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Benzocaine is known for its antibacterial, anticancer, antitumor, and antifungal properties. Herein, a series of three new Schiff bases is synthesized by reacting benzocaine with salicylaldehyde (E4AS), 2,3-dihydroxybenzaldehyde (E4ADH), and 5-chlorosalicylaldehyde (E4ACl). These benzocaine-based Schiff bases were characterized by a variety of spectroscopic methods, including FTIR, NMR, (1H and 13C), and elemental analysis (CHN). Additionally, the single crystal X-ray diffraction method was used to reveal the molecular structures of the derivatives. Solid-state X-ray crystal structures of E4AS and E4ACl adopted enol tautomeric form, whereas keto-tautomeric form was found in E4ADH. The supramolecular assembly of the compounds was probed by Hirshfeld surface analysis. The void analysis was executed to predict the mechanical response of the compounds. Additionally, UV–Vis spectroscopy and molecular docking practices were used to look into the DNA binding abilities of the benzocaine-based Schiff bases. The geometries of the molecules were fully optimized and studied for their electronic structural properties of respective compounds. The frontier molecular orbitals and molecular electrostatic potentials were studied to predict the properties of molecules. The study provides molecular-level intuitions into the synthesis and prospective uses of these Schiff bases in the arena of general and medicinal chemistry. [ABSTRACT FROM AUTHOR]

The current study involves the synthesis of two azomethine compounds, (E)‐2‐((6‐nitrobenzo[d][1,3]dioxol‐5‐yl)methylene)amino)phenol (2AP6NO) and (E)‐2‐((4‐ethylbenzylidene)amino)phenol (2AP4ETH), as well as their theoretical investigations. The synthesized azomethine compounds were then characterized by combustion analysis (CHN), FT‐IR, NMR (1H and 13C), and single crystal X‐ray diffraction (SC‐XRD) analysis. The SC‐XRD study confirmed the enol tautomeric form of 2AP6NO as well as 2AP4ETH. The strong and comparatively weak intermolecular interactions were elaborated by Hirshfeld surface analysis. For both compounds, intermolecular interaction energies between the pair of molecules, energy framework, and void analysis were calculated to visualize the three‐dimensional topology of the crystal packing. Additionally, quantum chemical computations were also utilized to study the optical and nonlinear optical (NLO) response. The molecular geometries were optimized at the M06‐2X/6‐311G* method and equated to their respective experimental counterparts. The third‐order NLO polarizabilities were also calculated at the same level of theory. The calculated average third‐order NLO polarizabilities were 62.55×10−36 esu and 55.08×10−36 esu, respectively, predicting the modest behavior of the above compounds when displaying NLO properties. [ABSTRACT FROM AUTHOR]

Schiff base 4-(((3-(trifluoromethyl)phenyl)imino)methyl)phenol (TPP) was successfully synthesized and characterized by FT-IR, NMR and SC-XRD. Crystal analysis pointed up the presence of two crystallographically independent molecules in an asymmetric unit that are linked with each other through O–H···N and comparatively weak C–H···O bonding to form an infinite one-dimensional chain of ...ABAB...sequence. In addition to H-bonding, crystal packing is further stabilized by weak C–F···Cg and π–π stacking interactions. Hirshfeld surface analysis revealed that the most significant contribution to packing is from H–F/F–H interatomic contact with percentage contributions of 27.8% and 27.4% for molecules A and B, respectively. Quantum mechanical approach was used for comparison analysis between experimental and calculated parameters. Photometric behavior of TPP was studied in a wide pH range. Furthermore, redox mechanism was also suggested for TPP based on detailed electrochemical characterization. This effort just provides preliminary data to explore some structural and computational aspects of TPP. [ABSTRACT FROM AUTHOR]

