H. Khanmohammadi et al. / Dyes and Pigments 98 (2013) 557e564
559
1148, 851 and 766. Anal. Calcd. for C14H12N2O3: C, 65.62; N,10.93; H,
4.72. Found: C, 65.53; N, 10.72; H, 4.58%.
stand at room temperature for several days to give solid product.
The resultant product was collected by filtration and washed suc-
cessively with methanol and then dried in air overnight.
2.4.3. General procedure for the synthesis of azo-azomethine dyes,
L1eL3
2.4.4.1. [NiL1]$0.5H2O, I. Brown crystals, Yield: 73%, m. p. >270 ꢀC. IR
(KBr, cmꢁ1);1606 (C]N),1574,1462,1342 (CeO),1153,1142, 835, 748,
582, 547, 497 and 418. Anal. Calcd. for C40H29Cl2N6NiO2.5S2: C, 58.06;
N,10.16; H, 3.53; S, 7.75. Found: C, 57.58; N, 9.93; H, 3.52; S, 7.33%. lmax
A solution of 1,2-bis(2-aminophenylthio)ethane (0.28 g, 1 mmol)
in absolute EtOH (10 mL) was added to a stirred solution of azo-
coupled precursors, 1e3, (2 mmol) in absolute EtOH (50 mL) dur-
ing a period of 30 min at 50 ꢀC. The solutionwas heated inwater bath
for 4 h at 80 ꢀC with stirring. The mixture was filtered whilst hot and
the obtained solid was washed with hot ethanol (three times) and
then with diethyl ether. The resulted product was dried in air.
(nm) (
(molꢁ1 dm3 cmꢁ1)): 415 (42883), 430 (43892) in DMF.
3
2.4.4.2. [NiL2(ClO4)]$CH3OH, II. Brown powder, Yield: 81%, m. p.
>270 ꢀC. 1H NMR (DMSO-d6, 300 MHz, ppm):
2.78 (s, 2H), 2.91 (s,
d
2H), 3.76 (s, 3H), 3.83 (s, 3H), 6.53 (m, 1H), 6.74 (m, 1H), 6.93 (s, 3H),
7.10 (m, 7H), 7.28 (d, 1H, J ¼ 7.4 Hz), 7.48 (s, 1H), 7.85 (d, 3H,
J ¼ 7.4 Hz), 8.03 (m, 4H), 8.21 (s, 1H), 9.07 (s, 1H), 10.34 (s, 1H), 11.46
(br, 1H). IR (KBr, cmꢁ1); 1614 and 1599 (C]N), 1579, 1501, 1385,
1356 (CeO), 1151, 1109, 1026, 837, 758, 667, 623, 521, 501, 436 and
415. Anal. Calcd. for C43H39ClN6NiO9S2: C, 54.82; N, 8.92; H, 4.17; S,
6.81. Found: C, 54.67; N, 9.39; H, 4.10; S, 6.98%. lmax (nm) (
(molꢁ1 dm3 cmꢁ1)): 393 (46787), 429 (44243) in DMF.
2.4.3.1. 1,2-bis((4-((4-chlorophenyl)diazenyl)-2-((phenylimino)
methyl)phenol)thio)ethane, L1. Yield: 77%, m. p. 238e240 ꢀC. 1H
NMR (DMSO-d6, 300 MHz, ppm):
d 3.24 (s, 4H), 7.13 (d, 2H,
J ¼ 8.8 Hz), 7.29e7.51 (m, 8H), 7.63 (d, 4H, J ¼ 8.3 Hz), 7.85 (d, 4H,
J ¼ 8.3 Hz), 7.99 (d, 2H, J ¼ 8.8 Hz), 8.26 (s, 2H), 9.08 (s, 2H), 13.73
(br, 2H). IR (KBr, cmꢁ1); 1612 (C]N), 1578 (phenol ring), 1470
(N]N), 1350, 1281(CeO), 1082, 837 and 738. m/z ¼ 43.0, 57.1, 81.0,
109.0, 145, 207.0, 247.0, 301.0, 368.0, 565.0, 617.0. Anal. Calcd. for
3
C
40H30Cl2N6O2S2: C, 63.07; N, 11.03; H, 3.97; S, 8.42. Found: C,
2.4.4.3. [NiL3(ClO4)]$CH3OH, III. Brown powder, Yield: 83%, m. p.
63.21; N, 10.64; H, 4.32; S, 8.65%. lmax (nm) (
3
(molꢁ1 dm3 cmꢁ1)):
>270 ꢀC. 1H NMR (DMSO-d6, 300 MHz, ppm):
d 2.39 (s, 3H), 3.24 (s,
359 (48881) in DMF.
2H), 6.92 (m, 1H), 7.11 (m, 2H), 7.19 (s, 6H), 7.28 (m, 2H), 7.38 (d, 2H,
J ¼ 7.0 Hz), 7.50 (s, 1H), 7.77 (d, 2H, J ¼ 4.6 Hz), 7.97 (s, 4H), 8.16 (s,
1H), 8.25 (s, 1H), 9.10 (s, 1H), 10.36 (s, 1H). IR (KBr, cmꢁ1); 1606
(C]N), 1385, 1356 (CeO), 1292, 1142, 1109, 1016, 831, 760, 667, 623,
551, 503, 470 and 416. Anal. Calcd. for C43H39ClN6NiO7S2: C, 56.75;
N, 9.23; H, 4.32; S, 7.05. Found: C, 56.47; N, 9.19; H, 4.26; S, 6.52%.
