Sonochemical synthesis and characterization of nano-sized copper(I) thiosemicarbazone complex: crystal structure and thermal study

Article abstract of DOI:10.1007/s13738-019-01592-8

In this work, we report the synthesis, characterization, crystal structure, and thermal and antibacterial studies of a new nano-sized copper(I) thiosemicarbazone complex prepared by an ultrasonic bath assisted synthesis in an acetonitrile solution. Charac

Full text of DOI:10.1007/s13738-019-01592-8

Journal of the Iranian Chemical Society
https://doi.org/10.1007/s13738-019-01592-8
ORIGINAL PAPER
Sonochemical synthesis and characterization of nano-sized copper(I)
thiosemicarbazone complex: crystal structure and thermal study
1
2
3
3
Aliakbar Dehno Khalaji · Ensieh Shahsavani · Michal Dusek · Monika Kucerakova
Received: 25 April 2018 / Accepted: 7 January 2019
©
Iranian Chemical Society 2019
Abstract
In this work, we report the synthesis, characterization, crystal structure, and thermal and antibacterial studies of a new
nano-sized copper(I) thiosemicarbazone complex prepared by an ultrasonic bath assisted synthesis in an acetonitrile solu-
tion. Characterization of the complex and its ligand (EHB-tsc = 3-ethoxy-4-hydroxybenzaldehyde-thiosemicarbazone)
1
13
was performed using elemental analysis, FT-IR, H and C-NMR, UV–Vis spectroscopy, thermal gravimetry, and single-
crystal X-ray diffraction. In addition, the complex was characterized by X-ray powder diffraction and scanning electron
microscopy.
Keywords Nano-sized copper(I) complex · Thiosemicarbazone · Ultrasonic bath · Spectroscopy · Crystal structure · XRD ·
SEM
Introduction
stability of copper(I) thiosemicarbazone complexes in the
absence of PPh [17]. Lobana et al. reported that copper(I)
3
Thiosemicarbazones, an important class of compounds
with many applications, are prepared from the reaction of
thiosemicarbazide and compounds with an active carbonyl
group (aldehyde or ketone) [1, 2]. From structural point
of view, thiosemicarbazones act as mono- or multidentate
ligands giving rise to various coordination geometries with
all of the transition metal ions [3]. Thiosemicarbazone com-
plexes of 3D metal ions were generally prepared by the
reaction of metal ions and ligands in methanol or acetoni-
trile as solvent [3]. They are used as mild steel corrosion
inhibitors [1], antityrosinases and antimicrobial agents [2],
anticancer [4, 5], fungistatic and bacteriostatic activities
complexes with thiosemicarbazone ligand have various
substituents on phenyl ring such as methyl, phenyl, and
etc [8–13]. In these complexes, thiosemicarbazone ligands
coordinate to copper(I) ion by various bonding modes, such
as monodentate S [9–13, 16] and bidentate NS [14, 15].
The coordination number around the copper(I) ion in these
complexes varies from 3 to 4, and then, the geometries are
distorted trigonal planar, tetrahedral, and square planar
(Scheme 1) [3].
In continuation of our studies of copper(I) thiosemicar-
bazones complexes [14, 15], we report herein the synthesis,
characterization, crystal structure, and thermal and antibac-
terial studies of a new nano-sized copper(I) thiosemicarba-
zone complex (Scheme 2).
[
6], and DNA binding [7]. Among large number of already
reported complexes of thiosemicarbazones [3–7], copper(I)
complexes [8–16] are less investigated because of their
insolubility in common organic solvents [15] and also low
Experimental
*
Aliakbar Dehno Khalaji
alidkhalaji@yahoo.com
Materials and physical measurements
1
2
3
Department of Chemistry, Faculty of Science, Golestan
University, Gorgān, Iran
All materials were commercially available and used as
received without further purifications. Fourier transform
infrared (FT-IR) spectra were recorded as a KBr disk on
an FT-IR Perkin–Elmer spectrophotometer. Elemental
analyses were carried out using a Heraeus CHN–O-Rapid
Department of Chemistry, Payame Noor University,
Mashhad, Iran
Institute of Physic of the Czech Academy of Sciences, Na
Slovance 2, 182 21 Prague, Czech Republic
Vol.:(0
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Journal of the Iranian Chemical Society
Scheme 1 The geometries
around the copper(I) ion in thio-
semicarbazone complexes
NH
X
N
X
Cu
Cu
S
Cu
S
S
Ph P
3
S
S
HN
NH
N
PPh3
Scheme 2 Schematic diagram
Ph P
3
I
of CuI(PPh ) (EHB-tsc)
3
2
OH
Slow evaporation
Ultrasonic bath
Cu
Single crystal of complex
Nano-sized of complex
H
N
N
Ph P
3
S
O
NH2
CH3
analyzer, and results agreed with the calculated values.
