Spectroscopic, DFT and antimicrobial activity of Zn(II), Zr(IV), Ce(IV) and U(VI) complexes of N,N- chelated 4,6-bis (4-chlorophenyl)-2-amino-1,2-dihydropyridine-3-carbinitrile

Article abstract of DOI:10.1002/aoc.4457

Four novel metal complexes of 4,6-bis (4-chlorophenyl)-2-amino-1,2-dihydropyridine-3-carbinitrile (H₂L) with Zn(II), Zr(IV), Ce(IV) and U(VI) were synthesized. The structure was elucidated using elemental analysis, melting point, molar conductivity; spectroscopic techniques (IR, ¹H NMR, UV–Vis., mass spectra) as well as thermo gravimetric analysis. The spectroscopic data proved that H₂L chelated with the metal ions as a bidentate ligand through N_amino and N_carbinitrile atoms. The molecular structure of the complexes was determined using density functional theory (DFT). The central metal ion in each complex is six-coordinate and the angles around it vary from 62.74° to 166.46°; these values agree with distorted octahedral geometry. The calculated total energy of the complexes found in the region – 406.342 to ?459.717 au and the dipole moment change from 4.675 to 13.171D. The antibacterial and antifungal activities of the ligand, metal salts and complexes were estimated on some microorganisms. The complexes showed significant antibacterial profile in comparison to the free ligand.

Full text of DOI:10.1002/aoc.4457

Received: 14 March 2018
DOI: 10.1002/aoc.4457
Revised: 9 May 2018
Accepted: 13 May 2018
F U L L P A P E R
Spectroscopic, DFT and antimicrobial activity of Zn(II),
Zr(IV), Ce(IV) and U(VI) complexes of N,N‐ chelated 4,6‐bis
(
4‐chlorophenyl)‐2‐amino‐1,2‐dihydropyridine‐3‐carbinitrile
1
1
1,2
S.A. Sadeek | S.M. Abd El‐Hamid
| W.A. Zordok
1
Department of Chemistry, Faculty of
Four novel metal complexes of 4,6‐bis (4‐chlorophenyl)‐2‐amino‐1,2‐
Science, Zagazig University, Zagazig,
Egypt
dihydropyridine‐3‐carbinitrile (H L) with Zn(II), Zr(IV), Ce(IV) and U(VI)
2
2
Department of Chemistry, University
were synthesized. The structure was elucidated using elemental analysis, melt-
College of Quanfudha, Umm Al‐Qura
University, KSA
1
ing point, molar conductivity; spectroscopic techniques (IR, H NMR, UV–Vis.,
mass spectra) as well as thermo gravimetric analysis. The spectroscopic data
Correspondence
proved that H L chelated with the metal ions as a bidentate ligand through
2
S. A. Sadeek, Department of Chemistry,
Faculty of Science, Zagazig University,
Zagazig, Egypt.
Namino and Ncarbinitrile atoms. The molecular structure of the complexes was
determined using density functional theory (DFT). The central metal ion in
each complex is six‐coordinate and the angles around it vary from 62.74° to
Email: s_sadeek@zu.edu.eg
166.46°; these values agree with distorted octahedral geometry. The calculated
total energy of the complexes found in the region – 406.342 to −459.717 au and
the dipole moment change from 4.675 to 13.171D. The antibacterial and anti-
fungal activities of the ligand, metal salts and complexes were estimated on
some microorganisms. The complexes showed significant antibacterial profile
in comparison to the free ligand.
KEYWORDS
1
H NMR, biological activity, DFT, IR, metal complexes
1
| INTRODUCTION
inhibit or activate some metalloenzymes of pyridine
compounds depending on the structure and position of
[
9]
Several pyridine derivatives have various pharmacologi-
cal activities, immuno‐suppressive and fibro‐suppressive
properties and capability of protecting certain enzymes
from heat inactivation.
very interesting class of compounds due to their signifi-
cant, versatile biological and pharmacological activi-
substituent on pyridine ring. The synthesized N‐hetero-
cyclic compounds derivatives from pyridine have been
widely used as strong ligands forming chelating com-
pounds with higher oxidation states transition metal
and these metal complexes have been exploited in mate-
[1–3]
Cyano pyridines include a
[
10–15]
rials and medicinal chemistry.
The molecular and
[
4,5]
ties.
The physiological activity and pharmacological
electronic structure of pyridine and some its complexes
[
16]
of 3‐cyanopyridines has attracted more attentions in
recent years with the synthesis and study of the non
glycosidiccardiotonic agent milrinone, as well as with a
number of 3‐cyanopyridine derivatives which proved to
be active against the human immunodeficiency virus
were studied earlier.
Transition metal complexes of
heterocyclic compounds have been attracting the public's
attentions for their potential in inducing cytotoxicity
towards a wide range of tumors. For example, platinum
complexes are used widely in clinical treatment for its
[6–8]
[17–19]
and the herpes virus.
A literature survey showed that,
potential anti‐tumor properties.
Appl Organometal Chem. 2018;e4457.
wileyonlinelibrary.com/journal/aoc
Copyright © 2018 John Wiley & Sons, Ltd.
1 of 16
https://doi.org/10.1002/aoc.4457

