To the stirring solution of Schiff base ligands (2.0 mmol) in 5 ml methanol, were dropwise added
the metal(III) nitrates (1.0 mmol) in methanol solution. The reaction mixtures were stirred for 30
min then refluxed at 80 °C for 3-4 hrs. The resulting solutions were then cooled and the
Ln
3+
Ln = Ce
3+
(
1
), Nd
3+
(
2
), Pr
3+
(
3
)
2 : 1
N
N
N
S
N
S
NO
2
O
2
N
Ln
N
N
N
S
N
S
NO
2
O
2
N
N
N
N
S
N
S
NO
2
NO
2
+
Methanol
80-85 °C, 3-4 h
L1
Ln
3+
2 : 1
N
N
N
S
N
S
Ln
N
N
N
S
N
S
+
N
N
N
S
S
N
CH
3
CH
3
Methanol
80-85 °C, 3-4 h
Ln = Ce
3+
(
4
), Nd
3+
(
5
), Pr
3+
(
6
)
L2
(a)
(b)
Scheme 2
: Synthesis of complexes
1
-
3
based on
L1
and
4
-
6
comprising
L2
.
N
N
N
S
N
S
NO
2
O
2
N
Ce
N
N
N
S
N
S
NO
2
O
2
N
N
N
N
S
N
S
H
3
C
CH
3
N
N
N
S
N
S
H
3
C
CH
3
Ce
N
N
N
S
N
S
H
3
C
CH
3
N
N
N
S
N
S
H
3
C
CH
3
Nd
N
N
N
S
N
S
H
3
C
CH
3
N
N
N
S
N
S
H
3
C
CH
3
Pr
N
N
N
S
N
S
NO
2
O
2
N
Nd
N
N
N
S
N
S
NO
2
O
2
N
N
N
N
S
N
S
NO
2
O
2
N
Pr
N
N
N
S
N
S
NO
2
O
2
N
1
4
2
5
3
6
Figure 1
: Structures of lanthanide complexes
1
-
6
containing of
L1
and
L2
1)
(N,N'E,N,N'E)-N,N'-(1,3-phenylenebis(methanylylidene))bis(5-nitrobenzo[d]thiazoL2-
amine)cerium(III)
(1).
The reaction was carried out following the general procedure by
using
L1
(2.0 mmol, 0.976 g) and Ce(NO
3
)
2
(1.0 mmol, 0.434 g) as metal (III) nitrate; light
yellow, yield 1.070 g (76 %); FTIR (cm
-1
): 3047.66 (C-H aromatic), 1687 (C=N), 738 (C-
H); UV/vis
(λ
max
): 211 nm, 330 nm; Mass (ESI-MS, 100 %): 1118.117 (Calculated:
1115.98) anal. for C
44
H
24
CeN
12
O
8
S
4
; Elemental Analysis: C, 47.28; H, 2.21; N, 15.10; O,
11.42; S, 11.51(Calculated: C, 47.31; H, 2.17; N, 15.05; O, 11.46; S, 11.48).
2)
(N,N',E,N,N'E)-N,N'-(1,3-phenylenebis(methanylylidene))bis(5-nitrobenzo[d]thiazoL2-
amine)neodymium(III)
(2):
The reaction was carried out following general procedure by
using
L1
(2.0 mmol, 0.976g) and Nd(NO
3
)
2
(1.0 mmol, 0.438 g) as metal (III) nitrate; pale
yellow, yield 1.145 g (81 %); mp-203 °C; FTIR (cm
-1
): 1689 (C=N), 739 (C-H); UV/vis
(λ
max
): 229 nm, 342 nm; Mass (ESI-MS, 100 %): 1122.23 (Calculated:1117.98) anal. for
C
44
H
24
N
12
NdO
8
S
4
; Elemental Analysis: C, 47.17; H, 2.12; N, 15.09; O, 11.53; S, 11.34
(Calculated: C, 47.13; H, 2.16; N, 14.99; O, 11.42; S, 11.44).
3)
(N,N'E,N,N'E)-N,N'-(1,3-phenylenebis(methanylylidene))bis(5-nitrobenzo[d]thiazoL2-
amine)praseodymium(III
)
(3):
The reaction was carried out following general procedure by
using
L1
(2.0 mmol, 0.976 g) and Pr(NO
3
)
3
(1.0 mmol, 0.435 g) as metal (III) nitrate;
cinnamon; yield 0.931 g (66 %); mp-210 °C; FTIR (cm
-1
): 3213.45 (C-H aromatic), 1642.02
(C=N), 882.16 (C-H); UV/vis
(λ
max
): 207 nm, 222 nm, 340 nm; Mass (ESI-MS, 100 %):
1118.08 (Calculated: 1117.90); Anal. for C
44
H
24
N
12
O
8
PrS
4
; Elemental Analysis: C, 47.22;
H, 2.19; N, 15.11; O, 11.41; S, 11.51 (Calculated: C, 47.27; H, 2.16; N, 15.04; O, 11.45; S,
11.47).