• Synthesis of hydrazone-based schiff base • Structural confirmation through various spectroscopic techniques • Exploration of electronic properties and optical nonlinearity via TDF • Study of electronic properties at M06/6–311G (d,p) functional A new thiosemicarbazide-based Schiff base (TSDHB) was synthesized from thiosemicarbazide and 2,3-dihydroxybenzaldehyde. The prepared thiosemicarbazone was characterized by elemental (CHN), FT-IR, 1H and 13C NMR techniques. Furthermore, the molecular structure was probed using the single-crystal X-ray diffraction (SC-XRD) technique, which confirmed the enol tautomeric form with two independent molecules in asymmetric unit. The dissimilarity between the molecular units was determined by molecular overlay plots. The various intermolecular interactions and solid-state assembly stabilization were explored by Hirshfeld surface analysis. Void analysis was executed to examine the mechanical stability of crystalline units. The bioactivity of thiosemicarbazone was probed with the help of its binding capacity with salmon sperm DNA (SS-DNA) by means of the absorption interaction method. Accompanied by biological activity, optoelectronic properties such as nonlinear optical properties of yielded crystal were also explored through the DFT approach at M06/6–311 G (d,p). For this, various kinds of investigations such as frontier molecular orbital (FMO), UV–Vis, global reactivity parameters (GRPs), transition density matrix (TDM), density of states (DOS), natural population analysis (NPA), and natural bond orbital analysis (NBO) were executed at M06 functional. A good agreement was examined between XRD and DFT findings of molecular geometric parameters. Notably, in comparison with urea, TSDHB demonstrated enhanced nonlinear optical properties (linear polarizability=4.766 × 10−23 esu and third-order hyperpolarizability=5.939 × 10−35 esu). These findings position TSDHB as a promising candidate for DNA binding as well as for photonic materials due to its unique molecular characteristics and enhanced nonlinear optical behavior. [ABSTRACT FROM AUTHOR]

A series of novel azomethine precursors were synthesized by the condensation reactions of 3-(trifluoromethyl)benzenamine (tfmb) with 2-hydroxybenzaldehyde (HL1) (tfmbs), 2,3-dihydroxybenzaldehyde (HL2) (tfmbdh), 2-hydroxy-1-naphthaldehyde (HL3) (tfmbnd) and 5-chloro-2-hydroxybenzaldehyde (HL4) (tfmbCl). The oxidovanadium(IV) complexes of the type [VO(tfmbs)2] (1), [VO(tfmbdh)2] (2), [VO(tfmbnd)2] (3) and [VO(tfmbCl)2] (4) were also prepared by the reaction of ligands HL1–HL4 with vanadyl(V) isopropoxide [VO(OCHMe2)3]. The synthesized compounds were characterized by elemental analysis, FT-IR, multinuclear (1H and 13C) NMR spectroscopies, magnetic susceptibility measurements and thermogravimetry. The studies revealed that binding of precursors with metal took place through azomethine nitrogen and phenolic oxygen. The single-crystal analysis of HL1, HL4 and 3 has been carried out. The intercalation mode of interaction of the complexes with Salmon sperm DNA (SS-DNA) was established by the observed hypochromicity through UV–vis spectroscopic studies. The determined negative ΔG values confirmed the spontaneity of the binding process of complexes with SS-DNA. All the synthesized precursors and complexes were screened for their alkaline phosphatase inhibition, antimicrobial, hemolytic and insulin-mimetic properties, which exhibited significant activities with a few exceptions. [ABSTRACT FROM AUTHOR]

