ) (1 mmol),
absolute methanol (20 mL) and dibenzyltin dichloride (1 mmol) or butyltin trichloride (1 mmol) or
dibutyltin oxide (1 mmol) were added to microwave reactor, the reaction continued for about 30
min at 120℃. After that, the solvent was removed by evaporation in vacuo and the residual
solution was filtered, and the solids were recrystallized by absolute methanol.

ACCEPTED MANUSCRIPT
[3,5-Cl2C6H2(O)C=NC6H3(O)-5-NO2](MeOH)(PhCH2)SnCl·MeOH (C1): The product was
orange crystal, Yield: 73.3%. m.p.: 138 ~ 139 ℃. Anal. Calc. (C22H21Cl3N2O6Sn): C 41.65, H 3.34,
N 4.42%. Found: C 41.69, H 3.31, N 4.40%. IR (KBr, cm-1): 3586 (s), 3499 (s), 3058 (w), 3025
(w), 1610 (s), 1589 (s), 1311 (s), 1164 (s), 651 (m), 554 (m), 503 (m), 439 (s). 1H NMR(DMSO-d6,
400MHz, δ/ppm): 9.46, (s, 1H), 8.81 (d, J = 1.6 Hz, 1H), 8.15 (dd, J1 = 8.8 Hz, J2 = 1.6 Hz, 1H),
7.85 (s, 2H), 7.39 (d, J = 7.2 Hz, 2H), 7.26 (t, J = 7.2 Hz, 2H), 7.12 (t, J = 7.2 Hz, 1H), 7.03 (d, J
= 8.8 Hz, 1H). 13C NMR (DMSO-d6, 100MHz, δ/ppm): 162.03, 161.78, 160.57, 137.74, 137.49,
134.58, 133.55, 129.16, 129.03, 127.82, 126.18, 125.76, 124.61, 120.21, 119.44, 118.31, 113.28,
48.41, 35.68.
[3,5-Cl2C6H2(O)C=NC6H4(O)](MeOH)(PhCH2)SnCl (C2): The product was brown-yellow
crystal, Yield: 71.8%. m.p.: 155 ~ 156 ℃. Anal. Calc. (C21H18Cl3NO3Sn): C 45.25, H 3.25, N
2.51%. Found: C 45.13, H 3.31, N 2.50%. IR (KBr, cm-1)：3431 (s), 3057 (w), 3025 (w), 1605 (s),
1
1591 (s), 1477 (s), 1259 (m), 1173 (s), 747 (s), 542 (m), 505 (w), 447 (w), 408 (w). H
NMR(DMSO-d6, 400MHz, δ/ppm): 9.18 (s, 1H), 7.76 (m, 3H), 7.38(d, J = 7.0 Hz, 2H), 7.24 (t,
J=7.6 Hz, 3H), 7.07-7.11(t, J = 7.0 Hz, 1H), 6.88 (d, J = 7.9 Hz, 1H), 6.78-6.82 (t, J = 7.3 Hz, 1H),
3.03 (d, J = 11.8 Hz, 1H), 2.96 (d, J = 11.8 Hz, 1H). 13C NMR (DMSO-d6, 100MHz, δ/ppm):
160.17, 157.87, 155.99, 138.37, 133.45, 132.70, 130.46, 129.10, 127.71, 125.96, 124.31, 119.71,
119.65, 118.32, 117.00, 116.05, 48.39, 35.37.
[3,5-Cl2C6H2(O)C=NC6H3(O)-5-Cl](MeOH)(n-Bu)SnCl (C3): The product was orange
crystal, Yield: 74.6%. m.p.: 149 ~ 152 ℃. Anal. Calc. (C18H19Cl4NO3Sn): C 38.75, H 3.43, N
2.51%. Found: C 38.80, H 3.41, N 2.49%. IR (KBr, cm-1): 3579(w), 3075 (w), 2958 (w), 2927 (w),
1605 (s), 1526 (s), 1479 (s), 1382 (s), 1254(s), 1185(s), 771 (s), 680 (m), 546 (m), 511 (w), 440
(w). 1H NMR (DMSO-d6, 400MHz, δ/ppm): 9.23 (s, 1H), 7.90 (s, 1H), 7.79 (s, 1H), 7.73 (s, 1H),
7.26 (d, J = 8.5 Hz, 1H), 6.87 (d, J1 = 8.5 Hz, 1H), 1.78 (m, 2H), 1.45-1.59 (m, 4H), 0.93 (t, J =
7.2 Hz, 3H). 13C NMR (DMSO-d6, 400MHz, δ/ppm): 160.20, 159.50, 155.01, 133.85, 132.95,
130.14, 129.81, 126.02, 120.46, 119.65, 119.63, 119.59, 116.19, 48.41, 27.53, 26.71, 25.05, 13.46.
[3,5-Cl2C6H2(O)C=NC6H4(O)](MeOH)(n-Bu)SnCl (C4): The product was yellow crystal,
Yield: 59.3%. m.p.: 262 ~ 263 ℃. Anal. Calc. (C18H20Cl3NO3Sn): C 41.30, H 3.85, N 2.68%.
Found: C 41.25, H 3.92, N 2.65%. IR (KBr, cm-1)：3456(w), 3071(w), 2952 (w), 2926 (w), 1606
1
(s), 1521 (m), 1481 (m), 1256(s), 1174(s), 742 (s), 544 (m), 507 (w), 436 (w), 418 (w). H

