Synthesis, spectral, magnetic, DFT calculations, antimicrobial studies and phenoxazinone synthase biomimetic catalytic activity of new binary and ternary Cu(II), Ni(II) and Co(II) complexes of a tridentate ONO hydrazone ligand

Article abstract of DOI:10.1080/24701556.2020.1770794

New mononuclear copper(II), nickel(II) and cobalt(II) hydrazone complexes of 2-cyano-N′-((4-oxo-4H-chromen-3-yl)methylene)acetohydrazide have been synthesized. Structure identification of the prepared complexes was carried out by physicochemical and spectroscopic techniques including elemental analyses, infrared, electronic, mass and electron spin resonance spectra, thermal analysis, conductivity and magnetic susceptibility measurements, powder x-ray diffraction and transmission electron microscope. The isolated binary complexes are neutral mononuclear complexes (with 1:1 and 1:2; M:L stoichiometries) and ternary complexes (with 1:1:1; M:L:L′ stoichiometry). The analytical and spectroscopic techniques illustrated the monoanionic tridentate behavior of the hydrazone ligand with γ-pyrone oxygen, enolic oxygen and azomethine nitrogen coordinating sites. The metal complexes displayed square planar, tetrahedral and octahedral geometries. Density Functional Theory calculations were carried out for the chelating agent and its copper(II) chelates. The phenoxazinone synthase activity of the binary copper(II) complexes was studied and discussed. The antimicrobial activity of the hydrazone ligand and its complexes was evaluated toward some sorts of Gram–positive bacteria, Gram–negative bacteria, yeast and fungus.

Full text of DOI:10.1080/24701556.2020.1770794

Inorganic and Nano-Metal Chemistry
ISSN: 2470-1556 (Print) 2470-1564 (Online) Journal homepage: https://www.tandfonline.com/loi/lsrt21
Synthesis, spectral, magnetic, DFT calculations,
antimicrobial studies and phenoxazinone synthase
biomimetic catalytic activity of new binary and
ternary Cu(II), Ni(II) and Co(II) complexes of a
tridentate ONO hydrazone ligand
Magdy Shebl, Akila A. Saleh, Saied M. E. Khalil, Magdah Dawy & Amira A. M.
Ali
To cite this article: Magdy Shebl, Akila A. Saleh, Saied M. E. Khalil, Magdah Dawy & Amira
A. M. Ali (2020): Synthesis, spectral, magnetic, DFT calculations, antimicrobial studies and
phenoxazinone synthase biomimetic catalytic activity of new binary and ternary Cu(II), Ni(II) and
Co(II) complexes of a tridentate ONO hydrazone ligand, Inorganic and Nano-Metal Chemistry, DOI:
10.1080/24701556.2020.1770794
To link to this article: https://doi.org/10.1080/24701556.2020.1770794
View supplementary material
Published online: 02 Jun 2020.
Submit your article to this journal
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at
https://www.tandfonline.com/action/journalInformation?journalCode=lsrt21

INORGANIC AND NANO-METAL CHEMISTRY
https://doi.org/10.1080/24701556.2020.1770794
Synthesis, spectral, magnetic, DFT calculations, antimicrobial studies and
phenoxazinone synthase biomimetic catalytic activity of new binary and ternary
Cu(II), Ni(II) and Co(II) complexes of a tridentate ONO hydrazone ligand
Magdy Shebla, Akila A. Saleha, Saied M. E. Khalila, Magdah Dawyb, and Amira A. M. Alia
b
aFaculty of Education, Department of Chemistry, Ain Shams University, Cairo, Egypt; Department of Physical Chemistry, National Research
Centre, Dokki, Egypt
ABSTRACT
ARTICLE HISTORY
New mononuclear copper(II), nickel(II) and cobalt(II) hydrazone complexes of 2-cyano-N0-((4-oxo-
4H-chromen-3-yl)methylene)acetohydrazide have been synthesized. Structure identification of the
prepared complexes was carried out by physicochemical and spectroscopic techniques including
elemental analyses, infrared, electronic, mass and electron spin resonance spectra, thermal analysis,
conductivity and magnetic susceptibility measurements, powder x-ray diffraction and transmission
electron microscope. The isolated binary complexes are neutral mononuclear complexes (with 1:1
and 1:2; M:L stoichiometries) and ternary complexes (with 1:1:1; M:L:L0 stoichiometry). The analyt-
ical and spectroscopic techniques illustrated the monoanionic tridentate behavior of the hydra-
zone ligand with c-pyrone oxygen, enolic oxygen and azomethine nitrogen coordinating sites. The
metal complexes displayed square planar, tetrahedral and octahedral geometries. Density
Functional Theory calculations were carried out for the chelating agent and its copper(II) chelates.
The phenoxazinone synthase activity of the binary copper(II) complexes was studied and dis-
cussed. The antimicrobial activity of the hydrazone ligand and its complexes was evaluated toward
some sorts of Gram–positive bacteria, Gram–negative bacteria, yeast and fungus.
Received 18 February 2020
Accepted 22 April 2020
KEYWORDS
Hydrazone; binary and
ternary complexes; DFT
calculations; antimicrobial
activity; phenoxazinone
synthase; chromone
Introduction
hydroxyquinoline) usually improve the pharmacological and
therapeutical properties of the metal complexes.[20]
Hydrazones are simply synthesized and form stable metal
complexes with nearly all metal ions. There is a great inter-
est in the chemistry of hydrazones and their metal com-
plexes as a result of their diverse applications such as
antimicrobial, antioxidant, antihypertensive, antitubercular
and antitumor agents in addition to other important
pharmacological applications.[1–10]
Synthesis and characterization of compounds containing
chromone moiety have attracted a special interest due to
importance of these compounds and their variable applica-
tions including antimicrobial, antioxidant, antitumor, anti-
inflammatory, and anti-HIV properties in addition to other
potential biological and pharmaceutical properties.[11–17]
In addition to its vital roles in different biological processes,
copper(II) ion has an important task in various enzyme activ-
ities.[18] Also, nickel and cobalt are vital trace elements in
humans. Moreover, a large number of copper(II), nickel(II)
and cobalt(II) complexes have been broadly examined because
of their diverse medical applications.[19]
Considering the above facts, the coordinating ability of
the hydrazone ligand, 2-cyano-N0-((4-oxo-4H-chromen-
3-yl)methylene)acetohydrazide; HL (Scheme 1) toward
copper(II), nickel(II) and cobalt(II) ions was explored in the
present work. A series of binary and ternary complexes
(containing 8-hydroxyquinoline as an auxiliary chelating
agent) were prepared and fully characterized by different
analytical and spectroscopic techniques. The binary
copper(II) complexes were prepared in absence and presence
of cetyltrimethyl ammonium bromide (CTAB). Density
Functional Theory (DFT) calculations were carried out to
explore the optimized structure of the chelating agent and
its complexes. The phenoxazinone synthase activity of the
binary copper(II) complexes was studied and discussed.
The biological activity of the ligand and its complexes was
investigated against some bacterial and fungal strains.
Experimental
Materials
Recently, mixed-ligand (ternary) complexes have attracted
an extensive interest as a result of their fundamental
functions in biological processes. In addition, heterocyclic
2-Cyano-N0-((4-oxo-4H-chromen-3-yl)methylene)acetohydrazide
was synthesized following the method described earlier[21]
nitrogen donor ligands (1,10-phenanthroline and 8- (Scheme 2). Ethylcyanoacetate, hydrazine hydrate, EDTA
CONTACT Magdy Shebl
magdy_shebl@hotmail.com; magdyshebl@edu.asu.edu.eg
Faculty of Education, Department of Chemistry, Ain Shams University,
Roxy, Cairo 11341, Egypt.
Supplemental data for this article can be accessed at https://doi.org/10.1080/24701556.2020.1770794.
ß 2020 Taylor & Francis Group, LLC