• Two new Schiff bases are synthesized which adopt enol and keto tautomeric forms. • The dihedral angles indicate the planar nature of molecules of both Schiff bases. • Both compounds have the potential for optical applications. • The molecular structure of both compounds is stabilized by hydrogen bonding. • Smaller void volumes indicate that the molecules are closely packed. The current work focuses on the synthesis of the two new Schiff base ligands derived from o -aminophenol named 2-[(E)-(3-chlorophenyl)methylidene]amino-phenol (2AP3Cl) and 4-Chloro-2-(E)-[(2-hydroxyphenyl)iminio]methyl-phenolate (2AP5Cl). The synthesized Schiff bases were characterized by different Spectro analytical techniques like CHN, FT-IR, and NMR (1H and 13C) analysis. Moreover, a single crystal X-ray diffraction (SC-XRD) study was carried out for both compounds, which inferred that 2AP3Cl and 2AP5Cl adopted enol and keto tautomeric forms, respectively. The supramolecular assembly with respect to strong and comparatively weak non-covalent interactions was explored by Hirshfeld surface analysis. The interaction energy between molecular pairs, energy frameworks, and void analysis was performed to further investigate the crystal packing environment. Both compounds were screened for their DNA binding abilities. Moreover, quantum chemical methods were applied to study the electronic structure, linear and nonlinear optical (NLO) polarizabilities of the synthesized Schiff bases. The 2AP3Cl and 2AP5Cl molecules exhibited good NLO hyperpolarizability of 9.62 × 104 and 7.90 × 104 au., respectively. The calculation of molecular electrostatic potentials, 3-D visualization of frontier molecular orbitals, and their orbital gaps were also studied. Overall, reasonably good third-order NLO response properties were calculated, which show a decent potential of synthesized compounds for their potential for NLO applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Three diorganotin(IV) complexes of general formula R 2 Sn[(O)C 10 H 6 CHN 2 CH(O)] have been synthesized by the interaction of dimethyltin(IV) dichloride, diphenyltin(IV) dichloride, di- tert -butyltin(IV) chloride and novel ligand N′-(2-hydroxynaphthalen-1-yl)methylene)formohydrazide in toluene. Spectroscopic and single crystal X-ray studies confirm coordination of dibasic tridentate ligand to the diorganotin(IV) moieties via ONO donor sites and formation of pentacoordinated tin center. Furthermore, antibacterial screening, cytotoxicity assessment and docking study for the synthesized compounds have also been carried out. [Display omitted] Three organotin(IV) complexes [Me 2 SnL(1), Ph 2 SnL(2), tert -Bu 2 SnL(3)] have been synthesized by the reaction of a novel ligand N'-(2-hydroxynaphthalen-1-yl)methylene)formohydrazide (H 2 L) with dialkyltin(IV) dichlorides [R 2 SnCl 2 (R = Me, Ph, tert -Bu) in presence of Et 3 N. The ligand and complexes have been characterized by elemental analysis, mass spectrometry, FT-IR, 1H, 13C and 119Sn NMR spectroscopic techniques. The spectroscopic data suggests coordination of ligand to the diorganotin(IV) moieties via oxygen nitrogen donor sites and five coordinated tin centers. The molecular structures of ligand (H 2 L) and complexes (1, 3) were also confirmed by single crystal X-ray analysis. The solid state structure of ligand showed it to be in the amido form whereas the single crystal X-ray analysis of complexes revealed the dibasic tridentate nature of ligand and monometallic nature of complexes. In both the complexes (1, 3) the Sn atom is in a distorted five-coordinate square pyramidal geometry with trigonality index(τ) 0.33 and 0.41, respectively. Packing diagrams reveal the important role of H ... H, C H ... π and O ... H interactions in generating the supramolecular assembly. The antibacterial potential of all the compounds was investigated against two gram-positive bacteria (Bacillus subtilis, Stephlococcus aureus) and four gram-negative bacterial strains (Escherichia coli, Shigella flexenari, Pseudomonas aeruginosa, Salmonella typhi), using imipenem as the standard drug. Complex 2 exhibited highest activity against Bacillus subtilis and highest cytotoxicity against brine shrimp nauplii with LD 50 1.01 μg/mL. Molecular Docking investigations revealed the best target protein, the positive impact of diphenyltin(IV) moiety on the compound-protein binding and the important role of hydrogen bonding, pi-pi and hydrophobic forces in such type of interaction. [ABSTRACT FROM AUTHOR]

Eight different di- and triorganotin(IV) complexes of vanillin-Schiff base of the type RSnClL and RSnL [R = Me ( 1, 6), n-Bu ( 2, 7), Ph ( 3, 8), tert-Bu ( 4), Cy ( 5) and L = 4-((3,5-dimethylphenylimino)methyl)-2-methoxyphenol] were synthesized. The products were characterized by elemental analysis, FT-IR, H, C and Sn NMR spectroscopy. The ligand 4-((3,5-dimethylphenylimino)methyl)-2-methoxyphenol is also characterized by single crystal X-ray analysis. In the H NMR spectra of 1 and 6, the J(Sn-H) in the Sn-CH moiety has 57 and 54 Hz values, respectively, that confirm the formation of four-coordinated Sn species. Moreover, the C NMR value for ipso carbon of SnPh is 139 ppm which also confirms the formation of four-coordinated Sn species. The title ligand and its complexes were also screened for their biological activities such as interaction with DNA, enzymatic, antimicrobial, cytotoxic and antioxidant activities. The antimicrobial and cytotoxic activities of triorganotin(IV) derivatives are relatively higher than their corresponding diorganotin(IV) analogues due to their greater lipophilicity and permeability through cell membrane. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A series of organotin(IV) complexes has been synthesized by reacting 4-piperidine carboxamide with CS2and R2SnCl2/R3SnCl in 1 : 1 M/L ratio at room temperature. The synthesized complexes were further treated with benzaldehyde to synthesize Schiff bases under stirring. All the complexes were characterized by elemental analysis, FT-IR,1H and13C NMR. FT-IR and semi-empirical study confirm the bidentate nature of ligand. The complexes exhibit four-coordinate geometry in solution. Thermodynamic parameters and molecular descriptors were calculated by using semi-empirical PM3 method. HOMO–LUMO calculations show that chlorodiorganotin complexes are more susceptible to nucleophilic attack when compared with triorganotin complexes. Negative heats of formation at 298 K demonstrate that1,4,and7are thermodynamically stable. The antimicrobial results have shown that complexes containing Schiff base exhibit significantly better activity compared to complexes with carboxamide derivatives. [ABSTRACT FROM PUBLISHER]

