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M. Montazerozohori et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 138 (2015) 517–528
Ac voltage of 15 kV. TEM image was obtained on instruments of Phi-
Introduction
lips CM-10 TEM microscope operated at 100 kV. X-ray powder dif-
fraction (XRD) spectra were recorded on a STOE type STIDY-MP-
Bioinorganic chemistry is an active research area for inorganic
chemists that it has been initiated from the successive synthesis
of cis-platin as an anticancer drug [1,2]. As found in many reports,
metal ions have enhanced the efficacy of organic drugs when the
metals placed in their structures [3,4]. Metal coordination com-
pounds have a constructive role in biological activity point of view
[5–9]. Among various complexes, Schiff base metal complexes are
more pleasant than many other ones [10]. They are easily synthe-
sized and have excellent characteristics and applications in various
scientific fields such as biochemistry, optical, catalysis, agriculture,
dye and enzyme modeling [11–13]. A literature survey shows
notable biological activities of the Schiff base metal complexes
including antibacterial, antifungal, anti-flammatory, analgesic,
anti-tubercular, anti-oxidant activities and antiviral effects [14–
20]. In addition, possibility of ligand exchange in Schiff base com-
plexes provides an opportunity to design and synthesize of new
product for especial biological usage with regard to bacterial resis-
tant to current organic-based drugs. The interaction of these com-
plexes with DNA leading to binding or cleavage proposes their
anti-cancer potentials as new therapeutic agents [21–23]. These
useful utilities cause the Schiff bases play an important role in
medicinal chemistry field and are considered as target substance
for many synthetic scientists. The study of nano structure com-
pounds is an extremely popular field because of their unique prop-
erties that are absolutely different with respect to them in bulk
phase that is related to the large numbers of surface molecules.
Choosing the proper synthetic process is an important factor in
control of the size of materials at the sub micrometer scale so that
selecting a proper method is a serious step in nanotechnology field
[24,25]. Nano structure inorganic zinc compounds have been
reported [26,27] but the reports for nano structure coordination
zinc compound are rarely found.
Germany X-ray diffractometer with Cu K
a radiation (k = 1.5418).
The high-power ultrasonic unit Bandelin Super Sonorex RK-100H
with ultrasonic peak output 320 W and HF power 80 Weff has been
used for preparation of nano structure complexes.
Synthesis of ligand
The ligand was synthesized according to previous report via a
condensation reaction between trans-3-phenyl-2 propenal, and
diethylenetriamine in 2:1 M ratio in ethanol solvent under vigor-
ous stirring at room temperature [33].
Synthesis of zinc complexes
For the synthesis of the zinc complexes, the fresh ligand solu-
tion was gradually added to zinc halide, thiocyanate or azide salts
solution as equimolar in ethanol under severe stirring and then the
mixture was stirred about 1–2 h at room temperature. At the end,
the obtained precipitate of zinc complexes was filtered and washed
with ethanol. For more purification, the products were recrystal-
lized from dichloromethane/ethanol mixture (1:1) and then dried
in vacuum. The physical and spectral data (IR and UV–visible) of
the compounds have been compiled in Tables 1 and 2. The 1H
and 13C NMR data of zinc complexes based on Scheme 1 are listed
as follow:
Ligand(L); 1HNMR(in DMSO): 7.79(d, 1Hf, J = 10.02 Hz), 7.76(dd,
0
2Hc, J = 6.80 Hz, J = 3.30 Hz), 7.61(bd, 2Hc , J = 7.49 Hz), 7.48(m,
0
0
0
0
7Hbb ,aa ,e ),
7.11(d,
1Hd,
J = 16.22 Hz),
7.00(d,
1Hd ,
J = 16.21 Hz), 6.87(dd, 1He, J = 15.96 Hz, J = 7.59 Hz), 4.05(m,
0
0
0
1Hf ), 3.98(m, 2Hg ), 3.89(m, 2Hh ), 3.82(m, 2Hh), 3.74(bs, 2Hg),
3.19(bs, 1HNH). 13CNMR (in DMSO): 13C NMR (in DMSO):
Herein, in continuation of our previous reports [28–33] the syn-
thesis and characterization of some new zinc complexes of a tri-
dentate Schiff base ligand entitled as (E)-N1-((E)-3-
0
0
0
167.02(C7),
146.79(C5,5 ),
131.22(C4,4 ),
129.07(C1,1 ),
0
0
0
0
128.72(C2,2), 128.49(C3,3 ), 127.47(C6,6 ), 108.37(C7 ) 55.52(C9 ),
phenylallylidene)-N2-(2-((E)-((E)-3-phenylallylidene)
amino)
0
49.87(C9), 43.63(C8), 42.37(C8 ) ppm [33].