2
M. SHEBL ET AL.
Scheme 1. Structure and tautomeric forms of the hydrazone ligand.
Scheme 2. Synthesis of the hydrazone ligand.
Table 1. Analytical and physical data of metal complexes of the hydrazone ligand.
Elemental analysis, found %(calcd %)
% H % N
61.31 (61.17) 3.84 (3.52) 16.0 (16.47)
42.59 (42.31) 3.52 (3.31) 13.57 (13.16) 15.33 (14.92)
51.97 (52.13) 3.58 (3.2) 13.80 (14.03) 10.02 (10.61)
48.12 (48.67) 3.02 (3.16) 13.05 (12.90) 12.21 (11.70)
44.39 (43.72) 3.86 (4.32) 12.5 (12.00) 12.5 (12.57)
52.05 (52.6) 3.8 (4.22) 11.00 (10.67) 11.6 (11.18)
Xm (ohmꢁ1
No. Complex
HL
Molecular formula [F. Wt]
Colour
Yield (%)
% C
% M
cm2 molꢁ1
)
C13H9N3O3 [255]
White
Brown
Pale brown
Brown
Brown
Green
85
80
74
77
40
47
–
–
1
2
3
4
5
[Cu(L)(NO3)] ꢀ EtOH
C15H14N4O7Cu [425.85]
C26H19N6O7.5Cu [599.02]
C22H17N5O8Cu [542.96]
C17H20N4O8Ni [467.08]
C23H22N4O7Ni [525.16]
10
14
9
12
12
[Cu(L)2] ꢀ 1 ꢀ 5H2O
[Cu(L)(8HQ)NO3] ꢀ H2O
[Ni(L)(NO3)] ꢀ 2EtOH
[Ni(L)(8HQ)(H2O)] ꢀ 1 ꢀ
5H2O ꢀ 0 ꢀ 5EtOH
6
7
[Co(L)2].2H2O
C26H20N6O8Co [603.42]
Deep red
Brown
62
74
51.33 (51.75) 3.70 (3.34) 14.15 (13.93)
9.37 (9.77)
15
20
[Co(L)(8HQ)(H2O)].H2O C22H18N4O6Co [493.34]
53.55 (53.56) 3.34 (3.68) 11.84 (11.36) 11.59 (11.95)
disodium salt, sodium acetate, Cu(NO3)2.3H2O, Ni(NO3)2 ꢀ 812Weilheium-conductivity meter; LBR, fitted with a
cell model LTA100. Thermal gravimetric analysis (TGA)
6H2O, Co(NO3)2 ꢀ 6H2O, 8-hydroxyquinoline (8HQ), nitric
measurements were performed on a Shimadzu-50 ther-
mal analyzer. Powder X-ray diffraction measurements
were recorded on Bruker AXS D8 Advance diffractom-
eter equipped with a graphite monochromator. The
morphology of nanoparticles was observed using trans-
mission electron microscope (TEM) equipped with
energy dispersive spectroscopic (EDS) microanalysis
system (JEM-2100CX (JEOL).
acid, ammonium hydroxide, mureoxide, cetyltrimethyl
ammonium bromide (CTAB) and o-aminophenol were
obtained from BDH or Aldrich.
Measurements
The elemental microanalyses were performed at Perkin-
Elmer 2400II elemental analyzer. Copper, nickel and
cobalt content was evaluated by EDTA complexometri-
cally after decomposition of the chelates with conc.
nitric acid. Decomposition temperatures of the chelates
were estimated by a Stuart SMP3 melting point equip-
ment. FT-IR spectra (4000–400 cmꢁ1) were performed
on a Nicolet IS10 spectrometer as potassium bromide
disks. Electronic spectra were measured by a Jasco V-
550 UV-Visible spectrophotometer as dimethylforma-
mide (DMF) solutions. Mass spectra were performed at
70 eV on a shimadzu QP spectrometer model MS-5988.
Electron spin resonance (ESR) spectra were performed
by using Elexsys, E500, Bruker Company. Magnetic sus-
ceptibility measurements were performed at room tem-
perature on a Johnson Matthey, Alfa products MKI
magnetic susceptibility balance. Molar conductivities
were measured for 1 ꢂ 10ꢁ3 M solution of the solid
Synthesis of the metal complexes
[Cu(L)(NO3)] ꢀ EtOH (1)
To an ethanolic solution of the hydrazone ligand, HL,
a solution of copper(II) nitrate, in ethanol, was added in
a 1:1 (L:M) molar ratio. Sodium acetate (0.1 g) was used to
adjust the pH to ꢃ5. The resultant solution was stirred
for ꢃ1 h then heated under reflux for 8 h. The solid complex
was filtered off, washed with hot ethanol and diethylether
and lastly dried in a desiccator.
[Cu(L)2] ꢀ 1 ꢀ 5H2O (2)
Ethanolic solutions of Cu(NO3)2.3H2O and CTAB were
mixed in molar ratio (1:0.1), respectively, and heated under
reflux for ꢃ0.5 h after that an ethanolic solution of the
complexes in dimethylformamide using WTWD- hydrazone ligand was added in a 1:1 (L:M) molar ratio. The

INORGANIC AND NANO-METAL CHEMISTRY
3
mixture was heated under reflux for 8 h. The solid complex
was filtered off, washed with hot ethanol and diethylether
and lastly dried in a desiccator.
[Cu(L)(8-HQ)NO3] ꢀ H2O (3)
Ethanolic solutions of the ligand and Cu(NO3)2.3H2O were
mixed in a 1:1 (L:M) molar ratio and stirred for ꢃ0.5 h after
that an ethanolic solution of 8-hydroxyquinoline in the
molar ratio 1:1:1 (L:M:L0) was added. The resultant solution
was continuously stirred for 2 h then heated under reflux
for 6 h. The solid complex was filtered off, washed with hot
ethanol and diethylether and lastly dried in a desiccator.
[Ni(L)(NO3)] ꢀ 2EtOH (4)
To an ethanolic solution of the hydrazone ligand, HL, a solution
of nickel(II) nitrate, in ethanol, was added in a 1:1 (L:M) molar
ratio. Sodium acetate (0.1 g) was used to adjust the pH to ꢃ5.
The resultant solution was stirred for ꢃ1h then heated under
reflux for 8 h. The solid complex was filtered off, washed with
hot ethanol and diethylether and lastly dried in a desiccator.
[Ni(L)(8HQ)(H2O)] ꢀ 1 ꢀ 5H2O ꢀ 0 ꢀ 5EtOH (5)
Ethanolic solutions of the ligand and Ni(NO3)2 ꢀ 6H2O were
mixed in a 1:1 (L:M) molar ratio and stirred for ꢃ0.5 h after
that an ethanolic solution of 8-hydroxyquinoline in the
molar ratio 1:1:1 (L:M:L0) was added. The resultant solution
was continuously stirred for 2 h then heated under reflux for
6 h. The solid complex was filtered off, washed with hot
ethanol and diethylether and lastly dried in a desiccator.
[Co(L)2] ꢀ 2H2O (6)
To an ethanolic solution of the hydrazone ligand, HL, a solution
of cobalt(II) nitrate, in ethanol, was added in a 1:1 (L:M) molar
ratio. Sodium acetate (0.1 g) was used to adjust the pH to ꢃ5.
The resultant solution was stirred for ꢃ1h then heated under
reflux for 8 h. The solid complex was filtered off, washed with
hot ethanol and diethylether and lastly dried in a desiccator.
[Co(L)(8HQ)(H2O)] ꢀ H2O (7)
Ethanolic solutions of the ligand and Co(NO3)2.6H2O were
mixed in a 1:1 (L:M) molar ratio and stirred for ꢃ0.5 h after
that an ethanolic solution of 8-hydroxyquinoline in the
molar ratio 1:1:1 (L:M:L0) was added. The resultant solution
was continuously stirred for 2 h then heated under reflux for
6 h. The solid complex was filtered off, washed with hot
ethanol and diethylether and lastly dried in a desiccator.
DFT calculations
By using Gaussian 09 program package,[22] DFT calculations
were achieved for the free chelating agent and its copper(II)
chelates. The geometry optimization was performed using
RB3LYP calculation method and the 6-311 G(d,p) bases set
and the resultant-optimized geometries were used as inputs
for vibrational frequencies calculations

4
M. SHEBL ET AL.
Table 3. Electronic spectral data and magnetic moment values of the hydrazone ligand and its complexes.
Electronic spectral bandsa k (nm)
ꢅ
ꢅ
No.
Compound or complex
p–p (aromatic system)
p–p (C ¼ O)
CT
d-d transtion
leff (B.M.)
a
HL
268 (0.42)
271
304 (0.39)
349
423 (0.09)
414
—
588
508, 686
526, 671
579
500, 704
543
558
—
1
2
3
4
5
6
7
[Cu(L)(NO3)].EtOHb
1.42
1.98
1.43
3.65
3.12
4.93
4.77
[Cu(L)2].1.5H2Ob
231
272
280
234
279
275
351
377
349
347
385
325
420
489
480
449
440
448
[Cu(L)(8-HQ)NO3].H2Ob
[Ni(L)(NO3)].2EtOHb
[Ni(L)(8-HQ)(H2O)].1.5H2O.0.5EtOHb
[Co(L)2].2H2Ob
[Co(L)(8-HQ)(H2O)].H2Ob
aSolutions in DMF (1 ꢂ 10ꢁ3 M), values of emax are in parentheses and multiplied by 1 ꢂ 10ꢁ4 (L molꢁ1cmꢁ1).
bConcentrated solutions
Table 4. Thermal analyses data (TG) of some metal complexes of the hydrazone ligand.
Complex
Temperature range (oC)
% Wt. loss found/(calc.)
Lost fragment (No. of molecules)
1.5 H2O (non-coord.)
1 O2
1 H2O (non-coord.)
NO2
[Cu(L)2] ꢀ 1 ꢀ 5H2O (2)
31-127
128-259
34-108
109-249
45-167
168-398
4.50/(4.51)
5.68/(5.34)
3.35/(3.32)
8.75/(8.47)
9.8/(9.52)
[Cu(L)(8-HQ)NO3] ꢀ H2O (3)
[Ni(L)(8-HQ)(H2O)] ꢀ 1 ꢀ 5H2O ꢀ 0 ꢀ 5EtOH (5)
0.5 EtOH (non-coord.) þ 1.5 H2O (non-coord.)
35.6/(36.4)
1 H2O (coord.) þ N2 þ 8-HQ
Phenoxazinone synthase activity
The phenoxazinone synthase activity of the binary copper(II)
chelates was explored by the reaction with o-aminophenol
(OAPH) at room temperature in methanol using UV-Visible
spectroscopy. The kinetics of the aerobic oxidation of
2-aminophenol was measured by observing the change
in the absorbance against time (at k ¼ 433 nm) (at time
interval of 5 min.). To calculate the reliance of rate
on concentration of the substrate and different kinetic
parameters, 1 ꢂ 10ꢁ3 M solutions of both chelates were
treated individually with 10 ꢂ 10ꢁ3 M, 20 ꢂ 10ꢁ3
30 ꢂ 10ꢁ3 and 40 ꢂ 10ꢁ3 M solutions of o-aminophenol.
,
Antimicrobial activity
Following the disk-agar diffusion technique,[23] the anti-
microbial activity of the hydrazone ligand and its metal che-
lates was checked against two Gram positive bacteria; S.
aureus (ATCC 25923) and B. subtilis (ATCC 6635), two
Gram negative bacteria; S. typhimurium (ATCC 14028) and
E. coli (ATCC 25922), C. albicans (ATCC 10231) and
A. fumigatus.
Determination of minimum inhibitory concentration (MIC)
By using agar dilution technique,[24] MIC values of the
prepared compounds were evaluated. Concentrations of each
compound (with an antimicrobial effect shown in the disk dif-
fusion test) was further diluted with dimethylformamide to get
concentrations; 512, 256, 128, 64, 32, 16, 8, 4, 2, and 1 lg/mL
respectively. After that, 100 lL of every diluted compound was
mixed with 10 mL of cooled (50 ꢄC) melted Mueller-Hinton
agar and 10 lL of specific microbial culture (at concentration
of 108 cells/mL) which were grown in nutrient broth medium
Figure 1. TEM images of copper(II) nano complex 2.

