Three mononuclear coordination complexes of 1-butyl-2-((5-methyl-1
H
-pyrazol-3-yl)methyl)-1
H
-benzimidazole (
L
), namely CoLCl
2
(
C1
), Co
2
L
2
Cl
2
·H
2
O (
C2
) and Zn
2
L
2
Cl
2
(
C3
), have ...been synthesized and characterized spectroscopically. Their single-crystal X-ray diffraction analysis revealed that
C1
and
C2
display pseudopolymorphism. The presence of N-H Cl and C-H Cl hydrogen bonding in the crystal structure of
C1
and
C3
assists the formation of a 2D hydrogen bonded sheet and orthogonal packing 2D sheet + a pair of 1D chains, respectively, leading to supramolecular structures. A combination of N-H Cl, C-H Cl, O-H Cl, and C-H O interactions results however in a 2D corrugated hydrogen bonded sheet with inclusion of water molecules in
C2
. Hirshfeld surface analysis confirms that hydrogen bonding and π-stacking contacts stabilize the crystal structures. These metal complexes display good performance towards their antimicrobial activity against
Escherichia coli, Pseudomonas aeruginosa
, and
Staphylococcus aureus
. In particular a normalized minimum inhibitory concentration as low as 6.25 μg mL
−1
for the bacterial strains was recorded for
C2
. Its structure-bioactivity correlation is discussed in detail.
Three pseudopolymorphs based on a coordination complex of a pyrazolyl-benzimidazole ligand have been synthesized and characterized by single crystal X-diffraction, and showed remarkable antibacterial properties.
A new triazolopyrimidine derivative, namely, 6-hydroxy-7-phenyl-6,7-dihydro-1,2,4triazolo1,5-apyrimidin-5(4H)-one (HPTP) was synthesized. Its corrosion inhibition performance on mild steel in 1M HCl ...solution was researched through weight loss, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) approaches. The experimental results show that the inhibition efficiency of HPTP increases with the increase of concentrations, whereas decreases as the temperature rises. PDP data reveal that the HPTP acts as a mixed type inhibitor. EIS results imply that the HPTP molecules form an antiseptic layer at the steel/solution interface. The adsorption of the inhibitor molecules on the steel surface follows Langmuir's adsorption isotherm. In addition, density functional theory (DFT) calculations were also employed to gain further insight into the adsorption behavior and inhibition mechanism.
Two mononuclear coordination complexes of
N
-(2-aminophenyl)-2-(5-methyl-1
H
-pyrazol-3-yl)acetamide (
L
1
), namely Cd(
L
1
)
2
Cl
2
(
C
1
) and Cu(
L
1
)
2
(C
2
H
5
OH)
2
(NO
3
)
2
(
C
2
) and one ...mononuclear complex Fe(
L
2
)
2
(H
2
O)
2
(NO
3
)
2
·2H
2
O (
C
3
), obtained after
in situ
oxidation of
L
1
, have been synthesized and characterized spectroscopically. As revealed by single-crystal X-ray diffraction, each coordination sphere made of two heterocycles is completed either by two chloride anions (in
C
1
), two ethanol molecules (in
C
2
) or two water molecules (in
C
3
). The crystal packing analysis of
C
1
,
C
2
and
C
3
, revealed 1D and 2D supramolecular architectures, respectively,
via
various hydrogen bonding interactions, which are discussed in detail. Furthermore, evaluation
in vitro
of the ligands and their metal complexes for their antibacterial activity against
Escherichia coli
(ATCC 4157),
Pseudomonas aeruginosa
(ATCC 27853),
Staphylococcus aureus
(ATCC 25923) and
Streptococcus fasciens
(ATCC 29212) strains of bacteria, revealed outstanding results compared to chloramphenicol, a well-known antibiotic, with a normalized minimum inhibitory concentration as low as 5 μg mL
−1
.
