Synthesis, Characterization, and Antibacterial Activity of Complexes of Hg(II) with Mixtures of 3-Hydrazonoindolin-2-one and Diphosphine, or Diimine Ligands

Article abstract of DOI:10.1134/S1070363220060213

Abstract: In the current study, six new tetrahedral Hg(II) complexes of 3-hydrazonoindolin-2-one (HZI) with diphosphines (dppm, dppe, dppp, dppb) or diimines (bipy, phen) ligands have been prepared and characterized by molar conductivity, IR, ¹

Full text of DOI:10.1134/S1070363220060213

ISSN 1070-3632, Russian Journal of General Chemistry, 2020, Vol. 90, No. 6, pp. 1069–1073. © Pleiades Publishing, Ltd., 2020.
Synthesis, Characterization, and Antibacterial Activity
of Complexes of Hg(II) with Mixtures
of 3-Hydrazonoindolin-2-one and Diphosphine, or Diimine Ligands
a,
a
b
c
A. A. Irzoqi *, M. M. Salih , H. M. Jirjes , and M. K. Mensoor
a
Department of Chemistry, College of Education for Pure Science, University of Tikrit, Tikrit, 34001 Iraq
b
Department of Chemistry, College of Science, University of Tikrit, Tikrit, 34001 Iraq
c
International Center for Training, Research and Development (ICTRD), Baghdad, 10011 Iraq
*
e-mail: ahmedirzoqi@tu.edu.iq
Received April 5, 2020; revised May 27, 2020; accepted May 30, 2020
Abstract—In the current study, six new tetrahedral Hg(II) complexes of 3-hydrazonoindolin-2-one (HZI) with
diphosphines (dppm, dppe, dppp, dppb) or diimines (bipy, phen) ligands have been prepared and characterized
1
13
31
by molar conductivity, IR, H, C, and P NMR spectra. Antibacterial activity of these complexes has been
tested against three bacterial species: Staphylococcus epidermidis and Staphylococcus aureus (gram positive) and
Citrobacer freundii (gram negative). All complexes are more active against Staphylococcus aureus than amikacin,
while [Hg (HZI) (dppm) ]Cl (1), [Hg(HZI)(dppe)]Cl (2), and [Hg(HZI)(Phen)]Cl (6) complexes are more active
2
2
2
4
2
2
against Staphylococcus epidermidis than amikacin. The complexes 2, [Hg(HZI)(dppp)]Cl (3), and 6 are active
2
against Citrobacter freundii.
Keywords: isatin, shiff base, mercury complexes, diphosphines, antibacterial activity
DOI: 10.1134/S1070363220060213
INTRODUCTION
Electrical conductivity of the prepared complexes
–
3
measured in DMSO solutions (10 M) was within the
Isatin hydrazone derivatives can act as chelating
ligands and demonstrate antibacterial, antifungal,
anticonvulsant, and anti-HIV activities [1, 2]. High
affinity to chelation of the Schiff bases towards transition
metal ions is employed in preparing their complexes [3]
that are characterized by a wide range of antibacterial
–
1
2
–1
range of 70.86 to 84.67 Ω cm mol , and indicated the
complexes 2–6 as 1 : 2 electrolytes. While the complex
[
1
[
Hg(HZI) (μ-dppm) ]Cl 1 conductivity value of
2
1
2
4
–
2
–1
45.16 Ω cm mol indicated it as 1 : 4 electrolyte
9, 10].
In IR spectrum of 3-hydrazonoindolin-2-one ligand
the azomethine group ν(C=N) was recorded by the band
[
4, 5], antifungal [5, 6], antimicrobial [4, 7], and many
other activities [8, 9].
–1
at 1589 cm . Spectra of the complexes 1–6 demonstrated
The current study targeted synthesis of some Hg(II)
complexes with 3-hydrazonoindolin-2-one (HZI) ligand
in combination with phosphine or imine derivatives, and
testing their biological activity against three bacterial
species Staphylococcus epidermidis and Staphylococcus
aureus (gram positive, and Citrobacer freundii (gram
negative) using the antibiotic amikacin as a standard.
the carbonyl amide group bands within the range of
–
1
1
681–1687 cm , and their shifts indicated the carbonyl
amide groups bonding with mercury.
The organomercury derivatives [Hg(bipy)Cl ] and
2
[
2
Hg(phen)Cl ] interacted readily with 3-hydrazonoindolin-
2
-one in the equimolar ratio giving the corresponding
tetrahedral complexes 5 and 6 (Scheme 2).