INORGANIC AND NANO-METAL CHEMISTRY
5
Scheme 3. Synthesis and proposed structures of the binary complexes.
for 16 h at 30 ꢄC then plated into 6 cm sterile Petri dish. Every disappeared on adding D2O while the other signals still exist at
1
dilution was prepared in duplication and every concentration the same positions in the H NMR spectrum. Mass spectrum
was prepared for two dishes. All plates were incubated at 33 ꢄC of the ligand showed the molecular ion peak at m/z 255,
for 24 hours. MIC of each compound was measured from the confirming its structure.
Elemental analyses, physical properties and molar
conductivities of the metal complexes are tabulated in Table
1. All the complexes have high decomposition temperatures;
>300 ꢄC. Elemental analyses showed formation of 1:1 and
1:2; M:L binary complexes and 1:1:1; M:L:L0 ternary
complexes. The molar conductivity values of the complexes
are in the range 9-20 ohmꢁ1 cm2 molꢁ1 (Table 1),
demonstrating neutral character of the complexes.[25]
plate with the lowest concentration with no visible growth of
the specific organism.
Results and discussion
The infrared spectrum of the ligand showed five bands at 3215,
2260, 1692, 1633 and 1564 cmꢁ1, which may be ascribed to
ꢀ(NH), ꢀ(CꢆN), ꢀ(C¼O)amide, ꢀ(C¼O)pyron ring and
ꢀ(C¼N) groups, respectively. The electronic spectrum of the
ligand (as solution in DMF) showed three bands at 268, 304
IR spectra
ꢅ
and 423 nm. The higher energy band may be assigned to p-p
The infrared spectral data of the metal complexes and their
tentative assignments are recorded in Table 2. The com-
transitions within the aromatic rings. The moderate energy
ꢅ
band may be due to n-p transitions while the lower energy
band may be related to charge transfer within the whole mol-
plexes displayed a strong band in the range 3384-3447 cmꢁ1
,
1
ecule. The HNMR spectra of the ligand relative to TMS in that may be ascribed to ꢀ(OH) of the non-coordinated or
DMSO-d6 without and with D2O were carried out. The H coordinated water or ethanol molecules linked to complexes.
1
NMR spectrum of ligand showed signals at d (ppm) 4.22 due The bands due to (C¼O) and (C¼N) groups in the free
to (CH2 ); (7.52–8.13) d (ppm) due to (aryl-Hb); 8.32 d (ppm) hydrazone were detected at lower wavenumber in the com-
a
due to (CHc) and 11.81 due to (NHe$OHe) (Scheme 1). The plexes, pointing to the involvement of the c-pyrone O and
ligand showed signal at d (ppm) 8.88 due to (CHd). The signals azomethine N in complex-formation.[26–29] However, the
due to the protons of (NH$OH) groups completely band at 1692 cmꢁ1 assigned to the CO amide (C¼O) in the

6
M. SHEBL ET AL.
Scheme 4. Synthesis and proposed structures of the ternary complexes
Scheme 5. Catalytic oxidation of 2-aminophenol (OAPH).
Figure 3. Plot of the initial rates vs. the OAPH concentrations at a fixed concen-
tration of complex (1). The insert showed the reciprocal Lineweaver–Burk plot.
2
2
analogous to the B1g ! A1g transition in a square-planar
geometry.[47–50] Complexes 2 and 3 showed two absorption
bands at 508–526 and 671–686 nm, which can be attributed
2
2
2
2
to B1g ! Eg and B1g ! B2g transitions, respectively, in
an octahedral structure.[51,52]
The effective magnetic moment of the binary Ni(II) com-
plex 4 is 3.65 B.M., which agrees very well with the range
reported for tetrahedral Ni(II) complexes (3.2–4.1 B.M.).[53]
The electronic spectrum of the complex 4 showed band at
579 nm, which may be assigned to the 3T1(F) ! 3T1(P)
transition in a tetrahedral geometry. The coordination of
DMF with Ni(II) ion to form octahedral structure may be
responsible for the observed shift of the band to lower wave-
length.[54] However, the ternary nickel(II) complex 5 have
magnetic moment ¼ 3.12 B.M., indicating an octahedral
geometry.[53] This is supported by the electronic spectrum
of the complex, which showed two bands at 500 and
Figure 2. The increase in the characteristic 2-aminophenoxazine-3-one absorp-
tion band at 433 nm upon addition of 2-aminophenol to a solution containing
complex 1 in MeOH.
free hydrazone disappeared in metal complexes,
demonstrating contribution of this group in complex-forma-
tion in the enolic form. The presence of monodentate
nitrate group in complexes 1 and 3 is evidenced by appear-
ance of new bands observed between 1242–1246 and
1029–1035 cmꢁ1 [30–33]
In ternary complexes (3, 5 and 7),
.
new bands were observed in the range 1489-1498 cmꢁ1
(Table 2), which may be ascribed to the C¼N group of the
8-hydroxyquinoline moiety.[31,34–36] The (M-O) and (M-N)
bands were detected -as new bands- in the ranges 534–564
and 417–432 cmꢁ1, respectively.[37–40]
3
3
704 nm, respectively, assigned to A2g(F) ! T1g(P) and
3
3A2g(F) ! T1g(F) transitions in an octahedral geometry.[53]
Co(II) complexes 6 and 7 have magnetic moment values
in the range 4.77-4.93 B.M., which are consistent with the
values reported for octahedral Co(II) complexes (4.8–5.2
B.M.).[55] The octahedral geometry is further supported by
Magnetic moment measurements and electronic spectra
the appearance of an electronic spectral band in the
The effective magnetic moments of the prepared complexes
and their electronic spectral data measured in dimethyl-
formamide are recorded in Table 3. The magnetic moment
values of the copper(II) complexes 1–3 are in the range
1.42–1.98 B.M., indicating one unpaired electron (d9).[41,42]
The anti-ferromagnetic interaction may be responsible for
the subnormal value of complexes 1 and 3.[27,43] The elec-
tronic spectral bands of the chelating agent were observed in
4
range 543–558 nm, which may be assigned to the T1g
!
4T1g(P) transition in an octahedral geometry.[48]
ESR spectra
As solid samples, ESR spectra of the copper(II) chelates (1 and
2) were recorded (Figure S1; supplementary materials). A broad
band (g ¼ 2.08) was observed for complex 1 whereas two sig-
its complexes with a blue or red shift. Also, new bands due
[44–46]
nals with two g values; g ¼ 2.17 and g┴ ¼ 2.08 were observed
to complexation process
were detected. The electronic
jj
spectrum of Cu(II) complex 1 showed a band at 588 nm in the spectrum of complex 2. The shapes of the spectra reveal

INORGANIC AND NANO-METAL CHEMISTRY
7
Figure 4. Plot of the initial rates vs. the OAPH concentrations at a fixed concen-
tration of complex (2). The insert showed the reciprocal Lineweaver–Burk plot.
Table 5. Kinetic parameters for the oxidation of OAPH for the binary
Cu(II) complexes.
Complex
Vmax (M min-1)
KM (M)
Kcat (h-1)
1
2
2.458 ꢂ 10-2
8.568 ꢂ 10-2
24.58
20.04
2.004 ꢂ 10-2
4.456 ꢂ 10-2
square planar geometrical arrangement for complex 1 and octa-
hedral for complex 2.[48,54,56,57]
It was reported that the covalent nature of metal–ligand
bonds is governed by g value.[58]
ionic character and for covalent character g is less than
g
is higher than 2.3 for
ll
ll
Figure 5. Optimized structure, HOMO and LUMO energy levels of the hydra-
zone ligand.
ll
2.3. For the present complexes, g ¼ 2.17 demonstrating
ll
observed in the range 168-398 ꢄC, with mass loss of
35.6%, analogous to loss of one coordinated water, N2
and 8-hydroxyquinoline molecules; calc. 36.4%.
considerable covalent nature for the Cu-hydrazone bond.
For complex 2, the value of the exchange interaction
parameter term “G” calculated from the equation G¼ (g ꢁ2)/
ll
[59]
(g
ꢁ2)
is lower than 4, demonstrating the existence
┴
Mass spectra
of copper–copper exchange interaction.
The mass spectra of the chelates; 1, 3, 5 and 6 are carried
out as representative examples and Figures S4 and S5; (sup-
plementary materials) depict the spectra of the complexes.
The molecular ion peaks are coincident with the suggested
anhydrous formula weights of the complexes. The molecular
ion peaks for 1, 3, 5 and 6 were observed at m/z 379, 525,
475 and 567, respectively, verifying the anhydrous formula
weights of these complexes; [Cu(L)(NO3)] (F. Wt ¼ 379.85),
[Cu(L)(8HQ)NO3] (F. Wt ¼ 524.96), [Ni(L)(8HQ)(H2O)] (F.
Wt ¼ 475.16) and [Co(L)2] (F. Wt ¼ 567.42), respectively.
Thermal analysis
Thermal gravimetric analysis was performed for complexes
2, 3 and 5 as examples (Figures S2 and S3; supplementary
materials), to confirm the presence of water or ethanol mol-
[60–62]
ecules and investigate their linkage to the complexes
and the results are tabulated in Table 4. The thermogram of
complex 2 showed a decomposition stage in the temperature
range 31–127 ꢄC, with mass loss of 4.50%, analogous to loss
of one and half non-coordinated water molecule; calc. 4.51%.
The second degradation step was observed in the range
128–259 ꢄC, with mass loss of 5.68%, analogous to loss of an
oxygen molecule; calc. 5.34%. The thermogram of complex 3
showed a decomposition stage in the range 34–108 ꢄC, with
mass loss of 3.35%, analogous to loss of one non-coordinated
water molecule; calc. 3.32%. The second degradation step was
observed in the range 109–249 ꢄC, with mass loss of
8.75%, analogous to loss of a NO2 molecule; calc. 8.47%.
Finally, the thermogram of complex 5 showed a decom-
position stage in the range 45–167 ꢄC, with mass loss of
9.8%, analogous to loss of half non-coordinated ethanol
molecule and one and half non-coordinated water mol-
Crystal structure and morphological studies
X-ray powder diffraction (XRD) measurements of the
copper(II) nano complex 2 were performed. Figure S6;
supplementary materials showed the powder X-ray
diffraction pattern of the complex. The spectrum appeared
as a broad band, indicating amorphous nature of the
complex. Absence of sharp peaks confirmed the absence of
ordered crystalline structure in the complex.
The texture and morphology of the copper(II) nanocom-
plex 2 was observed by transmission electron microscope
ecule; calc. 9.52%. The second degradation step was as shown in Figure 1, which revealed that complex is

