Electronic Supporting Information
Surfactant-Copper(II) Schiff base complexes: Synthesis, structural
investigation, DNA interaction, docking studies and cytotoxic activity†
Jagadeesan Lakshmipraba,a Sankaralingam Arunachalam,a, Rajadurai Vijay Solomon,a
Ponnambalam Venuvanalingam,a , Anvarbatcha Riyasdeen,b Rajakumar Dhivya,c
Mohammad Abdulkader Akbarshab
a
School of Chemistry, Bharathidasan University, Tiruchirappalli - 620 024, Tamil Nadu, India
Mahatma Gandi-Doerenkamp Centre, Bharathidasan University, Tiruchirappalli - 620 024,
Tamil Nadu, India
c
Department of Biomedical Science, Bharathidasan University, Tiruchirappalli - 620 024, Tamil
Nadu, India
b
Email: arunasurf@yahoo.com
S1
Experimental Section
Preparation of surfactant-Schiff base ligand
The Schiff base ligands containing long aliphatic chain were prepared by condensation of
a mixture of ethanolic solution (20 ml) of salicylaldehydeor 5-methoxy-salicylaldehyde (15
mmol) and long chain aliphatic amine (dodecylamine (DA) / tetradecylamine (TA) / cetylamine
(CA), 15 mmol) and trace amount of p-toluenesulfonic acid under reflux for 30 min. At the end
of the reaction, the solution was concentrated to 5 ml using rotary evaporator and the yellow
solid mass obtained upon cooling was dried under vacuum and recrystallized from methanol.
R2
N
O
R1
OH
+
R2-NH2
sal-DA: R1 = H, R2 = C12H25
sal-TA: R1 = H, R2 = C14H29
sal-CA: R1 = H, R2 = C16H33
R1
OH
5-OMe-sal-DA: R1 = OCH3, R2 = C12H25
5-OMe-sal-TA: R1 = OCH3, R2 = C14H29
5-OMe-sal-CA: R1 = OCH3, R2 = C16H33
Scheme 1. Formation of surfactant-Schiff base ligand
Spectral data of surfactant-Schiff base ligand
sal-DA: IR (KBr, cm-1): 3125 (O-H), 1631 (C-N), 1277 (C-O). 1H-NMR (400 MHz, DMSO-d6) (δ
ppm): 13.6 (s, 1H, OH), 8.3 (s, 1H, CH=N), 7.2-6.8 (m, 4H, aromatic), 3.4 (t, 2H, NCH2), 1.71.2 (m, 20H, CH2), 0.8 (t, 3H, CH3).
sal-TA: IR (KBr, cm-1): 3315 (O-H), 1638 (C-N), 1272 (C-O). 1H-NMR (400 MHz, DMSO-d6) (δ
ppm): 13.8 (s, 1H, OH), 8.5 (s, 1H, CH=N), 7.3-6.5 (m, 4H, aromatic), 3.5(t, 2H, NCH2), 1.6-1.2
(m, 24H, CH2), 0.7 (t, 3H, CH3).
sal-CA: IR (KBr, cm-1): 3257 (O-H), 1635 (C-N), 1271 (C-O). 1H-NMR (400 MHz, DMSO-d6) (δ
ppm): 13.7 (s, 1H, OH), 8.4 (s, 1H, CH=N), 7.3-6.9 (m, 4H, aromatic), 3.3(t, 2H, NCH2), 1.6-1.3
(m, 28H, CH2), 0.8 (t, 3H, CH3).
S2
sal-DA: IR (KBr, cm-1): 3187 (O-H), 1639 (C-N), 1271 (C-O). 1H-NMR (400 MHz, DMSO-d6) (δ
ppm): 13.7 (s, 1H, OH), 8.4 (s, 1H, CH=N), 7.3-6.7 (m, 3H, aromatic), 3.8 (s, 3H, OCH3), 3.5 (t,
2H, NCH2), 1.6-1.4 (m, 20H, CH2), 0.7 (t, 3H, CH3).
sal-TA: IR (KBr, cm-1): 320 (O-H), 1633 (C-N), 1270 (C-O). 1H-NMR (400 MHz, DMSO-d6) (δ
ppm): 13.7 (s, 1H, OH), 8.4 (s, 1H, CH=N), 7.2-6.9 (m, 3H, aromatic), 3.6 (s, 3H, OCH3), 3.4 (t,
2H, NCH2), 1.6-1.3 (m, 24H, CH2), 0.8 (t, 3H, CH3).
sal-CA: IR (KBr, cm-1): 3220 (O-H), 1636 (C-N), 1275 (C-O). 1H-NMR (400 MHz, DMSO-d6) (δ
ppm): 13.6 (s, 1H, OH), 8.3 (s, 1H, CH=N), 7.3-6.9 (m, 3H, aromatic), 3.8 (s, 3H, OCH3), 3.3 (t,
2H, NCH2), 1.6-1.2 (m, 28H, CH2), 0.8 (t, 3H, CH3).
S3
Table S1. Crystal data and structure refinement for [Cu(sal-TA)2] (2)
Empirical formula
Formula weight
Colour
Temperature (K)
Radiation type
Wavelength (Å)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
 (°)
 (°)
 (°)
Volume (Å3)
Z
Calculated density (Mg m-3)
Absorption coefficient (mm-1)
F(000)
Crystal size (mm)
Theta range (°)
Limiting indices
Reflections collected/unique
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I>2(I)]
R indices (all data)
Largest diff. peak and hole (e. Å-3)
S4
C42H68CuN2O2
696.52
Brown
293(2)
Mo K
0.71073
Monoclinic
P21/c
24.18(2)
9.527(8)
9.238(8)
90.00
98.033(14)
90.00
2107(3)
2
1.098
0.551
758
0.30 x 0.21x 0.03
1.70 to 26.33
-29 ≤ h ≤ 29,
-11 ≤ k ≤ 11,
-11 ≤ l ≤ 11
21222/4226
Full-matrix least-squares on F2
4226/0/214
1.042
R1 = 0.0623, wR2 = 0.1587
R1 = 0.1046, wR2 = 0.1386
0.000 and 0.000
Table S2. Selected bond lengths and bond angles for [Cu(sal-TA)2] (2)
Bond lengths (Å)
Bond angles (°)
Crystal
Optimized
Crystal
Optimized
data
data
data
data
Cu1-O1
1.896(2)
1.939
O1-Cu1-O1a
180.000(1)
180.00
Cu1-N1
1.988(3)
2.035
O1-Cu1-N1a
88.88(8)
89.39
C7-N1
1.281(3)
1.314
O1-Cu1-N1
91.12(8)
90.61
O1-C1
1.306(3)
1.335
Cu1-N1-C7
122.9(2)
124.53
Cu1-O1-C1
129.20(17)
131.28
C8-N1-Cu1
120.75(18)
118.85
ESD in parenthesis
S5
a) Crystal structure
b) B3LYP optimized geometry
Cu
C
N
O
H
Fig. S1. Crystal structure and optimized geometries the complex (2)
S6
complex(1)
Complex(4)
Complex(2)
Complex (3)
Complex(5)
Complex(6)
Fig. S2. Molecular docking view of complexes (1-6) with DNA
S7