2
of 16
SADEEK ET AL.
In this study we consider the synthesis, characteriza-
tion and the structure of new solid 4,6‐bis (4‐
chlorophenyl)‐2‐amino‐1,2‐dihydropyridine‐3‐carbinitrile
2.3 | Synthesis of the metal complexes
The yellow solid complex [Zn(H L) (H O) ](NO ) was
2
2
2
2
3 2
prepared by adding 0.5 mmol (0.297 g) of Zn
NO ) .6H O in 20 ml ethanol drop wise to a stirred
(
H L) (Scheme 1) ligand from pyridine derivatives in our
2
(
lab and their complexes with Zn(II), Zr(IV), Ce(IV) and
U(VI). The compounds were characterized with different
analytical and spectroscopic tools and the optimal set and
geometry of the prepared compounds were studied by
3 2
2
suspended solution 1 mmol (0.340 g) of H L in 50 ml
2
ethanol. The mixture was refluxed for 5 h and the precip-
itate was filtered off and dried under vacuum over
[
20]
anhydrous CaCl . The yellowish white, yellow and
using the GAUSSIAN 98 W package of programs
B3LYP/CEP‐31G
at
level of theory. In addition the ligand
and its metal complexes were tested for antibacterial.
2
[21]
dark yellow solid complexes [ZrO(H L) (H O)]Cl .4H O,
2
2
2
2
2
[
Ce(H L) (H O) ](SO ) ,
and
[UO (H L) (H O)]
2 2 2 2
2
2
2
2
4 2
(
CH COO) were prepared in a similar mannar described
3
2
above by using ZrOCl .8H O, Ce(SO ) and UO2
2
2
4 2
2
2
| MATERIALS AND METHODS
.1 | Chemicals
(CH
3
COO)
2
.2H
2
O in 2:1 (H L:M) molar ratio. The new
2
complexes were characterized by their elemental analysis,
IR, UV–Vis., H NMR, mass spectra and thermal analysis.
Single crystal suitable for X‐ray crystallographic measure-
ments was not obtained.
1
All chemicals and solvents used for the preparation of
H L and its metal complexes were used with high purity
2
of the analytical reagent grade commercially available
from different sources and used without further purifica-
tion.
4‐benzaldehyde,
ethyl
cyanoacetate,
4‐
2
.4 | Antimicrobial and antifungal
chloroacetophenone, ammonium acetate, glacial acetic
acid, and ethanol, and were purchased from Fluka
Chemical Co. Zn(NO ) .6H O, ZrOCl .8H O, Ce(SO )
4 2
investigation
3
2
2
2
2
Antibacterial activity of the ligand and its metal com-
plexes was investigated by modified method of Beecher
and UO (CH COO) .2H O from Aldrich Chemical Co.
2
3
2
2
[
22]
and Wong
as Staphylococcus aureus (S. aureus), Bacillus subtilis
B. subtilis), Escherichia coli (E. coli) and Pseudomonas
against different bacterial species, such
2
.2 | Preparation of 4,6‐bis (4‐
chlorophenyl)‐2‐amino‐1,2‐dihydropyridine
3‐carbinitrile (H L)
(
aeruginosa (P. aeruginosa) and antifungal screening
were studied against two species, Candida albicans
and Aspergillus fumigatus. The tested microorganisms
were isolated from Egyptian soil. The nutrient agar
medium for antibacterial was (0.5% Peptone, 0.1% Beef
extract, 0.2% Yeast extract, 0.5% NaCl and 1.5% Agar‐
Agar) and czapeks Dox medium for antifungal (3%
Sucrose, 0.3% NaNO3, 0.1% K HPO , 0.05% KCl,
−
2
A mixture of 5,7‐bis (4‐chlorophenyl)‐tetrazolopyridine‐8‐
carbonitrile (0.01 mol), zinc dust (0.01 mol) and 10 ml
glacial acetic acid was stirred at room temperature for
ο
2
h and then heated on water bath at 80 C for 8 h. The
reaction mixture was poured into water, extracted with
chloroform and the extract was evaporated under reduced
pressure. The formed solid compound was recrystallized
using ethanol as a solvent. The proposed formula of
H L (C H N Cl , M.Wt. = 340) is in good agreement
2
4
[23]
0.001% FeSO , 2% Agar‐Agar) was prepared
and
4
ο
then cooled to 47 C and seeded with tested microor-
ganisms. Sterile water agar layer was poured, solidified
then pour, the prepared growth medium for fungi and
bacteria (plate of 12 cm diameter, 15 ml medium
plate). After solidification 5 mm diameter holes were
punched by a sterile cork‐borer. The investigated com-
pounds,i.e., ligand and its complexes, were introduced
in Petri‐dishes (only 0.1 ml) after dissolving in DMF
2
18 11
3
2
.
+
with mass spectrum (M ) at m/z = 339.0 (25%) and also,
confirmed by IR and H NMR spectral data.
1
−
3
at 1.0 × 10 M. These culture plates were then incu-
bated at 37 C for 20 h for bacteria and for seven days
at 30 C for fungi. The activity was determined by mea-
ο
ο
suring the diameter of the inhibition zone (in mm).
Bacterial growth inhibition was calculated with refer-
ence to the positive control,i.e., Ampicilin, Amoxycillin
and Cefaloxin.
2
SCHEME 1 Structure of H L

SADEEK ET AL.
3 of 16
TABLE 1 Elemental analysis and physico‐analytical data for H
2
L and its metal complexes
2
Compounds
Λ (S cm
mol )
Found (Calcd.) (%)
−1
Mp/
C
Yield%
ο
M.Wt. (M.F.)
Color
C
H
N
M
Cl
S
H
2
L
85.70
77.45
73.96
64.98
68.46
327
Dark
yellow
(63.55)
63.52
(3.26)
3.24
(12.35)
12.32
‐
(20.84)
20.82
‐
10.55
3
40.21 (C18
Zn(H L) (H
05.86 (C36
L)
48.62(C36
Ce(H L) (H
048.68 (C36
UO (H L) (H
086.54 (C40
H
11
N
3
Cl
](NO
Cl
O)]Cl
2
)
[
9
2
2
2
O)
2
3
)
2
335
Yellow
(47.73)
47.71
(2.89)
2.86
(12.37)
12.34
(7.22)
7.20
(15.65)
15.63
‐
‐
169.51
230.60
210.22
170.83
H
26
N
8
O
8
4
Zn)
[
ZrO(H
2
2
(H
2
2
.4H
2
O
>360 Yellowish (45.58)
(3.40)
3.38
(8.86)
8.83
(9.62)
9.60
(22.42)
22.40
9
H
32
N
6
O
6
Cl Zr)
6
white
45.55
[
1
2
2
2
O)
2
](SO
4
)
2
>360 Yellow
(41.23)
41.21
(2.50)
2.47
(8.01)
8.00
(13.36)
13.34
(13.52)
13.51
(6.12)
6.10
H
26
N
6
O
10Cl
4
S
2
Ce)
COO)
U)
[
1
2
2
2
2
O)](CH
Cl
3
2
343
Dark
yellow
(44.22)
44.19
(2.78)
2.76
(7.73)
7.70
(21.91)
21.90
(13.05)
13.03
‐
H
30
N
6
O
7
4
3
| RESULTS AND DISCUSSION
Zn(II), Zr(IV), Ce(IV) and U(VI) complexes with a color
characteristic of the metal ion formed by the reaction of
H L with Zn(II), Zr(IV), Ce(IV) and U(VI) salts in ethanol
2
as a solvent. The structure of the complexes suggested from
the elemental analysis agrees with proposed formula and
the physical characteristics are given in (Table 1). The IR
spectroscopic and thermogravimetric data confirm water
molecules in the composition of the complexes. Qualitative
reactions revealed the presence of nitrate, chloride, sul-
phate and acetate ions as counter ions (outside the coordi-
2
SCHEME 2 The coordination mode of H L with M M = Zn(II)
and Ce(IV)
[24]
nation sphere).
ligand found at 10.55 S cm mol and the corresponding
values of the complexes were found in the region from
The molar conductance value of free
2
−1
2
−1
1
69.51, to 230.60 S cm mol at room temperature suggest
that these are 1:2 electrolytes.
3.1 | IR absorption spectra
The infrared spectra of H L and its complexes are listed
2
in Table 2 and recorded in Figure S1. As expected, the
absorption bands characteristic of H L acting as bidentate
2
unit in the complexes are observed with small changes in
2
SCHEME 3 The coordination mode of U(VI) with H L
2
TABLE 2 The characteristic IR bands of H L and it metal complexes
Compounds ν H
2
O
ν (N‐H)
ν (C≡N)
ν (M‐N)
ν (M = O)
H
2
L
‐
3392 ms
3289 m
3144 m
3311w
2205 s
2208 s
2200 m
2214w
2209 m
‐
‐
[Zn(H
[ZrO(H
[Ce(H L)
[UO (H L)
2
L)
L)
(H
2
(H
2
O)
O)]Cl
O) ](SO
O)](CH
2
](NO
3
)
2
3511mbr
3467mbr
3433mbr
3514mbr
721 m, 497sh
741sh, 548w
652 m, 610 m
675 ms, 462sh
‐
2
2
(H
2
2
.4H
2
O
877w
2
2
2
2
4
)
2
‐
2
2
2
(H
2
3
COO)
2
3132w
ν
ν
as = 918 s
= 822 m
s
Keys: s = strong, w = weak, v = very, m = medium, br = broad, ν = stretching