The Schiff base has been synthesized by reacting tranexamic acid with indol-3-carboxyaldehyde in the first step and then with carbon disulfide at room temperature in the second step. The homobimetallic complexes have been synthesized by reaction of Schiff base with R2SnCl2 and R3SnCl in 1 :2M ratio under stirring, where R=methyl, n-butyl and phenyl. The ligand and complexes have been characterized by elemental analysis, FT-IR, multinuclear NMR (1H, 13C and 119Sn) and semiempirical study. IR data reveal the bidentate nature of the ligand. Five- or six-coordinate geometry was confirmed in solution by NMR spectroscopy. The homobimetallic complexes and ligand were tested in vitro against some pathogenic bacteria and fungi to assess their antimicrobial properties. The complexes show biological activities with few exceptions. [ABSTRACT FROM AUTHOR]

Abstract: The novel azomethine, 3-((3,5-dimethylphenylimino)methyl)benzene-1,2-diol (HL) was synthesized and characterized by elemental analysis, FT-IR, 1H, 13C NMR spectroscopy and single crystal analysis. The title compound has been screened for its biological activities including enzymatic study, antibacterial, antifungal, cytotoxicity, antioxidant and interaction with CTDNA, and showed remarkable activities in each area of research. The titled compound interacts with DNA via two binding modes: intercalation and groove binding. In intercalation the compound inserts itself into the base pairs of DNA and the compound–DNA complex is stabilized by π–π stacking. Interaction via groove binding may be due to hydrogen bonding to bases, typically to N3 of adenine and O2 of thymine. The synthesized compound was also found to be an effective antioxidant of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and gives percent inhibition (%I) of 90.7 at a concentration level of 31.3μg/mL. [Copyright &y& Elsevier]

Abstract: Novel azomethine adducts of Sn(IV) have been synthesized by the reaction of R n SnCl4− n (n =1–3, R=CH3, n-C4H9, C6H5, C6H11) with 2-((3,5-dimethylphenylimino)methyl)phenol (HL). The products were characterized by elemental analysis, FT-IR, 1H, 13C and 119Sn NMR spectroscopy. Triphenyltin(IV) chloride [2-((3,5-dimethylphenylimino)methyl)phenol] (3) was also characterized by single crystal analysis. Spectroscopic and crystal data suggest that in all the complexes the ligand acts as a monodentate neutral molecule and is coordinated through oxygen to the tin atom forming pentacoordinated tin species. The phenolic hydrogen within the ligand is transferred to the imine nitrogen atom due to the coordination of oxygen with tin after complex formation. The ligand and its complexes have been screened for their biological activities, including DNA interaction, enzymatic, antibacterial, antifungal and cytotoxicity studies. Moreover, the electrochemical behavior of the synthesized compounds was also studied and the results obtained evidenced their irreversible oxidation. [Copyright &y& Elsevier]