ACCEPTED MANUSCRIPT
NMR(DMSO-d6, 400MHz, δ/ppm): 9.18 (s, 1H), 7.75 (s, 3H), 7.24 (t, J=7.6 Hz, 1H), 6.84 (d, J =
7.6 Hz, 1H), 6.79 (t, J = 7.6 Hz, 1H), 1.80 (quint, J = 7.2 Hz, 2H), 1.54-1.55 (m, 2H), 1.45-1.58
(m, 2H), 0.93 (t, J = 7.2 Hz ,3H). 13C NMR (DMSO-d6, 100MHz, δ/ppm): 160.33, 157.90, 156.21,
133.38, 132.67, 130.40, 129.29, 125.92, 119.79, 119.48, 118.29, 116.83, 116.06, 48.41, 27.41,
26.76, 25.09, 13.47.
[3,5-Cl2C6H2(O)C=NC6H3(O)-5-NO2]n-Bu2Sn (C5a): The product was orange crystal, Yield:
35.1%. m.p.: 120 ~ 122 ℃. Anal. Calc. (C21H24Cl2N2O4Sn): C 45.20, H 4.35, N 5.02%. Found: C
45.23, H 4.31, N 5.00%. IR (KBr, cm-1): 3058 (w), 2956 (w), 2921 (w), 1603 (s), 1587 (s), 1521
(s), 1490 (s), 1313(s), 1214(m), 1158 (s), 649 (m), 512 (m), 488 (w), 423 (w). 1H NMR(DMSO-d6,
400MHz, δ/ppm): 9.27 (s, 1H), 8.64 (d, J = 1.8 Hz, 1H), 8.05 (dd, J1 = 8.8 Hz, J2 = 1.8 Hz, 1H),
7.72 (m, 2H), 6.81 (d, J = 9.1 Hz, 1H), 1.35-1.43 (m, 8H), 1.17-1.27 (m, 4H), 0.73 (t, J = 7.2 Hz,
6H). 13C NMR (DMSO-d6, 100MHz, δ/ppm): 166.48, 164.03, 161.96, 136.13, 134.40, 133.77,
131.92, 125.78, 125.58, 119.39, 117.80, 117.69, 113.33, 26.49, 26.33, 25.43, 13.17.
{[3,5-Cl2C6H2(O)C=NC6H3(O)-5-NO2]n-Bu2Sn}2 (C5b): The product was red-brown crystal,
Yield: 38.5%. m.p.: 188 ~ 192 ℃. Anal. Calc. (C21H24Cl2N2O4Sn): C 45.20, H 4.35, N 5.02%.
Found: C 45.25, H 4.33, N 5.02%. IR (KBr, cm-1): 3106 (w), 3059 (w), 2954 (w), 2919 (w), 1603
(s), 1583 (s), 1517 (s), 1495 (s), 1302(s), 1215(m), 1153 (s), 650 (m), 520 (m), 484 (w), 423 (w).
1H NMR(DMSO-d6, 400MHz, δ/ppm): 9.27 (s, 1H), 8.64 (d, J = 1.8 Hz, 1H), 8.05 (dd, J1 = 8.8
Hz, J2 = 1.8 Hz, 1H), 7.72 (m, 2H), 6.81 (d, J = 9.1 Hz, 1H), 1.35-1.43 (m, 8H), 1.17-1.27 (m, 4H),
0.73 (t, J = 7.2 Hz, 6H). 13C NMR (DMSO-d6, 100MHz, δ/ppm): 166.48, 164.03, 161.96, 136.13,
134.40, 133.77, 131.92, 125.78, 125.58, 119.39, 117.80, 117.69, 113.33, 26.49, 26.33, 25.43,
13.17.
2.3. Determination of crystal structure
X-ray diffraction data for crystals were performed with graphite monochromated Mo-Kα
radiation ( λ= 0.71073 Å ) on a Bruker Smart Apex II CCD diffractometer, and collected by the
φ-ω scan technique at ambient temperature. Multi-scan absorption correction was applied to the
data. The crystal structures were solved by direct methods and refined by full-matrix least-squares
on F2. All the non-hydrogen atoms were located in successive difference Fourier syntheses and
then refined anisotropically. Hydrogen atoms were placed in calculated positions or located from
the Fourier maps, and refined isotropically with the isotropic vibration parameters related to the