The TG/DTA measurements were performed on a Per-
kin Elmer TG/DTA lab system 1 (Technology by SII) in
air atmosphere with a heating rate of 20 °C/min in the
temperature span of 50–800 °C. UV–Vis spectra were
Table 1 Crystallographic data and structural refinement details of
EHB-tsc and its copper(I) complex
EHB-tsc
CuI(PPh ) (EHB-tsc)
3 2
Empirical formula
Formula weight
Crystal system
space group
C H O2.5N3S C H O N SP ICu
10 14 46 43 2 3 2
1
239.27
Triclinic
P-1
954.25
Triclinic
P-1
recorded on a PerkinElmer Lambda 25 spectrometer. H
1
3
and C-NMR spectra were recorded on a BRUKER DRX-
4
00 AVANCE spectrometer at 400 MHz. All chemical
Cell length (Å)
a: 7. 2345 (5)
b: 8.5427(5)
c: 20.5356(7)
α: 81.710(4)
β: 86.235(4)
γ: 66.863(6)
1154.81(12)
2
a: 15. 2755 (4)
b: 16.3342(4)
c: 18.2924(5)
α: 89.346(2)
β: 68.541(2)
γ: 85.180(2)
4231.9(2)
shifts are reported in δ units downfield from tetramethyl-
silane (TMS). X-ray powder diffraction (XRD) pattern of
the complex was recorded on a Bruker AXS diffractome-
ter D8 ADVANCE with Cu–Kα radiation with nickel beta
filter in the range 2θ = 10°–80°. The scanning electron
microscopy (SEM) images were obtained from a Philips
XL-30ESEM.
Cell angles (°)
Cell volume (Å3)
Z
2
T (K)
293(10)
119.98(10)
Theta range for data col-
4.35<θ<66.83 3.71<θ<67.02
X‑ray structure determination
lection
ρcalc (g cm−3)
1.4197
2.471
1.4979
7.958
Suitable single crystals of EHB-tsc and its copper(I) com-
plex were chosen for the X-ray diffraction study. Crystal-
lographic measurements were performed at 120 K with a
four-circle CCD diffractometer Gemini (Oxford diffrac-
tion, Ltd.), equipped with mirror-collimated Cu–Kα radia-
tion (λ = 1.54184 Å). The crystal structure could be easily
solved by the charge flipping program SUPERFLIP [18].
The refinement was carried out by the Jana2006 program
package [19] employing a full-matrix least-squares tech-
nique on F2. The molecular structure plots were prepared
by Diamond 4.0 [20]. The hydrogen atoms were mostly
discernible in difference Fourier maps and could be
refined to a reasonable geometry. According to common
practice, the hydrogen atoms attached to carbons were
kept in ideal positions during the refinement with a C–H
−1
µ (mm
)
F (000)
Index ranges
521
−7≤h≤8
1936
−17≤h≤18
−19≤k≤14
−21≤l≤21
14,728
−
−
10≤k≤10
16≤l≤23
Reflections no.
Rint
6361
0.024
0.031
distance of 0.96 Å, and their isotropic atomic displace-
ment parameters were set to 1.2 Ueq of their parent atoms.
Crystallographic data, details of the data collection, struc-
ture solution, and refinements are listed in Table 1.
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Journal of the Iranian Chemical Society
Preparation of EHB‑tsc
as a solvent led to the formation of thiosemicarbazone
compound EHB-tsc, which was used as a ligand in the
The thiosemicarbazone ligand EHB-tsc was prepared in
high yield following the literature [21] using 3-ethoxy-
presence of CuI and PPh in acetonitrile solution under
3
ultrasonic irradiation. A new nano-sized copper(I) com-
plex CuI(PPh ) (EHB-tsc) was formed in 50% yield.
4
-hydroxybenzaldehyde instead of alpha-bromocin-
3
2
nanmaldhyde. M.p: 200 °C, yield: 81%. Anal. Calc. for
For preparing single crystals, instead of the ultrasonic
irradiation, we used slow evaporation of the solvent for
3 days. Results of elemental analysis confirmed the pro-
posed formula C H O N SP ICu for both synthetic
C H O N S: C, 50.20; H, 5.43; N, 17.57; S, 13.39%;
1
0
13
2
3
found: C, 50.31; H, 5.48; N, 17.63; S, 13.35%. FT-IR
−
1
data (KBr, cm ): 3522 (OH), 3189, 3421, 3145 (NH
2
46 43
2
3
2
and NH), 3015, 2970 (H aromatic and aliphatic), 1584
approaches.