RESULTS AND DISCUSSION
3
1
P{1H} NMR spectrum of the complex 1 (Fig. 1)
3
1
The complexes under study (Schemes 1, 2) were
characterized by the ratio of their components Hg(II):
HZI ligand: diphosphine or diamine derivatives 1 : 1 : 1.
They were determined to be stable in the air, partially
soluble in common organic solvents and well soluble in
DMF and DMSO.
demonstrated a singlet at 23.54 ppm. P{1H} NMR
spectrum of the complex 2 indicated formation of two
isomers with two equivalent atoms of phosphorus in 2a
and dppe acting as a bidentate ligand. In the spectrum
2
of isomer 2b two doublets at 30.44 ppm ( J
=
PP
2
44.10 Hz) and –14.21ppm ( J = 44.62 Hz) indicated
PP
1
069

1070
IRZOQI et al.
Scheme 1. Structures of complexes [Hg (HZI) (μ-dppm) ]Cl (1), [Hg(HZI)(dppe)]Cl (2a), [Hg(HZI)(dppe)Cl]Cl (2b),
2
2
2
4
2
[
Hg(HZI)(dppp)]Cl (3), [Hg(HZI)(dppb)]Cl (4).
2
2
Scheme 2. Preparation of complexes [Hg(HZI)(bipy)]Cl (5) and [Hg(HZI)(phen)]Cl (6).
2
2
two phosphorus atoms as nonequivalent with dppe acting
as a monodentate ligand (Fig. 1). P{1H} NMR spectra
of complexes 3, 4 demonstrated singlets at 26.74 and
31.12 ppm, receptively, pointing out equivalence of two
phosphorus atoms and the bidentate character of dppp
and dppb ligands [11, 12].
3
1
Biological activity of the prepared compounds.
Biological activity of the complexes was tested
(
0.01, 0.001, 0.0001 mg/mL) against three bacterial
species: Staphylococcus epidermidis, Staphylococcus
aureus (gram positive), and Citrobacer freundii (gram
negative) using the antibiotic amikacin as a standard.
All complexes demonstrated activity (Fig. 2a) against
Staphylococcus aureus higher than that of amikacin.
Whereas the synthesized complexes 1–6 were selectively
active against Citrobacter freundii and Staphylococcus
epidermidis (Figs. 2b, 2c).
EXPERIMENTAL
All chemicals were used without purification. NMR
spectra were measured on a Bruker 400 MHz spectrometer
using DMSO-d as a solvent. IR spectra (KBr) were
6
recorded on a Shimadzu FT-IR 8400S spectrophotometer.
Melting points were recorded on an Automatic SMP30
–3
melting point apparatus. Molar conductivity of 10 M
freshly prepared DMSO solutions of the complexes was
measured on a Starter 3100c digital conductivity meter.
CHN analysis was carried out on an Elementar vario El
III CHN analyzer.
Fig. 1. 31P{H} NMR spectra of complexes (1) 1, (2) 2, (3)
3
, and (4) 4.
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SYNTHESIS, CHARACTERIZATION, AND ANTIBACTERIAL ACTIVITY OF COMPLEXES OF Hg(II)
1071
Fig. 2. Inhibitory activity of complexes 1–6 against the above bacteria: (a) Staphylococcus aureus, (b) Citrobacter freundii, and
c) Staphylococcus epidermidis.
(
Preparation of 3-hydrozonoindolin-2-one (HZI)
ligand [8]. A solution of hydrazine (0.055 g, 1.1 mmol)
in 10 mL of absolute ethanol was added to a solution of
isatin (0.161 g, 1 mmol) in 10 mL of absolute ethanol,
and a few drops from glacial acetic acid were added. The
mixture was refluxed for 1 h then cooled down to room
temperature, and a yellow solid was precipitated. It was
filtered off and washed with cold ethanol, dried under
vacuum and recrystallized from a mixture of EtOH–DMF
to give yellow crystals. Yield 92%, mp 240–242°C. FTIR
C H N O. Calculated, %: C 59.61; H 4.39; N 26.07. Λ
8 7 3 o
3.24 Ω cm mol .