ACCEPTED MANUSCRIPT
non-hydrogen atom to which they are bonded. All calculations were performed with SHELXL-97
[19] programs within WINGX [20]. The crystal data and structure refinement parameters of
complexes are listed in Table 1.
Table 1 Crystallographic data of the complexes
Complex
C1
C2
C3
C4
C5a
C5b
Empirical formula
C22H21Cl3N2O6Sn
634.30
C21H18Cl3NO3Sn
557.28
C18H19Cl4NO3Sn
557.83
C18H20Cl3NO3Sn
523.39
C21H24Cl2N2O4Sn
557.84
C21H24Cl2N2O4Sn
558.01
Mr
Temperature / K
296(2)
296(2)
296(2)
296(2)
296(2)
296(2)
Crystal system
Triclinic
Triclinic
Monoclinic
C2/c
Monoclinic
C2/c
Triclinic
Monoclinic
C2/c
—
—
—
Space group
P1
P1
P1
a / Å
9.29820(10)
11.2766(2)
13.6215(2)
109.1450(10)
97.9130(10)
106.9480(10)
1246.91(3)
2
6.8846(3)
12.4977(6)
13.0816(6)
76.668(2)
77.733(2)
79.382(2)
1059.34(8)
2
23.4004(4)
9.6340(2)
19.6692(3)
90
26.2445(13)
9.5746(5)
19.4558(10)
90
9.9404(2)
10.5990(2)
11.2964(2)
98.4720(10)
99.9630(10)
95.1310(10)
1151.33(4)
2
28.818(10)
9.317(3)
21.093(8)
90
b / Å
c / Å
α / °
β / °
98.0530(10)
90
120.0070(10)
90
122.884(5)
90
γ/ °
Volume / Å3
Z
4390.49(14)
8
4233.6(4)
8
4756(3)
8
Dc / Mg/m3
Absorption coefficient /
mm-1
1.689
1.747
1.688
1.642
1.609
1.559
1.387
1.607
1.669
1.603
1.371
1.328
F(000)
632
552
2208
2080
560
2240
Crystal size / mm
θ range / (°)
0.19×0.18×0.17
2.37 - 25.10
-11≤h≤11,
-13≤k≤13,
-16≤l≤16
0.17×0.13×0.11
2.10 - 25.10
-8≤h≤8,
0.19×0.17×0.13
1.76 - 25.10
-27≤h≤21,
-9≤k≤11,
0.31×0.24×0.19
2.31 - 25.09
-22≤h≤31,
-11≤k≤11,
-23≤l≤19
0.21×0.20×0.19
1.86 - 25.10
-11≤h≤11,
-12≤k≤11,
-13≤l≤13
0.46×0.37×0.35
2.40 - 25.10
-34≤h≤34,
-11≤k≤11,
-25≤l≤25
Limiting indices
-14≤k≤14,
-15≤l≤15
-23≤l≤23
Reflections collected
unique
/
12857 / 4426
[R(int)=0.0181]
99.7 %
11062 / 3770
[R(int)=0.0163]
99.9 %
12215 / 3909
[R(int)=0.0234]
100.0 %
10428/3772
[R(int)=0.0159]
99.6 %
12289 / 4101
[R(int)=0.0149]
99.8 %
12721 / 4216
[R(int)=0.0164]
99.8 %
Completeness
Max.
transmission
Data restraints
and
min.
0.7984
0.7786
and
0.8430
0.7717
and
0.8123
0.7422
and
0.7505
0.6364
and
0.7807
0.7617
and
0.6537
0.5803
and
/
/
4426 / 0 / 314
4861 / 0 / 263
3909 / 26 / 250
3772 / 0 / 258
4101 / 1 / 253
4216 / 22 / 273
parameters
Goodness-of-fit on F2
1.043
1.037
1.082
1.081
1.110
1.034
R1=0.0225,
wR2=0.0539
R1=0.0266,
wR2=0.0553
R1=0.0186,
wR2 = 0.0478
R1=0.0203,
wR2 = 0.0488
0.267 and -0.383
R1=0.0430,
wR2 = 0.1218
R1=0.0556,
wR2 = 0.1285
1.897 and -1.188
R1=0.0231,
wR2=0.0605
R1=0.0260,
wR2=0.0620
0.603 and -0.513
R1=0.0342,
wR2=0.0919
R1=0.0363,
wR2=0.0937
R1=0.0335,
wR2=0.0926
R1=0.0374,
wR2=0.0950
1.300 and -0.625
Final R indices [I>2δ(I)]
R indices (all data)
ꢀρmax and ꢀρmin (e. Å-3)
0.427 and -0.525
0.735 and -0.838

ACCEPTED MANUSCRIPT
2.4. UV-Vis property
The solutions of C1 ~ C5b were prepared with (CH3)2CO at room temperature, respectively,
and their concentration was 1×10-5 mol/L. The UV-Vis absorption spectra was measured by
UV-2550 spectrometer.
2.5. Anticancer activity studies
Primary human liver HL-7702 cells were purchased from institute of Biochemistry and Cell
Biology, Chinese Academic of science. NCI-460, HEPG2 and MCF-7 cells were obtained from
American Tissue Culture Collection (ATCC). HL-7702 cells were cultured in Dulbecco’s modified
Eagle’s medium (Thermo Fischer Scientific) containing 4500 mg/L glucose, supplemented with
10% fetal bovine serum (Thermo Fischer Scientific) and L-glutamine. The other cells were
maintained at 37°C in a 5% CO2 incubator in RPMI 1640 (GIBICO, Invitrogen) containing 10%
fetal bovine serum (GIBICO, Invitrogen). The test drug was added from a stock solution in
DMSO to result in a final DMSO concentration of less than 0.1%. Cell proliferation was assessed
by MTT assay. The cells were exposed to treatment for 24 hrs, and the number of cells used per
experiment for each cell line was adjusted to obtain an absorbance at 570nm. Six concentrations
(0.1 nM-10 ꢁM) were set for the compounds and at least 3 parallels of every concentration were
used. All experiments were repeated at least three times. The data was calculated using Graph Pad
Prism version 7.0. The IC50 were fitted using a non-linear regression model with a sigmoidal dose
response.
3. Results and Discussion
3.1. FT-IR Spectra
In contrast to the FT-IR spectra of L1 and C1, the presence of a single band in the 3445cm-1
(L1) was assigned to phenolic hydroxyl, the absorption peak at 3499 cm-1 is attributed to the
methanol hydroxyl absorption peak in the C1. The peak position of hydroxyl has changed, it
indicated that the phenolic hydroxyl group in the L1 was involved in the coordination. Besides, a
series of new absorption peak appeared in the low frequency region, the absorption bands at the
554 cm-1 and 503 cm-1 correspond to the ν(Sn-O) and ν(Sn-N), respectively. There is a good
indication of complex formation.
To summarize, the FT-IR spectra of ligands (L1 ~ L3) and complexes (C1 ~ C5b) show
broad bands at 3431 ~ 3586 cm-1 assignable to ν(OH) [21]. The bands present in the region