2.4.3.2. 1,2-bis((4-((4-methoxyphenyl)diazenyl)-2-((phenylimino)
methyl)phenol)thio)ethane, L2. Yield: 72%, m. p. 258e260 ꢀC. 1H
NMR (DMSO-d6, 300 MHz, ppm): d 3.24 (s, 4H), 3.86 (s, 6H), 7.12 (m,
6H), 7.34e7.50 (m, 8H), 7.86 (d, 4H, J ¼ 8.7 Hz), 7.95 (d, 2H,
J ¼ 7.9 Hz), 8.22 (s, 2H), 9.08 (s, 2H), 13.50 (br, 2H). IR (KBr, cmꢁ1);
1614 (C]N), 1584 (phenol ring), 1468 (N]N), 1358, 1279 (CeO),
1105, 1067 and 835. m/z ¼ 29.0, 43.0, 57.0, 83.0, 111.0, 140.0, 206.9,
250.0, 316.0, 332.0. Anal. Calcd. for C42H36N6O4S2: C, 67.00; N, 11.16;
H, 4.82; S, 8.52. Found: C, 67.11; N,11.43; H, 4.66; S, 8.42%. lmax (nm)
lmax (nm) (
(molꢁ1 dm3 cmꢁ1)): 403 (40124), 431 (37819) in DMF.
3
3. Result and discussion
The condensation reaction of 5-(4-X-phenyl)-azo-salicylade-
hyde (X ¼ Cl, OMe, Me) with 1,2-bis(2-aminophenylthio)ethane in
ethanol afforded new azo-azomethines, L1eL3, in good yield. All
synthesized compounds, with N, S and O donor set of atoms, are
thermally stable solids, intensely colored, soluble in THF, DMF and
DMSO. The prepared compounds also exhibited dye character. L1eL3
have been used to prepare nickel(II) complexes, IeIII. All prepared
mononuclear complexes have been characterized by FT IR and UVe
Vis spectroscopes and 1H NMR as far as possible. Also, the crystal
structure of I has been determined. Moreover, thermal and spectral
properties of L1eL3 and their complexes have been reported.
(
(molꢁ1 dm3 cmꢁ1)): 367 (48265) in DMF.
3
2.4.3.3. 1,2-bis((4-((4-methylphenyl)diazenyl)-2-((phenylimino)
methyl)phenol)thio)ethane, L3. Yield: 78%, m. p. 220e222 ꢀC. 1H
NMR (DMSO-d6, 300 MHz, ppm): d 2.39 (s, 6H), 3.24 (s, 4H), 7.13 (d,
2H, J ¼ 8.8 Hz), 7.32e7.52 (m, 12H), 7.76 (d, 4H, J ¼ 7.8 Hz), 7.98 (d,
2H, J ¼ 8.8 Hz), 8.24 (s, 2H), 9.09 (s, 2H), 13.56 (br, 2H). IR (KBr,
cmꢁ1); 1612 (C]N), 1580 (phenol ring), 1470 (N]N), 1350, 1281
(CeO), 1105, 1067 and 824. m/z ¼ 29.0, 57.0, 85.0, 113.0, 141.0, 207.0,
253.0, 309.0, 365.0, 581.0. Anal. Calcd. for C42H36N6O2S2: C, 69.97;
N, 11.66; H, 5.03; S, 8.90. Found: C, 69.55; N, 11.23; H, 4.54; S, 9.04%.
lmax (nm) (
(molꢁ1 dm3 cmꢁ1)): 357 (47345) in DMF.
3
3.1. IR spectra
2.4.4. General procedure for the synthesis of nickel(II) complexes
A solution of Ni(ClO4)2$6H2O (0.37 g, 1 mmol) in absolute
ethanol (10 mL) was added to a suspension of L1eL3 (1 mmol) in
CHCl3 (50 mL) over a period of 5 min. The reaction mixture was
allowed to stirred for 24 h at 45 ꢀC. The obtained solution was left to
The position of some of the prominent bands in the IR spectra
of L1eL3 and their nickel(II) complexes along with their tentative
assignments based on extensive data accessible for related com-
pounds [26,36,37] are depicted in Table 2. The total absence of
y(C]O) band of azo-coupled salicylaldehyde precursors in the IR
Table 2
Tentative assignments of some selected IRa frequencies (cmꢁ1) and UVeVis data of the prepared azo-azomethine ligands and their Ni(II) complexes.
Compounds
n(C]N)
n
(CeO)
n(CeS)
n(ClO4)
n(NieN)
n(NieO)
lmax (nm) ( 3
(molꢁ1 dm3 cmꢁ1)) in DMF
L1
L2
L3
I
1612
1614
1612
1606
1599
1281
1279
1281
1342
1356
786
785
787
748
758
e
e
e
359 (48881)
367 (48265)
357 (47345)
415 (42883), 430 (43892)
393 (46787), 429 (44243)
e
e
e
e
e
e
e
497
436
548
501
II
1151, 1109, 1026
667, 623
III
1606
1356
760
1142, 1109, 1016
667, 623
470
503
403 (40124), 431 (37819)
a
KBr discs.