8
M. SHEBL ET AL.
arranged in rodes with average size 85 nm. Also, the complex 1. By using the initial rate method, the rate for
every concentration of 2-aminophenol was determined. The
slope of the absorbance vs. time plot was employed to calcu-
late the rate constant for each complex–(2-aminophenol)
reaction. Analysis of the rate vs. concentration of 2-amino-
phenol data was achieved by using Michaelis-Menten
method of enzymatic kinetics, which gave the Lineweaver-
Burk (double reciprocal) plot. The latter was then utilized to
analyze various kinetic parameters including the maximum
complex showed the amorphous nature of nanoparticles,
which is comparable to that of XRD study.
Based on the above results obtained from analytical and
spectroscopic studies, metal chelates are presented in
Schemes 3 and 4.
Phenoxazinone synthase activity
reaction velocity; Vmax
, Michaelis constant; KM and
The phenoxazinone oxidase biomimetic catalytic activity of
the binary copper(II) chelates in the oxidation of 2-amino-
phenol (OAPH) to 2-aminophenoxazine-3-one, according to
the reaction shown in Scheme 5, was studied. The product
2-aminophenoxazine-3-one exhibited a strong absorption
band at 433 nm (e ¼ 24 ꢂ 103 Mꢁ1 cmꢁ1), which is character-
istic in methanol.
To test the ability of the complexes for the oxidation of
2-aminophenol, 1 ꢂ 10ꢁ4 M methanolic solutions of the
complexes were reacted with 100 equivalents of substrate
OAPH at room temperature under aerobic condition. In
order to preserve the pseudo-first-order conditions, the
concentration of 2-aminophenol was reserved 10 times
higher than that of the complex. The UV–Vis. spectrum of
the mixture was recorded at 5 min time’s interval to check
the progress of the reaction. There is a regular increase in
the absorption band at 433 nm as shown in Figure 2 for
Turnover number; Kcat. The initial rate vs. OAPH concen-
tration plot and Lineweaver-Burk plot for complexes 1 and
2 were illustrated in Figures 3 and 4, respectively. The
kinetic parameters of both complexes are given in Table 5.
The results indicated that both complexes show phenoxazi-
none synthase activity and complex 1 is more active than
complex 2. The higher activity of complex 1 may be due to
the replacement of nitrate group by 2-aminophenol during
the catalytic action.[63]
Figure 6. Optimized structure, HOMO and LUMO energy levels of complex 1.
Figure 7. Optimized structure, HOMO and LUMO energy levels of complex 2.

INORGANIC AND NANO-METAL CHEMISTRY
9
DFT calculations
interaction between the chelating agent and its metal ion in
coordination sphere. It is reported that HOMO energy
measures the donation character, the higher HOMO energy
means that the molecule has the ability to donate electron
while LUMO energy measures the electron affinity (accept-
ing property).[64] The results, Table 6, showed that the EHOMO
and ELUMO and their neighboring orbitals are all negative, indi-
cating that the prepared chelats are stable.[65] Also, the HOMO
– LUMO energy gap (Eg) is a considerable factor to determine
the reactivity and kinetic stability of molecules. When the
energy gap decreases the interaction between the reactants
increases and the stability of the isolated complexes
increases.[66] The calculated (Eg) of the chelating agent is higher
than that of the copper(II) chelates, indicating the affinity of
the chelating agent to bind with the copper(II) ion. Finally, the
dipole moment measures the charge isolation on the molecules.
The formed copper(II) chelates have higher dipole moment
than the chelating agent (HL).
Geometry optimization
The optimized structures of the free hydrazone and its
copper(II) chelates are obtained by means of B3LYB/6-311G
(p,d) level. Figures 5–8 represent optimized structures,
HOMO (Highest Occupied Molecular Orbitals) and LUMO
(Lowest Unoccupied Molecular Orbitals) of the chelating
agent and its complexes. The calculated values of EHOMO
ELUMO and other parameters of the chelating agent and its
copper(II) chelates are tabulated in Table 6.
,
Highest Occupied Molecular Orbitals and Lowest
Unoccupied Molecular Orbitals are very important quantum
parameters, which are largely used in prediction of the
Charge distribution analysis
The net charge on active centers in the chelating agent (HL)
and its copper(II) chelates and the quantity of charge
migrated from the chelating agent to copper ion (HL !
Cu) are shown at Table 7. The data indicated that copper
ion received 0.691 e, 1.107 e and 1.235 e for 1, 2 and 3,
respectively, from the ligand (HL). On comparing of the
charge values of atoms in free ligand with the same atoms
in the copper complexes, a rising in the charge density on
the donation sites occurs.
Vibrational frequency analysis
The experimental and theoretical infrared spectra of the chelat-
ing agent (HL) and its copper chelates are illustrated in Figures
9–12. Also, a comparison between important experimental and
scaled calculated IR bands of the chelating agent (HL) and its
copper(II) chelates and their assignments (with the scaling fac-
tor 0.96 [67]) are tabulated in Table 8. The data proved large
concurrence between the calculated vibrational frequencies and
the experimental values. However, a small difference is
observed between the calculated and experimental values. This
difference may be due to the fact that experimental data have
been attained in the solid state whereas the calculated ones
have been deduced from sole gaseous molecules without taking
into account lattice interactions.[68]
Structure activity relationship
The biological activity of the chelating agent and its
copper(II) chelates can be illustrated by means of ground
state properties. The energy gap (Eg) is a main factor to
Figure 8. Optimized structure, HOMO and LUMO energy levels of complex 3.
Table 6. Total energy (au), energy of HOMO (eV), of LUMO (eV), energy gap (eV) and dipole moment (Debye) for the ligand and its
copper(II) complexes.
No.
Compound
Total energy (a.u)
Dipole moment (Debye)
EHOMO (eV)
ELUMO (eV)
Eg (eV)
HL
ꢁ890.598
ꢁ2811.211
ꢁ3402.381
ꢁ3340.340
3.381
11.823
12.821
9.061
ꢁ6.643
ꢁ6.564
ꢁ4.360
ꢁ4.300
ꢁ2.292
ꢁ3.319
ꢁ3.573
ꢁ2.887
ꢁ4.351
ꢁ3.245
ꢁ0.786
ꢁ1.412
(1)
(2)
(3)
[Cu(L)(NO3)].EtOH
[Cu(L)2].1.5H2O
[Cu(L)(8-HQ)NO3].H2O

10
M. SHEBL ET AL.
measure the chemical reactivity of the compounds. When a 2 < complex 3 < complex 1 < (HL); Table 6. So the
compound has a small energy gap, it becomes more polar-
ized and soft. This means that charge transfer can happen
easily concerning the biological activity of the compound.
The energy gap of the chelating agent (HL) and its
copper(II) complexes follow the following order: complex
copper(II) complexes have higher reactivity than the chelat-
ing agent (HL) and the order of activity is: complex
2 > complex 3 > complex 1. This result is coincident with
the experimental data (see later; antimicrobial activity item).
Table 7. Net Charges on metal and active centers of the ligand and its Antimicrobial activity
copper(II) complexes.
The biological activity of the chelating agent and its chelates
Net charges
Complex (2)
was inspected toward two Gram positive bacteria; S. aureus
(ATCC 25923) and B. subtilis (ATCC 6635), two Gram
negative bacteria; S. typhimurium (ATCC 14028) and E. coli
(ATCC 25922), C. albicans (ATCC 10231) and A. fumigatus
and the obtained results are recorded in Table 9. The min-
imum inhibitory concentration (MIC) was determined for
the hydrazone ligand and its complexes and the results are
summarized at Table 10. The chelating agent is merely
active against Candida albicans and the chelates are more
Center
HL
Complex (1)
Complex (3)
Cu
—
1.309
ꢁ0.632
ꢁ0.473
ꢁ0.439
ꢁ0.0545
ꢁ0.209
ꢁ0.360
ꢁ0.215
—
0.893
0.765
ꢁ0.455
ꢁ0.559
ꢁ0.588
ꢁ0.302
ꢁ0.331
ꢁ0.584
ꢁ0.468
ꢁ0.444
ꢁ0.246
1.235
Oenolic
Nazomethine
Opyron
Onitrate
Namide
Ohetero
Nitrile
O8HQ
ꢁ0.543
ꢁ0.232
ꢁ0.373
—
ꢁ0.250
ꢁ0.490
ꢁ0.093
—
ꢁ0.507, ꢁ0.552
ꢁ0.566, ꢁ0.595
ꢁ0.504, ꢁ0.608
—
ꢁ0.368, ꢁ0.344
ꢁ0.559, ꢁ0.495
ꢁ0.480, ꢁ0.469
—
N8HQ
HL ! Cu
—
—
—
0.691
—
1.107
Figure 11. Calculated and experimental IR spectra of the copper(II) complex 2.
Figure 9. Calculated and experimental IR spectra of the hydrazone ligand (HL).
Figure 12. Calculated and experimental IR spectra of the copper(II)
complex 3.
Figure 10. Calculated and experimental IR spectra of the copper(II) complex 1.