4
of 16
SADEEK ET AL.
band intensities and wavenumber. The infrared spectra of
metal complexes exhibit a broad band in the region
The spectra of the isolated solid complexes showed a
group of bands with different intensities which character-
istics for (M‐N). The ν(M‐N) bands observed at 721 and
−
1
3
514–3433 cm , which corresponds to the νH O vibra-
2
−
1
−1
tion and confirms the presence of water molecules in all
497 cm for Zn(II) complex, at 741 and 548 cm for
[
25,26]
−1
complexes.
2
The two bands observed at 3392 and
Zr(IV) complex, at 652 and 610 cm for Ce(IV) complex,
−
1
−1
205 cm in the spectrum of free ligand have been
and finally at 675 and 462 cm
for U(VI) complex
assigned to the stretching vibration ν(N‐H) and the
carbinitrile group ν(C≡N), respectively. The shift of
the characteristic peak of N‐H vibration to a lower value
from 3392 cm to the region 3311–3132 cm also, the
shift of the characteristic peak of the carbinitrile group ν
(Table 2). According to the above discussion the H L is
bonded to metal ions as a bidentate ligand through nitro-
gen atoms of amino and carbinitrile groups.
In Zn(II) and Ce(IV) complexes metal ions react with
H L forming complexes of monomeric structure where
2
2
−
1
−1
(
C≡N), to lower or higher values indicate the chelation
the metal ions is six coordinated (Scheme 2) and the
equatorial positions may be occupied by the four nitrogen
atoms of the ligand and the axial positions are occupied
by the oxygen atoms of the two coordinated water mole-
of ligand through nitrogen atoms of amino and
carbinitrile groups.
[27,28]
[
29–31]
cules.
The structures of the complexes possess one
plane of symmetry and may belong to C symmetry.
s
The C complexes, Zn(II) and Ce(IV) are expected to
s
display 219 vibrational fundamentals, which are all
/
monodegenerate. These are distributed between A and
//
A motions; all are IR and Raman active.
For U(VI) complex the two oxygen of uranyl group
occupy axial positions perpendicular to a plane occupied
by the different coordinating sites of the ligand. Thus
in this complex we propose that the uranyl group is
2
SCHEME 4 The coordination mode of Zr(IV) with H L
FIGURE 1 Electronic reflection spectra for (a) H
SO and (E) [UO (H L) (H O)](CH COO)
2 2 2 2 2 3 2 2 2 2 2 2 2 2 2 2
L, (B) [Zn(H L) (H O) ](NO ) , (C) [ZrO(H L) (H O)]Cl .4H O, (D) [Ce(H L) (H O) ]
(
4
)
2
2
2
2
2
3
2

SADEEK ET AL.
5 of 16
surrounded by two carbinitrile and two nitrogen of amine
groups of the bidentate ligand and one oxygen atom of
water molecule in a plane forming an irregular
quite well with those known for many dioxouranium
[
28]
(VI) complexes.
The ν (U=O) value was used to calcu-
s
late both the bond length and the bond stretching force
[32]
pentagon.
Accordingly, U(VI) complex may take the
constant, F(U=O), for UO bond according to the known
2
[
28,29]
structure shown in (Scheme 3) where H L is coordinated
method.
The calculated bond length and force
constant values are 1.771 Å and 646.53 Nm .
2
−
1
to U(VI) in a plane with the uranyl group, UO , perpen-
2
[33]
dicular to it with C point group.
For Zr (IV) complex which contains only plane of sym-
s
Under such symmetry, the ν (U=O) and ν (U=O)
metry may belong to C symmetry (Scheme 4) and display
as
s
S
absorption bands occurs as a very strong singlet at 918
and 822 cm , respectively. These assignments for the
213 vibrational fundamentals and all vibrations are distrib-
−
1
\
\\
uted between motions of the types A and A and the ν
1
−
1
stretching vibrations of the uranyl group, UO , agree
(Zr = O) found as a medium band at 877 cm (Table 2).
2
2
TABLE 3 UV–Vis. spectra of H L; Zn (II), Zr (IV), Ce (IV) and U (VI) complexes
Ligand‐metal
Ligand transitions
charge transfer
‐
1
‐1
Compounds
λ
max (nm)
(cm )ν
λ
max (nm)
(cm )ν
H
2
L
255, 298
39.216, 33.557
‐
‐
[
[
[
[
Zn(H
ZrO(H
Ce(H L)
UO (H L)
2
L)
L)
(H
2
(H
2
O)
O)]Cl
O) ](SO
O)](CH
2
](NO
3
)
2
299, 325, 389
282, 334, 382, 391
340
33.445, 30.769, 25.707
35.461, 29.940, 26.178, 25.575
29.412
422, 519
525
23.697, 19.268
19.048
2
2
(H
2
2
.4H
2
O
2
2
2
2
4
)
2
515
19.417
2
2
2
(H
2
3
COO)
2
277
36.101
499, 522
20.040, 19.157
1
FIGURE 2 H NMR spectra for (a) H
e) [UO (H L) (H O)](CH COO)
2 2 2 2 2 3 2 2 2 2 2 2 2 2 2 2 4 2
L, (b) [Zn(H L) (H O) ](NO ) , (c) [ZrO(H L) (H O)]Cl .4H O, (d) [Ce(H L) (H O) ](SO ) and
(
2
2
2
2
3
2

6
of 16
SADEEK ET AL.
3
.2 | UV–Visible solid reflection Spectra
spectra of H
2
L and its metal complexes, which was car-
ried out in DMSO‐d as a solvent. On comparing main
6
The formation of the complexes was confirmed by UV–
visible spectra. Figure 1 shows the electronic solid reflec-
tion spectra of H L, Zn(II), Zr(IV), Ce(IV) and U(VI)
compounds in the wavelength interval from 200 to
peaks of H L with its complexes, it is observed that all
2
the peaks of the free ligand are present in the spectra of
the complexes with chemical shift upon binding of ligand
to the metal ion.
showed peak at δ: 6.89 ppm corresponding to
amine group and at 7.08–8.14 ppm for
Comparison of the H NMR spectra of complexes with
that of ligand showed a significant perturbation of the
chemical shift of the aromatic protons and also exhibit
new peak in the range 3.32–3.39 ppm, due to the presence
of water molecules in the complexes and peaks in the
2
[31]
1
The H NMR spectrum of H2L
8
00 nm, (Table 3). It can be seen that free ligand reflected
ـ
NH of
CH aromatic.
2
at 255 and 298 nm, the first band may be attributed to
π‐π transition and the second band is assigned to n‐π
transitions.
the shift of the reflection bands to higher values and pres-
ence of new bands in the reflection spectra of complexes
indicated the formation of their metal complexes. The
complexes have new bands in the range from 422 to
ـ
*
*
1
[34]
The absence of the band at 255 nm and
range 7.04–7.17 ppm to
ـ
2
5
25 nm which may be assigned to the ligand to metal
7.28–8.17 ppm for
ـ
[35,36]
charge‐transfer.
3
.4 | Thermal analysis
1
3
.3 | The H NMR spectra
Thermrmogravimetric analysis (TGA) was mainly used to
proof the proposed formula and associated water or sol-
vent molecules to be in the coordination sphere or outer
The formation of the metal complexes was also confirmed
by H NMR spectra. Figure 2 represents the H NMR
1
1
2 2 2 2 2 3 2 2 2 2 2 2 2 2 2 2 4 2
FIGURE 3 TGA and DTG diagram for (a) H L, (b) [Zn(H L) (H O) ](NO ) , (c) [ZrO(H L) (H O)]Cl .4H O, (d) [Ce(H L) (H O) ](SO )
and (e) [UO (H L) (H O)](CH COO)
2
2
2
2
3
2