A series of bimetallic organotin(IV) complexes with ferrocene-based azomethines (Schiff bases) were synthesized by reacting sodium salt of tranexamic acid, 4-amino butanoic acid, and phenyl alanine with trimethyltin and tributyltin chloride in 1 : 1 molar ratio under inert atmosphere. The synthesized trialkyl organotin complexes condense with formyl ferrocene under inert atmosphere to yield organotin(IV) ferrocenyl Schiff bases. Composition of the organotin(IV) complexes, bonding behavior of donor groups, and structural assignments were studied by elemental analysis, FT-IR, 1H, 13C, 119Sn NMR, and mass spectrometry. The spectral data suggest that the ligand is bidentate, coordinating through oxygens. Spectroscopic techniques reveal distorted tetrahedral geometry in solution for the complexes. As solids, the complexes are trigonal bipyramidal, confirmed by semi-empirical study. Mass spectrometric and elemental analysis data support the solid and solution spectroscopic results. Bioactivity screenings show in vitro biological potential. [ABSTRACT FROM AUTHOR]

The title compound, C15H19NO3, a Schiff base, crystallizes as a zwitterion with the hydroxyl H atom transfered to the imine N atom. This leads to the formation of an intra­molecular N—H⋯O hydrogen bond. In the crystal structure, symmetry-related mol­ecules are linked by an inter­molecular O—H⋯O hydrogen bond, forming chains extended in the a-axis direction. The mol­ecules are also connected via C—H⋯O hydrogen bonds, forming a two-dimensional network. [ABSTRACT FROM AUTHOR]

Copper(II) complexes with a general formula [Cu2(3,4-F2C6H3CH2COO)4(L)2], where L = 2-methylpyridine (1) and 3-methylpyridine (2), are reported here. The FTIR spectra of the complexes confirmed the bridging bidentate coordination mode of the carboxylate ligand. The low (475 and 449 cm−1) and strong (727 & 725 cm−1) intensity bands in the FTIR spectra, due to Cu-N stretches and pyridyl ring vibrations, confirmed coordination of the 2-/3-methyl pyridine co-ligands in complexes 1 and 2, respectively. A binuclear paddlewheel structural arrangement with a square pyramidal geometry was confirmed for copper atoms in the complexes via single-crystal X-ray analysis. The DPPH, •OH radical, and α-amylase enzyme inhibition assays showed higher activities for the complexes than for the free ligand acid. The binding constant (Kb = 1.32 × 105 for 1 and 5.33 × 105 for 2) calculated via UV-VIS absorption measurements and docking scores (−6.59 for 1 and −7.43 for 2) calculated via molecular docking showed higher SS-DNA binding potential for 2 compared to 1. Viscosity measurement also reflected higher DNA binding ability for 2 than 1. Both complexes 1 and 2 (docking scores of −7.43 and −6.95, respectively) were found to be more active inhibitors than the free ligand acid (docking score of −5.5159) against the target α-amylase protein. This in silico study has shown that the herein reported compounds follow the rules of drug-likeness and exhibit good potential for bioavailability. [ABSTRACT FROM AUTHOR]

Six new Schiff based diorganotin(IV) complexes have been synthesized and structurally characterized through multitude analytical techniques. The compound-DNA interaction study has been performed through UV–Visible spectroscopy that revealed high binding potential through a spontaneous process. The complexes have further been investigated for in vitro antimicrobial and anticancer studies. [Display omitted] • Synthesis of six diorganotin(IV) complexes based on two new Schiff base ligands derived by the condensation reaction of aldehydes with acid hydrazides. • Spectroscopic characterization and structural elucidation of all complexes were performed. • Compound-DNA interaction study was performed through UV–Visible spectroscopy. • The compounds were investigated for in vitro antimicrobial studies. • The compounds were evaluated for their anticancer activities. Herein, two Schiff base ligands Ń-(4-diethylamino-2-hydroxybenzylidene) isonicotinohydrazide (L1) and Ń-(2,3-dihydroxybenzylidene) isonicotinohydrazide (L2) and their six di-organotin(IV) complexes (R = C 4 H 9 (1 , 4), C 6 H 5 (2 , 5) and CH 3 (3 , 6)) were synthesized. The solid state and solution chemistry of the ligands and their organotin(IV) complexes was explored through single crystal XRD, FTIR and NMR (1H, 13C and 119Sn) spectroscopy. The single crystal XRD analysis was carried out for complexes 1 , 2 and 5 , reveals the presence square pyramidal, trigonal bipyramidal and pentagonal bipyramidal geometries, respectively. All structures showed distorted geometries because of the constraint offered by five and six membered chelate rings. The results obtained from the interaction study of ligands and complexes with SS-DNA were indicative of high binding potential through a spontaneous process. The results of in vitro antimicrobial studies validated the well-known theory of chelation and overtone concept. Anticancer activities conducted for the ligands and complexes revealed evident anti-proliferative activity of 1 , 2 , 4 and 5 complexes. Complex 2 being the most active one, exhibited pro-apoptotic, cytotoxic effect after PI and DAPI stains. Moreover, after H2DCF-DA staining the treated cancerous cells, an induced oxidative stress was detected. Complexes 2 and 4 also revealed the activation of mitochondrial pathway of apoptosis in treated cancer cells. [ABSTRACT FROM AUTHOR]

