Azomethine Group Research Articles

Preparation and Characterization of Novel Schiff Base Derived From 4-Nitro Benzaldehyde and Its Cytotoxic Activities.

Normal drugs exhibit activities against both normal and cancer cells. Furthermore, cancer cells may develop resistance to these drugs that alternative treatment must be explored. The main objective of this study was to examine the anticancer activity of Schiff base against Tongue Squamous Cell Carcinoma Fibroblasts (TSCCF) and normal human gingival fibroblasts (NHGF) and to propose its mechanism. A Novel Schiff base ligand was synthesized from the reaction of 5-C-2-4-NABA (5-chloro-2-((4-nitrobenzylidene) amino) benzoic acid). These Schiff bases possessed azomethine group (-HC=N-) and aromatic group (CH) as analyzed by Fourier transforms infrared (FTIR) spectroscopy and UV-Vis spectra. The in vitro cytotoxicity screening assay suggested promising activity against TSCCF with IC50 of 446.68 µg/mL, but insignificant activity against NHGF cells (IC50 of 977.24 µg/mL) after 72 h. The evidence of apoptotic induction was supported by DAPI staining of apoptotic nuclei with reduced cell numbers, suggesting that Schiff base could induce apoptotic bodies in cancer cells being observed. Based on the Schiff base structure, the anti-cancer mechanism may be attributed to the -HC=N- azomethine group. For the first time, our findings highlighted the anticancer activities of the new Schiff base against oral cancer cell lines.

In vitro antifungal studies of Ruthenium (III) complex derived from chitosan Schiff bases

The complex formation property is one of the versatile natures of chitosan Schiff base; this has been achieved by chemical modification of chitosan with various aldehydes. The vanillin, salicylaldehyde and ortho vanillin were used for chemical modification through a condensation reaction with chitosan. The primary amino group (–NH2) in chitosan biopolymer molecule readily react with an aldehyde (–CHO) to form Schiff base (imine). The chitosan Schiff base becomes a complexing agent or ligand containing azomethine group which is the yardstick for complex formation with metal ions. The Ruthenium (III) complexes were obtained by complexation of Ruthenium metal ion with Schiff base ligands. Ruthenium (III) complexes were screened by Scanning Electron Microscope with Electron Dispersive X-ray (SEM-EDAX) analysis. The newly synthesized chitosan Schiff base Ruthenium (III) complexes were administered for antifungal study by disc diffusion method. The antifungal results showed that the synthesized metal complexes having significant antifungal activities against fungal pathogens.

Synthesis of New 1,2,4-Triazole Derivatives with Expected Biological Activities

To further study novel N-aceyl, N-thiourea and imidazole derivatives were synthesized. We used a multi-step reaction protocol that began with symmetrical 4-amino- 1,2,4-Triazole [I]. The new Schiff base [II] was derived by condensation of compound [I] with 4-aminoacetophenone in Ethanol and some drops from glacial acetic acid as a catalyst, whereas the Schiff base [III] was synthesized by reacting compound [II] with 4-hydroxyacetophenone in ethanol. N- acyl derivative [IV] was prepared by addition reaction of acetyl chloride to azomethine group of Schiff base [III] in dry benzene. Then, N-thiourea derivative [V] was prepared from reaction of thiourea with N-aceyl derivative [IV] in alkaline solution. The third step involved cyclization reaction of derivative [V] with 2-hydroxy-1,2-diphenylethan-1-one in dimethyl formamide (DMF) to obtain new imidazole derivative [VI]. The synthesized compounds were characterized on the spectroscopic data and their physical properties. Also, we studied the anti-bacterial activity of the prepared compounds against three types of bacteria: Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa, some of which showed best antibacterial activity comparable with Ampicillin, as standard antibiotic. Furthermore, the cytotoxic effect of various concentrations of the prepared compounds [II] and [VI] was investigated against MCF-7 (human breast carcinoma cells), Hep G2 (human liver cancer cell line) and WRL-68 (human hepatic cell line), revealing a moderate activity at 400 μl/ml, which had no effect on the growth of normal WRL-68 cells, and confirmed the safety of using this type of molecules in medications.

