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P. Pattanayak et al. / Inorganica Chimica Acta 418 (2014) 171–179
2.4. Syntheses
2.4.1. Synthesis of ligand1
OH
OH
To a (30 mL) ethanol solution of 2-hydroxy-1-naphthaldehyde
(1.01 g, 5.86 mmol) was slowly added a (20 mL) ethanol solution
of 2-(benzylthio)aniline (1.26 g, 5.86 mmol). After complete addi-
tion, the reaction mixture was stirred at room temperature for
6 h and allowed to stand for 2 h at room temperature. The product
was separated as yellow precipitation that was collected by filtra-
tion and used for further reactions. The filtrate on standing for an
additional 24 h provides a little crop of product and the combined
yield was 90%. Anal. Calc. for C24H19NOS: C, 78.04; H, 5.14; N, 3.79.
N
N
S
Ph
S
R
1
A
Found: C, 78.21; H, 5.29; N, 3.42%. IR (KBr, cmꢀ1): 3435 (
m
O–H),
Structure. A and 1.
1613 and 1601 (C@N), 1324 (C–O), 751
m
m
m
(C–S). 1H NMR
(400 MHz, CDCl3): 4.11 (CH2, s, 2H), 7.11–7.20 (ArH, m, 5H), 7.25
(ArH, d, 2H), 7.29–7.36 (ArH, m, 3H), 7.40 (ArH, d, 1H), 7.52 (ArH,
t, 1H), 7.72 (ArH, d, 1H), 7.81 (ArH, d, 1H), 8.07 (ArH, d, 1H), 9.21
(CH@N, d, 1H), 15.31 (Ar–OH, s, 1H).
2. Experimental
2.1. Materials
The solvents used in the reactions were of reagent grade (E.
Marck, Kolkata, India) and were purified and dried by general
procedure [32]. Copper nitrate trihydrate (99%), nickel nitrate
hexahydrate (99%), cobalt(III) nitrate hexahydrate (99%), benzyl
alcohol (99%) were purchased from Emark, India. 4-Iodobenzyl
alcohol (98%), 3-methoxybenzyl alcohol (98%), 4-nitrobenzyl alco-
hol (99%) were purchased from Spectrochem, India. 2-Hydroxy-1-
naphthaldehyde (98%), 2-aminothiophenol (99%), 4-chlorobenzyl
alcohol (99%) and 4-methylbenzyl alcohol (98%) were purchased
from Aldrich. 2-(Benzylthio)aniline was prepared following
reported procedure [33]. Ferrocene (98%) was bought from Emark,
India.
2.4.2. Synthesis of complex 2
A solution of copper(II) nitrate trihydrate (0.1 g, 0.413 mmol) in
methanol (15 mL) a solution of ligand HL (0.153 g, 0.413 mmol) in
methanol (10 mL) was added under constant stirring. The colour of
the solution changes immediately to olive green which gradually
turned into green as the stirring was continued for 6 h at room
temperature. The resulting green solution was then filtered and
allowed to stand. After slow evaporation of the solvent at room
temperature, green colored X-ray quality crystals were obtained.
Yield: 80%. Anal. Calc. for C48H36Cu2N4O8S2: C, 58.29; H, 3.64; N,
5.66. Found: C, 58.35; H, 3.70; N, 5.60%. IR (KBr, cmꢀ1): 1615 and
1597 m(C@N), 1383 m(O–C), 1295 m(N–O), 747 m(C–S). E1/2 [V]: 1.36.