(
C=N), 1481, 1509 (C=C), 956 (N–N), 891 (C=S).
UV–Vis [DMSO, λ
(nm)]: 270 (n − π*), 375 (π − π*).
Spectroscopic characterization
max
1
H-NMR (DMSO-d , δ ppm): 11.2 (s, 1H, NH), 9.3 (s,
6
1
H, OH), 7.94–8.0 (s, 2H, NH ), 7.92 (s, 1H, HC=N),
The details of FT-IR spectra for the free thiosemicarba-
zone ligand EHB-tsc and its copper(I) complex are listed
in the experimental section and are also shown in Fig. 1.
By comparing the details of FT-IR spectra, it was con-
firmed that the ligand EHB-tsc coordinated to copper(I)
ion from sulfur atom. For example, the peak concerning
2
7
4
.4 (d, 1H, PhH), 7.0 (dd, 1H, Ph), 6.7 (d, 1H, PhH),
1
3
.0–4.1(q, 2H, CH ); 1.3 (t, 3H, CH ). C-NMR (DMSO-
2
3
d , δ ppm): 177.7 (C=S), 147.6 (C=N), 110.8, 115.6,
6
1
22.7, 126.0, 143.3, 149.4 (C aromatic), 64.3 (CH ), 15.1
2
(
CH ).
3
−
1
the stretching of C=S bond appeared at 891 cm for
−
1
EHB-tsc, while this peak was shifted to 869 cm in the
complex. In addition, the complex showed the presence
Preparation of CuI(PPh ) (EHB‑tsc)
of O–H, N–H, NH , and C=N peaks at 3448, 3327, 3130,
3
2
2
−
1
and 1564 cm , respectively. The difference between these
peaks position in the complex and in the free ligand sug-
gested that the EHB-tsc coordinated to copper(I) ion as a
neutral form.
The copper(I) thiosemicarbazone complex
CuI(PPh ) (EHB-tsc) (single crystals and nano-sized) was
3
2
prepared in high yield following the literature [16], using
EHB-tsc instead of Brcatsc. M.p: 205 °C, yield: 50%.
Anal. Calc. for C H O N SP ICu: C, 57.89; H, 4.51;
In the UV–Vis spectrum of the free ligand, there is
an intraligand transitions π − π* observed at 270 nm and
n − π* at 375 nm. There is no change in the position of
π−π* transition of EHB-tsc and the complex. On the other
hand, the n − π* transition for the complex showed a that
blue shift and appeared at 366 nm, confirming the coordi-
nating of the ligand-to-copper(I) ion.
4
6
43
2
3
2
N, 4.40; S, 3.35%; found: C, 57.78; H, 4.61; N, 4.36; S,
−
1
3
.42%. FT-IR data (KBr, cm ): 3448 (OH), 3327, 3130
(
(
NH , NH), 3040, 2967 (H aromatic and aliphatic), 1564
2
C=N), 1479 (C=C), 959 (N–N), 869 (C=S), 472 (Cu–S).
UV–Vis [DMSO, λ
(nm)]: 270 (n − π*), 332 (n − π*),
max
1
3
66 (π − π*). H-NMR (DMSO-d , δ ppm): 11.4 (s, 1H,
The ligand EHB-tsc and its copper(I) complex
exhibit diamagnetism, and can be characterized with
6
NH), 9.4 (s, 1H, OH), 8.2–8.3 (s, 2H, -NH ), 7.8 (s, 1H,
2
1
13
HC=N), 7.4 (d, 1H, PhH), 7.2–7.4 (m, 30H, PPh ), 7.0 (dd,
H and C-NMR (Figs. 2, 3). However, the solubility
3
1
H, PhH), 6.7–6.8 (d, 1H, PhH), 4.0–4.1(q, 2H, CH ), 1.3
of them is low in common organic solvents such as
methanol, ethanol, acetonitrile, and chloroform, and
they are completely soluble only in DMF and DMSO.
2
1
3
(
t, 3H, CH ). C-NMR (DMSO-d , δ ppm): 175.4 (C=S),
3
6
1
44.6 (C=N), 110.9, 115.7, 123.1, 125.6, 147.7, 149.7 (C
1
13
aromatic), 128.8-134.1 (PPh ), 64.3 (CH ), 15.1 (CH ).