Synthesis and characterization of a new 1-methyl imidazole derived ligand with its ionic complexes Pd(II) and Pt(IV) and study of biological activity as anticancer and antioxidant

The preparation and spectral identification of metal complexes for Pd(II) and Pt (IV) ions with new heterocyclic azo dye as ligand 2′[2′-(1-Hydroxy-4-methyl phenyl)azo] −1-methyl imidazole (HPA-1-MeI) were prepared by reacting diazonium chloride salt solution of 2-amino -4- methyl phenol with 1-methyl imidazole in alkaline ethanolic solution. Differing spectral techniques have been used to study the structures of the azo dye ligand (HPA-1-MeI) and chelate complexes such as elemental analysis (C.H.N), spectrum, 1H NMR, FT-IR, UV-Vis, XRD, thermal analysis (TGA-DTA), FE-SEM, and magnetic measurements. The molar conductivity indicates that the Pd(II) complex is not an electrolyte and does not contain conductive species, while the Pt(IV)-complex is the electrolyte because it contains Cl outside the coordination sphere. The results confirmed that the ligand (N, N, O) behaves as a tridentate and coordinates to the metal ion via the nitrogen atom of the azomethine group (CN) of heterocyclic imidazole molecule, nitrogen atom of the azo group (NN) which is the farthest of imidazole ring and the oxygen atom of the phenolic ring. Antioxidant studies of synthesized compounds were also performed by measuring the DPPH radical scavenging assay. The DPPH radical scavenging assay was used to measure the antioxidant activity of produced compounds and compared them with the known antioxidant ascorbic acid. However, in vitro anticancer and toxicity of ligand (HPA-1-MeI) and Pd (II)-Complex were assessed by MTT cytotoxicity assay against breast cancer cell line (MCF-7). Furthermore, molecular docking studies have been conducted on the potent compounds that have several crucial interactions with STI-571 proteins.

Synthesis, Spectroscopy of New Lanthanide Complexes with Schiff Base Derived From (4-Antipyrinecarboxaldehyde with Ethylene Di-Amine) and Study the Bioactivity

The study involved preparing a new compound by combining Schiff bases generated from compounds for antipyrine, including lanthanide ions (lanthanum, neodymium, erbium, gadolinium, and dysprosium). The preparation of the ligand from condensation reactions (4-antipyrinecarboxaldehyde with ethylene di-amine) at room temperature, and was characterization using spectroscopic and analytical studies ( FT-IR, UV-visible spectra, 1H-NMR, mass spectrometry, (C.H.N.O), thermogravimetric analysis (TGA), in addition to the magnetic susceptibility and conductivity measurement of the synthesis complexes, among the results we obtained from the tests, we showed that the ligand behaves with the (triple Valence) lanthanide ions, the multidentate behavior through two oxygen atoms of the carbonyl group and two nitrogen atoms of the azomethine group with all the prepared complexes in a molar ratio (1:1). The participation of six groups of bidentate nitrate in the coordination and indicating that their complexes have values of magnetic moment and paramagnetic character and, based on the results of those measurements, the geometrical shape of the complexes was proposed. The biological activity of the prepared complexes was studied using the antibacterial activity, as the results of its effectiveness showed the direction of the bacteria used (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae) at the concentration of 1×10-3M

Synthesis of polydentate, multi metal ion sensing, unsymmetrical Schiff bases with complimented antifungal activity.

Polydentate, unsymmetrical, and multi metal ion sensing Schiff bases comprised of ferrocenecarboxaldehyde attached azomethine group at one side and aromatic aldehyde linked imine on the other side have been synthesized. Cumulative addition of different metal salts solution to receptors solution, changes the electronic spectra contrarily and for the addition of Cu2+ ions, generation of MLCT charge transfer band responsible for the coordination of metal ion with a receptor is observed. Electrochemical data (ΔEp) arrived from the cyclic voltammograms suggest a quasi-reversible process. The modest concentration of metal ions required for effective sensing by the sensory material is calculated from the Ipa values observed for metal ion added and metal free sensor solutions. Inhibition zones noticed in in vitro analysis for two fungi, two gram positive and two gram negative bacterial stains interpret that the new compounds possess high antifungal activity. Binding energy calculation using molecular docking software also ascertains the antifungal bustle.