ACCEPTED MANUSCRIPT
3025~3086 cm-1 are attributed to ν(C-H). Characteristic bands at 1499 ~ 1596 cm-1 are assigned to
stretching vibration of the ν(C=N) [22, 23]. The bands at 1164 ~ 1292 cm-1 are assigned to the
ν(C-O) [24]. The low-frequency bands of complex (C1 ~ C5b): new bands in the ranges from 520
to 554 cm-1 and 484 to 511 cm-1 which appeared in the spectra of the synthesized metal complex
were probably due to (Sn-O) and (Sn-N) bond vibration frequencies [25, 26].
3.2. NMR Spectra
The 1H NMR spectrum show the ratio of the integral area of each group is consistent with the
expected number of protons in each group [27, 28]. Two phenolic hydroxy peaks at 14.68 ~ 15.51
and 10.19 ~ 11.69 ppm of the ligand disappeared in the complex, and the hydrogen absorption
peaks of butyl and benzyl methylene groups were found in the high field, it is shown that the
Schiff bases ligand have coordinated with organotin. The results are consistent with the X-ray
structure. It is worth noting that the methylene protons (Ph-CH2-) of C1 and C2 were two double
peaks, not a normal single peak, this is mostly because the steric hindrance of methanol molecule
and chlorine atom bonding to Sn atom in C1 and C2 is relatively large so that the benzyl groups
can not be freely oriented and two methylene protons exhibit carbon coupling signals.
In the 13C NMR spectrum, the imino carbon of C1 ~ C5b can be clearly identified, the single
peak in 160.17 ~ 166.48 ppm are assigned to the imino carbon. The peak positions of the other
carbon atoms in the complexes are basically consistent. In brief, the peaks of each group are
consistent with the theoretical prediction of the number of carbon atoms in the structure [27].
3.3. Description of the structures
The structures of C1 ~ C5b are illustrated in Fig.1 ~ Fig.6. Selected bond distances and angle
are list in Table S1~S6.
From the Fig.1 ~ Fig.4, it can be seem that the structures of C1 ~ C4 are similar, the central
tin atom is six-coordinate geometry. For C1 ~ C4, the coordinated environment is distorted
octahedron with one nitrogen and two oxygen atoms from Schiff base ligand, one carbon atom
from the benzyl or butyl group, one oxygen from methanol molecule and one chlorine atom.
Furthermore, C1 and C2 were product of the de-alkylation reaction and one benzyl was laid off on
the tin. Taking C1 as an example, the O1, O2, N1 and C15 were placed in equatorial sites, the sum
of the angles [O1-Sn1-N1 84.82(7)°, O2-Sn1-N1 76.87(7)°, O2-Sn1-C15 99.28(9)°, O1-Sn1- C15
98.15(9)° ] is 359.12°, which shows that Sn1, O1, O2, N1 and C15 are basically planar, but the

ACCEPTED MANUSCRIPT
bond lengths [Sn1-O1 2.0363(17) Å, Sn1-O2 2.0741(17) Å, Sn1-N1 2.2095(19) Å, Sn1-C15
2.139(2) Å ] are unequal, the axis position were occupied by one oxygen (O5) from methanol
molecule and one chlorine atom (Cl3), and the angle of O5-Sn1-Cl3 is 168.01(6)°, which is
obviously deviates from linear angle 180°. It indicated that the central tin atom is six-coordinate in
a distorted octahedron geometry. The C2, C3, C4 and C1 possess similar structure features, and
the parameters of the four complexes have little difference, and they are distorted octahedral
geometry, it is similar to the complex that have been reported [15, 16, 29, 30].
For the structure of C5a and C5b, C5a is a monomer structure, the central tin atom is
five-coordinate in a distorted trigonal bipyramid geometry, it is similar to the complex [31-34],
C5b is a binucleus molecules, a Sn2O2 four membered ring was formed in the middle of molecule
through ꢀ-carboxyl oxygen atom bridges the two Sn(IV) atoms. The Sn1-O2i distance 2.864 Å,
which is slightly greater than the sum of the covalent radii of Sn-O, and is less than the sum of the
Van der Waals radii for Sn-O, indicating the strong bond of Sn1-O2i interactions in C5b, it is
similar to the literature [17, 35, 36], so the central tin atom is six-coordinate in a distorted
octahedron geometry.
Fig.1 Molecular structure of C1

ACCEPTED MANUSCRIPT
Fig.2 Molecular structure of C2
Fig.3 Molecular structure of C3

ACCEPTED MANUSCRIPT
Fig.4 Molecular structure of C4
Fig.5 Molecular structure of C5a

