Solvent-free synthesis of some N4O2, N4S2 and N6 Schiff-base ligands assisted by microwave irradiation

Keypour, Hassan; Rezaeivala, Majid; Fall, Yagamare; Dehghani-Firouzabadi, Ahmad Ali

doi:10.3998/ark.5550190.0010.a26

Cited by 9 publications

(5 citation statements)

References 19 publications

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“…1 H NMR (400 MHz, CDCl 3 , ppm) δH: 1.81 (m, 4H, 9-H), 2.33−2.40 (m, 12H, 10-H, and 11-H), 3.58 (t, 3 J = 8.0 Hz, 4H, 8-H), 6.79−7.31 (m, 6H, aromatic ring), 8.20 (s, 2H, 7-H, CN), 13.49 (bs, 2H, OH). 13 C NMR (400 MHz, CDCl 3 , ppm) δC: 27.8 (t, C-9), 53.2 (t, C-11), 55.8 (t, C-10), 57.4 (t, C-8), 109.8 (s, C-6), 119.1 (d, C-5), 120.1 (s, C-2), 153.2, 154.8 (d, C-3 or C-4), 160.5 (s, C-5) (aromatic ring), 163.8 (d, C-7, CN) . Scheme shows the structure of the synthesized Schiff base.…”

Section: Methodsmentioning

confidence: 99%

Application of Rank Annihilation Factor Analysis to the Spectrophotometric Determination of the Formation Constants of Complexes of a New Schiff Base and Some Transition Metals in Different Media

et al. 2010

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The complex formation between a new synthesized Schiff base and the cations Ni2+, Co2+, Cu2+, and Zn2+ in ethanol, dimethylformamide (DMF), and acetonitrile (AN) was studied spectrophotometrically using rank annihilation factor analysis (RAFA). According to molar ratio data and Job’s plots, the stoichiometry of complexation between the Schiff base and the cations Co2+, Ni2+, and Zn2+ was 1:2, and that between the Schiff base and Cu2+ in all solvents and Zn2+ in AN was 1:1. Formation constants of these complexes were derived using RAFA on spectrophotometric data. In this process the contribution of the ligand is removed from the absorbance data matrix when the complex stability constant acts as an optimizing object, and simply combined with the pure spectrum of ligand, the rank of the original data matrix can be reduced by one by annihilating the information of the ligand from the original data matrix. Also the effect of surfactants such as sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and Triton X-100 on the complex formation constant of Cu2+ with the Schiff base in DMF was investigated.

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Section: Methodsmentioning

confidence: 99%

Application of Rank Annihilation Factor Analysis to the Spectrophotometric Determination of the Formation Constants of Complexes of a New Schiff Base and Some Transition Metals in Different Media

et al. 2010

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“…However, it has rarely been used in the synthesis of imines. N -Alkyl or N -aryl imines have been prepared by microwave irradiation in the absence of a catalyst or in the presence of calcium oxide, silica gel, or the solid acid montmorillonite K-10 or a ZrO 2 /S 2 O 8 2– solid superacid as a catalyst.…”

Section: Introductionmentioning

confidence: 99%

Microwave-Assisted Solvent-Free Synthesis of Enantiomerically Pure N-(tert-Butylsulfinyl)imines

et al. 2012

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A simple, environmentally friendly, and very efficient procedure for the synthesis of optically pure N-(tert-butylsulfinyl)imines has been developed with microwave-promoted condensation of aldehydes and ketones using (R)-2-methylpropane-2-sulfinamide in the presence of Ti(OEt)(4), under solvent-free conditions. This procedure allows for the preparation of a variety of sulfinyl aldimines with excellent yields and purities in only 10 min, making any further purification of the imines unnecessary. Several sulfinyl ketimines have also been prepared in good yields by extension of the reaction times to 1 h. This methodology has proved to be equally efficient for the synthesis of aromatic, heteroaromatic, and aliphatic N-(tert-butylsulfinyl)imines. Conventional heating has also been shown to be useful to promote these reactions, especially for the synthesis of aldimines.

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“…An Agilent Technologies® 5975C spectrometer was then used to scan the mass spectra according to the estimated index (EI)method at 70 eV. The 1 H and 13 C NMR spectra of the compounds were scanned using a Bruker® 500 MHz spectrometer. Tetramethylsilane (TMS) was utilised as a reference for internal standards.…”

Section: Instrumentation and Spectral Measurementsmentioning

confidence: 99%

“…The 1 HNMR spectrum of H2L2 (Figure 3) displayed the same signals with the absence of the CH=C signal due to the chloride atom. The 13 CNMR spectrum of the two ligands indicated that the signal for C=N was between 194.9 to 198ppm and C-OH at 159.38 to 158.5 ppm for H2L1 and H2L2, respectively. Signals for the other carbon atoms were also noted.…”

Section: Characterization Of Ligands and Complexesmentioning

confidence: 99%

“…Tetradentate β-ketoenamine Schiff base ligands that have been produced via the condensation of β-diketone with diamine or monoamine contain N2O2 donor atoms [2][3][4][5][6][7][8][9][10][11]. Moreover, polydentate and macrocycle Schiff base ligands that have various donor atoms; such asN2S2, N2O2, N4,and N2O [12][13][14] ;are known to cooperatewell with a variety of metal ions [15][16][17][18]. A wealth of articles that extend from pure synthesis to contemporary physically-and biochemically-relevant investigations indicate that the metal complexes of β-ketoenamine ligands have played an essential role incoordination chemistry-based studies [19][20][21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

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Novel Schiff Bases Ligands and Their Complexes: Thermal Analysis, Antibacterial Activity, and Molecular Docking

et al. 2021

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The transition metal complexes of novel tetradentate-ketoenamine ligands were synthesised by condensing β-diketone (acetylacetone, 3-chloro acetylacetone) with 4,4'-methylenedianiline. Fourier-transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance ( 1 H NMR) spectroscopy, carbon-13 NMR ( 13 C NMR) spectroscopy, electron ionisation mass spectrometry (EIMS), elemental analysis, and UV-visible (UV-Vis) spectroscopy were used to describe the compounds while thermogravimetric (TG/DTG) analysis was used to investigate the thermal breakdown of the complexes. All of the complexes showed outstanding stability as well as different degrees of thermal decomposition. Antibacterial activity was tested using gram-positive (Bacillus subtilis, Staphylococcus aureus) and gram-negative (Bacillus subtilis, Staphylococcus aureus) bacteria (Escherichia coli, Salmonella typhi). Minimal inhibitory concentrations (MICs) of 0.5 to 2 mM/ml and minimum bacterial concentrations (MBCs) of 2 to 4 mM/ml were used in this study. A molecular docking study was also conducted to ensure that the compounds connected well to the active sites of the target enzymes; such as topoisomerase II DNA gyrase enzymes (2XCT) and methicillin-resistant Staphylococcus aureus (MRSA,2x3f.pdb).

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Solvent-free synthesis of some N4O2, N4S2 and N6 Schiff-base ligands assisted by microwave irradiation

Cited by 9 publications

References 19 publications

Application of Rank Annihilation Factor Analysis to the Spectrophotometric Determination of the Formation Constants of Complexes of a New Schiff Base and Some Transition Metals in Different Media

Application of Rank Annihilation Factor Analysis to the Spectrophotometric Determination of the Formation Constants of Complexes of a New Schiff Base and Some Transition Metals in Different Media

Microwave-Assisted Solvent-Free Synthesis of Enantiomerically Pure N-(tert-Butylsulfinyl)imines

Novel Schiff Bases Ligands and Their Complexes: Thermal Analysis, Antibacterial Activity, and Molecular Docking

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