SADEEK ET AL.
7 of 16
[
37,38]
sphere of the complex.
Thermogravimetric (TG) and
3.5 | Mass spectra
differential thermogravimetric (DTG) analyses for H2L
The idea of mass spectrometer builds up on the separation
of fragments ions dependent to the variation of these ions
with the ratio of mass to charge (m/z). Mass spectrum of
and its isolated solid complexes were carried out under
ο
N flow with heating rates were controlled at 10 C/min
2
(
Figure 3). The H L is thermally stable at room
2
ο
the synthesized H
gested structure (Scheme 5). The H
2
2
L is in a good agreement with the sug-
temperatureand the decomposition started at 50 C and
finished at 350 C with one stage at a maximum 316 C
with weight loss of 82.35% (Table 4).
ο
ο
L shows molecular
.
+
2+
ion peak (M ) at m/z = 339 (25%) and M at m/z = 341
12%). The molecular ion peak [a] loses Cl to give frag-
(
2
−
The decomposition of Zn(II) complex at maximum
ο
ment [b] at m/z = 269 (12%) and it loses Cl to give frag-
ment [c] at m/z = 304 (11%). It loses CN to give [d] at
2
61 C with weight loss of 82.47% in agreement with the
−
loss of 11C H + 3 N + HCN + 7CO + 2Cl + NH living
2
2
2
2
3
m/z = 313 (12%). The molecular ion peak [a] gave fragment
ZnO as a final product. The decomposition of Zr(IV)
complex occurs at two main degradation step. The first
stage of decomposition occurred in the 40–69°C tempera-
ture with a weight loss of 7.55% corresponds to the loss of
hydrated water molecule. The second stage of decomposi-
tion occurred at 371°C temperature with a weight loss of
[
(
e] at m/z = 323 (17%), [f] at m/z = 91 (45%), [g] at m/z = 85
34%), [h] at m/z = 117 (6%), [i] at m/z = 215 (10%), [j] at
m/z = 228 (5%) and also [k] at m/z = 212 (22%). The frag-
mentation patterns of our studied complexes were
obtained from mass spectra (Figure S2). The mass spectra
of (1), (2), (3) and (4) complexes displayed molecular ion
peaks at m/z = 903, 945, 1046 and 1084 with the abundance
at 7%, 6%, 9% and 11%, respectively.
7
1.95% corresponding to loss of 12C H + 6NCCl. The
2 2
thermal decompostion of Ce(IV) and U(VI) complexes
proceeds with one main degradation step. The step of
ο
decomposition occurs at 280 and 214, 325 C with a
weight loss of 63.88%, and 72.52% corresponding to the
3.6 | Antimicrobial activity
loss of 13C H2
+
N2
+
4NCCl
+
2CO and
2
1
5C H + 1.5 N + 3NCCl + 5CO + 0.5Cl giving Ce
The results of antimicrobial activity testing in vitro of
2
2
2
2
(
SO ) and UO as a final product. The IR spectra of
H L and its complexes are shown in Figure 4 and listed
2
4
2
2
the final products of complexes, agree well with that
of Ce (SO ) and metal oxides with the absence of all
bands charactaristic of the free ligand.
in Table 5. The test objects were gram‐negative
Escherichia coli (E. coli), Pseudomonas aeruginosa
(P. aeruginosa) and gram‐positive bacteria Bacillus
4
2
TABLE 4 The maximum temperature Tmax(οC) and weight loss values of the decomposition stages for H
2
L, Zn(II), Zr(IV), Ce(IV) and U(VI)
complexes
Weight loss (%)
T
( C)
max
ο
Compounds
Decomposition
Calc.
Found
Lost species
H
2
L
First step
316
82.35
82.35
5C
2
H
2
+ HCN + 2NCCl
(
C
18
H
11
N
3
Cl
2
)
Total loss
Residue
82.35
17.64
82.35
17.64
5C
[
(
Zn(H
2
L)
2
(H
2
O)
2
](NO
3
)
2
First step
261
83.05
82.47
11C
2
H
2 2 2 3
+ 3 N + HCN + 7CO + 2Cl + NH
C
36
H
26
N
8
O
8
4
Cl Zn)
Total loss
Residue
83.05
16.94
82.47
17.53
ZnO + 6C
4H
12C
[
(
ZrO(H
2
L)
2
(H
2
O)]Cl
Zr)
2
.4H
2
O
First step
60
7.59
7.55
2
O
C
36
H
32
N
6
O
6
Cl
6
Second step
Total loss
Residuex
371
71.79
79.38
20.62
71.95
79.50
20.50
2
H
2
+ 6NCCl
ZrO
13C
2
+ 6C
2
+ N + 4NCCl + 2CO
[
(
Ce(H
2
L)
2
(H
2
O)
2
4
](SO
4
)
2
First step
280
63.72
63.88
2
H
2
C
36
H
30
N
6
O
10Cl
S
2
Ce)
Total loss
Residue
63.72
36.27
63.88
36.12
Ce(SO
15C
4
)
2
+ 4C
[
(
UO
2
(H
2
L)
2
(H
2
O)](CH
U)
3
COO)
2
First step
214, 325
72.92
72.52
2
H
2
+ 1.5 N + 3NCCl + 5CO + 0.5Cl2
2
C
40
H
30
N
6
O
7
Cl
4
Total loss
Residue
72.92
27.07
72.52
27.48
2
UO + 2C

8
of 16
SADEEK ET AL.
SCHEME 5 Fragmentation pattern of
H L
2
subtilis (B.subtilis), Staphylococcus aureus (S. aureus)
and Candida albicans (C. albicans, Aspergillus fungi
the cell favors the passage of only lipid‐soluble materials
in which liposolubility is an important factor that con-
trols the antimicrobial activity. On chelation the polarity
of the metal ion will be reduced to a greater extent due
to overlap of ligand orbital and partial sharing of
the positive charge of the metal ion with donor groups.
Further it increases the delocalization of π‐electrons over
the whole chelate ring and enhances the lipophilicity of
(
A. fumigates). A comparative study of H L and its metal
2
complexes showed that the metal complexes exhibit high
antibacterial and antifungal activity (Table 5). The Zr(IV)
and U(VI) complexes showed high significant for
(
E. coli), Ce(IV) Complex showed highly significant for
P. aeruginosa and S. aureus but U(VI) complex showed
highly significant C. Albicans. Zn(II) Complex showed
significant as antibacterial against E. coli, P. Aeruginosa
and B. subtilis and antifungal activity against C. Albicans
and Aspergillus fumigates (A. Fumigates). These results
clearly, obviously that, some metal ions after complexa-
tion give the sensitive nature of the ligand against
some bacteria and fungi, these results are compared
[
42]
the complexes.
This increased lipophilicity enhances
the penetration of complexes into the lipid membranes
and blocks the metal binding sites in enzymes of
microorganisms.
4
| COMPUTATIONAL DETAILS
.1 | Computational method
[39–41]
with the previous studies.
The increased activity
4
of metalchelate can be explained on the basis of the
oxidation state of the metal ion, overtone concept and
chelation theory. According to the overtone concept of
cell permeability, the lipid membrane that surrounds
Density functional theory (DFT) used to detect the exact
structure of the complexes with different coordination
numbers. The atomic charges were computed using

SADEEK ET AL.
9 of 16
2
FIGURE 4 Statistical representation for biological activity of H L and its metal complexes
the natural atomic orbital populations. The B3LYP is the
C13C9C15N16 and C8C9C15N16 are 0.00° and 180.00°
which confirms –CN group in the same plane of mole-
cule. The value of bond angle C9C15N16 is 152.54°
reflects on sp hybridization of C15. The values of bond
[43]
keyword for the hybrid functional,
which is a linear
combination of the gradient functionals proposed by
Becke and Lee, Yang and Parr, together with the
[44–46]
Hartree‐Fock local exchange function.
distances of H L are compared with that obtained from
2
[
47]
crystal structure data.
Table 6 gives equilibrium
geometric parameters bond lengths (Å), bond angles
4
.2 | Structural parameters and models
(°), dihedral angles (°) and charge density of H L and
2
Figure 5 showed the optimized geometry of H L as
2
4.2.1 | 4,6‐bis (4‐chlorophenyle)‐2‐amino‐
1,2‐dihydropyridine‐carbinitrile (H L)
obtained from theoretical calculations.
2
There is a significant built up of charge density on the
nitrogen atoms of carbinitrile and amino groups so H2L
molecule react as bi‐dentate through Ncarbinitrile and
Namino atoms with the energy value is −136.23 au and
dipole μ = 1.366.
The calculated dihedral angles of H L molecule indicate
that the two benzene rings of the H L found in the
same plane of the pyridine ring which indicate the
molecule is not sterically‐hindered. The dihedral angles
2
2