–
1
2
–1
Synthesis of [Hg(HZI)(diphos)]Cl complexes 1–4,
2
diphos = dppm, dppe, dppp, dppb. A solution of 1 M
of HZI in absolute ethanol was added to 1 M suspension
of [Hg(diphos.)Cl ] in absolute ethanol, then the mixture
2
was stirred for 1 h at room temperature. The white
precipitate was separated by filtration, dried in an oven
under vacuum, and recrystallized from ethanol to give
the corresponding products 1–4.
–1
spectrum, ν, cm : 3355 s, 3153 s, 3053 w, 1685 s, 1654 s,
1
Complex 1. Pale yellow solid, yield 83%, mp 273–
1
589 s, 1552 s, 1463 m, 1197 s, 977 m, 748 s. H NMR
–1
2
76°C. FTIR spectrum, ν, cm : 3357 m, 3217 m, 3076 w,
spectrum, δ, ppm: 6.78 d (1H, J = 7.87 Hz), 6.98 t (1H,
J = 7.70 Hz), 7.16 t (1H, J = 7.86 Hz), 7.36 d (1H, J =
1
681 s, 1652 s, 1556 s, 1433 m, 1195 m, 1099 m, 744 s,
1
3
1
1
8
.03 Hz), 9.53 d (1H-NH , J = 13.92 Hz), 10.54 d (1H-
686 s. P{ H} NMR spectrum, δ, ppm: 23.54. H NMR
spectrum, δ, ppm: 2.87 t (2H, J = 1.94 Hz, CH2), 6.86 d
2
1
3
3
NH , J = 13.95 Hz), 10.67 s (NH). C NMR spectrum,
2
3
3
δ, ppm: 111.35, 120.85, 121.9, 122.41, 129.54, 136.48,
(1H, J = 7.56 Hz), 6.97 t (1H, J = 7.52 Hz), 7.16 t (1H,
3
1
40.48, 162.91. Found, %: C 59.88; H 4.52; N 26.31.
J = 7.64 Hz), 7.34 m, 7.47 m (21H, HZI, Ph), 9.64 d (2H,
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 90 No. 6 2020

1072
IRZOQI et al.
2
2
J = 14.62 Hz, NH ), 10.64 d (2H, J = 14.08 Hz,
Complex 5. Creamy solid, yield 81%, mp 212–215°C.
FTIR spectrum, ν, cm : 3384 m, 3220 m, 3015 w, 1685 s,
2
–1
NH ), 10.76 s (NH). Found, %: C 48.01; H 3.42; N
2
5
1
.23. Calculated, %: C 48.51; H 3.58; N 5.14. Λ
1658 s, 1589 m, 1548 m, 1463 m, 1193 m, 981 w, 748 w,
676 w. H NMR spectrum, δ, ppm: 6.85 d (1H, J =
o
–1
2
–1
1
3
45.16 Ω cm mol .
Complex 2. Pale yellow solid, yield 87%, mp 247–
3
3
7
.66 Hz), 6.97 t (1H, J = 7.48 Hz), 7.16 t. d (1H, J =
–1
4
3
2
1
6
3
4
4
50°C. FTIR spectrum, ν, cm : 3355 m, 3213 m, 3078 w,
683 s, 1652 s, 1558 s, 1434 m, 1193 m, 1101 m, 746 m,
88 m. 13P{ H} NMR spectrum, δ, ppm: 30.67 (2a),
7.65, J = 1.29 Hz), 7.37 d (1H, J = 7.52 Hz), 7.69 m
(2H, bipy), 8.16 t. d (2H, J = 7.88, J = 1.81 Hz,
bipy), 8.54 d (2H, J = 8.04 Hz, bipy), 8.87 d. d (2H,
J = 5.25, J = 1.71 Hz, bipy), 9.52 d (2H, J =
3
4
1
3
2
2
3
4
2
0.44 d (2b) ( J = 44.10 Hz), –14.21 d ( J
=
PP
PP
3
1
2
4.62 Hz). H NMR spectrum, δ, ppm: 2.04 t (4H, J =
14.92 Hz, NH ), 10.53 d (2H, J = 12.76 Hz, NH ), 10.68 s
2 2
3
13
.33 Hz, 2CH ), 6.87 d (1H, J = 7.23 Hz), 6.97 t. d
(NH). C NMR spectrum, δ, ppm: 110.44, 117.93,
121.83, 122.74, 126.76, 127.52, 129.15, 139.14,
140.05, 149.87, 163.26. Found, %: C 36.48; H 2.42;
2
3
4
3
(
1H, J = 7.50, J = 1.15 Hz), 7.15 t. d (1H, J = 7.62,
J = 1.39 Hz), 7.33 m (21H, HZI, Ph), 9.54 d (2H, J =
4
2
2
14.42 Hz, NH ), 10.55 d (2H, J = 14.37 Hz, NH ), 10.66 s
N 11.71. Calculated, %: C 36.71; H 2.57; N 11.89. Λ
71.42 Ω cm mol .