Highlights: [•] Synthesis of potential bioactive Schiff base compounds. [•] Structural and spectroscopic characterization. [•] Biological activities. [•] Interaction with SSDNA via intercalative mode of interaction. [•] Excellent antioxidant activity. [ABSTRACT FROM AUTHOR]

A feature of diabetes is that the rate of protein glycation and the formation of advanced glycation endproducts (AGEs) increases spontaneously due to the abnormally elevated levels of sugar in the blood. The glycation of proteins is associated with a large number of late diabetic complications (retinopathy, neuropathy, atherosclerosis, end stage renal diseases, rheumatoid arthritis and neurodegenerative diseases). The increase in diabetic complications is a major cause of morbidity and mortality, which has increased significantly in the last two decades. Therefore, there is a considerable recent interest in the identification of lead molecules, which can inhibit the glycation process or slow it down considerably. A new class of anti-glycation agents has been identified, based on the spectrofluorimetric analysis of fluorescent advanced glycation endproducts (AGEs), benzenediol Schiff bases, and their structure-activity relationships have been studied. Some of these compounds have shown a promising anti-glycation potential in vitro. [ABSTRACT FROM AUTHOR]

This paper demonstrates a Schiff base i. e. 5‐(diethylamino)‐2‐((2,6‐diethylphenylimino)methyl)phenol (5‐DDMP) that was sensed by DNA biosensor. dsDNA was immobilized onto GCE modified with functionalized multi‐walled carbon nanotubes to prepare a biosensor. The efficiency of dsDNA biosensor was determined and binding of 5‐DDMP with dsDNA was searched by UV‐vis spectrophotometry and differential pulse voltammetry. Molecular docking simulations between 5‐DDMP and dsDNA were explored and as a result, a hydrogen bond and a π‐π contact were observed between 5‐DDMP and deoxyguanosine base (dG22) of the strand B, deoxyadenosine base (dA5) of the strand A, respectively. These studies could be useful for new anticancer drug design and development. [ABSTRACT FROM AUTHOR]

Three new copper and zinc complexes have been prepared. These complexes have structural as well as biological relevance. Their anti-diabetic as well as docking studies have been presented. [Display omitted] Three new mononuclear mixed ligand copper(II) and zinc(II) complexes were synthesized having general formulae [Cu (L 1) (L 2) 2 ] (1), [Cu 2 (L 3) (L 2) 2 ] (2), [Zn (L 3) 2 (L 2)] (3), where L 1 = 3, 4-dichloro phenylacetate, L 2 = 1, 10-phenathroline and L 3 = 2-bromophenylacetate. All the complexes were structurally characterized by FT-IR and single crystal X-ray diffraction analysis. Compound 1 is penta-coordinated where Cu(II) ion is surrounded by 3, 4-dichlorophenyacetate and two 1,10-phenanthroline moities. Compound 2 has hexa -coordinated Cu(II) surrounded by two 1,10-phenanthroline moieties and a 2-bromophenylacetate. Compound 3 is hexa -coordinated Zn(II) complex surrounded by 1,10-phenanthroline and two 2-bromophenylacetate moities. DNA binding mechanism of all complexes was examined by molecular docking studies. Based on molecular bonding results the binding energies for complexes 1 – 3 were found to be −5.86 kcal/mol, −5.81 kcal/mol and −5.85 kcal/mol, respectively. These stable complexes indicated spontaneous interaction ability with DNA which may have further biological potential. This has been supported by the in-vitro DNA-binding activity of the complexes as well using spectrophotometry. All the complexes were subjected for their anti-diabetic potential. All the complexes exhibited potent inhibitory capability against the α-glucosidase with IC 50 values in the range of 2.63–6.19 µM compared with the available marketed drug acarbose (IC 50 = 873.34 ± 1.67 µM). [ABSTRACT FROM AUTHOR]