10 of 16
SADEEK ET AL.
2
TABLE 5 The inhibition diameter zone values (mm) for H L and its metal complexes
Microbial species
Bacteria
Fungi
Compounds
E. coli
P. aeruginosa
B. subtilis
S. aureus
C. Albicans
A. Fumigatus
H
2
L
10 ± 0.22
12 ± 0.11
+1
15 ± 0.09
+1
18 ± 0.05
NS
14 ± 0.01
+1
16 ± 0.10
+1
+
1
[Zn(H
[ZrO(H
[Ce(H L)
[UO (H L)
2
L)
L)
(H
2
(H
2
O)
O)]Cl
O) ](SO
O)](CH
2
](NO
3
)
2
19 ± 0.22
18 ± 0.11
+1
20 ± 0.09
+1
20 ± 0.05
NS
20 ± 0.01
+1
20 ± 0.10
NS
+2
2
2
(H
2
2
.4H
2
O
20 ± 0.22
16 ± 0.11
21 ± 0.09
21 ± 0.05
18 ± 0.01
18 ± 0.10
+
1
+2
+1
+2
+1
NS
2
2
2
2
4
)
2
19 ± 0.22
20 ± 0.11
19 ± 0.09
25 ± 0.05
20 ± 0.01
19 ± 0.10
+2
+1
+1
+1
+2
+1
2
2
2
(H
2
3
COO)
2
21 ± 0.22
18 ± 0.11
21 ± 0.09
22 ± 0.05
22 ± 0.01
20 ± 0.10
Zn(NO
Ce(SO
3
)
2
.6H
2
O
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5 ± 0.22
4
)
2
0
0
Controul (DMSO)
Standard
Ampicilin
Amoxycilin
Cefaloxin
0
0
0
0
0
28 ± 0.40
22 ± 0.11
27 ± 1.15
0
0
0
0
0
0
0
18 ± 1.73
16 ± 0.52
24 ± 0.34
NS
+1
+2
+3
Statistical significance P P not significant, P < 0.05; P P significant, P > 0.05; P P highly significant, P > 0.01; P P very highly significant, P > 0.001;
student'st‐test (Paired).
4
.2.2 | The Zn(II) complex
Table 7. Zn(II) is coordinated with Namino and Ncarbinitrile
atoms with bond lengths Zn‐N9, Zn‐N48,Zn‐N2 and
The experimental data indicate that the complex is
six‐coordinate where the Zn(II) coordinated with two
molecules of H L and the other two coordinated bonds
may be with two water molecules or one nitrate ion
[49–52]
Zn‐N50 are 2.059, 2.058, 1.873 and 1.871 Å.
The
bond lengths between Zn(II) and oxygen atoms of water
2
molecules are 1.918 and 1.920 Å for Zn‐O72 and
[56,57]
Zn‐O69.
Also the angles around the central Zn(II)
−
NO3
to complete the coordination sphere. There
with surrounding oxygen and nitrogen atoms vary from
73.67° to 163.67°; these values agree with these expected
for a distorted octahedron. The bond angle between
N9ZnN48 is 94.46° (≈ 90°) and also the angle between
for the two structures, [Zn(H L) (NO )]NO and
2
2
3
3
[
Zn(H L) (H O) ](NO ) were theoretically investigated.
2 2 2 2 3 2
Description of the structure [Zn(H L) (NO )]NO
N2ZnN50 is 161.58° ≈ 180° so the two H L molecules
2
2
3
3
2
Figure 6 showed the optimized geometrical structure of
the complex with the atomic numbering and the
selected bond length and angles are given in Table 7.
The angles around the central metal ion Zn(II) vary
from 73.53° to 166.46° which indicate the complex is
distorted octahedral. Zn(II) is coordinated to one Namino
are perpendicular respect to each other with angle equal
90°. The angle between O69ZnO72 is 89.74° this value
reflects that the two water molecules are perpendicular
to each other.
The charge accumulated on Namino (−0.256
and − 0.252) and Ncarbinitrile (−0.151 and − 0.113), in
nitrate complex while, that for Namino (−0.266
and − 0.265) and Ncarbinitrile (−0.211 and − 0.213), in
water complex. There is a strong interaction between Zn
(II) which become has charge equal +0.216 in case of
water complex while, in case of nitrate complex the
charge accumulated on Zn(II) is 0.083. The energy of
the water complex is more negative than nitrate
complexes −459.717 au and a highly dipole 11.312D. So
Zn(II) favor coordinated with two molecules of water
more than one molecule of nitrate ion to complete the
octahedron structure.
atom and one N
oxygen atoms of NO3 group. The nitrate ion may be
coordinated by a single oxygen atom or by two oxygen
atom of H L ligand and two
2
carbinitrile
−
[48]
atoms with Zn(II).
The bond lengths of Zn‐N9,
Zn‐N48, Zn‐N2 and Zn‐N50, of Namino and Ncarbinitrile
atoms are 2.059, 2.055, 1.871 and 1.870 Å, respec-
[49–52]
tively
and the bond length between Zn‐O70 and
Zn‐O71 of nitrate ion are 1.923 and 1.922 Å while the
[
53–55]
bond angle O70NO71 of nitro group is 96.53°.
The energy of this complex is −434.924 au and the
dipole moment is 4.675D.
Description of the structure [Zn(H L) (H O) ](NO )
3 2
The Zr(IV) complex
2
2
2
2
The structure of complex is shown in Figure 7 and the
selected inter atomic lengths and angles are listed in
Two molecules of H L chelated with Zr(IV) and Zr(IV)
complete the coordination sphere by one water molecule
2