Two mononuclear coordination complexes of
N
-(2-aminophenyl)-2-(5-methyl-1
H
-pyrazol-3-yl)acetamide (
L
1
) and one mononuclear complex, obtained after
in situ
oxidation of
L
1
, have been synthesized and characterized spectroscopically.
Herein, the anti-corrosion of carbon steel in 1 M HCl by two newly synthesized pyrazolotriazole derivatives, namely, 6-methyl-1
-pyrazolo5,1-
1,2,4triazole-7-carbonitrile (CPT) and ...1-acetyl-6-methyl-1
-pyrazolo5,1-
1,2,4triazole-7-carbothioamide (MPT), was studied using electrochemical, density functional theory (DFT), and molecular dynamics (MD) simulation techniques. The experimental results showed that the concentrations of inhibitors had a significant influence on their inhibition efficiencies. Potentiodynamic polarization curves indicated that the two pyrazolotriazoles were mixed-type inhibitors. DFT calculations were employed to explore the molecular activity, and MD simulations were performed to obtain the interaction energy between the inhibitor molecules and the iron surface. The findings obtained using the theoretical calculation techniques were consistent with those obtained
experiments.
Three dinuclear coordination complexes generated from 1‐n‐butyl‐2‐((5‐methyl‐1H‐pyrazole‐3‐yl)methyl)‐1H‐benzimidazole (L), have been synthesized and characterized spectroscopically and structurally ...by single crystal X‐ray diffraction analysis. Reaction with iron(II) chloride and then copper(II) nitrate led to a co‐crystal containing 78 % of Cu(NO3)(μ‐Cl)(L’)2 (C1) and 22 % of Cu(NO3)(μ‐NO3)(L’)2 (C2), where L was oxidized to a new ligand L’. A mechanism is provided. Reaction with copper chloride led to the dinuclear complex Cu(Cl)(μ‐Cl)(L)2 (C3). The presence of N−H⋅⋅⋅O and C−H⋅⋅⋅O intermolecular interactions in the crystal structure of C1 and C2, and C−H⋅⋅⋅N and C−H⋅⋅⋅Cl hydrogen bonding in the crystal structure of C3 led to supramolecular structures that were confirmed by Hirshfeld surface analysis. The ligands and their complexes were tested for free radical scavenging activity and ferric reducing antioxidant power. The complex C1/C2 shows remarkable antioxidant activities as compared to the ligand L and reference compounds.
Benzodiazepines are known for their variety of applications. Herein, the corrosion inhibition efficiency on carbon steel in 1 M HCl solution in the presence and absence of two synthesized ...benzodiazepines 4-(2-Oxopropylidene)-1-propargyl-1,2,4,5-tetrahydro-3H-1,5-benzodiazepin-2-one (PTB) and 1-decyl-4-(2-oxopropylidene)-1,2,4,5-tetrahydro-3H-1,5-benzodiazepine-2-one (DTB) was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) methods at various concentrations from 10−3 to 10−6 K. The obtained structures were characterized using NMR spectroscopy. Potentiodynamic polarization measurements showed that 1,5-benzodiazepine derivatives act as a mixed type inhibitor. The various parameters of activation determining the kinetic data such as energy, enthalpy and entropy of the inhibitors were evaluated and discussed. The adsorptive behavior of PTB and DTB followed Langmuir-type isotherm. The standard free energies of adsorption were negative due to better inhibition performance. DFT calculations at the B3LYP/6-31 + G (d,p) level of theory in polarizable continuum model reveal that the high inhibition of efficiency of DTB compared with PTB may refer mainly to the easy electron transfer from the former to the carbon steel surface.
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•Synthesis sand structural characterization of two new 1,5-benzodiazepines PTB and DTB.•Corrosion inhibition efficiency of PTB and DTB increases with concentration.•.The adsorptive behavior of PTB and DTB followed Langmuir-type isotherm.•The higher inhibition efficiency of DTP may refer to its low potential energy.