1
ethyl) ethane-1,2-diamine are presented. The nano-structure zinc
complexes were also prepared under ultrasonic irradiation. Zinc
azide complex structure was analyzed by X-ray crystallography.
Furthermore, antibacterial/antifungal properties and thermal
behaviors (TG/DTG/DTA) of all zinc complexes are investigated.
0
[ZnLCl2]: HNMR (in DMSO): 8.26 (d, 2Hff , J = 8.99 Hz), 7.78(m,
0
0
0
0
0
2Hee ), 7.60(d, 4Hcc , J = 6.98 Hz), 7.47(m, 6Hbb ,aa ), 7.25(d, 2Hdd
,
0
0
J = 15.67 Hz), 3.66(bs, 4Hhh ), 2.90(bs, 4Hgg and 1HNH) ppm.
13CNMR (in DMSO): 166.07(C7,7 ), 143.81(C5,5 ), 135.36 (C4,4 ),
0
0
0
0
0
0
0
129.78(C1,1 ),
129.04(C2,2 ),
128.66(C3,3 ),
127.45(C6,6 ),
0
0
56.02(C8,8 ), 48.14(C9,9 ) ppm.
1
0
[ZnLBr2]: HNMR (in DMSO): 8.31(d, 2Hff , J = 8.99 Hz), 7.80 (dd,
Experimental
0
0
2Hee , J = 15.80 Hz, J = 8.40 Hz), 7.62(d, 4Hcc , J = 7.19 Hz), 7.47
0
0
0
(m, 6Hbb,
)
7.27(d, 2Hdd
,
J = 16.00 Hz), 3.68(m, 4Hhh ),
aa
Materials and methods
ppm. 13CNMR (in DMSO):
0
2.93(bs, 4Hgg and 1HNH
)
0
0
0
0
All chemicals such as trans-3-phenyl-2 propenal, diethylenetri-
amine and zinc salts were provided from the Aldrich and/or Merck
chemical companies in high purity. Zinc thiocyanate and azides
were freshly prepared according to our previous report [28]. Infra-
red spectra were obtained by a JASCO-FT/IR680 instrument on the
range of 4000–400 cmꢁ1 as KBr pellets. A Bruker DPX FT/NMR-
400 spectrometer was applied to record 1H and 13C NMR spectra
in dimethylsulfoxide. The electronic spectra of the compounds in
chloroform were obtained from a JASCO-V570 spectrophotometer
instrument in the range of 200–800 nm. BUCHI B-545 instrument
was applied for recording of melting points or decomposition tem-
perature of the complexes. A Metrohm-712 conductometer with a
dip-type conductivity cell made of platinum black was applied for
measurements of molar conductivities of the compound in chloro-
form and/or dimethylformamide. A Perkin–Elmer Pyris model
instrument was applied for record of thermo-gravimetric diagrams.
Scanning electron microscopy (SEM) images were captured on a
Hitachi S-1460 field emission scanning electron microscope using
166.46(C7,7 ), 144.31(C5,5 ), 135.30 (C4,4 ), 129.92(C1,1 ),
0
0
0
0
129.09(C2,2 ), 127.50 (C3,3 ), 126.86(C6,6 ), 55.98(C8,8 ), 48.14
0
(C9,9 ) ppm.
1
0
[ZnLI2]: HNMR (in DMSO): 8.37(d, 2Hff , J = 8.69 Hz), 7.78(md,
0
2Hee
, J = 25.12 Hz), 7.63(d, 2Hc, J = 7.23 Hz), 7.56(d, 2Hc,
0
0
0
J = 7.45 Hz), 7.47(m, 6Hbb ,aa ), 7.43(d, 2Hdd
,
J = 22.51 Hz),
3.64(bs, 4Hhh ), 2.95(bs, 4Hgg and 1HNH ) ppm. 13CNMR (in
0
0
0
Table 1
Analytical and physical data of the zinc complexes.
Run Complexes Color
M.P(Dec.a)
Yield
(%)
K°
M
(°C)
(cm2 ꢁ1 Mꢁ1
X )
1
2
3
4
5
ZnLCl2
ZnLBr2
ZnLI2
Cream
150
40
65
70
84
40
0.018
0.014
0.31
0.019
0.017
Orange 159
Orange 130
Yellow 208
ZnL(NCS)2
ZnL(N3)2
Cream
137
a
(Dec.) refers to decomposition temperature of the compounds.