SADEEK ET AL.
11 of 16
TABLE 6 Equilibrium geometric parameters bond lengths (Å),
octahedron. The energy of this complex is −419.584 au
2
bond angles (°), dihedral angles (°) and charge density of H L ligand
and has greater dipole moment is 13.17D.
Bond length (Å)
Description of the structure [ZrO(H L) (Cl)]Cl
2
2
C11‐N12 1.361 [58]
C1‐Cl7 1.737
C20‐Cl23 1.738
In Figure S4, the bond angles between N15ZrCl,
N37ZrN17 and N44ZrN15 are 166.34° (≈ 180°),
156.85° ≈ 180° and 86.66° ≈ 90° so the two units of
C8‐C9 1.401 [57]
C9‐C13 1.413 [57]
C13‐N14 1.398 [59]
C13‐N12 1.355 [58]
H L molecule are not lying in the same plane they are
C8‐C10 1.400 [58]
C15‐N16 1.218 [60]
2
perpendicular respect to each other with angle equal
9
0°. As listed bond angles (Table S1) the Zr(IV) complex
Bond angle (°)
is six‐coordinate with distorted octahedral environment
and the bond length Zr‐N15, Zr‐N44,Zr‐N17 and Zr‐
N37are 2.241, 2.242, 2.065, and 2.064 Å of H L ligand
C9 C15 Nl6 152.54
C9 C8 C10 116.04
C10 C11 C12 123.63
N14 C13 N12 122.57
C8 C9 C15 129.25
Dihedral angles (°)
C5 C8 C10 129.74
N14 C13 C9 116.15
C11 N12 C13 117.34
C17 C11 N12 114.09
H33 N14 H34 123.42
2
[60,61]
and Cl ion with bond distance Zr‐Cl is 2.443 Å.
Also, the angles around Zr(IV) with surrounding oxygen
and nitrogen atoms vary from 68.65 to 166.34°; these
values agree with these expected for a distorted
octahedron.
C8C9C15N16–180.00
N14C13C9C15 0.00
N14C13N12C11 0.00
C21C17C11N12 180.00
C21C17C11N12 180.00
Charges
C4C5C8C9–180.00
C13C9C15N16 0.00
C8C9C13N14–180.00
C18C17C11N12 0.00
C9C8C5C6 0.00
The comparison between stability of water and chlo-
ride complexes can be depended on some factors, as
bond distances between Zr(IV) and surrounded oxygen
and nitrogen atoms of H L in water complex are shorter
2
than that in chloride complex as shown in Table S1, so
that Zr(IV) is bonded strongly with surrounded oxygen
and nitrogen atoms of H L in water complex more than
2
that in chloride complex. Also, the charge accumulated
on Namino (−0.247 and − 0.221) and Ncarbinitrile (−0.183
and − 0.216), in water complex while, Namino (−0.249
and − 0.256) and Ncarbinitrile (−0.117 and − 0.123), in
chloride complex. There is a strong interaction between
Zr(IV) which become has charge equal +0.395 in case
of water complex while, in case of chloride complex
the charge accumulated on Zr(IV) is 0.338. The energy
of the chloride complex is −406.302 au is less negative
than water complex and less dipole 6.99D. For all
these reasons the water complex is more stable than
chloride complex and Zr(IV) favor coordinated with
one water.
Cl7–0.287
Cl23–0.292
C20 0.244
C13 0.328
C11 0.192
C1 0.242
−186.223
1.366
N16–0.315
C15 0.155
N14–0.403
N12–0.312
Total energy/au
Total dipole moment/D
or chloride ion beside oxygen atom of Zr(IV). There
are two possible structures can be obtained [ZrO
(
H L) (H O)]Cl and [ZrO(H L) (Cl)]Cl, so we study
2 2 2 2 2 2
theoretically these two states to detect the more stable
structure.
The Ce(IV) complex
The Ce(IV) may be chelated with two molecules of H2L
through Namino and Ncarbinitrile from each molecule. The
experimental data set that the result complex is six‐coor-
dinate so, the complex complete its octahedral structure
through chelation with two coordinated bonds with two
water molecules or one sulfate ion. We study theoretically
these two structures which can be obtained, [Ce
(H L) (H O) ](SO ) and [Ce(H L) (SO )]SO and also
Description of the structure [ZrO(H L) (H O)]Cl
2
2
2
2
Table S1 listed selected inter atomic distances and angles
where the structure of complex with atomic numbering is
shown in Figure S3. In this complex Zr(IV) bonded with
one water molecule to complete the six‐coordination
sphere. The Zr‐N17, Zr‐N46, Zr‐N19 and Zr‐N39 bond
2
2
2
2
4 2
2
2
4
4
[
58,59]
lengths are 2.339, 2.272, 2.027 and 2.039 Å
also,
The
detect the exact stable structure of them.
Description of the structure [Ce(H L) (SO )]SO
4
Figure S5 shows the optimized geometrical structure of
the complex and the selected bond lengths and angles
[
60]
the bond distance between Zr‐OH2O is 2.161 Å.
angles around Zr(IV) with surrounding oxygen and
nitrogen atoms vary from 68.99° to 164.51°; these
values differ legally from these expected for a regular
2
2
4

12 of 16
SADEEK ET AL.
2
FIGURE 5 The optimized geometrical structure of H L
2 2 3 3
FIGURE 6 Optimized geometrical structure of trans‐isomer of [Zn(H L) (NO )]NO complex

SADEEK ET AL.
13 of 16
TABLE 7 Equilibrium geometric parameters bond lengths (Å),
are given in Table S2. The complex is six‐coordinate with
distorted octahedral environment around the metal ion
and Ce(IV) is coordinated to one NAmino atom and one
bond angles (°) and charge density of [Zn(H
L) (H O) ](NO complexes
2
L)
2
(NO
3
)]NO
3
and [Zn
(
H
2
2
2
2
3 2
)
N
atom of H L ligand and two oxygen atoms of
2
[
Zn (H
2
L)
2
(NO
3
)]N0
3
[Zn (H
2
L)
2
(H
2
O)
2
](NO
3
)
2
carbinitrile
2
−
SO4 group. The bond lengths Ce‐N2, Ce‐N50,Ce‐N9
and Ce‐N48 are 2.265, 2.260, 2.433 and 2.432 Å
and the bond distance between Ce‐O70 and Ce‐O71 of
sulfate group are 2.312 and 2.309 Å.
around the central metal ion Ce(IV) with surrounding
four oxygen atoms and nitrogen atoms vary from 62.74°
to 151.53°; these values differ legally from a regular
octahedron.
The energy of the complex is −423.050au while the
dipole moment is 7.432D (slightly weak) also, the charge
accumulated on N2 and N9 of the first molecule are
Bond length (Å)
Zn‐N9 2.059
[62–64]
Zn‐N9 2.059
[
65,66]
Zn ‐N2 1.871
Zn –N48 2.055
Zn –N50 1.870
Zn –O70 1.923
Zn –O71 1.922
C4‐N9 1.528
Zn ‐N2 1.873
Zn –N48 2.058
Zn –N50 1.871
Zn –O69 1.920
Zn –O72 1.918
C4‐N9 1.528
Also, the angles
C47‐N48 1.528
C1‐N2 1.147
C47‐N48 1.528
C1‐N2 1.147
−0.228 and − 0.281 while for N48 and N50 of the second
molecule are −0.273 and − 0.231. The bond angle of
C49‐N50 1.147
Bond angle (°)
N2 Zn N9 73.53
C49‐N50 1.147
[
67,68]
O72SO73 of sulfate group is 133.53°.
Description of the structure [Ce(H L) (H O) ](SO )
4 2
N2 Zn N9 73.67
2
2
2
2
N2 Zn O71 101.93
N2 Zn O70 157.68
N2 Zn N50 104.45
N2 Zn N48 93.65
N9 Zn O71 92.72
N9 Zn O70 89.21
N9 Zn N50 166.46
N9 Zn N48 92.83
O71 Zn O70 64.09
O71 Zn N50 100.77
O71 Zn N48 164.38
O70 Zn N50 95.58
O70 Zn N48 101.40
N50 Zn N48 73.83
Charges
N2 Zn O72 101.66
N2 Zn O69 90.22
N2 Zn N50 161.58
N2 Zn N48 95.04
N9 Zn O72 90.89
N9 Zn O69 163.67
N9 Zn N50 92.39
N9 Zn N48 94.46
O72 Zn O69 89.74
O72 Zn N50 90.31
Table S2 lists selected inter atomic lengths and angles
and the structure of complex is shown in Figure S6. The
bond angle between N49CeN20 and N42CeN22 are
1
44.66° ≈ 180° and 83.22° (≈ 90°) so the two H L mole-
2
cules are are perpendicular respect to each other with
angle equal 90°. The angle between O1CeO4 is 78.86° this
value reflects that the two water molecules are lying in
cis‐form and perpendicular to each other. The complex
consists of two units of H L molecule and two water
2
molecules with Ce(IV) ion. Ce(IV) is coordinated with
Namino and Ncarbinitrile atoms of H L ligand and two oxy-
2
gen atoms of two water molecules. The Ce‐N20, Ce‐N49,
Ce‐N22 and Ce‐N42 bond lengths are2.432, 2.430, 2.265
O72 Zn N48 163.29
O69 Zn N50 103.92
O69 Zn N48 89.53
N50 Zn N48 73.69
[
62–64]
and 2.264 Å
and the bond length between Ce(IV)
and oxygen atom of water molecule vary between 2.311
[
69]
and 2.313 Å for Ce‐O1 and Ce‐O4.
around Ce(IV) with surrounding oxygen atoms vary from
3.49° to 144.66°; these values agree with these expected
Also, the angles
6
Zn 0.083
N50–0.113
N46–0.275
C47 0.298
C43–0.057
C49 0.213
O70–0.352
O71–0.331
Zn 0.216
N9–0.266
N2–0.211
N6–0.272
C1 0.259
C3–0.211
C4 0.302
N48–0.265
N50–0.213
N46–0.272
C47 0.303
C43–0.079
C49 0.147
O69–0.303
O72–0.303
for a distorted octahedron.
Also, the charge accumulated on Namino are −0.281
and − 0.273 and Ncarbinitrile are −0.228 and − 0.231, in
sulfate complex while, that for Namino are −0.285
and − 0.290 and Ncarbinitrile are −0.279 and − 0.281, in
water complex. There is a strong interaction between Ce
(IV) which become has charge equal +0.899 in case of
water complex while, in case of sulfate complex the
charge accumulated on Ce(IV) is 0.620. The energy of
the water complex is more negative than sulfate com-
plexes −458.393 au and relatively weak dipole 10.79D.
For all these reasons the water complex is more stable
than other complexes and Ce(IV) favor coordinated with
two molecules of water more than one molecule of sulfate
ion to complete the octahedron structure.
N9–0.256
N2–0.151
N6–0.271
C1 0.217
C3–0.065
C4 0.299
N48–0.252
Total energy/au
Total dipole moment/D
434.924
.675
−
−459.717
4
11.312