4)
(N,N'E,N,N'E)-N,N'-(1,3-phenylenebis(methanylylidene))bis(5-methylthiazoL2-amine)
cerium(III
)
(4):
The reaction was carried out following general procedure by using
L2
(2.0
mmol, 0.652 g) and Ce(NO
3
)
2
(1.0 mmol, 0.434 g) as metal (III) nitrate; lemon yellow; yield
0.847 g (78 %); mp-198 °C; FTIR (cm
-1
): 3616 (C-H aromatic), 1687 (C=N), 1287 (C-H);
UV/vis
(λ
max
): 217 nm, 250 nm, 345 nm; Mass (ESI-MS, 100 %): 793.55 (Calculated:
792.04); Anal. for C
32
H
28
CeN
8
S
4
; Elemental Analysis: C, 48.49; H, 3.39; N, 14.12; S, 16.11
(Calculated: C, 48.47; H, 3.56; N, 14.13; S, 16.17).
5)
(N,N'E,N,N'E)-N,N'-(1,3-phenylenebis(methanylylidene))bis(5-methylthiazoL2-amine)-
neodymium(III
)
(5):
The reaction was carried out following general procedure except using
L2
(2.0 mmol, 0.652 g) and Nd(NO
3
)
2
(1.0 mmol, 0.438 g) as metal (III) nitrate; golden
yellow, yield 0.915 g (84 %); mp-205 °C; FTIR (cm
-1
): 3616.47 (C-H aromatic ), 1687.49
(C=N), 771.55(C-H); UV/vis
(λ
max
): 206 nm, 250 nm, 339 nm; Mass (ESI-MS, 100 %):
798.127 (Calculated: 797.12) Anal. for C
32
H
28
N
8
NdS
4
; Elemental Analysis: C, 48.18; H,
3.57; N, 14.11; S, 16.17 (Calculated: Elemental Analysis: C, 48.22; H, 3.54; N, 14.06; S,
16.09).
6)
(N,N'E,N,N'E)-N,N'-(1,3-phenylenebis(methanylylidene))bis(5-methylthiazoL2-amine)-
praseodymium(III)
(6):
The reaction was carried out following general procedure by using
L2
(2.0 mmol, 0.652 g) and Pr(NO
3
)
3
(1.0 mmol, 0.435 g) as metal (III) nitrate; brown
powder; yield 0.782 g (72 %); mp-203 °C; FTIR (cm
-1
): 3740 (C-H aromatic ), 1687 (C=N),
773 (C-H); UV/vis
(λ
max
): 204 nm, 259 nm, 344 nm; Mass (ESI-MS, 100 %): 793.77
(Calculated: 793.04); Anal. for C
32
H
28
N
8
PrS
4
; Elemental Analysis: C, 48.38; H, 3.61; N,
14.14; Pr, 17.72; S, 16.13 (Calculated: C, 48.42; H, 3.56; N, 14.12; Pr, 17.75; S, 16.16).
Anti-microbial study:
Stored bacterial standard cultures were revived by inoculating into Luria-
Burtani broth overnight at 37
°
C. Inoculums was prepared from this fresh overnight grown
culture on 1 ml Luria-Burtani broth and incubated till the turbidity reached up to 0.5 McFarland
solutions at 595 nm. Initially, the freshly prepared Muller Hinton agar plates were kept ready to
the media plates by making 8 mm wells by cork borer at equal distance. Each of the broth
suspension of bacterial culture was inoculated on to and freshly prepared 100
μl
of synthesized
materials (200 PPM /ml dissolved in DMSO) poured on to the each well. These culture plates
were incubated at 37 °C for 24 hrs via wall diffusion method. The zone of the inhibition shown
was measured in mm after the incubation period.
Instrumentation
FT-IR spectra were recorded with
BRUKER ART II
spectrophotometer.
1
H NMR spectral study
was done in dmso
-d
6
at low temperature on ECS 400 MHz (Jeol). ESI-MS spectral analysis is
recorded in aqueous solution at rt with Xevo G2-S Q-Tof. UV/vis spectra were recorded at rt on
PerkinElmer Lambda 35 spectrophotometer. Emission spectra analyzed in water-ethanol solution
at rt on Perkin Elmer LS55 spectrophotometer.
Do'stlaringiz bilan baham: 