Synthesis, characterization, biological studies, molecular docking and theoretical calculation of some transition metal complexes with new azo dye 2-[2′-(6-methoxybenzothiazolyl)azo]-3-methyl-4-nitrophenol

Ag(I), Pt(IV), and Au(III) metal complexes of novel ligand 2-[2′-(6-methoxybenzothiazolyl)azo]-3-methyl-4-nitro phenol (6-MBTAMN) have been synthesized and characterized by 1H NMR, 13C NMR, FT-IR, UV–vis, Mass spectra, CHNS, atomic absorption spectrophotometry, molar conductance and magnetic susceptibility. Results confirmed that the ligand coordinates the metal ion to form a mononuclear complex via (N, N, O) atoms of the azomethine group, azo group, and phenolic group, respectively. Tetrahedral geometry is suggested for Ag(I)-Complex, an octahedral geometry is proposed for Pt(IV)-Complex, and a square planar geometry is suggested for Au(III)-Complex. The density functional theory (DFT) was used to calculate significant parameters for ligand and metal complexes, including optimization energy, HOMO, and LUMO. Newly synthesized azo compounds have also been demonstrated to have antimicrobial properties against bacteria and fungi. The complexes are more effective against bacteria than standard antimicrobials (Novobiocin and Cycloheximide), but less effective against fungi. Based on in silico molecular docking, the study demonstrated that the azo fused compounds interact critically with the androgen receptor prostate cancer mutant H874Y ligand binding domain bound with testosterone and an AR 20–30 peptide (ART) using the Molecular Operating Environment module (MOE). Further, the antioxidant activity of novel azo compounds was evaluated using DPPH radical scavenging, which demonstrated that Ag (I) metal complex possess potent antioxidant properties. The cytotoxic abilities of selected compounds by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays against PC3 (human prostate adenocarcinoma) and HUVECs (normal human umbilical vein endothelial cells).

Computational, Hirshfeld surface, and molecular docking analysis of 2-(((4-methoxyphenyl)imino)methyl)-4-nitrophenol: In-vitro anticancer, antimicrobial, anti-inflammatory, and antioxidant studies

A Schiff base, 2-(((4-methoxyphenyl) imino) methyl)-4-nitrophenol (1) was synthesized with high yield. We have focused on its computational investigation using density functional theory (DFT) approach with B3LYP/6-311G+(d,p) level and in-vitro pharmacological, antioxidant activity, and molecular docking studies. The computational results were evaluated with experimental FT-IR, UV-Vis, NMR and crystal diffraction data. Moreover, elucidation of molecular electrostatic potential (MEP), natural bond orbital (NBO), global reactivity parameters, frontier molecular orbitals, and density of state of the compound were done. In addition, 3D energy framework, Hirshfeld surface, and ADMET profiles were also performed. The characteristic peak of the azomethine group was found in FT-IR, NMR, powder XRD spectra, and single crystal data. The experimental n → π* and π → π* electronic transitions were well matched with the computed data. The title compound exhibited more binding affinity with the target (1GTV) in molecular docking study. Besides, the studied compound showed similar activity in experimental and docking results as compared to kanamycin. The O⋯H/ H⋯O, H⋯H/ H⋯H, C⋯H/ H⋯C, and N⋯H/ H⋯N contacts were found in the two-dimensional fingerprint plots with 32.1, 33.3, 14.5, and 4.2% contribution. The dispersion energy framework was prevalent over the electrostatic energy framework. Drug like character of 1 was assessed by Lipinski’s rule of five. The studied compound has potential activity against B. megaterium and E. coli bacteria and moderate activity against A. niger fungus. It has promising anti-inflammatory activity and exhibited protective power to stabilize the human red blood cell (HRBC). The title Schiff base offered highest cytotoxic activity with IC50 value of 82.04 μg/mL against A549 lung cancer cells. The title compound showed potential free radical scavenging activity with IC50 value of 6.24 ppm in DPPH scavenging assay.