ACCEPTED MANUSCRIPT
Fig.6 Molecular structure of C5b
In the crystal of these complexes, there are rich hydrogen bonding interaction. For C1, the
dimer structure (Fig.7) was formed by O-H…O hydrogen bonds (H5A…O6i 1.8515(457)Å,
∠O5-H5A…O6i 168.341(5107)°; H6Ai…O4ii 2.0497(28)Å, ∠O6i –H6Ai…O4ii 163.216(263)°; i:
-1-x, -y, -z; ii: -1-x, -y, -1-z ), the C-H…Cl interactions [H7…Cl3i 2.8992(9)Å, ∠C7-H7…Cl3i
150.617(149)°, i: -x, -y, -1-z] were observed between the adjacent dimer structures, so that the 1D
ribbon-like structure of C1 was constituted (Fig.8). The hydrogen bonding interactions in C2 are
similar to the C1 molecule. The 1D ribbon-like structure of C2 was constituted by C-H…Cl
interactions linking the adjacent dimer structures (Fig.9). The nearest Sn…Sn distance of the
adjacent dimer structures is 6.8856(4) Å in the ribbon, it is less than the Sn…Sn distance of C1
(9.2982(3)Å), and the Sn atoms are arrange in a relationship with the Sn…Sn…Sn angle of 180.0°
in C2.
For C3, the molecules were linked through O-H…O (H3A…O1i 1.9199(577)Å,
∠O3-H3A…O1i 163.064(6290)°; i: 0.5-x, -0.5+y, 0.5-z) and C-H…Cl (H15Bi…Cl3 2.879(16)Å,
∠C15i-H15Bi…Cl3 145.956(491)°; i: x, 1-y, -0.5+z) interamolecular hydrogen bonding into a
interesting 2D network structure of C3 (Fig.10). For C4, the O-H…O Hydrogen bonding
interactions [H3A…O2i 1.8297(385)Å, ∠C3-H3A…O2i 164.323(3943)°, i: 0.5-x, 0.5+y, 0.5-z]
were observed between adjacent molecular, 1D infinite chain structure of C4 are formed through
this interamolecular hydrogen bonding (Fig.11). The Sn atoms were arranged in a relationship
with the Sn…Sn…Sn angle of 107.133(3)°, so it showed a jagged arrangement on the each sides
of the 1D infinite chain. In addition, C5a and C1 are similar, the dimer structure was constituted
by C-H…O interactions in C5a (H1…O3i 2.5208(28)Å, ∠C1-H1…O3i 163.925(206)°; H9…O3i

ACCEPTED MANUSCRIPT
2.6644(33)Å, ∠C9-H9…O3i 161.169(215)°; H7…O4i 2.5298(28)Å, ∠C7-H7…O4i
162.141(205)°; i: -1-x, -1-y, -z) (Fig.12).
Fig.7 The dimer structure of C1
Fig.8 1D ribbon-like structure of C1
Fig.9 1D ribbon-like structure of C2

ACCEPTED MANUSCRIPT
Fig.10 2D network structure of C3
Fig.11 1D infinite chain structure of C4
Fig.12 The dimer structure of C5a
3.4. UV-Vis
The UV-Vis absorption spectra of C1 ~ C5b were shown in Fig.13. It can been seem that a
absorption at about 350nm were presented in the C1, C5a and C5b, because the n→π transition
*
of the nitro group have occurd, and the nitro is a chromophoric group so that it has a slight red
shift [37]. The C1 ~ C5b have a large absorption at about 450nm, which is due to coordination of
nitrogen atoms with tin atoms on Schiff bases, and the electrons transfer from the ligand to the Sn

ACCEPTED MANUSCRIPT
atom, the Schiff base plane is relatively fixed so that it formd a rigid plane. The polarization of the
C=N bond was induced and the energy levels of the related conjugated molecular orbital were
affected [16]. It further verified that Schiff base ligand have coordinated organotin, and the Schiff
base organotin(IV) complexes were synthesized.
C1
C2
C3
0.15
C4
C5a
C5b
0.10
0.05
0.00
350
400
450
500
550
600
Wavelength / nm
Fig.13 UV-Vis spectrum of the complexes
3.5. Anticancer activity
Table 2 lists the half inhibitory concentration of the complexes and carboplatin on cultured
cancer cells (MCF7, Colo205, NCI-H460, Hela, HepG2) and the human normal cell (HL7702) in
vitro. All ligands are relatively low-toxic for the human normal cell HL7702, the activity
decreased in the following order: L3 > L1 > L2, which corresponds to their IC50 value at 32.67,
33.05, and 37.36 respectively, and the toxicity activity of complexes (C1 ~ C5b) are greater than
the corresponding ligands.
At the same time, the organotin complexes (C1 ~ C5b) exhibited significant anticancer
activity for the five kinds of cancer cells in comparison with the ligand, and the activity was
greater than carboplatin. So the complexes (C1 ~ C5b) may be potential candidates after further
chemical optimization and cancer therapy. The molecular structure difference of complexes C3
and C4 only lies in the substituted group on the Schiff base ligand, the difference of C2 and C4 is
type of alkyl groups on tin, so are C1, C5a and C5b. It can infer that the anticancer activity is
influenced by the types of organic groups on tin and ligand. From the Table 2, it can been seen
that C3, C4, C5a and C5b showed higher anticancer activity compared with C1 and C2, it
indicated the butyl group attached to the centre Sn atom of the same ligand enhanced anticancer

