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S. Naskar et al. / Inorganica Chimica Acta 363 (2010) 3641–3646
2.2.4. Ligand L4H2
A mixture of anthraniloyl hydrazide (0.755 g, 5 mmol) and 2,6-
diacetyl pyridine monooxime (0.890 g, 5 mmol) was refluxed in
220 ml MeOH for 5 h. Reduction of volume and subsequent filtra-
tion, followed by washing with diethyl ether gives light yellow col-
or solid. Yield: 0.813 g, 52.3%. M.P.: 204 °C. Anal. Calc. for
N
*
N
N
O
*
HO
NH
z
C
16H17N5O2: C, 61.73; H, 5.46; N, 22.50. Found: C, 61.66; H, 5.59;
N, 22.37%. Selected IR bands (cmÀ1): 3242 br (
O–H), 1656 (amide
N–O). ESI-MS: 312 (MH+),
*
m
X
Y
I), 1617 (mC=N), 1570 (amide II), 1019 (m
334 (M+Na+).
X
Y
Z
2.2.5. Ligand L5H2
L1H2
CH
CH
N
CH
CH
CH
CH
N
OH
H
Isonicotinoyl hydrazide (0.685 g, 5 mmol) and 2,6-diacetyl pyr-
idine monooxime (0.890 g, 5 mmol) was refluxed in 250 ml MeOH
for 7 h. The volume was reduced and pale yellow colored solid was
filtered, washed with (5 ml  2) MeOH and (10 ml  3) diethyl
ether. Yield 0.674 g, 45.7%. M.P.: 188 °C. Anal. Calc. for
L2H2
L3H2
L4H2
L5H2
H
C
15H15N5O2: C, 60.60; H, 5.05; N, 23.56. Found: C, 60.52; H, 5.23;
N, 23.35%. Selected IR bands (cmÀ1): 3231 br (
O–H), 1666 (amide
N–O). ESI-MS: 298 (MH+),
CH
CH
NH2
H
m
I), 1603 (mC=N), 1556 (amide II), 1020 (m
320 (M+Na+).
Fig. 1. Schematic diagram of the ligands.
2.3. Synthesis of the complexes
electrode. The ferrocene/ferrocenium couple was observed at
E0(
Ep) = 0.48V (100 mV) under our experimental condition.
All the complexes were prepared following a similar method. A
typical example is described below.
D
2.3.1. Ni(L1H)2 (1)
2.2. Synthesis of the ligands
One mmol of L1H2 (0.312 g) was dissolved in 35 ml MeOH, to
which 1 mmol of triethylamine (0.101 g) was added, when a clear
solution was obtained. Addition of 0.5 mmol Ni(ClO4)2Á6H2O
(0.182 g) results in a reddish brown color solution, which was stir-
red at 70 °C for half an hour, when reddish brown colored solid
separated out. The stirring was continued for additional 2 h. The
solid was filtered under vacuum, washed successively with 2 ml
of MeOH, and 10 ml diethyl ether. Yield: 0.155 g (45.6%). X-ray
quality single crystals, containing the solvated 1 (1ÁDMFÁ0.5H2O)
were obtained by diffusion of diethyl ether into a DMF solution
of the compound. Analysis of 1: Anal. Calc. for C32H30N8O6Ni: C,
56.41; H, 4.40; N, 16.45. Found: C, 56.33; H, 4.71; N, 16.18%. Elec-
2,6-Diacetyl pyridine monooxime and aroyl hydrazides were
prepared by published procedures [27,8,9]. All the ligands were
prepared following a similar procedure.