Synthesis, spectroscopic and antimicrobial studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes derived from benzoic acid bidentate Schiff base ligand

The Schiff base was synthesized by condensation of 2-hydroxy-1-naphthaldehyde with 3- aminobenzoic acid in 1:1 molar ratio. The Schiff base ligand formed complexes with Co (II), Ni (II), Cu (II) and Zn (II) acetate via mechanochemical synthesis. The synthesized compounds were characterized by solubility test, thermal analysis, FT-IR, powder x-ray diffraction, molar conductance measurement, magnetic susceptibility and elemental analysis. The Schiff base has a melting point of 190 oC. The decomposition temperature of complexes was found to be in the range 289 – 302 oC. The Schiff base and its metal (II) complexes were soluble in DMF, DMSO and sparingly soluble in acetonitrile, chloroform, diethyl ether and insoluble in n-hexane which indicate the polar nature of the synthesized compounds. The IR spectral analysis of the free Schiff base shows a band at 1622 cm-1, assigned to v(C=N) stretching vibrations. This band was shifted in the spectra of complexes (1607 – 1633 cm-1), indicating coordination of the Schiff base to the metal ion through the azomethine group. The molar conductance of complexes determined are in the range 9.51 – 14.87 Ohm-1cm2mol-1 which indicate the non-electrolytic nature in DMF. Magnetic susceptibility measurements of Co (II), Ni (II) and Cu (II) complexes exhibit a magnetic moment in the range 1.25 – 3.08 BM. The values correspond to square-planar geometry. The magnetic moment value of Zn (II) complex indicates a diamagnetic behaviour. The elemental analysis of the complexes for C, H and N determined showed that the observed and the calculated percentages of the elements are in good agreement.

Synthesis, Spectral, Crystal structure, Hirshfeld surface, Computational analysis, and Antimicrobial studies of Ethyl-(E)-4-(2-(2-arylidenehydrazinyl)-2-oxoethyl)piperazine-1-carboxylates

A new series of ethyl-(E)-4-(2-(2-arylidenehydrazinyl)-2-oxoethyl)piperazine-1-carboxylates (hydrazones) 4a-4e and 5a-5c were designed and synthesized from 1-ethoxycarbonylpiperazine. The hydrazones structure interpretations were achieved by spectroscopic analysis using FT-IR, 1D and 2D NMR and mass. Among the aforementioned hydrazones 4a-4e and 5a-5c, single crystal XRD structure was reported for hydrazone 4a. Both NMR and single crystal XRD analysis are clearly indicated the existence of E configuration of the azomethine group (-C=N-) and cis conformation of the amide group. Hirshfeld surface analysis and 2D fingerprint plot were employed to get a better understanding of non-covalent interactions (NCIs), which showed that the NH···O and CH···O intermolecular hydrogen bonding interactions are the key contributor to stabilize the molecular solids. Density functional theory (DFT) study was carried out to explore the geometrical parameters and electronic properties of frontiers molecular orbitals (FMO), global chemical reactivity descriptor parameter (GCRD), natural bond orbital (NBO), and non-linear optical (NLO) properties for 4a at B3LYP/6–311G(d,p) level. The molecular docking study was performed for hydrazone 4a with nCoV-SARS-2 main protease for COVID-19. Finally, the hydrazones in this synthetic series were screened for their antibacterial and antifungal activities using selected strains. Antimicrobial studies revealed that 4a and 5b against A. niger, 4c and 5c against K. pneumonia, 4e against B. subtilis, 5a, 5b, and 5c against A. flavus, A.niger and C. neoformans, respectively exhibits remarkable antibacterial and antifungal activity at a minimum concentration of 6.25 µg/mL.

Organosilane-functionalized graphene oxide hybrid material: Efficient adsorbent for heavy metal ions in drinking water

Organosilane-functionalized and chemically activated graphene-supported Schiff base ligand were synthesized and characterized with XRD, SEM, EDX, TEM, UV–vis, FT-IR, and TG/DTA techniques. Graphene oxide (GO) obtained with the route of Hummer’s method was reacted with 3-(trimethoxysilyl)propylamine, then, the organosilane functionalized and amine-activated-GO was reacted with 3,5-di-tert-butylsalicylaldehyde obtained the hybrid material containing azomethine group on GO surface. The material was used as an adsorbent in order to remove cobalt(II) and zinc(II) ions in drinking water and standard solutions. The adsorption capacity of the material to cobalt(II) and zinc(II) ions were investigated by using batch method. The effect of pH, contact time, temperature, and concentration on the adsorption capacity of the material was also investigated. The enrichment factors were calculated as 441 and 675 for zinc(II) and cobalt(II), respectively. The recovery performance of the material was determined in 98.65–101.75% and 98.55–104.0% range for zinc(II) and cobalt(II) ions, respectively.