INORGANIC AND NANO-METAL CHEMISTRY
11
Table 8. Vibrational assignments of the IR bands along with the theoretically computed wave number for the hydrazone ligand and its copper(II) complexes.
FT-IR (cm-1)
HL
Complex (1)
Complex (2)
Complex (3)
Exp.
Calc.
Exp.
Calc.
Exp.
Calc.
Exp.
Calc.
Assignments
3192
3126
2986
2260
1692
1633
1564
—
1493
1405
1336
1270
—
3185
3114
2989
2258
1688
1643
1572
—
1483
1411
1332
1260
—
—
—
—
—
—
—
ꢀNH
ꢀCHar
ꢀCHal
ꢀCN
ꢀCOamide
ꢀCOpyron
ꢀC ¼ N
(ꢀC ¼ N)8HQ
ꢀC ¼ C
ꢀC ¼ C
ꢀCH
ꢀC–O
ꢀNO3\bar
ꢀNN
3059
2976
2225
—
1613
1525
—
1477
1395
1354
1316
1246
1111
1035
562
3054
2983
2246
—
1619
1524
—
1470
1407
1360
1321
1239
1109
1023
560
3095
2973
2265
—
1615
1522
—
1473
1442
1387
1310
—
3092
2968
2293
—
1618
1532
—
1471
1440
1385
1315
—
3055
2855
2230
—
3041
2870
2228
—
1627
1518
1495
1462
1409
1323
1282
1242
1110
1029
561
1621
1527
1493
1450
1416
1314
1271
1237
1108
1023
553
1115
—
—
1117
—
—
1102
—
564
1098
—
570
ꢀNO3\bar
ꢀCu–O
ꢀCu–N
—
—
432
435
429
424
417
407
ꢀ: Stretching; ar: aromatic ring; al: aliphatic chain.
Table 9. Antimicrobial activity of the hydrazone ligand and its metal complexes.
Meana of zone diameter, nearest whole mm.
Gram - negative bacteria
Salmonella
Gram - positive bacteria
Yeasts and Fungib
Staphylococcus
Bacillus subtilis
typhimurium
Escherichia coli
Candida albicans
Aspergillus
fumigatus
Organism
aureus (ATCC 25923)
(ATCC 6635)
(ATCC 14028)
(ATCC 25922)
(ATCC 10231)
Concentration Sample
1 mg/mLd
HL
(1)
(2)
(3)
(4)
(5)
(6)
(7)
–
–
–
–
–
–
–
–
35
–
–
–
–
–
–
–
–
–
36
–
–
–
–
–
–
–
–
38
11 L
23 I
22 I
22 I
8 L
15 I
6 L
–
–
–
–
–
–
–
–
37
21 I
28 H
27 H
17 I
22 I
19 I
21 I
35
10 L
35
c
Control
a¼ Calculated from 3 values.
b¼ identified on the basis of routine cultural, morphological and microscopical characteristics.
– ¼ No effect.
L: Low activity ¼ Mean of zone diameter ꢇ 1/3 of mean zone diameter of control.
I: Intermediate activity ¼ Mean of zone diameter ꢇ 2/3 of mean zone diameter of control.
H: High activity ¼ Mean of zone diameter > 2/3 of mean zone diameter of control.
c: Chloramphenicol in the case of Gram-positive bacteria, cephalothin in the case of Gram -negative bacteria and cycloheximide in the case of fungi.
d: Compounds were dissolved in DMF, which has no inhibition activity.
active than it except complexes 4, 6 and 7. The higher activ-
Table 10. Minimum inhibitory concentration (MIC) (lg/mL) of the biologically
ity of chelates than the hydrazone ligand is simply due to
decreasing metal ion polarity on complex-formation. Also,
the increase in delocalization of p-electrons over the chelate
ring leads to an increase in the lipophilic nature of the com-
plex. This facilitates diffusion of the chelate into the lipid
membrane and prevents new growth of microorganisms.[69]
Against Bacillus subtilis, complexes exhibited intermediate to
high activity with the highest activity given by the nano
copper(II) complex 2. The order of activity in binary com-
plexes is: copper(II) complexes > cobalt(II) complexes >
nickel(II) complexes. In ternary complexes, copper(II) complex-
es > nickel (II) complexes > cobalt (II) complexes. It was
reported that the biological activity of the metal complexes is
affected by differnt factors: (a) the nature of the metal ion, (b)
active compounds.
MIC lg/mL
Gram - positive bacteria;
Bacillus subtilis (ATCC 6635)
Candida albicans
(ATCC 10231)
Compound
HL
(1)
(2)
(3)
(4)
(5)
(6)
ND
8
2
2
32
8
16
8
1
128
32
32
32
256
64
256
128
3
(7)
Controla
aChloramphenicol in the case of Gram-positive bacteria and cycloheximide in
the case of fungi.
bND ¼ Not determined.