The details of H- and C-NMR spectra of the ligand
and its complex are present in the “Experimental” sec-
tion. In addition, the presence of sharp peaks in the
NMR spectrum of the complex confirmed the stability
of the complex in DMF.
3
2
3
3
1
P-NMR (DMSO-d , δ ppm): − 7.3.
6
Results and discussion
Thermal studies
Synthesis
To examine the thermal stability of ligand and its com-
plex, we performed thermal gravimetry between 30 and
780 °C in air atmosphere (Fig. 4). As shown in Fig. 4,
Reaction of 3-ethoxy-4-hydroxybenzaldehyde with
thiosemicarbazide under reflux condition in ethanol
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Journal of the Iranian Chemical Society
Fig. 1 FT-IR spectra of ligand (top) and its complex (bottom)
ligand EHB-tsc is stable until 240 °C, and after this tem-
perature, two weight loss steps occur. The first weight loss
at 250–310 °C corresponds to the removal of C H O-,
and the second weight loss at 310–780 °C corresponds
to the removal of C H N S fragment. In the TGA curve
8
5
2
of complex, weight loss is not observed to 310 °C. Then,
2
5
HO-, and H N- fragments (exp = 34.5%, theor. 32.63%),
to the temperature of 580 °C, the complex weight loss is
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Journal of the Iranian Chemical Society
Fig. 2 H- and 13C-NMR spec-
1
tra of ligand EHB-tsc
observed with 55%, which is the main stage of complex
decomposition. After that, the complex loses 10% of its
weight slowly to 800 °C. In the end, there is about 35% of
the complex weight remaining.
and shows that a new product was obtained without any
JCPDS. The intense and sharp diffraction peaks suggest
that the obtained product is crystalline. The crystallite
size of the product was calculated from the major diffrac-
tion peak at 2θ = 27° using the Debye–Scherrer formula,
XRD pattern and SEM image of the complex
D = 0.89λ/βcosθ. The average crystallite size was 55 nm
c
that is in good agreement with the observation of the SEM
image (Fig. 6). The SEM image shows the particles have
practically uniform shapes and sizes.
Figure 5 shows XRD pattern of the complex prepared via the
ultrasonic bath-assisted synthesis in the range 5°<2θ<75°,
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Journal of the Iranian Chemical Society
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13
Fig. 3 H- and C-
NMR spectra of complex
CuI(PPh ) (EHB-tsc)
3
2
Fig. 4 TGA curves of the ligand
EHB-tsc and its copper(I)
complex
X‑ray crystallography
system with space group P-1. The molecular structures
of ligand EHB-tsc and CuI(PPh ) (EHB-tsc) are shown
3
2
The thiosemicarbazone ligand EHB-tsc and its copper(I)
complex CuI(PPh ) (EHB-tsc) crystallized in triclinic
in Figs. 7 and 8, respectively. Selected bond distances and
angles are presented in Tables 2 and 3, respectively. Figure 7
3
2
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Journal of the Iranian Chemical Society
Fig. 5 XRD pattern of copper(I)
complex prepared via ultrasonic
bath assisted
Figure 8 shows that the copper(I) ion is coordinated
to two P atoms from two PPh molecules, one S atom
3
of the thiosemicarbazone ligand EHB-tsc in its neutral
form and one iodine atom, and has distorted tetrahedral
[
CuNIP ] coordination geometry with bond distances
2
Cu–I = 2.67 Å, Cu–S = 2.35 Å and Cu–P = 2.28 Å. All
of these bonds are similar to those in already reported
copper(I) thiosemicarbazone complexes [9–13]. The bond
angles around the copper(I) ion vary from 101° to 122°,
corresponding to strongly distorted tetrahedral geometry
similar to that found for copper(I) thiosemicarbazone com-
plexes [9–13]. The distortion of the tetrahedral geometry
is caused by the bulky PPh molecules. The ligand EHB-
3
tsc acts as a monodentate ligand through its sulfur atom.
In addition, there are several intermolecular hydrogen
bonds in the ligand and its copper(I) complex (Tables 4,
Fig. 6 SEM image of copper(I) complex prepared via ultrasonic bath
assisted
5
, respectively).
shows that the ligand formed by two symmetry-independent
molecules and one H O molecule.