ACCEPTED MANUSCRIPT
activity [38-40]. Those results suggest that organotin complexes possess significant anticancer
activity and may lead to more promising metal complexes.
Table 2 Inhibition action of ligands and complexes to cancer cell in vitro
IC50 (uM)
Complex
MCF7
Colo205
7.93 ± 0.71
8.91 ± 1.27
15.85 ± 2.35
3.02 ± 0.11
2.85 ± 0.75
2.47 ± 0.21
0.93 ± 0.15
0.82 ± 0.10
1.01 ± 0.13
3.88 ± 0.61
NCI-H460
16.32 ± 1.13
15.08 ± 0.96
13.25 ± 0.74
15.26 ± 0.82
13.25 ± 0.17
9.85 ± 1.32
14.33 ± 0.58
4.74 ± 0.07
4.97 ± 0.19
6.26 ± 1.02
Hela
HepG2
HL7702
13.25 ± 1.27
16.69 ± 1.36
10.37 ± 0.79
12.24 ± 1.34
14.37 ± 0.83
9.45 ± 0.77
13.25 ± 2.81
8.12 ± 0.25
6.20 ± 0.31
8.22 ± 1.29
7.16 ± 1.69
10.80 ± 0.59
8.56 ± 0.60
9.25 ± 0.21
8.56 ± 1.17
7.23 ± 1.04
7.16 ± 1.61
2.62 ± 1.04
3.04 ± 0.82
22.56 ± 1.79
10.56 ± 0.78 33.05 ± 2.71
18.22 ± 1.72 37.36 ± 1.09
22.87 ± 1.48 32.67 ± 0.81
19.88 ± 0.91 30.29 ± 0.94
22.87 ± 0.79 28.41 ± 1.37
10.56 ± 0.53 22.85 ± 0.31
20.32 ± 1.93 25.70 ± 1.09
2.11 ± 1.04 15.33 ± 2.05
2.58 ± 0.82 17.40 ± 0.74
1.70 ± 0.32 21.38 ± 2.41
L1
L2
L3
C1
C2
C3
C4
C5a
C5b
Carboplatin
4. Conclusion
Schiff base organotin (IV) complexes C1 ~ C5b have been synthesized, the central tin atom
of C1 ~ C4 is six-coordinated in a distorted octahedron geometry, C5a is five-coordinate in a
distorted trigonal bipyramid geometry, C5b is a binucleus molecules, a Sn2O2 four membered ring
was formed in the middle of molecule through ꢀ-carboxyl oxygen atom bridges the two Sn(IV)
atoms. The anticancer activity tests showed that C1 ~ C5b exhibited significant anticancer activity
for the five kinds of cancer cells in comparison with the ligand, and the activity was greater than
carboplatin, and they may be better potential candidates for further chemical optimization and
cancer therapy.
Acknowledgment
This work was supported by the Hunan Provincial Natural Science Foundation of China (Nos.
2017JJ3003, 2016JJ4008, 2016JJ5004); The Open Fund Project of Key Laboratory of Functional
Organometallic Materials of Hengyang Normal University (No. GN16K03).
Appendix A. Supplementary data
CCDC 1545306, 1545307, 1545308, 1545309, 1545310, and 1545311 contain the
supplementary crystallographic data for the complexes C1 ~ C5b. These data can be obtained free
of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge
Crystallographic Data Centre, 12 Union Road, CambridgeCB21EZ, UK; Fax(+44) 1223-336-033;

ACCEPTED MANUSCRIPT
or E-mail: deposit@ccdc.cam.ac.uk.
References
[1] X. Li, Z. Liu, Y. Xu, D. Wang, Synthesis, crystal structure and hydrolysis activity of a novel heterobinuclear
cobalt(ІІІ) sodium(І) Schiff base complex, Journal of Inorganic Biochemistry 171 (2017) 37-44.
[2] J. L. Segura, M. J. Mancheno, F. Zamora, Covalent organic frameworks based on Schiff-base chemistry:
synthesis, properties and potential applications, Chemical Society Reviews 45 (2016) 5635-5671.
[3] A. A. Abdel Aziz, A. N. M. Salem, M. A. Sayed, M. M. Aboaly, Synthesis, structural characterization,
thermal studies, catalytic efficiency and antimicrobial activity of some M(II) complexes with ONO tridentate
Schiff base N-salicylidene-o-aminophenol (saphH2), Journal of Molecular Structure 1010 (2012) 130-138.
[4] B. S. Kusmariya, A. P. Mishra, Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate ONO donor Schiff
base ligand: Synthesis, characterization, thermal, non-isothermal kinetics and DFT calculations, Journal of
Molecular Structure 1130 (2017) 727-738.
[5] P. Bhowmik, N. Aliaga-Alcalde, V. Gómez, M. Corbella, S. Chattopadhyay, Methylene spacer regulated
variation in structures and magnetic properties in copper(II) compounds with O, N, O donor Schiff bases,
Polyhedron 49 (2013) 269-276.
[6] T. A. K. Al-Allaf, L. J. Rashan, A. Stelzner, D. R. Powell, Organotin(IV) complexes with various donor
ligands and their cytotoxicity against tumour cell lines. Part(I): R2SnCl2 with Schiff bases; unusual C=N bond
cleavage of the bases and X-ray structures of the ionic products formed, Applied Organometallic Chemistry
17 (2003) 891-897.
[7] J. Liu, R. Zhou, L. Jia, D. Fan, X. Lü, Ring-opening copolymerization of CHO and MA catalyzed by the
asymmetrical Cr(III)-bis-Schiff-base complex, Inorganic Chemistry Communications 79 (2017) 86-88.
[8] M. Sedighipoor, A. H. Kianfar, W. A. Kamil Mahmood, M. H. Azarian, Synthesis and electronic structure of
novel Schiff bases Ni/Cu (II) complexes: Evaluation of DNA/serum protein binding by spectroscopic studies,
Polyhedron 129 (2017) 1-8.
[9] X. Shang, X. Meng, E. C. B. A. Alegria, Q. Li, M. F. C. Guedes da Silva, M. L. Kuznetsov, A. J. L. Pombeiro,
Syntheses, Molecular Structures, Electrochemical Behavior, Theoretical Study, and Antitumor Activities of
Organotin(IV) Complexes Containing 1-(4-Chlorophenyl)-1-cyclopentanecarboxylato Ligands, Inorganic
Chemistry 50 (2011) 8158-8167.
[10] D. B. Shpakovsky, C. N. Banti, E. M. Mukhatova, Y. A. Gracheva, V. P. Osipova, N. T. Berberova, D. V.
Albov, T. A. Antonenko, L. A. Aslanov, E. R. Milaeva, S. K. Hadjikakou, Synthesis, antiradical activity and