An Overview: Using Different Approaches to Synthesis New Schiff Bases Materials

Schiff base compounds are called relative to the scientist who first prepared them (Hugo Schiff). They are synthesized by the condensation reaction of the carbonyl group –C=O– of the aldehyde or ketone compound with a primary amine. This leads to the formation of azomethine or imine group –C=N– plus water molecule. Schiff base molecules have gained special importance due to their biological activity, such as anti-inflammatory and antibiotic. Schiff base compounds are also utilized in the industry as corrosion inhibitors, dyes, and photo-stabilizers of plastic polymers. This short review includes highlighting of recent approaches of synthesis novel Schiff base molecules. It also discusses the mechanism of the reaction and why it is a reversible condensation reaction.

Design, molecular docking and antimicrobial assessment of newly synthesized p-cuminal-sulfonamide Schiff base derivatives

Antibiotic resistance of bacteria and fungi has been brewing for decades and has now surfaced as a potential public health emergency, globally. Thus, newer potent drug candidates are needed urgently to overcome antibiotic-resistant episodes. As an attempt to overcome the antimicrobial multi-drug resistance problems, a new series of p-cuminal sulfonamide Schiff base congeners 3a-3h were designed, synthesized, and their structures confirmed by several spectral studies. The antimicrobial activities assessment of obtained products was carried out against pathogenic bacteria Staphylococcus aureus, Streptococcus pyogenes, Methicillin-resistant Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and against pathogenic fungi Candida tropicalis and Trichophyton rubrum. Among them, 3b exhibited significant inhibition of all the strains of bacteria with MIC as 3.12μg/mL and the compound 3e exhibited the most promising control against both C. tropicalis and T. rubrum (MIC 6.25μg/mL) in comparison to Ketoconazole as well as good inhibition against both S. aureus and MRSA at MIC 6.25 μg/mL The presence of sulfamoyl and azomethine groups and some of heteroaryl rings in individual molecules could have increased the antibacterial actions, while the antifungal action could be attributed to the presence of guanyl and acetyl groups in the molecular structure. Furthermore, in silico investigation and drug-likeness have been ascertained with biological targets.

Synthesis and characterization of new platinum(II) complexes with cyclic iminoether-type ligands having the azomethine group out of cycle

The trans isomer of cisplatin, transplatin, is an inactive platinum drug; however, a number of analogues, such as trans complexes with iminoether, thiazole and isopropylamine ligands, demonstrate promising antitumor activity in vitro and in vivo. In the particular case of iminoether ligands, HN=C(R)OR′, due to the presence of a double bond, two configurations, E and Z, can exist and isomerization between the two forms has been observed sometime in solution. An attempt to stabilize the ligand configuration was to block the geometry of the ligand by inserting the iminic double bond into a cycle; this led to the synthesis of platinum complexes with 5-methoxy-3,4-dihydropyrrole, ▪, and 2-methyl-4,5-dihydro-1,3-oxazole, ▪, in which, however, the ligand is deprived of a proton on the coordinating iminic nitrogen considered to be a key feature for the interaction of the platinum drug with target DNA. In this paper we describe the synthesis and characterization of platinum complexes with the 2-iminotetrahydrofuran ligand, ▪, where the iminic nitrogen is outside the cycle and can keep its proton. Apart from the isolation of the pure E and Z isomers (compounds 2-E and 2-Z) we also prepared the diiodido derivative (compound 1) and the cis isomer (compound 3).