14 of 16
SADEEK ET AL.
2 2 2 2 3 2
FIGURE 7 Optimized geometrical structure of trans‐isomer of [Zn(H L) (H O) ](NO ) complex
5
| CONCLUSION
REFERENCES
[1] C. Dette, H. Wätzig, H. Uhl, Pharmazie 1993, 48, 276.
The H2L has two donating centers Namino and
Ncarbinitrile, which chelated with metal ions (Ce(IV),
Zn(II), Zr(IV) and U(VI)). The complexes completed
octahedral structure through coordination with one or
two water molecules. According to DFT calculations,
the following reasons indicate that the coordination of
water with metal ions forming stable complexes more
than other complexes (i) There are more negative
charges are accumulated over donating atoms and large
positive charge on central metal ion. (ii) Highly dipole
greater than other complexes. (iii) Lower energy values
less than other studied complexes. The product
complexes are treated as distorted octahedral complexes.
Ce(IV) Complex showed significant antibacterial activity
for (E. coli), (B. subtilus) and highly significant for
[
2] N. K. Kaushik, N. Kaushik, P. Attri, N. Kumar, C. H. Kim, A.
K. Verma, E. H. Choi, Molecules 2013, 18, 6620.
[
[
[
3] Y. Li, Y. Chai, R. Yuan, W. Liang, Russ. J. Inorg. Chem. 2008,
53, 704.
4] A. K. Singh, P. Kumar, M. Yadav, D. S. Pandey, J. Organomet.
Chem. 2010, 695, 567.
5] D. H. Boschelli, B. Wu, A. C. B. Sosa, H. Durutlic, F. Ye, Y.
Raifeld, J. M. Golas, F. Boschelli, J. Med. Chem. 2004, 47, 6666.
[
[
6] M. J. Shiao, L. M. Shyu, C. F. Chen, Heterocycles 1990, 31, 523.
7] H. A. Saad, M. N. Mokbil, A. M. El‐Gendy, A. Z. Haikal, Synth.
Commun. 2002, 32, 1189.
[
8] V. Dolle, E. Fan, C. H. Nguyen, A. M. Aubertin, A. Kirn, M. L.
Andreola, G. Jamieson, L. T. Litvak, E. Bisagni, J. Med. Chem.
1995, 38, 4679.
[
9] D. L. Griggs, P. Hedden, K. E. Temple‐Smith, W. Rademacher,
Phytochemistry 1991, 30, 2513.
(P. aeruginosa) and (S. aureus), for U(VI) complex
showed highly significant for (E. coli), (C. Albicans)
and significant for (P. aeruginosa), (S. aureus) and
[
10] M. N. Hopkinson, C. Richter, M. Schedler, F. Glorius, Nature
2014, 510, 485.
(
A. Fumigates).
[11] D. J. Nelson, S. P. Nolan, Chem. Soc. Rev. 2013, 42, 6723.
[
12] H. Jacobsen, A. Correa, A. Poater, C. Costabile, L. Cavallo,
ORCID
Coord. Chem. Rev. 2009, 253, 687.
[
13] T. Droge, F. Glorius, Angew. Chem. Int. Ed. 2010, 49, 6940.
S.M. Abd El‐Hamid http://orcid.org/0000-0002-3658-3629
W.A. Zordok http://orcid.org/0000-0002-2919-5927
[14] L. Mercs, M. Albrecht, Chem. Soc. Rev. 2010, 39, 1903.