12
M. SHEBL ET AL.
4. Sathyadevi, P.; Krishnamoorthy, P.; Alagesan, M.; Thanigaimani,
K.; Muthiah, P. T.; Dharmaraj, N. Synthesis, Crystal Structure,
Electrochemistry and Studies on Protein Binding, Antioxidant
and Biocidal Activities of Ni(II) and Co(II) Hydrazone
Complexes. Polyhedron 2012, 31, 294–306. DOI: 10.1016/j.poly.
2011.09.021.
5. Singh, Y. P.; Patel, R. N.; Singh, Y.; Butcher, R. J.; Vishakarma,
P. K.; Singh, R. K. B. Structure and Antioxidant Superoxide
Dismutase Activity of Copper(II) Hydrazone Complexes.
Polyhedron 2017, 122, 1–15. DOI: 10.1016/j.poly.2016.11.013.
6. Bakale, R. P.; Naik, G. N.; Mangannavar, C. V.; Muchchandi,
I. S.; Shcherbakov, I. N.; Frampton, C.; Gudasi, K. B. Mixed
Ligand Complex via Zinc(II)-Mediated in Situ Oxidative
Heterocyclization of Hydrochloride Salt of 2-Chlorobenzaldehyde
Hydralazine Hydrazone as Potential of Antihypertensive Agent.
Eur. J. Med. Chem. 2014, 73, 38–45. DOI: 10.1016/j.ejmech.2013.
11.037.
7. Joshi, S. D.; Kumar, D.; Dixit, S. R.; Tigadi, N.; More, U. A.;
Lherbet, C.; Aminabhavi, T. M.; Yang, K. S. Synthesis,
Characterization and Antitubercular Activities of Novel Pyrrolyl
Hydrazones and Their Cu-Complexes. Eur. J. Med. Chem. 2016,
121, 21–39. DOI: 10.1016/j.ejmech.2016.05.025.
8. Shebl, M.; Khalil, S. M. E.; Kishk, M. A. A.; EL-Mekkawi, D. M.;
Saif, M. New Less Toxic Zeolite-Encapsulated Cu(II) Complex
Nanomaterial for Dual Applications in Biomedical Field and
Wastewater Remediation. Appl. Organometal. Chem. 2019, 33,
e5147. DOI: 10.1002/aoc.5147..
the nature of the donor atoms in the ligand, (c) the chelate
effect of the ligand, (d) the geometry of the complex, (e) the
total charge on the complex ion and (f) the nature of the
anions that neutralize the complex.[70,71] The higher activity of
the nano complex may be attributed to its small size, which
increases its absorption ability on the surface of the cell wall of
microorganisms and restricts further growth of them.[72] On
conclusion, copper(II) complexes showed the highest activity.
Ternary complexes are more active than binary complexes due
to the presence of 8-hydroxyquinoline moiety. Finally, the
nanocomplex 2 is promizing against Bacillus subtilis, as its
activity is comparable to that of the antibiotic chloramphenicol.
Conclusion
Reactions of 2-cyano-N0-((4-oxo-4H-chromen-3-yl)methyle-
ne)acetohydrazide with copper(II), nickel(II) and cobalt(II)
ions in absence and presence of 8-hydroxyquinoline yielded
binary and ternary complexes. In case of copper(II)ion, a
nano binary complex was synthesized in the presence of
cetyltrimethyl ammonium bromide. Structure identifica-
tion of the complexes was accomplished by physicochemi-
cal and spectroscopic techniques including analytical
data, conductivity and magnetic susceptibility measure-
ments, infrared, electronic, mass and electron spin reson-
ance spectra, thermal analysis, powder XRD and TEM.
The isolated binary complexes are neutral mononuclear
complexes (with 1:1 and 1:2; M:L stoichiometries) and
ternary complexes (with 1:1:1; M:L:L0 stoichiometries). In
absence of CTAB, a neutral square-planar copper(II)
complex 1 with 1:1; M:L molar ratio was obtained.
However, in the presence of CTAB, a neutral octahedral
nano copper(II) complex 2 with 1:2; M:L molar ratio was
obtained. The hydrazone ligand behaves as monoanionic
tridentate with c-pyrone O, enolic O and azomethine N
coordinating sites. DFT calculations were performed for
the hydrazone ligand and its copper(II) complexes and
the obtained results were interrelated with the practical
results. Binary copper(II) complexes exhibit phenoxazi-
none synthase activity. The ligand is biologically active
toward Candida albicans and its activity increases upon
complex-formation.
9. Liu, K.; Yan, H.; Chang, G.; Li, Z.; Niu, M.; Hong, M.
Organotin(IV) Complexes Derived from Hydrazone Schiff Base:
Synthesis, Crystal Structure, in Vitro Cytotoxicity and DNA/BSA
Interactions. Inorg. Chim. Acta 2017, 464, 137–146. DOI: 10.
1016/j.ica.2017.05.017.
10. Raja, D. S.; Ramachandran, E.; Bhuvanesh, N. S. P.; Natarajan,
K. Synthesis, Structure and in Vitro Pharmacological Evaluation
of
a Novel 2-Oxo-1,2-Dihydroquinoline-3-Carbaldehyde (2’-
methylbenzoyl) Hydrazone Bridged Copper(II) Coordination
Polymer. Eur. J. Med. Chem. 2013, 64, 148–159. DOI: 10.1016/j.
ejmech.2013.03.040.
11. Philip, J. E.; Antony, S. A.; Eeettinilkunnathil, S. J.; Kurup,
M. R. P.; Velayudhan, M. P. Design, Synthesis, Antimicrobial
and Antioxidant Activity of 3-Formyl Chromone Hydrazone and
Their Metal (II) Complexes. Inorg. Chim Acta 2018, 469, 87–97.
DOI: 10.1016/j.ica.2017.09.006.
12. Ammar, R. A.; Alaghaz, A. M.; Zayed, M. E.; Al-Bedair, L. A.
Synthesis, Spectroscopic, Molecular Structure, Antioxidant,
Antimicrobial and Antitumor Behavior of Mn(II), Co(II),
Ni(II), Cu(II) and Zn(II) Complexes of O2N Type Tridentate
Chromone-2-Carboxaldehyde Schiff’s Base Ligand. J. Mol.
Struct. 2017, 1141, 368–381. DOI: 10.1016/j.molstruc.2017.03.
080.
13. Pastuszko, A.; Majchrzak, K.; Czyz, M.; Kupcewicz, B.; Budzisz,
E. The Synthesis, Lipophilicity and Cytotoxic Effects of New
Ruthenium(II) Arene Complexes with Chromone Derivatives. J.
Inorg. Biochem. 2016, 159, 133–141. DOI: 10.1016/j.jinorgbio.
2016.02.020.
References
~
1. Bera, P.; Brandao, P.; Mondal, G.; Jana, H.; Jana, A.; Santra, A.;
14. Ilboudo, D. P.; Basilico, N.; Parapini, S.; Corbett, Y.; D’Alessandro,
S.; Dell’Agli, M.; Coghi, P.; Karou, S. D.; Sawadogo, R.; Gnoula, C.;
et al. Antiplasmodial and anti-Inflammatory Activities of Canthium
Henriquesianum (K. Schum), a Plant Used in Traditional Medicine
in Burkina Faso. J. Ethnopharmacol. 2012, 148, 763–769. DOI: 10.
1016/j.jep.2013.04.049.
15. Khadem, S.; Marles, R. J. Chromone and Flavonoid Alkaloids:
Occurrence and Bioactivity. Molecules 2012, 17, 191–206. DOI:
10.3390/molecules17010191.
Bera, P. Synthesis of a New Pyridinyl Thiazole Ligand with
Hydrazone Moiety and Its Cobalt(III) Complex: X-Ray
Crystallography, in Vitro Evaluation of Antibacterial Activity.
Polyhedron 2017, 134, 230–237. DOI: 10.1016/j.poly.2017.06.024.
2. Bakale, R. P.; Naik, G. N.; Machakanur, S. S.; Mangannavar,
C. V.; Muchchandi, I. S.; Gudasi, K. B. Structural
Characterization and Antimicrobial Activities of Transition
Metal Complexes of a Hydrazone Ligand. J. Mol. Struct. 2018,
1154, 92–99. DOI: 10.1016/j.molstruc.2017.10.035.
16. Grazul, M.; Budzisz, E. Biological Activity of Metal Ions Complexes
of Chromones, Coumarins and Flavones. Coord. Chem. Rev. 2009,
253, 2588–2598. DOI: 10.1016/j.ccr.2009.06.015.
17. Liu, Q.; Qiang, X.; Li, Y.; Sang, Z.; Li, Y.; Tan, Z.; Deng, Y.
Design, Synthesis and Evaluation of Chromone-2-Carboxamido-
Alkylbenzylamines as Multifunctional Agents for the Treatment
3. Kumar, S. S.; Biju, S.; Sadasivan, V. Synthesis, Structure
Characterization and Biological Studies on a New Aromatic
Hydrazone, 5-(2-(1,5-Dimethyl-3-Oxo-2-Phenyl-2,3-Dihydro-1H-
Pyrazol-4-Yl)Hydrazono)-2,2-Dimethyl-1,3-Dioxane-4,6-Dione,
and Its Transition Metal Complexes. J. Mol. Struct. 2018, 1156,
201–209. DOI: 10.1016/j.molstruc.2017.11.057.

