Abhranil De et al.
UV-Vis spectrophotometer. Elemental analyses were
2. Experimental
performed on a Perkin Elmer 2400 CHN microanalyser.
2
.1 Materials
Electrospray ionization (ESI) mass spectrum was re-
TM
corded on a Q-TOF Micro
Mass Spectrometer.
ꢁ
High purity 2,2 -dipyridylamine (Aldrich, UK)), cop-
per(II) perchlorate hexahydrate (Fluka, Germany),
ammonium thiocyanate chloride (E. Merck, India), 3,5-
di-tert-butylcatechol (Sigma Aldrich Corporation, St.
Louis, MO, USA), and all other materials were obtained
from commercial sources and used as received. All
other chemicals and solvents were of analytical grade
and were used as received without further purification.
Caution! Perchlorate salts of metal ions are poten-
tially explosive, especially in the presence of organic
ligands. Only a small amount of material should be
prepared and it should be handled with care.
Cyclic voltammograms were recorded in CH CN
3
◦
solutions containing 0.1 M TBAP at 25 C using a
three-electrode configuration (Pt working electrode,
Pt counter electrode, Ag/AgCl reference) and a PC-
controlled PAR model 273A electrochemistry system.
All the experimental solutions were degassed for 30
minutes with high-purity argon gas. The Electron Para-
magnetic Resonance (EPR) spectrum was recorded on
a Bruker EMX-X band spectrometer (Model: EMX).
2.4 X-ray diffraction
Single crystal X-ray diffraction data of the copper
complex were collected using a Rigaku XtaL ABmini
diffractometer equipped with Mercury CCD detector.
The data were collected with graphite monochromated
Mo-Kα radiation (λ = 0.71073 Å) at 293(2) K using
ω scans. The data were reduced using Crystal Clear
2
.2 General synthesis of the copper(II) complex (1)
The discrete hetero-geometric copper complex was syn-
thesized by dropwise addition of aqueous solution of
dipyridylamine (0.342 g, 2 mmol) into a solution of
Cu(ClO ) ·6H O (0.365 g, 1 mmol)] in the same sol-
4
2
2
16
suite 2.0. and the space group determination was
vent (20 mL) keeping the solution on magnetic stirrer
with slow stirring (450 rpm). Then solid ammonium
thiocyanate (0.076 g, 1 mmol) was added as solid into
the blue solution and stirring continued to 30 minutes
more. The blue solution turned into green and the super-
natant liquid was kept in air for slow evaporation. After
2
done using Olex . The structure was resolved by direct
method and refined by full-matrix least-squares proce-
17
dures using the SHELXL-2014/7 software package
18
using OLEX2 suite. The crystallorgraphic bond dis-
tance and bond angle were calculated using PARST19
and given in Tables 1 and 2, respectively.
7
–10 days, fine microcrystalline compound 1 was sep-
arated out, which was washed in hexane and dried
in vacuo over silica gel indicator. The spectroscopic
measurements and elemental analyses confirmed the
structural formation of the complex. Yield = 0.2870 g,
Table 1. Crystallographic parameters for 1.
Crystal parameters
Empirical formula
1
(
65.1% based on metal salt and thiocyanate). Anal. calc.
C64H54N22Cl2O8S4Cu3
1649.08
(
%) C H N Cl O S Cu (1): C, 46.61; H, 3.30; N,
64
54 22
2
8
4
3
1
8.69; Found (%): C, 46.66; H, 3.24; N, 18.73. Selected Formula weight
293(2) K
0.71073 Å
Monoclinic
−1
IR bands (KBr pellet, cm ): 3353 (s), 2142 (s), 1426 Temperature
−4
Wavelength
Crystal system
(
m), 1616 (s), 1096 (s). UV-Vis (λ, nm; 10 M, 1 cm
P2 /c
1
cell, abs): 250–269 (4.068), 290–320 (3.7201), ∼397
◦
Space group
a = 12.7156(8) Å α = 90
(
0.1688), ∼682 (0.0216) (broad); ESI-MS (MeCN):
◦
Unit cell dimensions
b=14.4230(9) Å ß = 93.802 (3)
+
m/z, 235.95 (calcd. 235.75) [Cu(dpa)]H ; m/z, 525.91
◦
c = 19.3355(12) Å γ = 90
+
(calcd. 525.05) [Cu(dpa) (NCS) ]H .
2
2
3
Volume
3538.3(4) Å
Z
8
−
3
Density (calculated)
Absorption coefficient
F(000)
1.548 g cm
1.158 mm
1682
3.0 to 27.5
35795
2
.3 Physical measurements
−1
◦
Infrared spectrum (KBr) was recorded with a FTIR- Theta range for data collection
8
4
400S SHIMADZU spectrophotometer in the range Reflections collected
−1
1
Independent reflections
R(int)
R indices (all data)
7978
0.056
00–3600 cm . H NMR spectrum in DMSO-d was
6
obtained on a Bruker Avance 300 MHz spectrometer
at 25 C and was recorded at 299.948 MHz. Absorp-
tion spectra were recorded with a Jasco model V-730
R1 = 0.0761, wR2 = 0.2239
◦
−3
Largest diff. peak and hole
1.31 and −0.92 e. Å