SADEEK ET AL.
15 of 16
[
[
15] S. B. Aher, P. N. Muskawar, K. Thenmozhi, P. R. Bhagat, Eur. J.
Med. Chem. 2014, 81, 408.
[39] I. Muhammad, I. Javed, I. Shahid, I. Nazia, Turk. J. Biol. 2007,
31, 67.
16] J. G. Małecki, M. Jaworska, R. Kruszynski, R. Gil‐Bortnowska,
Polyhedron 2005, 24, 1445.
[40] J. R. Anacona, C. Toledo, Trans. Met. Chem. 2001, 26, 228.
[41] E. K. Efthimiadou, A. Karaliota, G. Pasomas, J. Inorg. Biochem.
[
[
[
[
17] J. Reedijk, Chem. Commun. 1996, 7, 801.
2010, 104, 455.
18] K. Gkionis, J. A. Platts, Comput. Theor. Chem. 2012, 993, 60.
19] A. G. Quiroga, J. Inorg. Biochem. 2012, 114, 106.
[42] C. Dendrinou‐Samara, G. Psomas, C. P. Raptopoulou, D. P.
Kessissoglou, J. Inorg. Biochem. 2001, 83, 7.
[
43] W. A. Zordok, S. A. Sadeek, A. F. El‐Farargy, J. Iran. Chem.
Soc. 2017, 14, 2529.
20] Gaussian 98, Revision A.6, M. J. Frisch, G. W. Trucks, H. B.
Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, V. G.
Zakrzewski, J. A. Montgomery, Jr., R. E. Stratmann, J. C.
Burant, S. Dapprich, J. M. Millam, A. D. Daniels, K. N. Kudin,
M. C. Strain, O. Farkas, J. Tomasi, V. Barone, M. Cossi, R.
Cammi, B. Mennucci, C. Pomelli, C. Adamo, S. Clifford, J.
Ochterski, G. A. Petersson, P. Y. Ayala, Q. Cui, K. Morokuma,
D. K. Malick, A. D. Rabuck, K. Raghavachari, J. B. Foresman,
J. Cioslowski, J. V. Ortiz, B. B. Stefanov, G. Liu, A. Liashenko,
P. Piskorz, I. Komaromi, R. Gomperts, R. L. Martin, D. J. Fox,
T. Keith, M. A. Al‐Laham, C. Y. Peng, A. Nanayakkara, C.
Gonzalez, M. Challacombe, P. M. W. Gill, B. Johnson, W. Chen,
M. W. Wong, J. L. Andres, C. Gonzalez, M. Head‐Gordon, E. S.
Replogle, J. A. Pople, Gaussian, Inc., Pittsburgh PA, 1998.
[
44] W. A. Zordok, S. A. Sadeek, J. Therm. Anal. Calorim. 2017, 128, 971.
[45] S. Li Ning, S. Jingling, L. Jinhai, X. Laishun, L. M. Xiaoyu, J.
Yan, Opt. Express 2005, 13, 6750.
[
[
46] D. Tapu, O. J. Buckner, C. M. Boudreaux, B. Norvell, M. Vasiliu,
D. A. Dixon, C. D. McMillen, J. Organomet. Chem. 2016, 823, 40.
47] J. M. Gichumbi, H. B. Friedrich, B. Omondi, J. Mol. Catal. A:
Chem. 2016, 416, 29.
[48] H. Akkari, P. Bénard‐Rocherullé, H. Mérazig, T. Roisnel, J.
Rocherullé, Solid State Sci. 2006, 8, 704.
[
[
[
49] N. P. Kuzmina, I. A. Martynova, D. M. Tsymbarenko, K. A.
Lyssenko, Inorg. Chem. Comm. 2011, 14, 180.
[
[
[
[
[
21] W. J. Stevens, M. Krauss, H. Basch, P. G. Jasien, Can. J. Chem.
50] G. R. A. Wyllie, O. Q. Munro, C. E. Schulz, W. Robert Scheidt,
1
992, 70, 612.
22] D. J. Beecher, A. C. Wong, Appl. Environ. Microbial. 1994, 60,
646.
Polyhedron 2007, 26, 4664.
51] B. L. Westcott, G. Crundwell, M. Remesic, K. Knopf, K.
1
Chandler, J. McMaster, E. S. Davies, Inorg. Chem. Comm.
2016, 74, 79.
23] E. Fallik, J. Klein, S. Grinberg, E. Lomaniee, S. Lurie, A.
Lalazar, Plant Dis. 1993, 77, 985.
[
52] (a) H. A. Rudbari, M. R. Iravani, V. Moazam, B. Askari, M.
Khorshidifard, N. Habibi, G. Bruno, J. Mol. Struct. 2016, 1125,
24] Y. Y. Yu, H. D. Xian, J. F. Liu, G. L. Zhao, Molecules 2009, 14,
113. (b) T. Zhou, X. Wang, K. Xu, J. Song, F. Zhao, Inorg. Chim.
1
747.
25] T. Sakauge, I. Turel, E. Sletten, Inorg. Chim. Acta 2002, 339,
39.
Acta 2016, 453, 149.
[
53] M. Akhtar, M. A. Alotaibi, A. I. Alharthi, W. Zierkiewicz, M. N.
Tahir, M. Mazhar, A. A. Isab, M. Monim‐ul‐Mehboob, S.
Ahmad, J. Mol. Struct. 2017, 1128, 455.
2
[
[
26] G. Pasomas, J. Inorg. Biochem. 2008, 102, 1798.
27] S. A. Sadeek, W. A. Zordok, M. S. El‐Attar, M. S. Ibrahim, Bull.
Chem. Soc. Ethiop. 2015, 29, 75.
[
[
[
[
[
[
54] A. J. Wawrzycka, P. Rogala, G. Czerwonka, M. Hodorowicz, K.
Stadnicka, J. Mol. Struct. 2016, 1105, 357.
[
28] C. Chulvi, M. C. Munõz, L. Perelló, R. Ortiz, M. I. Arriortua, J.
55] J. Mondal, A. Dutta, P. K. Pal, R. Saha, P. Maji, G. K. Patra,
Via, K. Urtiaga, J. M. Amigó, L. E. Ochando, J. Inorg. Biochem.
Inorg. Chim. Acta 2016, 448, 70.
1
991, 42, 133.
56] N. K. Al Rasbi, H. Adams, I. AlShabibi, F. AlAmri,
[
[
29] W. A. Zordok, W. H. El‐Shwiniy, M. S. El‐Attar, S. A. Sadeek,
J. Mol. Struct. 2013, 1047, 267.
J. Photochem. Photobio. A: Chem. 2014, 285, 37.
57] L. D. Slep, R. Calvo, O. R. Nascimento, R. Baggio, M. T. Gar-
30] S. A. Sadeek, S. M. Abd El‐Hamid, M. M. El‐Asser, Monatsh.
Chem. 2015, 146, 1967.
land, O. Peña, M. Perec, Inorg. Chim. Acta 2007, 360, 2911.
58] M. Kumar, S. Roy, M. S. H. Faizi, S. Kumar, M. K. Singh, S.
[
[
[
31] B. M. Lomaestro, G. R. Bailie, Ann. Pharmacother. 1991, 25, 1249.
Kishor, S. C. Peter, R. P. John, J. Mol. Struct. 2017, 1128, 195.
32] M. Shebl, Spectrochim. Acta A 2008, 70, 850.
59] J. d'Angelo, G. Morgant, N. E. Ghermani, D. Desmaële, B.
Fraisse, F. Bonhomme, E. Dichi, M. Sghaier, Y. Li, Y. Journaux,
J. R. J. Sorenson, Polyhedron 2008, 27, 537.
33] S. A. Sadeek, W. H. El‐Shwiniy, W. A. Zordok, E. Kotb, J. Mol.
Struct. 2011, 1006, 192.
[
60] (a) M. Graser, H. Kopacka, K. Wurst, T. Müller, B. Bildstein,
Inorg. Chim. Acta 2013, 401, 38. (b) Q. Wang, H. Song, G. Zi,
J. Organomet. Chem. 2010, 695, 1583.
[
[
34] W. A. Zordok, Spectrochimica Acta A 2014, 129, 519.
35] S. A. Sadeek, M. S. El‐Attar, S. M. Abd El‐Hamid, J. Mol. Struct.
2
013, 1051, 30.
[
61] W. P. Leung, F. Q. Song, Z. Y. Zhou, F. Xue, T. C. W. Mak,
[
36] S. A. Sadeek, M. S. El‐Attar, S. M. Abd El‐Hamid, Synth. React.
Inorg. Met. Org. Nano‐Met. Chem. 2015, 45, 1412.
J. Organomet. Chem. 1999, 575, 232.
[
62] S. Lin, C. S. Diercks, Y. B. Zhang, N. Kornienko, E. M. Nichols,
Y. Zhao, A. R. Paris, D. Kim, P. Yang, O. M. Yaghi, C. J. Chang,
Science 2015, 349, 1208.
[
[
37] M. Shebl, Spectrochim. Acta A 2009, 73, 313.
38] A. M. Mansour, Inorg. Chim. Acta 2013, 408, 186.

16 of 16
SADEEK ET AL.
[
63] Z. Kartal, Spectrochim. Acta A. 2016, 152, 577.
SUPPORTING INFORMATION
Additional supporting information may be found online
in the Supporting Information section at the end of the
article.
[
64] C. Chen, H. Chen, P. Yan, G. Hou, G. Li, Inorg. Chim. Acta
2
013, 405, 182.
[
65] L. Li, F. Yuan, T. Li, Y. Zhou, M. Zhang, Inorg. Chim. Acta
013, 397, 69.
2
[
66] E. Szłyk, A. Wojtczak, L. Dobrzańska, M. Barwiołek, Polyhe-
dron 2008, 27, 765.
How to cite this article: Sadeek SA, Abd El‐
Hamid SM, Zordok WA. Spectroscopic, DFT and
antimicrobial activity of Zn(II), Zr(IV), Ce(IV)
and U(VI) complexes of N,N‐ chelated 4,6‐bis (4‐
chlorophenyl)‐2‐amino‐1,2‐dihydropyridine‐3‐
carbinitrile. Appl Organometal Chem. 2018;e4457.
https://doi.org/10.1002/aoc.4457
[
67] J. C. Berthet, P. Thuéry, M. Ephritikhine,Polyhedron 2006, 25, 1700.
[
68] A. Wojciechowska, J. Jezierska, A. Bienko, M. Daszkiewicz,
Polyhedron 2011, 30, 1547.
[
69] J. Olguín, M. Díaz‐Fernandez, J. I. De la Cruz‐Cruz, M. A. Paz‐
Sandoval, J. Organomet. Chem. 2016, 824, 33.