2
2
o
–
1
2
–1
(NH). Found, %: C 48.68; H 3.51; N 4.85. Calculated,
–
1
2
–1
%
: C 49.14; H 3.76; N 5.06. Λ 84.67 Ω cm mol .
o
Complex 6. Creamy solid, yield 83%, mp 217–220°C.
–1
Complex 3. Pale yellow solid, yield 92%, mp 232–
FTIR spectrum, ν, cm : 3357 m, 3161 m, 3058 w, 1685 s,
–1
2
1
5
35°C. FTIR spectrum, ν, cm : 3361 m, 3205 m, 3041 w,
1
7
7
656 s, 1585 s, 1550 s, 1463 m, 1197 s, 977 m, 842 s,
687 s, 1656 s, 1581 s, 1433 s, 1101 m, 746 s, 690 s,
1
3
21 m. H NMR spectrum, δ, ppm: 6.86 d (1H, J =
13
1
1
20 m. P{ H} NMR spectrum, δ, ppm: 26.74. H NMR
3
4
.53 Hz), 6.97 t. d (1H, J = 7.48, J = 1.04 Hz),
spectrum, δ, ppm: 1.86 s (2H, CH , 2.90 s (4H, CH , 6.84 d
3
4
2
2
7.16 t. d (1H, J = 7.60, J = 1.29 Hz), 7.36 d (1H,
3
3
(
1H, J = 3.74 Hz), 6.98 t (1H, J = 7.54 Hz), 7.15 t (1H,
J = 7.66 Hz), 7.35 d (1H, J = 7.56 Hz), 7.56 m, 7.73 m
3
J = 7.39 Hz), 8.07 m (2H, phen, 8.20 s (2H, phen),
3
3
3
3
8
.81 d. d (2H, J = 8.17 Hz, J = 1.70 Hz, phen), 9.20 s
2
(
20H, Ph), 9.54 d (2H, J = 14.92 Hz, NH ), 10.53 d (2H,
J = 14.15 Hz, NH ), 10.68 s (NH). Found, %: C 49.39;
2
2
(
2H, phen), 9.55 d (2H, J = 14.65 Hz, NH ), 10.55 d (2H,
J = 14.68 Hz, NH , 10.68 s (NH). C NMR spectrum,
2
2
2
13
2
2
H 3.43; N 5.15. Calculated, %: C 49.74; H 3.94; N 4.97.
Λ 80.27 Ω cm mol .
δ, ppm: 110.44, 117.92, 121.83, 122.72, 125.66, 126.69,
–1
2
–1
o
1
1
%
27.51, 127.56, 129.22, 139.13, 139.71, 140.48, 150.29,
63.24. Found, %: C 38.78; H 2.41; N 11.40. Calculated,
Complex 4. Pale yellow solid, yield 85%, mp 284–
–1
2
1
5
87°C. FTIR spectrum, ν, cm : 3353 m, 3212 m, 3054 w,
–1
2
–1
: C 39.20; H 2.47; N 11.43. Λ 70.86 Ω cm mol .
o
687 s, 1656 s, 1581 s, 1434 s, 1101 m, 746 s, 690 s,
13
1
1
CONCLUSIONS
20 m. P{ H} NMR spectrum, δ, ppm: 31.12. H NMR
3
spectrum, δ, ppm: 1.43 m (4H, CH ), 2.23 t (4H, J =
9
The tetrahedral complexes [Hg(HZI)(diphosphine)]Cl2
2
3
.18 Hz, CH ), 6.86 d (1H, J = 7.58 Hz), 6.97 t. d
and [Hg(HZI)(diimine)]Cl have been prepared. The
2
2
3
4
3
(
1H, J = 7.58, J = 1.05 Hz), 7.16 t. d (1H, J = 7.65,
J = 1.30 Hz), 7.35 m (21H, HZI, Ph, 9.54 d (2H, J =
HZI ligand behaved as a bidentate via N atom of the
azomethine group and O atom of the carbonyl group.