2
Fig. 7 An ORTEP view and unit cell of EHB-tsc. Dash lines shows H bonds
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Journal of the Iranian Chemical Society
Fig. 8 An ORTEP view and unit cell of CuI(PPh ) (EHB-tsc)
3
2
Table 2 Selected bond distances and angles of ligand EHB-tsc
Table 4 Hydrogen bonds in ligand EHB-tsc
D-H...A (Å) D-H... (Å) H...A (Å) D...A (Å)
N5 H2n5 N1 0.91 (2)
O5 H1o5 S1 0.87 (4)
D-H...A (°)
S1 C6
N1 N6
1.7040 (18)
1.379 (2)
S2 C15
N1 C1
1.6986 (18)
1.284 (2)
2.28 (2)
2.47 (4)
2.22 (2)
2.25 (2)
2.22 (2)
2.04 (2)
2.19 (2)
2.626 (2)
3.299 (2)
2.590 (2)
2.942 (2)
102.4 (15)
161 (3)
105.2 (16)
135.7 (18)
N2 N4
1.376 (2)
N2 C6
1.341 (2)
N3 C6
1.320 (2)
N4 C2
1.276 (2)
N3 H2n3 N4 0.88 (3)
N3 H2n3 O5 0.88 (3)
O3 H1o3 O1 0.82 (2)
O3 H1o3 O2 0.82 (2)
O2 H1o2 O4 0.83 (2)
N5 C15
1.326 (2)
N6 C15
1.339 (2)
N6 N1 C1
N2 N4 C2
N1 C1 C4
S1 C6 N2
N2 C6 N3
S2 C15 N6
115.02 (14)
117.30 (14)
122.07 (16)
120.31 (12)
117.24 (16)
120.42 (13)
N4 N2 C6
N1 N6 C15
N4 C2 C8
S1 C6 N3
S2 C15 N5
N5 C15 N6
117.89 (13)
119.21 (14)
120.08 (15)
122.44 (14)
122.11 (13)
117.44 (16)
2.6657 (18) 114 (2)
2.8216 (19) 158 (2)
2.6204 (19) 113 (2)
Table 5 Hydrogen bonds in ligand CuI(PPh ) (EHB-tsc)
3
2
Table 3 Selected bond distances and angles of complex
D-H...A (Å)
D-H... (Å) H...A (Å) D...A (Å) D-H...A (°)
CuI(PPh ) (EHB-tsc)
3
2
C92 H2c92 C76a 0.96
2.43
3.186 (13) 134.97
I1 Cu1
Cu1 S2
Cu1 P1
Cu1 P4
S1 C23
P1 C29
P1 C43
P1 C44
P3 C28
P3 C50
P3 C59
2.6622 (4)
2.3541 (8)
2.2668 (7)
2.2782 (6)
1.705 (2)
1.823 (3)
1.833 (2)
1.829 (3)
1.824 (3)
I2 Cu2
Cu2 P3
Cu2 P2
S2 C17
P2 C9
P2 C42
P2 C62
P4 C27
P4 C30
P4 C34
2.6739 (4)
2.2883 (7)
N1 H1n1 N5
N2 H1n2 N3
O2 H1o2 O1
O3 H1o3 O4
N2 H2n2 O3
N1 H2n1 O2
0.71 (3)
2.35 (4)
2.33 (4)
2.28 (4)
2.26 (4)
2.20 (4)
2.33 (4)
2.714 (4)
2.683 (4)
2.659 (3)
2.715 (4)
3.046 (4)
3.194 (4)
114 (4)
108 (3)
111 (3)
111 (3)
167 (3)
172 (3)
0.80 (3)
0.77 (4)
0.89 (4)
0.86 (4)
0.87 (4)
2.2889 (6)
1.699 (2)
1.828 (3)
1.838 (2)
1.833 (3)
1.829 (3)
1.822 (3)
1.830 (3)
Acknowledgements We are grateful to the Payame Noor University
and Golestan University for the financial support of this work. Struc-
ture analysis was supported by the project 18-10504S of the Czech
Science Foundation using instruments of the ASTRA lab established
within the Operation program Prague Competitiveness e project
CZ.2.16/3.1.00/2451.
1.835 (3)
1.799 (8)
I1 Cu1 S2
I1 Cu1 P4
S2 Cu1 P1
S2 Cu1 P4
P1 Cu1 P4
I1 Cu1 P1
Cu2 P2 C9
113.172 (18)
111.24 (2)
105.61 (3)
102.81 (3)
122.51 (2)
101.72 (2)
117.13 (8)
113.74 (8)
121.23 (8)
I2 Cu2 P2
I2 Cu2 P3
114.40 (2)
103.44 (2)
119.90 (2)
117.06 (8)
114.21 (8)
113.92 (8)
115.45 (7)
108.36 (8)
114.50 (7)
P2 Cu2 P3
Cu1 P1 C29
Cu1 P1 C43
Cu1 P1 C44
Cu2 P2 C42
Cu1 P4 C27
Cu1 P4 C34
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