Silanol-functionalized tetranuclear copper complex and its nanoscale-heterogenization by immobilization on glass surface from solution

3-Formylsalicylic acid (3-FSA) was treated in a weak acid medium with 1,3-bis(2-aminoethylaminomethyl)tetramethyldisiloxane to form a salen-type ligand, followed by the addition of copper(II) chloride to build the corresponding coordination compound in a one-pot procedure. Along with the CH=N bond formation, Si-O-Si bond was also broken down to form the Si-OH ones tailing the remained monoamine. As single crystal X-ray diffraction revealed, when the copper salt is added, a tetranuclear complex, [Cu4(L1)2(L2)2Cl2(H2O)2], is formed consisting in two asymmetric dinuclear units, [Cu2L1L2Cl(H2O)], in which a molecule of 3-FSA (H2L1) and one of derived azomethine (H2L2), both doubly deprotonated and tridentate, participate in the coordination of oxo-bridged {Cu4} core. The coordination sphere is completed by chlorine atoms and water molecules. In the tetranuclear structure, the azomethine groups and implicitly the silanol arms are located in trans-position. The thermal behavior of the complex was studied by TGA and DSC. Besides the intrinsic properties induced by the presence of the metal ion (magnetic, biological, etc.), the free reactive silanol group may allow post-functionalization of the complex or, as found herein, its chemical binding to a suitable substrate. The attachment of the complex to the glass surface was proven by XPS but also highlighted by MFM due to its intrinsic magnetism.

Synthesis, in vitro Antioxidant Activity, and Toxicity Evaluation of Hydrazone Derivatives Naphthalene-1-ylmethylene hydrazine

Hydrazone is a versatile organic compound that has a basic structure (-NHN=CH-) called the azomethine group. This structure is responsible for the physical and chemical of hydrazone, which makes this compound has variety bioactivities such as antioxidant, antitumor, and anticancer. In this work, two hydrazone derivatives from 1-naphthaldehyde and hydrazine (phenylhydrazine/hydrazine hydrate) have been synthesized under microwave irradiation. Their antioxidant activity and toxicity were evaluated by DPPH and BSLT method, respectively. Structures of the synthesized compounds were confirmed based on spectroscopic data included UV, FTIR, HRMS, and 1H-NMR. Based on the DPPH assay, hydrazone from phenylhydrazine has strong antioxidant (IC50 28.90 μg/mL) but inactive antioxidant for hydrazine hydrate (IC50 >1000 μg/mL). However, both compounds have a high toxicity effect on Artemia Salina Leach with each LC50 1.45 and 47.20 μg/mL, hence they have the potential to be developed into anticancer drugs.

Synthesis and characterization of cobalt(II) complexes with bidentate Schiff base ligand

The coordination complexes of Co(II) have been prepared from bidentate Schiff base. The Schiff base ligand was synthesized by the condensation of 4- hydroxy-3-methoxybenzaldehyde and 2-aminobenzhydroxamic acid in an alcoholic medium at room temperature. The ligand and cobalt (II) complexes were characterized by elemental analysis, molar conductance, electronic spectra, IR spectra, NMR spectra, electrical conductivity and magnetic susceptibility. The cobalt (II) complexes are colored and stable in air. In the metal complexes, the metal -ligand ratio was found to be 1:2. A sharp band at 1630 cm-1 is characteristics of the azomethine group present in the Schiff base ligand. This band was shifted to lower frequency (1605 – 1620 cm-1) in all the cobalt complexes, indicating the coordination of the azomethine nitrogen to the metal ion in complexes. The ν(N-OH) stretching vibration of the ligand obtained at 1080 cm-1 was raised up by 10-40 cm-1 in the complexes suggesting the deportation of (N-OH) hydrogen and coordination of hydroxy imino nitrogen atom in the bond formation with the Co(II) ions. The molar conductivity data of the complexes in DMF solution indicates that they are of non-electrolytic nature. On the basis of elemental analysis, magnetic susceptibility and electronic spectral data, geometry of complexes was proposed to be octahedral.

New Hybrid (E)‐4‐((pyren‐1‐ylmethylene)amino)‐N‐(thiazol‐2‐yl)benzenesulfonamide as a Potential Drug Candidate: Spectroscopy, TD‐DFT, NBO, FMO, and MEP Studies**