Diphosphine and diimine ligands are acting as bidentate
via P or N atoms, respectively. In complex 1 dppm
behaves as a bridge ligand. For the complex 2 two isomers
have been determined and distinguished by bidentate
or monodentate character of the dppe ligand. The
prepared complexes have demonstrated activity against
Staphylococcus aureus higher than amikacin. Some
complexes are active against Staphylococcus epidermidis
and Citrobacter freundii.
4
2
2
14.67 Hz, NH ), 10.54 d (2H, J = 14.52 Hz, NH ), 10.68 s
2
2
(NH). Found, %: C 49.98; H 3.86; N 4.67. Calculated,
–
1
2
–1
%
: C 50.33; H 4.11; N 4.89. Λ 78.87 Ω cm mol .
o
Synthesis of complexes [Hg(HZI)(bipy)]Cl (5) and
2
[
Hg(HZI)(phen)]Cl (6). A solution of HZI (0.500 g,
2
3
1
.103 mmol) in absolute ethanol (10 mL) was added to
M suspension of [Hg(bipy)Cl ] (1.326 g, 3.103 mmol, or
2
[Hg(phen)Cl ] (1.401 g, 3.103 mmol) in absolute ethanol
2
(10 mL). The mixture was refluxed for 2 h upon stirring,
then it was separated as a pale yellow precipitate, filtered
off, dried in the oven under vacuum, and recrystallized
from ethanol.
CONFLICT OF INTEREST
No conflict of interest was declared by the authors.
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SYNTHESIS, CHARACTERIZATION, AND ANTIBACTERIAL ACTIVITY OF COMPLEXES OF Hg(II)
1073
REFERENCES
7. Pandeya, S.N., Smitha, S., Jyoti, M., and Sridhar, S.K.,
Acta Pharm., 2005, vol. 55, no. 1, p. 27.
1
2
. Fadhil, G.F., Radhy, H.A., Perjéssy, A., Šamalíková, M.,
Kolehmainen, E., Fabian, W.M., Katri, L., and Šuste-
ková, Z., Molecules, 2002, vol. 7, no. 11, p. 833.
https://doi.org/10.3390/71100833
8
. Vatsa, G., Pandey, O.P., and Sengupta, S.K., Bioinorg.
Chem. Appl., 2005, vol. 3, nos. 3–4, p. 151.
https://doi.org/10.1155/BCA.2005.151
. Mariar, C.R., Belicchi, F.M., Franco, B., Corrado, P.,
Giorgio, P., Silvana, P., and Monica, S., J. Inorg. Biochem,
9. Alam, M., Ahmad, M., Rasheed, A., Saleem, M., Ja-
vaid, M.K., and Ikram, S., Indian J. Exp. Biol., 1990,
vol. 28, no. 10, p. 940.
2
004, vol. 98, p. 313.
https://doi.org/10.1016/j.jinorgbio.2003.10.006
1
0. Ali, I., Wani, W.A., and Saleem, K., Synth. React.
Inorg., Metal-Org., and Nano-Metal Chem., 2013, vol. 43,
no. 9, p. 1162.
3
4
. Mohamed, G.G., Omar, M.M., and Hindy, A.M., Turkish
J. Chem., 2006, vol. 30, no. 3, p. 361.
. Cerchiaro, G. and Ferreira, A.M.D.C., J. Brazilian Chem.
Soc., 2006, vol. 17, no. 8, p. 1473.
https://doi.org/10.1590/S0103-50532006000800003
https://doi.org/10.1080/15533174.2012.756898
1
1. Hamon, P., Toupet, L., Roisnel, T., Hamon, J.R., and
Lapinte, C., Eur. J. Inorg. Chem., 2020, vol. 2020, no. 1,
p. 84.
5
6
. Sharma, V., Srivastava, S., and Srivastava, A., Polish J.
Chem., 2006, vol. 80, no. 3, p. 387.
https://doi.org/10.1002/ejic.201901086
. Sharma, V.K., Srivastava, A., and Srivastava, S.,
J. Serbian Chem. Soc., 2006, vol. 71, nos. 8–9,
p. 917.
12. Mannu, A., Ferro, M., Möller, S., and Heller, D., J. Chem.
Res., 2018, vol. 42, no. 8, p. 402.
https://doi.org/10.2298/JSC0609917S
https://doi.org/10.3184/174751918X15333065984578
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