The novel coronavirus disease that arises in the end of 2019 (COVID-19) in Wuhan, China, has rapidly spread over the globe and was considered as a world pandemic. Currently, various antiviral ...therapies or vaccines are available, and many researches are ongoing for further treatments. Targeting the coronavirus’ main protease (key enzyme: 3CLpro) is growing in importance in anti-SARS-CoV-2 drug discovery process. The present study aims at predicting the antiviral activity of two novel compounds using in silico approaches that might become potential leads against SARS-CoV-2. The 3D structures of the new compounds are elucidated by single-crystal X-ray techniques. The interactions between different units of
4
and
5
were emphasized by analyzing their corresponding Hirshfeld surfaces and ESP plots. NBO and FMO analyses were investigated as well. Molecular docking combined with molecular dynamics simulations (MDs) was performed to investigate the binding modes and molecular interactions of
4
and
5
with the amino acids of coronavirus main protease (6LU7) protein. The best docking scores were obtained for both ligands through the major binding interactions via hydrogen/hydrophobic bonds with the key amino acids in the active site: HIS41, CYS145, MET49, MET165, HIS172, and GLU166 amino acids. A MD simulation study was also performed for 100 ns to validate the stability behavior of the main protease 3CLpro-ligand complexes. The MD simulation study successfully confirmed the stability of the ligands in the binding site as potent anti-SARS-CoV-2 (COVID-19) inhibitors. Additionally, MMPBSA energy of both docked complexes was determined as a validation assay of docking and MD simulations to validate compound conformation and interaction stability with 3CLpro. The synthesized compounds might be helpful in the fight against COVID-19 prior to biological activity confirmation in vitro and in vivo.
In this work, we describe the synthesis of new macrocycles derived from 3-phenyl-1,2,4-triazole-5-thione
in a heterogeneous medium using liquid-solid phase transfer catalysis (PTC) conditions. The ...structures of the two compounds (
and
) isolated were elucidated based on spectral data (
H-NMR,
C-NMR) and confirmed in the case of 3-phenyl-1,2,4-triazolo 3,4-h-13,4--thiaza-11-crown-4 (
) by a single-crystal X-ray diffraction analysis. Furthermore, the experimental spectral and the X-ray geometrical parameters were compared with their corresponding predicted ones obtained at the B3LYP/6-311++G(d,p) level of theory. The intercontacts between crystal units were investigated through Hirshfeld surface analysis. The drug-like macrocycles were predicted using ADMET and drug-likeness properties, which showed that
may act as an inhibitor of DNA-dependent protein kinase (DNA-PK). This assumption was confirmed by the well-binding fitting of
into the binding site of DNA-PK and the formation of a stable
-DNA-PK complex with a binding energy of -7 kcal-mol
. Finally, the anticancer activity of
was assessed by an MTT assay against A549 cells, which showed that
has moderate anticancer activity compared to that of the doxorubicin reference drug.
The processing and properties of nano-composites based on a matrix blend of Acrylonitrile-butadiene-styrene/Polyamide6/styrene-butadiene rubber
(
ABS/PA6/SBR) and filled with Fe
3
O
4
nano-particles ...are reported in this work. Firstly, a masterbatch of 10 wt% Fe
3
O
4
is prepared by extrusion and then diluted to produce different final content (1, 3 and 5 wt%). The morphological properties reveal a good dispersion and distribution of the nano-particles in the polymer matrix and the thermal stability of the nano-composites shifts towards higher temperature (415–440 °C) as the Fe
3
O
4
concentration increases from 1 to 5 wt%. Furthermore, as the ratio of Fe
3
O
4
increases, the Young’s modulus increases by up to 103% compared to the neat matrix. Finally, the electrical and magnetic properties were found to increase with Fe
3
O
4
content and the highest values were obtained at 5 wt%. In general, it can be concluded that the application range for these nano-composites can be very wide for the thermoplastic matrix selected.
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