2.2. Physical measurements
2.4.3. Synthesis of complex 3
solution of nickel(II) nitrate hexahydrate (0.100 g,
0.343 mmol) in methanol (15 mL) solution of ligand HL
Microanalysis (C, H, N) was performed using Perkin-Elmer 2400
C, H, N, S/O series II elemental analyzer. IR spectra were recorded
on Parkin-Elmer L120-00A FT-IR spectrometer with the samples
prepared as KBr pellets. Electronic spectra were recorded on Shi-
madzu UV-1800 PC spectrophotometer. 1H NMR spectra were
obtained on Brucker 400 NMR spectrometers in CDCl3 using TMS
as the internal standard. Emission spectra were recorded with Per-
kin Elmer LS-55 Luminescence Spectrometer. X-ray crystallogra-
A
a
(0.254 g, 0.687 mmol) in methanol (10 mL) was added under stir-
ring. The solution changes its colour from yellow to brown increas-
ingly upon addition of ligand into the methanolic solution of metal
substrate under the stirring and it was continued for 8 h at room
temperature. The resulting brown solution was then filtered and
allowed to stand. After slow evaporation of the solvent at room
temperature, dark coloured X-ray quality crystals were obtained.
Yield: 65%. Anal. Calc. for C48H36NiN2O2S2: C, 72.39; H, 4.52; N,
3.51. Found: C, 72.23; H, 4.68; N, 3.25%. IR (KBr, cmꢀ1): 1619 and
phy data were collected by
CCD diffractometer with Mo K
graphite crystal. Electrochemical measurements were made under
dinitrogen atmosphere using CH instruments model 600D
x
-scan technique on a Bruker Smart
a
radiation monochromated by
a
1601 m(C@N), 1393 m(O–C), 744 m(C–S). E1/2 [V]: 0.89.
potentiostat. A platinum disc working electrode, a platinum wire
auxiliary electrode and an aqueous saturated calomel reference
electrode (SCE) were used in a three-electrode configuration. Fer-
rocene reference was checked at the beginning and the end of
the experiment. All electrochemical data were collected at 298 K
and are uncorrected for junction potentials.
2.4.4. Synthesis of complex 4
A methanol (10 mL) solution of cobalt(III) nitrate hexahydrate
(0.1 g, 0.344 mmol) was added to the solution of ligand HL
(0.255 g, 0.688 mmol) in methanol (10 mL) under stirring at hot
condition (60 °C). The colour of the solution was changed immedi-
ately to brown and it was continued for 5 h. The resulting brown
solution was then filtered and allowed to stand at room tempera-
ture. After slow evaporation of the solvent at 25 °C, the dark col-
oured crystal was obtained, washed with cold methanol, and
dried in vacuum. Yield: 85%. Anal. Calc. for C48H36CoN3O5S2: C,
67.14; H, 4.19; N, 4.89. Found: C, 67.35; H, 4.05; N, 4.67%. IR
2.3. DFT calculations
Using the X-ray coordinates of the [Cu2(L)2(NO3)2] 2, and mono-
nuclear [Ni(L)2] 3 complexes, ground state electronic structure cal-
culations have been carried out using DFT methods with the ORCA
2.7 program [34]. Becke’s hybrid function with the Lee–Yang–Parr
(LYP) correlation function was used throughout the study [35,36].
The valence-only SV (P) SV/J basis set and B3LYP/G functional were
used [34,35]. All energy calculations were performed using the
self-consistent field ‘‘tight’’ option of the ORCA 2.7 program to
ensure sufficiently well converged values for the state energies
[34,37,38].
(KBr, cmꢀ1): 1611 and 1597
m(C@N), 1385 m(O–C), 1336 m(N–O),
750
m
(C–S). 1H NMR (400 MHz, CDCl3): 3.73 (CH2, d, 1H), 3.84
(CH2, d, 1H), 6.76 (ArH, d, 1H), 6.86 (ArH, d, 2H), 6.96 (ArH, t,
2H), 7.13 (ArH, t, 1H), 7.32–7.38 (ArH, m, 3H), 7.46 (ArH, d, 1H),
7.61 (ArH, t, 2H), 7.71 (ArH, t, 2H), 8.10 (ArH, d, 1H), 8.77 (CH@N,
s, 1H). E1/2 [V]: 1.33.