Tautomeric stability, molecular structure, NBO, electronic and NMR analyses of salicylideneimino-ethylimino-pentan-2-one

Kanaani, Ayoub; Ajloo, Davood; Grivani, Gholamhossein; Ghavami, Abbaseh; Vakili, Mohamad

doi:10.1016/j.molstruc.2016.02.024

Cited by 33 publications

(10 citation statements)

References 54 publications

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“…absorption spectrophotometer Shimadzu 1601-PC with 1 cm optical quartz cells. 1 H NMR spectra were recorded at 300 MHz and 13 C NMR spectra at 75 MHz on a Bruker AVANCE 300 instrument. Resonance patterns are reported with the following notations: br (broad), s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet), dd (doublet of doublets) (Figure S3-S4).…”

Section: Methodsmentioning

confidence: 99%

“…160 µL of this solution was mixed with 40 µl of the compound (free ligand or metal complex) in methanol and the absorbance was recorded at 734 nm after 10 minutes of reaction. Similarly, to DPPH • , the percentages of the scavenging activity of ABTS •+ was calculated following formula (1) and the IC 50 values were deduced from the inhibition curves measured for different concentrations of the compound. The results obtained with the compounds investigated in this work were also compared to BHA and BHT used as standards.…”

Section: 422-abts •+ Scavenging Activitymentioning

confidence: 99%

“…Schiff-based derivatives have received considerable attention due to their ease of production and their multiple uses. [1] The versatility of applications primarily derives from the presence of carbon-nitrogen double bond. [2] Schiff bases have found applications in many areas such as analytical, biological, [2][3][4] or inorganic chemistry.…”

Section: Introductionmentioning

confidence: 99%

“…The first methods employing stable free radicals such as DPPH• or ABTS •+ (bleaching assays) provided information on the radical scavenging capacities of the investigated systems (SET-based assays). As far as DPPH • is concerned, H 3 L1 and H 3 L2 were found to be the more efficient radical scavengers in the reduction of this neutral organic . By contrast with the free ligands, the complexes weakly inhibited DPPH • radical with IC 50 values greater than 100 µg/mL.…”

mentioning

confidence: 99%

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Coordination properties of two new Schiff-base phenoxy-carboxylates and comparative study of their antioxidant activities

Boussadia¹,

Beghidja²,

Gali³

et al. 2020

Inorganica Chimica Acta

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Two novel tridentate Schiff-base ligands containing carboxylate groups were obtained from the condensation of 3-amino-4-hydroxybenzoic acid with either acetylacetone (H 3 L 1 ) or salicylaldehyde (H 3 L 2 ). H 3 L 1 reacted with copper(II) acetate and pyridine (strongly coordinating solvent) to afford the C1 complex, while reaction of H 3 L 2 with nickel(II) acetate and pyridine afforded two types of complexes C2 and C3. The two ligands and their metal complexes were fully characterized by elemental analysis, XRD and spectroscopic analysis.Upon its fully deprotonated state, (L 1 ) 3coordinates in a keto-enamine fashion and acts as a ditopic binder through an ONO tridentate donor system and an O monodentate donor system (carboxylate). Upon its doubly deprotonated state, (HL 2 ) 2ligand acts either as monotopic tridentate binder (i.e. enol-imine form with an ONO donor system that lead to complex C2) or as a ditopic ligand (ONO tridentate and O monodentate donor systems to afford complex C3).The molecular structure of all the compounds were determined by single crystal X-ray diffraction studies and revealed several important characteristics. In complex C1, the Cu(II) cations are five-coordinated with a slightly distorted square pyramidal geometry, while in C2 and C3 complexes, the Ni(II) ions are four and six-coordinated with a square planar and a slightly distorted octahedral geometry, respectively. Following this structural investigation, the antioxidant activities of the free ligands and their metal complexes were then investigated and demonstrated interesting antioxidant features especially for H 3 L 2 and complex C3. Lastly, temperature dependent magnetic susceptibility measurements showed the presence of ferromagnetic interactions in C1 mediated through the phenoxido bridges.