Three newly synthesized Schiff bases have been synthesized and presented as efficient corrosion inhibitors for the protection of EN3B mild steel in 3.5% NaCl solution at acidic pH 1.5. The adsorbed NS(n) inhibitors create a barrier film over EN3B mild steel surface and hinder the attack of corrosive species (H 3 O+, Cl−) thereby preventing the dissolution of steel in an aggressive environment. [Display omitted] • Schiff bases have been synthesized, characterized and used as corrosion inhibitors. • The adsorbed layer of Schiff bases over EN3B mild steel surface has been characterized via RAIRS spectroscopy. • Electrochemical measurements revealed a strong inhibition potential, with the maximum inhibition efficiency of 99.8%. • The surface roughness of mild steel protected by NS16 was 10.41 nm, close to polished steel surface i.e. , 9.12 nm. • MD simulations predict a parallel mode of adsorption of NS16 over Fe(1 1 0) surface. Three newly synthesized Schiff bases; 5-(diethylamino)-2-[(n-undecylimino)methyl]phenol (NS11) , 5-(diethylamino)-2-[(n-tetradecylimino)methyl]phenol (NS14) and 5-(diethylamino)-2-[(n-hexadecylimino)methyl]phenol (NS16) have been presented as efficient corrosion inhibitors for the protection of EN3B mild steel in 3.5% NaCl solution at acidic pH 1.5. The inhibitors were characterized by multitude techniques i.e., Fourier transform-infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and single crystal X-ray diffraction (XRD) analysis. An anti-corrosive film of the inhibitors was generated on EN3B mild steel surface by dip-coating method and the presence of adsorbed molecules in a monolayer was detected via reflection absorption infrared spectroscopy (RAIRS). Electrochemical measurements revealed a strong inhibition potential of the inhibitors with the maximum inhibition efficiency of 99.8% achieved by NS16. These results were further complemented by morphological examinations and density functional theoretical (DFT) calculations revealing that the electron donating power of substituents is directly related to the inhibition potential of the inhibitors. [ABSTRACT FROM AUTHOR]

A new Schiff base, 1-((4-bromophenylimino) methyl) naphthalen-2-ol (BPIMN) was successfully synthesized and characterized by 1 H NMR, 13 C NMR, FTIR and UV–Vis spectroscopy. The results were compared with a structurally related Schiff base, 1-((4-chlorophenylimino) methyl) naphthalen-2-ol (CPIMN). The photometric and electrochemical fate of BPIMN and CPIMN was investigated in a wide pH range. The experimental findings were supported by quantum mechanical approach. The redox mechanistic pathways were proposed on the basis of results obtained electrochemical techniques. Moreover, pH dependent UV–Vis spectroscopy of BPIMN and CPIMN was carried out and the appearance of isosbestic points indicated the existence of these compounds in different tautomeric forms. [ABSTRACT FROM AUTHOR]

• Synthesis of novel ONO tridentate Schiff base ligand and its dioxomolybdenum complex • Single crystal X-ray diffraction (SC-XRD) analysis of complex • DFT calculation by DFT using B3LYP and PBE0 levels of theory at Def2-TZVP basis set • Oxidation of sulfides using H 2 O 2 with proposed mechanism A novel dioxomolybdenum Schiff base complex, [MoO 2 (L)(H 2 O)] , was synthesized by the reaction of MoO 2 (acac) 2 and an ONO donor Schiff base ligand (H 2 L: (E) -4-amino- N' -(3-ethoxy-2-hydroxybenzylidene)benzohydrazide) derived by the condensation of 4-aminobenzohydrazide and 3-ethoxysalicylaldehyde. The synthesized ligand and complex were characterized by various spectroscopic techniques like FT-IR, 1H NMR, 13C NMR, and elemental analysis (CHN). The structure of the complex was confirmed by single crystal X-ray diffraction analysis (SC-XRD). The geometry around the central metal ion in the complex was distorted octahedral as revealed by the data collected from diffraction studies. Theoretical calculations of the synthesized compounds, carried out by DFT using B3LYP and PBE0 levels of theory at the Def2-TZVP basis set, indicated that the calculated results are in agreement with the experimental findings. Moreover, the catalytic efficiency of the complex was investigated by oxidizing the aryl and alkyl sulfides in the presence of 30 % aqueous H 2 O 2 in ethanol. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: This article describes the synthesis of four new homobimetallic organotin(IV) complexes: [Et2Sn]2L (1), [Bu2Sn]2L (2), [Oct2Sn]2L (3) and [BuClSn]2L (4) (H 4 L = N 1′,N 6′-bis(5-bromo-2-hydroxybenzylidene)adipodihydrazide) and their structural elucidation by means of elemental analysis, mass spectroscopy, FT-IR, NMR (1H, 13C, 119Sn) and single crystal X-ray analysis. Spectroscopic studies indicate coordination of hexadentate ligand to the diorganotin(IV) moieties via ONO–ONO donor sites and pentacoordinated tin centers. Single crystal X-ray analysis of (1) and (2) revealed homobimetallic nature of complexes with each Sn atom in a distorted square pyramidal coordination geometry. Packing diagrams suggest the seminal role of Sn⋯N and Br⋯π interactions in generating supramolecular assembly. The synthesized compounds were screened for their antimicrobial activity and cytotoxicity. Compound (2) exhibit highest activity against several pathogenic microbes. [Copyright &y& Elsevier]