2.2.1. Ligand L1H2
A
mixture of 2,6-diacetyl pyridine monooxime (0.890 g,
5 mmol) and salicyloylhydrazide (0.760 g, 5 mmol) was refluxed
in 100 ml methanol for 4.5 h. The solvent was reduced to ꢀ20 ml
on a rotary evaporator and the solution was filtered. The light yel-
low solid obtained was washed with methanol (2 ml  3), followed
by diethyl ether (5 ml  2) and then dried in vacuum. Yield: 1.05 g,
67.6%. M.P.: 200 °C. Anal. Calc. for C16H16N4O3: C, 61.53; H, 5.12; N,
17.94. Found: C, 61.32; H, 5.24; N, 17.63%. Selected IR bands
tronic spectrum in MeOH solution k/nm (
(15603), 374 (29876), 393sh (25118). Selected IR bands (cmÀ1):
3406 br ( O–H), 1595 (Amide I + C=N), 1562 (amide II), 1023 ( N–O).
e
/dm3 molÀ1 cmÀ1): 293
m
m
m
(cmÀ1): 3254 br (
II), 1024 (
N–O). ESI-MS: 313 (MH+), 335 (M+Na+).
mO–H), 1645 (amide I), 1605 (mC=N), 1556 (amide
m
2.3.2. Ni(L2H)2 (2)
Yield: 0.179 g (55.1%). Anal. Calcd. for C32H30N8O4Ni: C, 59.19;
2.2.2. Ligand L2H2
H, 4.62; N, 17.26. Found: C, 59.29; H, 4.40; N, 17.15%. Electronic
Benzoyl hydrazide (0.680 g, 5 mmol) was refluxed with 2,6-dia-
cetyl pyridine monooxime (0.890 g, 5 mmol) in 180 ml MeOH for
4.5 h. The solid was isolated following the same procedure as
L1H2. Yield: 0.953 g, 64.4%. M.P.: 142 °C. Anal. Calc. for
spectrum in MeOH solution: k/nm
(25644), 330 (23539), 411sh (5584). Selected IR bands (cmÀ1):
3434 br ( O–H), 1589 (amide I + C=N), 1549 (amide II), 1051 ( N–O).
(e
/dm3 molÀ1 cmÀ1): 304
m
m
m
2.3.3. Ni(L3H)2 (3)
Yield: 0.139 g (42.7%). Anal. Calc. for C30H28N10O4Ni: C, 55.32; H,
4.30; N, 21.51. Found: C, 55.11; H, 4.40; N, 21.39%. Electronic spec-
C
16H16N4O2: C, 64.86; H, 5.40; N, 18.91. Found: C, 64.56; H, 5.36;
N, 18.88%. Selected IR bands (cmÀ1): 3217 br (
O–H), 1658 (amide
N–O). ESI-MS: 297 (MH+),
m
I), 1616 (mC=N), 1571 (amide II), 1016 (m
319 (M+Na+).
trum in MeOH solution: k/nm (
334sh (11017), 375sh (5508). Selected IR bands (cmÀ1): 3407 br
O–H), 1630 (amide I), 1595 ( C=N), 1558 (amide II), 1038 ( N–O).
e
/dm3 molÀ1 cmÀ1): 298 (17537),
2.2.3. Ligand L3H2
(m
m
m
Picolyl hydrazide (0.685 g, 5 mmol) and 2,6-diacetyl pyridine
monooxime (0.890 g, 5 mmol) were refluxed for 3 h in 200 ml
MeOH. Solid compounds were isolated as described above. Yield:
0.716 g, 48.6%. M.P.: 174 °C. Anal. Calc. for C15H15N5O2: C, 60.60;
H, 5.05; N, 23.56. Found: C, 60.53; H, 5.27; N, 23.45%. Selected IR
2.3.4. Ni(L4H)2 (4)
Yield: 0.198 g (58.3%). Anal. Calc. for C32H32N10O4Ni: C, 56.57; H,
4.71; N, 20.62. Found: C, 58.29; H, 4.40; N, 18.95%. Electronic spec-
trum in MeOH solution: k/nm (
397sh (5396). Selected IR bands (cmÀ1): 3423 br (
(amide I), 1594 ( C=N), 1575 (amide II), 1024 ( N–O).
e
/dm3 molÀ1 cmÀ1): 297(9524),
bands (cmÀ1): 3361 br (
(amide II), 1009 (
N–O). ESI-MS: 298 (MH+), 320 (M+Na+).
m
O–H), 1665 (amide I), 1591 (
mC=N), 1572
mO–H), 1605
m
m
m