AbstractA novel pyrene‐sulfathiazole‐based potential drug candidate 3 was designed, successfully synthesized by a condensation reaction of pyrenecarboxaldehyde (1) with sulfathiazole (2) in good yield, and fully characterized by NMR, IR, UV‐Vis, and HRMS spectroscopic techniques. The TD‐DFT/B3LYP calculations displayed that the recorded peaks at 396, 377, 280, and 236 nm were due to the mainly n‐π* and partially π‐π* transitions that occurred on pyrene, azomethine, and sulfathiazole moieties. The NBO results disclosed that the electron delocalizations happened onto sulfathiazole, aromatic rings (pyrene and Ph‐), and azomethine groups had the main responsibility of the lowering stabilization energy of compound 3. The NMR shifts were calculated by using the GIAO approaches in the DMSO phase and compared with the relevant data recorded. The thermodynamic and quantum chemical quantities were used for elucidating the physicochemical properties and reactivity behavior, in THF, DMSO, and water simulation environments. Accordingly, the calculated DM (D) and α (au) order of compound 3 were calculated in the order of vacuum<THF<DMSO<water, which indicated that the stability and thus reactivity of the compound strongly depended on the solvent environment. The FMO studies implied that the electron‐donating possibility of compound 3 was dominant to the electron‐accepting potency. In this work, the SMD version of IEFPCM was used in solvent media simulations.

Nano-Schiff base Ligand:Synthesis, Characterization, DFT, and Antibacterial Evaluation of Some Complexes Derived From 4-(-4-methoxybenzylidene)amino) -Antipyrinyl with Glycine amino acid ligand

Synthesized from a new Neutral tridentate N2O Schiff base 4-(4- methoxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one with amino acid ligand.forms stable complexes with transition metal ions such as Co (II), Ni (II), Cu (II), and Cd (II). The complexes were characterized on the basis of their Elemental analysis, molar conductivity, magnetic susceptibility data, IR, 1H-NMR, UV-Vis, XRD, Thermal Analysis (T.G, DTA, DSC), SEM, and Calculation Theoretical studies(DFT). Were used to characterize the complexes. The ligand acts as a tridentate chelating agent, According to physicochemical and spectral results, the ligand acts as a tridentate chelating agent. IR, UV-Vis., and magnetic susceptibility measurements all refer to an octahedral geometry. The general composition of all complexes [M(L)2] is (M=Co(II), Ni(II),Cu(II) and Cd(II), L=(K4-AMetB-Gly) The studies have led to the conclusion that, The coordination sites were established to be oxygen of the carboxyl COO- and two atoms nitrogen of the azomethine (CH=N) group based on the studies. The complexes non-electrolytic nature is verified by the lower conductivity data. The antibacterial activity of the ligand and its complexes was tested against Staphylococcus aureus, Escherichia coli, Klebsiella, and Psedomonas aeruginosa, it was found that these compounds show different activity of inhibition on the growth of the bacteria.

Synthesis, spectral characterization, SC-XRD, HSA, DFT and catalytic activity of a dioxidomolybdenum complex with aminosalicyl-hydrazone Schiff base ligand: An experimental and theoretical approach

A new dioxidomolybdenum(VI) complex has been successfully prepared by the reaction of an ONO donor Schiff base, derived by condensing 4-amino-2-hydroxybenzohydrazide and 3-methoxysalicylaldehyde, with MoO2(acac)2. The structures of synthesized products were explored spectroscopically through FT-IR, 1H &13C NMR and by elemental composition (CHN) through combustion analysis. The structural investigations of the dioxidomolybdenum(VI) complex were accomplished by taking its diffraction data through X-ray crystallography. The tridentate Schiff base ligand is bonded to the central metal through its deprotonated enolic and phenolic oxygen atoms and by the nitrogen of the azomethine group. The interpretation of the data obtained through diffraction analysis validates the distorted octahedral geometry of the prepared metal complex. QTAIM, MEP and NCI calculations and Hirshfeld surface analysis were performed to investigate the nature and types of non-covalent linkages present among the sample molecules. The theoretical calculations, performed by DFT using the B3LYP/Def2-TZVP level of theory, direct that the intended outcomes are in compliance with the actual consequences. Furthermore, the catalytic potential of the molybdenum complex was explored for the selective oxidation of benzylic alcohols to the desirable aryl aldehydes at room temperature in the presence of 70% aqueous tert-butyl hydroperoxide (TBHP) under solvent-free conditions. The main advantage of the present catalytic work is the accomplishment of reaction in a short period of time, high percentage yield and easy work-out procedure.