INORGANIC AND NANO-METAL CHEMISTRY
13
of Alzheimer’s disease. Bioorg. Med. Chem. 2015, 23, 911–923.
DOI: 10.1016/j.bmc.2015.01.042.
from 3-Carbaldehyde Chromone and Isonicotinyl Hydrazine. J.
Coord. Chem. 2010, 63, 1960–1968. DOI: 10.1080/00958972.2010.
496127.
18. Tamasi, G.; Chiasserini, L.; Savini, L.; Sega, A.; Cini, R.
Structural Study of Ribonucleotide Reductase Inhibitor
Hydrazones. Synthesis and X-Ray Diffraction Analysis of a
Copper(II)-Benzoylpyridine-2-Quinolinyl Hydrazone Complex. J.
Inorg. Biochem. 2005, 99, 1347–1359. DOI: 10.1016/j.jinorgbio.
2005.03.009.
29. Ilies, D.-C.; Pahontu, E.; Shova, S.; Georgescu, R.; Stanica, N.;
Olar, R.; Gulea, A.; Rosu, T. Synthesis, Characterization, Crystal
Structure and Antimicrobial Activity of Copper(II) Complexes
with
a
Thiosemicarbazone Derived from 3-Formyl-6-
Methylchromone. Polyhedron 2014, 81, 123–131. DOI: 10.1016/j.
poly.2014.05.074.
19. (a) Wu, H.-L.; Huang, X.; Liu, B.; Kou, F.; Jia, F.; Yuan, J.; Bai,
Y. Copper(II) Complex Based on a V-Shaped Ligand, 2,6- Bis
(2-Benzimidazolyl)Pyridine: Synthesis, Crystal Structure, DNA-
Binding Properties, and Antioxidant Activities. J. Coord. Chem
2011, 64, 4383–4396. DOI: 10.1080/00958972.2011.640934. (b)
Patel, M. N.; Joshi, H. N.; Patel, C. R. Cytotoxic, Antibacterial,
DNA Interaction and Superoxide Dismutase like Activities of
Sparfloxacin Drug Based Copper(II) Complexes with Nitrogen
Donor Ligands. Spectrochim Acta A Mol Biomol Spectrosc 2013,
104, 48–55. DOI: 10.1016/j.saa.2012.11.045. (c) Karadeniz, S¸.;
30. Khan, T. A.; Rather, M. A.; Jahan, N.; Varkey, S. P.; Shakir, M.
Synthesis and Characterization of Bis(Macrocyclic) Complexes
Based on the 13-Membered Pentaaza Unit. Synth. React. Inorg.
Met-Org. Chem. 1997, 27, 843–854. DOI: 10.1080/
00945719708000232.
31. Shebl, M. Synthesis, Spectral Studies, and Antimicrobial Activity
of Binary and Ternary Cu(II), Ni(II), and Fe(III) Complexes of
New Hexadentate Schiff Bases Derived from 4,6-
Diacetylresorcinol and Amino Acids. J. Coord. Chem. 2009, 62,
3217–3231. [Mismatch] DOI: 10.1080/00958970903012785.
32. Shebl, M. Mononuclear, Homo- and Hetero-Binuclear
_
€
Ataol, C. Y.; S¸ahin, O.; Idil, O.; Bati, H. Synthesis, Structural
Studies and Antimicrobial Activity of N’-((2Z, 3E)-3-
(Hydroxyimino)Butan-2-Ylidene)-2-Phenylacetohydrazide and Its
Co(II), Ni(II) Complexes. J. Mol. Struct. 2018, 1161, 477–485.
Complexes
of
1-(5-(1-(2-Aminophenylimino)Ethyl)-2,4-
Dihydroxyphenyl)Ethanone: Synthesis, Magnetic, Spectral,
Antimicrobial, Antioxidant, and Antitumor Studies. J. Coord.
Chem. 2016, 69, 199–214. DOI: 10.1080/00958972.2015.1116688.
33. Chan, S. C.; Koh, L. L.; Leung, P.-H.; Ranford, J. D.; Sim, K. Y.
Copper(II) Complexes of the Antitumour-Related Ligand
Salicylaldehyde Acetylhydrazone (H2L) and the Single-Crystal X-
Ray Structures of [fCu(HL)H2Og2] ꢀ 2(NO3) and [fCu(HL)
(Pyridine) (NO3)g2]. Inorg. Chim Acta 1995, 236, 101–108. DOI:
10.1016/0020-1693(95)04623-H.
34. Shebl, M.; Khalil, S. M. E. Synthesis, Spectral, X-Ray Diffraction,
Antimicrobial Studies, and DNA Binding Properties of Binary
and Ternary Complexes of Pentadentate N2O3 Carbohydrazone
Ligands. Monatsh. Chem. 2015, 146, 15–33. DOI: 10.1007/
s00706-014-1302-x.
35. Shebl, M.; Adly, O. M. I.; Abdelrhman, E. M.; El-Shetary, B. A.
Binary and Ternary Copper(II) Complexes of a New Schiff Base
Ligand Derived from 4-Acetyl-5,6-Diphenyl-3(2H)-Pyridazinone:
Synthesis, Spectral, Thermal, Antimicrobial and Antitumor
Studies. J. Mol. Struct. 2017, 1145, 329–338. DOI: 10.1016/j.mol-
struc.2017.05.064.
36. Seleem, H. S.; Emara, A. A.; Shebl, M. The Relationship between
Ligand Structures and Their CoII and NiII Complexes: Synthesis
and Characterization of Novel Dimeric CoII/CoIII Complexes of
Bis(Thiosemicarbazone). J. Coord. Chem. 2005, 58, 1003–1019.
DOI: 10.1080/00958970500066606.
37. Shebl, M. Coordination Behavior of New Bis(Tridentate ONO,
ONS and ONN) Donor Hydrazones towards Some Transition
Metal Ions: Synthesis, Spectral, Thermal, Antimicrobial and
Antitumor Studies. J. Mol. Struct. 2017, 1128, 79–93. DOI: 10.
1016/j.molstruc.2016.08.056.
38. Shebl, M.; Khalil, S. M. E.; Taha, A.; Mahdi, M. A. N. Structural
Diversity in Binuclear Complexes of Alkaline Earth Metal Ions
with 4,6-Diacetylresorcinol. J. Mol. Struct. 2012, 1027, 140–149.
DOI: 10.1016/j.molstruc.2012.05.067.
39. Chandra, S.; Pipil, P.; Sharma, S. D. Synthesis, EPR, and
Electonic Spectral Studies on Cr(III) and Mn(II) Complexes of
Some Oximes. Synth. React. Inorg. Met-Org. Chem. 2001, 31,
779–794. DOI: 10.1081/SIM-100104850.
40. El-Shazly, R. M.; Al-Hazmi, G. A. A.; Ghazy, S. E.; El-Shahawi,
M. S.; El-Asmy, A. Spectroscopic, Thermal and Electrochemical
Studies on Some Nickel(II) Thiosemicarbazone Complexes.
Spectrochim. Acta A Mol. Biomol. Spectrosc. 2005, 61, 243–252.
DOI: 10.1016/j.saa.2004.02.035.
DOI:
10.1016/j.molstruc.2018.01.087.
(d)
Nithya,
P.;
Rajamanikandan, R.; Simpson, J.; Ilanchelian, M.; Govindarajan,
S. Solvent Assisted Synthesis, Structural Characterization and
Biological Evaluation of Cobalt(II) and Nickel(II) Complexes of
Schiff Bases Generated from Benzyl Carbazate and Cyclic
Ketones. Polyhedron 2018, 145, 200–217. DOI: 10.1016/j.poly.
2018.02.008.
20. (a) Abd El-Halim, H. F.; Mohamed, G. G.; Anwar, M. N.
Antimicrobial and Anticancer Activities of Schiff Base Ligand
and Its Transition Metal Mixed Ligand Complexes with
Heterocyclic Base. Appl. Organometal. Chem. 2018, 32, e3899.
DOI: 10.1002/aoc.3899. (b) Neelaeni, R.; Vasantha, S.; Keerthana,
R.; Sivakolunthu, S.; Angeline, T. DNA Cleavage Activity of
Novel Schiff Base Copper(II) Complexes with Sulfur-Containing
Ligands:
(2-(2-Methylthio)Phenylimino)Methylphenol,
N-
Benzylidine-2-Methylthioaniline. Asian J. Pharm. Clin. Res. 2016,
9, 277–281.
21. E1-Shaaer, H. M.; Foltifnov, P.; Lacova, M.; Chovancova, J.;
Stankovicova, H. Synthesis, Antimicrobial Activity and Bleaching
Effect of Some Reaction Products of 4-Oxo-4H-Benzopyran-3-
Carboxaldehydes with Aminobenzothiazoles and Hydrazides. I1
Farmaco 1998, 53, 224–232. DOI: 10.1016/S0014-827X(98)00015-9.
22. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A. Gaussian 09. Revision A. 1; Gaussian Inc.:
Wallingford, CT, 2009.
23. Rahman, A. U.; Choudhary, M. I.; Thomsen, W. J. Bioassay
Techniques for Drug Development; Harwood Academic
Publishers: The Netherlands, 2001.
24. Andrews, J. M. Determination of Minimum Inhibitory
Concentrations. J. Antimicrob. Chemother. 2001, 48, 5–16. DOI:
10.1093/jac/48.suppl_1.5.
25. Geary, W. J. The Use of Conductivity Measurements in Organic
Solvents for the Characterisation of Coordination Compounds.
Coord. Chem. Rev. 1971, 7, 81–122. DOI: 10.1016/S0010-
8545(00)80009-0.
26. Shebl, M.; Saif, M.; Nabeel, A. I.; Shokry, R. New Non-Toxic
Transition Metal Nanocomplexes and Zn Complex-Silica Xerogel
Nanohybrid: Synthesis, Spectral Studies, Antibacterial, and
Antitumor Activities. J. Mol. Struct. 2016, 1118, 335–343. DOI:
10.1016/j.molstruc.2016.04.037.
27. Shebl, M.; Ibrahim, M. A.; Khalil, S. M. E.; Stefan, S. L.; Habib,
H. Binary and Ternary Copper(II) Complexes of a Tridentate
ONS Ligand Derived from 2-Aminochromone-3 Carboxaldehyde
and Thiosemicarbazide: Synthesis, Spectral Studies and
Antimicrobial Activity. Spectrochim. Acta A 2013, 115, 399–408.
DOI: 10.1016/j.saa.2013.06.075.
41. Shebl, M.; Khalil, S. M. E.; Al-Gohani, F. S. Preparation, Spectral
Characterization and Antimicrobial Activity of Binary and
Ternary Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Ce(III) and
UO2(VI) Complexes of a Thiocarbohydrazone Ligand. J. Mol.
Struct. 2010, 980, 78–87. DOI: 10.1016/j.molstruc.2010.06.040.
28. Li, Y.; Yang, Z. DNA-Binding Properties and Antioxidant
Activity of Lanthanide Complexes with the Schiff Base Derived