ACCEPTED MANUSCRIPT
in vitro cytotoxicity of novel organotin complexes based on 2,6-di-tert-butyl-4-mercaptophenol, Dalton
Transactions 43 (2014) 6880-6890.
[11] M. Sirajuddin, S. Ali, V. McKee, S. Zaib, J. Iqbal, Organotin(iv) carboxylate derivatives as a new addition to
anticancer and antileishmanial agents: design, physicochemical characterization and interaction with Salmon
sperm DNA, RSC Advances 4 (2014) 57505-57521.
[12] X. Xiao, Y. Li, Y. Dong, W. Li, K. Xu, N. Shi, X. Liu, J. Xie, P. Liu, “S” shaped organotin(IV) carboxylates
based on amide carboxylic acids: Syntheses, crystal structures and antitumor activities, Journal of Molecular
Structure 1130 (2017) 901-908.
[13] H. Yin, H. Liu, M. Hong, Synthesis, structural characterization and DNA-binding properties of organotin(IV)
complexes based on Schiff base ligands derived from 2-hydroxy-1-naphthaldy and 3- or 4-aminobenzoic acid,
Journal of Organometallic Chemistry 713 (2012) 11-19.
[14] Y. X. Tan, Z. J. Zhang, J. X. Yu, X. M. Zhu, Y. L. Feng, D. Z. Kuang, W. J. Jiang, Synthesis, Crystal
Structure and Biological Activity of the Schiff Base n-Butyltin Complex based on 4-(Diethylamino)
salicylaldehyde-2-Hydroxy-5-Nitroaniline, Shandong Chemical Industry, 22 (2016) 3-5.
[15] W. J. Jiang, X. M. Wu, C. Liu, J. X. Yu, X. M. Zhu, Y. L. Feng, F. X. Zhang, D. Z. Kuang, Syntheses,
Crystal Structures and Biological Activity of Schiff Base Organotin Complexes Based on o-Vanillin and
2-Amino-4-nitrophenol, Chinese J. Inorg. Chem. 07 (2015) 1321-1328.
[16] W. J. Jiang, D. Z. Kuang, Y. L. Feng, J. X. Yu, F. X. Zhang, X. M. Zhu, Microwave-Assisted Synthesis,
Characterization and Fluorescence Properties of the Salicylaldehyde-o-aminophenol Schiff Base with
Appended Donor Functionality and Their n-Butyltin(IV) Complexes, Chinese J. Organic Chem. 11 (2014)
2288-2295.
[17] Z. J. Zhang, D. Z. Kuang, W. J. Jiang, J. X. Yu, X. M. Zhu, F. X. Zhang, Synthesis, Crystal Structure, and
Thermal Stability of a Dibutyltin Complex {[4-Et2NC6H3(O)C=NC6H3(O)-5-NO2](n-Bu2Sn)}2 and Its
Interaction with DNA, Chinese J. Struct. Chem. 09 (2014) 1319-1325.
[18] K. Sisido, Y. Takeda, Z. Kinugawa, Direct Synthesis of Organotin Compounds. I. Di- and Tribenzyltin
Chlorides, J. Am. Chem. Soc. 83 (1961) 538-541.
[19] G. M. Sheldrick, SHELXL-97. A Program for Crystal Structure Refinement, University of Geöttingen,
Germany, 1997.
[20] L .J. Farrugia, WINGX: A Windows Program for Crystal Structure Analysis, University of Glasgow,
Germany, 1988.