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Section: Methodsmentioning

confidence: 99%

Section: 422-abts •+ Scavenging Activitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Coordination properties of two new Schiff-base phenoxy-carboxylates and comparative study of their antioxidant activities

Boussadia¹,

Beghidja²,

Gali³

et al. 2020

Inorganica Chimica Acta

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“…Herein, the large energy gap for [VO(A)] and [VO(B)], 3.36 and 3.31 eV, respectively, confirms high stability of the complexes. 19,[27][28][29]35,36…”

Section: Nbo Analysismentioning

confidence: 99%

Oxovanadium(IV) complexes of the pyridoxal Schiff bases: Synthesis, experimental and theoretical characterizations, QTAIM analysis and antioxidant activity

et al. 2020

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Two vanadyl complexes of the pyridoxal Schiff bases have been newly synthesized and characterized by several experimental methods, where the 4,4′-[1,4-butanediylbis-[(E)-nitrilomethylidyne])bis[5-hydroxy-6-methyl-3-pyridinemethanol] and trans-4,4′-[1,2-cyclohexanediylbis-[(E)-nitrilo-methylidyne]]bis[5-hydroxy-6-methyl-3-pyridinemethanol] Schiff base were used. Geometry optimization, assignment of the IR vibrational frequencies and the natural bond orbital (NBO) analysis of the complexes have been calculated by employing the density functional theory (DFT) approaches. Deprotonated form of the Schiff bases (L 2-) acts as a tetradentate N 2 O 2 ligand, which coordinates to the V(IV) via two phenolate oxygens and two imine nitrogens. In the square-pyramidal geometry of the [VO(L)], the apical position is occupied by an oxo ligand. The DFT-calculated vibrational frequencies show a good consistency with the corresponding experimental values, confirming suitability of the optimized geometries for the complexes. Characteristics of the bonding interactions have been explored using the quantum theory of atoms in molecule (QTAIM) analysis. The complex formation results in decrease in strength of the C-N bond of the azomethine group and increase in the strength of the CO bonds of the phenolate group. High-energy gaps approve stability of the complexes. Both of the complexes show significant radical scavenging activities against the ABTS and DPPH radicals, even higher than the BHA.

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Study of N‐methyl‐5‐nitroindazolylacrylonitriles as a Function of Quantum Parameters Employing Density Function Theory Methods: Comparative Theoretical Study and Nonlinear Optical Properties

et al. 2023

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The synthesis of N-methyl-5-nitroindazolylacrylonitriles 2 a-l by a Knoevenagel condensation reaction with a series of aldehydes in the presence of piperidine allowed the preparation of the desired products the yields are good to excellent. N-Methyl-5-nitroindazolylacrylonitriles (2 a-l) were verified by 1 H, 13 C NMR and mass spectrometry. In this current work, the reactivity indices defined within the Conceptual DFT of the targeted molecules through DFT/B3LYP/6-311G(d,p) calculations were studied. The 1 H NMR, UV-vis and IR spectroscopy chemical shifts of all synthesized 5-nitroindazoles 2 a-l were calculated and the results were compared to the results of the experimental data. In this series of compounds, the 2 e has the lowest hyperpolarizability, which results being the most stable and having the least response to nonlinear optics (NLO). In contrast, the compound 2 l has the highest hyperpolarizability, which fallouts being the least stable and having a high response to NLO. Every chemical has a significant threedimensional p-electronic delocalization, which is crucial for understanding NLO responses.

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Tautomeric stability, molecular structure, NBO, electronic and NMR analyses of salicylideneimino-ethylimino-pentan-2-one

Cited by 33 publications

References 54 publications

Coordination properties of two new Schiff-base phenoxy-carboxylates and comparative study of their antioxidant activities

Coordination properties of two new Schiff-base phenoxy-carboxylates and comparative study of their antioxidant activities

Oxovanadium(IV) complexes of the pyridoxal Schiff bases: Synthesis, experimental and theoretical characterizations, QTAIM analysis and antioxidant activity

Study of N‐methyl‐5‐nitroindazolylacrylonitriles as a Function of Quantum Parameters Employing Density Function Theory Methods: Comparative Theoretical Study and Nonlinear Optical Properties

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