14
M. SHEBL ET AL.
42. Shebl, M.; Khalil, S. M. E.; Ahmed, S. A.; Medien, H. A. A. 57. Khalil, S. M. E.; Seleem, H. S.; El-Shetary, B. A.; Shebl, M.
Synthesis, Spectroscopic Characterization and Antimicrobial
Activity of Mono-, Bi- and Tri-Nuclear Metal Complexes of a
New Schiff Base Ligand. J. Mol. Struct. 2010, 980, 39–50. DOI:
10.1016/j.molstruc.2010.06.034.
Mono- and Bi-Nuclear Metal Complexes of Schiff-Base
Hydrazone (ONN) Derived from o-Hydroxyacetophenone and
2-Amino-4-Hydrazino-6-Methyl Pyrimidine. J. Coord. Chem.
2002, 55, 883–899. DOI: 10.1080/0095897022000002213.
43. Shebl, M.; El-Ghamry, M. A.; Khalil, S. M. E.; Kishk, 58. Jasinski, J. P.; Bianchani, J. R.; Cueva, J.; El-Saied, F. A.; El-
M. A. A. Mono- and Binuclear Copper(II) Complexes of New
Hydrazone Ligands Derived from 4,6-Diacetylresorcinol:
Synthesis, Spectral Studies and Antimicrobial Activity. Spectrochim.
Acta A Mol. Biomol. Spectrosc. 2014, 126, 232–241. DOI: 10.1016/j.
saa.2014.02.014.
Asmy, A. A.; West, D. X. Hexanedione Bis(3-
Azacyclothiosemicarbazones). Z Anorg. Allg. Chem. 2003, 629,
202–206. DOI: 10.1002/zaac.200390032.
59. Hathaway, B. J.; Billing, D. E. The Electronic Properties and
Stereochemistry of Mono-Nuclear Complexes of the Copper(II)
Ion. Coord. Chem. Rev. 1970, 5, 143–207. DOI: 10.1016/S0010-
8545(00)80135-6.
60. Shebl, M. Synthesis, Spectroscopic Characterization and
Antimicrobial Activity of Binuclear Metal Complexes of a New
Asymmetrical Schiff Base Ligand: DNA Binding Affinity of
44. Shanker, K.; Rohini, R.; Ravinder, V.; Reddy, P. M.; Ho, Y. P.
Ru(II) Complexes of N4 and N2O2 Macrocyclic Schiff Base
Ligands: Their Antibacterial and Antifungal Studies. Spectrochim.
Acta A Mol. Biomol. Spectrosc. 2009, 73, 205–211. DOI: 10.1016/
j.saa.2009.01.021.
45. Shakir, M.; Azim, Y.; Chishti, H. T. N.; Parveen, S. Synthesis,
Characterization of Complexes of Co(II), Ni(II), Cu(II) and
Zn(II) with 12-Membered Schiff Base Tetraazamacrocyclic
Ligand and the Study of Their Antimicrobial and Reducing
Power. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2006, 65,
490–496. DOI: 10.1016/j.saa.2005.11.029.
Copper(II) Complexes. Spectrochim. Acta A Mol. Biomol.
Spectrosc. 2014, 117, 127–137. DOI: 10.1016/j.saa.2013.07.107.
61. El-Shafiy, H. F.; Shebl, M. Oxovanadium(IV), Cerium(III),
Thorium(IV) and Dioxouranium(VI) Complexes of 1-Ethyl-4-
Hydroxy-3-(Nitroacetyl)Quinolin-2(1H)-One: Synthesis, Spectral,
Thermal, Fluorescence, DFT Calculations, Antimicrobial and
Antitumor Studies. J. Mol. Struct. 2018, 1156, 403–417. DOI: 10.
1016/j.molstruc.2017.11.081.
46. Prasad, R. N.; Mathur, M. CrIII, FeIII, CoII, NiII, CuII and ZnII
Complexes of 26- and 28-Membered Tetraazamacrocycles. J.
Indian Chem. 2006, Soc. 83, 1208–1213.
62. (a) El-Shafiy, H. F.; Shebl, M. Binuclear Oxovanadium(IV),
47. Saleh, A. A.; Tawfik, A. M.; El-Ghamry, M. A.; Abu El-Wafa, S. M.
Interaction of SO2 with Unsaturated Schiff-Base Complexes;
Thermal, Magnetic, and Spectroscopic Studies. J. Coord. Chem.
2009, 62, 3377–3383. DOI: 10.1080/00958970903060008.
48. Shebl, M. Synthesis and Spectroscopic Studies of Binuclear Metal
Complexes of a Tetradentate N2O2 Schiff Base Ligand Derived
from 4,6-Diacetylresorcinol and Benzylamine. Spectrochim. Acta
A Mol. Biomol. Spectrosc. 2008, 70, 850–859. DOI: 10.1016/j.saa.
2007.09.035.
49. Khalil, S. M. E. Synthesis, Spectroscopic and Magnetic Studies
on Metal Complexes of 5-Methyl-3-(2-Hydroxyphenyl)Pyrazole.
J. Coord. Chem. 2003, 56, 1013–1024. DOI: 10.1080/
0095897031000135289.
Cerium(III) and Dioxouranium(VI) Nano Complexes of a
Bis(Bidentate) Ligand: Synthesis, Spectroscopic, Thermal, DFT
Calculations and Biological Studies. J. Mol. Struct. 2019, 1194,
187–203. DOI: 10.1016/j.molstruc.2019.05.063. (b) Samy, F.;
Shebl, M. Synthesis, Spectroscopic, Biological, and Theoretical
Studies of New Complexes from (E)-3-(2-(5, 6- Diphenyl-1,2,4-
Triazin-3-
yl)Hydrazono)Butan-2-
One
Oxime.
Appl.
Organometal. Chem. 2020, 34, e5502. DOI: 10.1002/aoc.5502.
63. Sarkar, N.; Das, M.; Chattopadhyay, S. Two New Manganese(III)
Complexes with Salicylaldimine Schiff Bases: Synthesis,
Structure,
Self-Assembly
and
Phenoxazinone
Synthase
Mimicking Activity. Inorg. Chim. Acta 2017, 457, 19–28. DOI:
10.1016/j.ica.2016.11.009.
50. Khalil, S. M. E.; Shebl, M.; Al-Gohani, F. S. Zinc(II) 64. Sagdinc, S.; Ko€ksoy, B.; Kandemirli, F.; Bayari, S. H. Theoretical
Thiosemicarbazone Complex as Ligand towards Some
a
and
Spectroscopic
Studies
of
5-Fluoro-Isatin-3-(N-
Transition Metal Ions: Synthesis, Spectroscopic and
Antimicrobial Studies. Acta Chim. Slov. 2010, 57, 716–725.
Benzylthiosemicarbazone) and Its Zinc(II) Complex. J. Mol.
Struct. 2009, 917, 63–70. DOI: 10.1016/j.molstruc.2008.06.033.
51. Karaoglu, K.; Baran, T.; Serbest, K.; Er, M.; Degirmencioglu, I. 65. Parr, R. G.; Yang, W. Density-Functional Theory of Atoms and
Two Novel Macroacyclic Schiff Bases Containing Bis-N2O2
Donor Set and Their Binuclear Complexes: Synthesis,
Spectroscopic and Magnetic Properties. J. Mol. Struct. 2009, 922,
39–45. DOI: 10.1016/j.molstruc.2009.01.037.
Molecules; Oxford University Press, Oxford, 1989.
66. Yousef, T. A.; Abu El –Reash, G. M.; El Morshedy, R. M.
Quantum Chemical Calculations, Experimental Investigations
and
DNA
Studies
on
(E)-2-((3-Hydroxynaphthalen-2-
52. Shebl, M.; Khalil, S. M. E.; Taha, A.; Mahdi, M. A. N. Synthesis,
Spectroscopic Studies, Molecular Modeling and Antimicrobial
Activity of Binuclear Co(II) and Cu(II) Complexes of 4,6-
Diacetylresorcinol. Spectrochim. Acta A Mol. Biomol. Spectrosc.
2013, 113, 356–366. DOI: 10.1016/j.saa.2013.04.131.
53. Cotton, F. A.; Wilkinson, G. Advanced Inorganic Chemistry. A
Comprehensive Text, 4th ed.; John Wiley and Sons: New York,
1986.
Yl)Methylene)-N-(Pyridin-2-yl)Hydrazinecarbothioamide and Its
Mn(II), Ni(II), Cu(II), Zn(II) and Cd(II) Complexes. Polyhedron
2012, 45, 71–85. DOI: 10.1016/j.poly.2012.07.041.
67. El-Nahass, M. M.; Kamel, M. A.; El-Menyawy, E. M.
Spectroscopic Analysis of 2-(2,3-Dihydro-1,5-Dimethyl-3-Oxo-2-
Phenyl-1H-Pyrazol-4-Ylimino)-2-(4-Nitro-Phenyl) Acetonitrile.
Spectrochim. Acta A Mol. Biomol. Spectrosc. 2011, 79, 618–624.
DOI: 10.1016/j.saa.2011.03.044.
54. El-Ghamry, M. A.; Saleh, A. A.; Khalil, S. M. E.; Mohammed, 68. Mohamadi, M.; Faghih-Mirzaei, E.; Ebrahimipour, S. Y.;
A. A. Mono, Bi- and Trinuclear Metal Complexes Derived from
New Benzene-1,4-Bis(3-Pyridin-2-Ylurea) Ligand. Spectral,
Magnetic, Thermal and 3D Molecular Modeling Studies.
Spectrochim. Acta A Mol. Biomol. Spectrosc. 2013, 110, 205–216.
DOI: 10.1016/j.saa.2013.03.016.
Sheikhshoaie, I.; Haase, W.; Foro, S. Synthesis, Spectroscopic
Studies, DFT Calculations, Electrochemical Evaluation, BSA
Binding and Molecular Docking of an Aroylhydrazone -Based
Cis-Dioxido Mo(VI) Complex. J. Mol. Struct. 2017, 1139,
418–429. DOI: 10.1016/j.molstruc.2017.03.047.
55. Bailar, J. C.; Emeleus, H. J.; Nyholm, R.; Trotman-Dickenson, 69. Fahmi, N.; Gupta, I. J.; Singh, R. V. Sulfur Bonded Palladium(II)
A. F. Comprehensive Inorganic Chemistry; vol. 3, Pergamon
Press, Oxford, 1975.
56. Shebl, M. Synthesis, Spectral and Magnetic Studies of Mono-
and Platinum(II) Complexes of Biologically Potent Thioamides.
Phosphorus, Sulfur, Silicon Related Elem. 1998, 132, 1–8. DOI:
10.1080/10426509808036968.
and Bi-Nuclear Metal Complexes of a New Bis(Tridentate NO2) 70. Abdel Aziz, A. A.; Salem, A. N. M.; Sayed, M. A.; Aboaly, M. M.
Schiff Base Ligand Derived from 4,6-Diacetylresorcinol and
Ethanolamine. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2009,
73, 313–323. DOI: 10.1016/j.saa.2009.02.030.
Synthesis, Structural Characterization, Thermal Studies, Catalytic
Efficiency and Antimicrobial Activity of Some M(II) Complexes
with ONO Tridentate Schiff Base N-Salicylidene-o-Aminophenol

INORGANIC AND NANO-METAL CHEMISTRY
15
(Saphh2). J. Mol. Struct. 2012, 1010, 130–138. DOI: 10.1016/j.
Bioactivity. J. Inorg. Biochem. 2007, 101, 525–535. DOI: 10.1016/
molstruc.2011.11.043.
j.jinorgbio.2006.11.020.
71. Efthimiadou, E. K.; Psomas, G.; Sanakis, Y.; Katsaros, N.; 72. Joseyphus, R. S.; Nair, M. S. Antibacterial and Antifungal Studies
Karaliota, A. Metal Complexes with the Quinolone Antibacterial
Agent N-Propyl-Norfloxacin: Synthesis, Structure and
on Some Schiff Base Complexes of Zinc(II). Mycobiology 2008,
36, 93–98. DOI: 10.4489/MYCO.2008.36.2.093.