ACCEPTED MANUSCRIPT
[21] M. Hong, H. Yin, X. Zhang, C. Li, C. Yue, S. Cheng, Di- and tri-organotin(IV) complexes with
2-hydroxy-1-naphthaldehyde 5-chloro-2-hydroxybenzoylhydrazone: Synthesis, characterization and in vitro
antitumor activities, Journal of Organometallic Chemistry 724 (2013) 23-31.
[22] T. S. Basu Baul, P. Kehie, A. Duthie, N. Guchhait, N. Raviprakash, R. B. Mokhamatam, S. K. Manna, N.
Armata, M. Scopelliti, R. Wang, U. Englert, Synthesis, photophysical properties and structures of
organotin-Schiff bases utilizing aromatic amino acid from the chiral pool and evaluation of the biological
perspective of a triphenyltin compound, Journal of Inorganic Biochemistry 168 (2017) 76-89.
[23] Y. Yang, M. Hong, L. Xu, J. Cui, G. Chang, D. Li, C. Z. Li, Organotin(IV) complexes derived from Schiff
base N’-[(1E)-(2-hydroxy-3-methoxyphenyl)methylidene]pyridine-3-carbohydrazone: Synthesis, in vitro
cytotoxicities and DNA/BSA interaction, Journal of Organometallic Chemistry 804 (2016) 48-58.
[24] M. Nath, P. K. Saini, A. Kumar, Synthesis, structural characterization, biological activity and thermal study
of tri- and diorganotin(IV) complexes of Schiff base derived from 2-aminomethylbenzimidazole, Applied
Organometallic Chemistry 23 (2009) 434-445.
[25] T. Sedaghat, M. Monajjemzadeh, Some new organotin(IV) schiff base adducts: Synthesis, spectroscopic
characterization and thermal studies, Journal of the Iranian Chemical Society 8 (2011) 477-483.
[26] L. J. Zhang, Y. S. Zhou, X. R. Zeng, J. J. Vittal, X. Z. You, Synthesis, molecular, and crystal structure of a
new organotin/Schiff-base complex C28H31Cl3NO4Sn, Journal of Chemical Crystallography 30 (2000)
259-263.
[27] E. Pretsch, P. Buhlmann, B. Martin. Structure Determination of Organic Compounds, Tables of Spectral Data.
Fourth. Springer-Verlag, Berlin Heidelberg, 2009.
[28] G. R. Fulmer, A. J. M. Miller, N. H. Sherden, H. E. Gottlieb, A. Nudelman, B. M. Stoltz, J. E. Bercaw, K. I.
Goldberg, NMR Chemical Shifts of Trace Impurities: Common Laboratory Solvents, Organics, and Gases in
Deuterated Solvents Relevant to the Organometallic Chemist, Organometallics 29 (2010) 2176-2179.
[29] C. Pettinari, F. Marchetti, R. Pettinari, D. Martini, A. Drozdov, S. Troyanov, Synthesis and characterisation of
tin(IV) and organotin(IV) derivatives 2-{[(2-hydroxyphenyl)imino]methyl}phenol, Inorganica Chimica Acta
325 (2001) 103-114.
[30] H. D. Yin, S. W. Chen, Synthesis and characterization of organotin(IV) compounds with Schiff base of
o-vanillin-2-thiophenoylhydrazone, Journal of Organometallic Chemistry 691 (2006) 3103-3108.
[31] V. M. Jimenez-Perez, M. C. Garcia-Lopez, B. M. Munoz-Flores, R. Chan-Navarro, J. C. Berrones-Reyes, H.
V. R. Dias, I. Moggio, E. Arias, J. A. Serrano-Mireles, A. Chavez-Reyes, New application of fluorescent

ACCEPTED MANUSCRIPT
organotin compounds derived from Schiff bases: synthesis, X-ray structures, photophysical properties,
cytotoxicity and fluorescent bioimaging, J. Mater. Chem. B, 3 (2015) 5731-5745
[32] T. S. Basu Baul, P. Kehie, A. Duthie, H. Höpfl, Dinuclear organotin(IV) coordination polymers derived from
Schiff bases with l-aspartic acid, Journal of Organometallic Chemistry 838 (2017) 24-36.
[33] M. Hong, H. Geng, M. Niu, F. Wang, D. Li, J. Liu, H. Yin, Organotin(IV) complexes derived from Schiff
base N′-[(1E)-(2-hydroxy-3-methoxyphenyl)methylidene]pyridine-4-carbohydrazone: Synthesis, in vitro
cytotoxicities and DNA/BSA interaction, European Journal of Medicinal Chemistry 86 (2014) 550-561.
[34] M. C. García-López, B. M. Muñoz-Flores, V. M. Jiménez-Pérez, I. Moggio, E. Arias, R. Chan-Navarro, R.
Santillan, Synthesis and photophysical characterization of organotin compounds derived from Schiff bases for
organic light emitting diodes, Dyes and Pigments 106 (2014) 188-196.
[35] M. Nath, P. K. Saini, Chemistry and applications of organotin(iv) complexes of Schiff bases, Dalton Trans.
40 (2011) 7077-7121.
[36] S. Basu, C. Masharing, B. Das, Diorganotin(IV) complexes of polyaromatic azo-azomethine ligand derived
from salicylaldehyde and ortho-aminophenol: Synthesis, characterization, and molecular structures,
Heteroatom Chemistry 23 (2012) 457-465.
[37] J. H. Chang; Q. G. Dong, Spectral theory and analysis, Science Press, Beijing, 2012.
[38] M. K. Amir, S. Khan, R. Zia ur, A. Shah, I. S. Butler, Anticancer activity of organotin(IV) carboxylates,
Inorganica Chimica Acta 423, Part B (2014) 14-25.
[39] M. I. Khan, M. K. Baloch, M. Ashfaq, G. J. Peters, In vivo toxicological effects and spectral studies of
organotin(IV) N-maleoylglycinates, Applied Organometallic Chemistry 19 (2005) 132-139.
[40] V. I. Bregadze, S. A. Glazun, P. V. Petrovskii, Z. A. Starikova, V. Y. Rochev, H. Dalil, M. Biesemans, R.
Willem, M. Gielen, D. de Vos, Synthesis, characterization, X-ray crystal structure and in vitro antitumour
activity of bis(1,2-dicarba-closo-dodecaborane-9-carboxylato)di-n-butyltin, Applied Organometallic
Chemistry 17 (2003) 453-457.

ACCEPTED MANUSCRIPT
Highlights
Five new Schiff base organotin(IV) complexes have been synthesized and characterized.
The crystal structures of complexes exhibit dimer structure, one-dimensional chain or 2D network
structure.
All compounds exhibited significant anticancer activity and may be better potential candidates for
further chemical optimization and cancer therapy.