Abstract: This article describes the synthesis, characterization and bioactivity of dimethyl (1), diethyl (2), diphenyl (3), di-n-octyl (4), di-tert-butyl (5), n-butylchlorotin(IV) (6) derivatives of N′-(2-hydroxy-3-methoxybenzylidene)formohydrazide ligand. On the basis of presence or absence of steric factor, these compounds are either mononuclear in which Sn atom is in distorted trigonal bipyramidal geometry (3) or homobimetallic with each Sn atom in pentagonal bipyramidal environment (1). Packing diagrams suggest that the H⋯N, H⋯π and π⋯π interactions play a seminal role in generating fascinating supramolecular structures. These complexes show good antileishmanial, antiurease, antibacterial and antifungal activities. Moreover, the antileishmanial activity of 3 and 5 is comparable with standard antileishmanial drug Amphotericin B. [Copyright &y& Elsevier]

Abstract: The paper describes the synthesis and structural characterization of six new diorganotin(IV) compounds 1–6, [R2SnL] and a monoorganotin(IV) derivative, C4H9SnClL (7). Here L = N′-(5-bromo-2-oxidobenzylidene)-N-(oxidomethylene)hydrazine ligand with ONO tridentate chelation capability and R = CH3 (1), C2H5 (2), n-C4H9 (3), C6H5 (4), C8H17 (5), tert-C4H9 (6), The packing diagram offers a supramolecular structure for 1 and a dimeric structure for 4 with distorted square-pyramidal and distorted trigonal geometry, respectively. The different geometry of 1 than 4 can be attributed to the presence of intermolecular non-covalent Sn---O and Sn---H interactions in the former. The antifungal, antibacterial, antiurease and antileishmanial activities of these complexes proved them to be active biologically and may be formulated as new metal-based drugs in future. [Copyright &y& Elsevier]

Abstract: Six new diorganotin(IV) derivatives of N′-(2-hydroxybenzylidene)formohydrazide (H2L) with general formula R2SnL, where R = Ph (1), Me (2), Bu (3), Oct (4), t-Bu (5), Et (6), and L = [OC6H4CHNNCHO] have been synthesized and characterized by different analytical techniques. Crystal structure of Me2SnL (2) authenticated distorted square-pyramidal geometry around the Sn atom. The CV and UV–Vis spectroscopic data indicated intercalation of complexes into DNA with binding affinity varying in the sequence: 3 (1.69 × 104 M−1) > 1 (1.10 × 104 M−1) > 2 (9.61 × 103 M−1). Some of these compounds were found to be good antibacterial, antifungal and leishmanicidal agents. [Copyright &y& Elsevier]

The title Schiff base, C15H19NO4, crystallizes with two mol­ecules per asymmetric unit. In the solid state, a zwitterion is observed, with a strong intra­molecular N—H⋯O hydrogen bond involving the NH imine H atom and the phenolate O atom. In the crystal structure, the two crystallographically independent mol­ecules are linked by O—H⋯O hydrogen bonds to create centrosymmetric dimers. These dimers are connected by inter­molecular C—H⋯O hydrogen bonds to form layers. [ABSTRACT FROM AUTHOR]