Vanadium(IV) Schiff base Complex: Synthesis, Characterization, Crystal Structure and Thermal Decomposition into V2O5 Particles

New mononuclear copper(I) Schiff base complex Cu((Cl-NO2-ba)2en)I(CH3CN) (1) containing a bidentate Schiff base ligand (Cl-NO2-ba)2en = 2,4-dichloro-5-nitro-benzylidene-1,2-diaminopropane, was prepared in an acetonitrile solution and characterized by elemental analyses (CHN), FT-IR and UV-Vis spectroscopy. Suitable dark-orange single crystals were obtained by slow evaporation of solvent at 5 ºC for several days. Crystal structure of the title compound 1 was determined by single-crystal X-ray diffraction. The complex 1 crystallizes in orthorhombic space group Pna21, a = 16.8634 (5) Å, b = 8.4460 (5) Å, c = 17.4786 (2) Å, V = 2489.45 (17) Å3 and Z = 4. In addition, the title compound 1 was used as new precursor for the synthesis of copper(II) oxide nanoparticles via solid state thermal decomposition. The as prepared CuO product was characterized by FT-IR, XRD and SEM.

Synthesis, spectral characterization, crystal structures, biological activities, theoretical calculations and substitution effect of salicylidene ligand on the nature of mono and dinuclear Zn(II) Schiff base complexes

A close insight into the nature of intra- and intermolecular interactions in new Cu(II) Schiff base complexes derived from halogenated salicylaldehydes and allylamine: Theoretical and crystallographic studies

A new copper(II) Schiff base complex containing asymmetrical tetradentate N2O2 Schiff base ligand: Synthesis, characterization, crystal structure and DFT study

New dinuclear methoxo-bridged manganese(III) complex [Mn2((MeO-bph)en)2Cl2(m-CH3O)2] (1) was synthesized by template reaction of 2-hydroxy-4-methoxybenzophenone, 1,2-ethanediamine and MnCl2×6H2O with molar ration (1:1:1) in methanol as solvent. The title compound 1 was characterized by elemental analyses (CHN), Fourier Transform infrared spectroscopy (FT-IR) and single crystal X-ray diffraction. X-ray result reveal that 1 is dimeric with methoxo bridges between two symmetry equivalent manganese ions. The Mn ions are surrounded in a distorted octahedral geometry influenced by Jahn-Teller effect. The tridentate Schiff base ligand MeO-bp-en and one of the methoxo-bridges bind in the equatorial mode, whereas in the axial positions, other metoxo-bridge and Cl atom bind to the Mn ions. Thermogravimetric analysis of 1 was studied and display the title compound 1 decompose in three stages. Finally, by calcination of 1 at 500 °C for 3 h, we prepared Mn2O3 particles and characterized by FT-IR, XRD and SEM.

'Beta version' of neuroplasticity or absolute beta power in preterm infants as electroencephalographic correlate of synaptogenesis

A new copper(I) coordination polymer, [Cu((3,4-MeO-ba)2bn)I]n (1), using a bridging Schiff base ligand, N,N′-bis(3,4-dimethoxybenzylidene)butane-1,4-diamine, (3,4-MeO-ba)2bn, containing a flexible spacer (=N–CH2–CH2–CH2–CH2–N=) has been synthesized and characterized by elemental analyses (CHN) and FTIR spectroscopy, thermal analysis and powder X-ray structure analysis. In 1, Cu(I) ions are bridged by Schiff base ligands and iodine atoms forming 1D-chain. The thermal stability of 1 was studied by thermal gravimetric and differential thermal analyses. 1 is used to prepare CuO nanoparticles via solid state thermal decomposition in air and nanoparticles thus formed are characterized by scanning electron microscopy, transmission electron microscopy and powder X-ray diffraction techniques.

Mononuclear copper(II) Schiff base complexes, Cu(BrSal2Pn) (I) and Cu(BrSal2MePn) (II), where BrSal2Pn = N,N′-bis(5-bromo-2-hydroxybenzylidene)propane-1,3-diamine and BrSal2MePn = N,N′-bis(5-bromo-2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine, have been synthesized and characterized by elemental analyses and single-crystal X-ray diffraction. Also, the optimized geometries of them have been calculated using density functional theory method (B3LYP/6–31g). Obtained structural parameters are in agreement with the experimental data. The geometry around the copper atoms display a distorted square-planner structure by coordinating with two oxygen atoms from the phenols moieties and two nitrogen atoms from the imino groups of ligands and thus established three 6-membered rings.

A combined experimental and theoretical study to demonstrate the importance of V2O4 synthon in the crystal packing of an oxo-bridged dinuclear vanadium(V) complex with V2O4 core

A new Schiff base complex, Bis {2-[(cyclohexylimino)methyl]-4,6-dihydroselenophenol}copper(II), has been synthesized and structurally characterized by elemental analyses and X-ray diffraction. The title complex C26H32N2O2·Se4Cu crystallizes in the monoclinic space group P21/c with the cell parameters a = 15.308(3) A, b = 12.857(2) A, c = 14.161(3) A, β = 93.23(3)°, V = 2782.8(10) A3 and Z = 4. The central Copper(II) atom is four-coordinated by two O and two N atoms from the two Schiff base ligands, 2-[(cyclohexylimino)methyl]-4,6-dihydroselenophenol, forming a distorted square-planar coordination. A new Schiff base complex, Bis {2-[(cyclohexylimino)methyl]-4,6-dihydroselenophenol}copper(II), has been synthesized and structurally characterized by elemental analyses and X-ray diffraction. The central Copper(II) atom is four-coordinated by two O and two N atoms from the two Schiff base ligands, 2-[(cyclohexylimino)methyl]-4,6-dihydroselenophenol, forming a distorted square-planar coordination.

Synthesis, structural analysis and evaluation of the catalytic activity of a non-symmetric N-(salicylidene)diethylenetriamine complex of copper(II)

Oxidation of ethylbenzene using some recyclable cobalt nanocatalysts: The role of linker and electrochemical study

Two novel bpy-bridged Co(II) Schiff base complexes have been synthesized by the hydro(solvo)thermal reactions of corresponding amino-acid-based Schiff bases, bpy and Co(NO(3))(2)·6H(2)O. The following formulae identify the two complexes: {[Co(napala)(bpy)(0.5)]·H(2)O}(n) (1) and [Co(napgly)(bpy)(0.5)](n) (2) [H(2)napala = N-(2-hydroxy-1-naphthylmethylidene)-D/L-alanine, H(2)napgly = N-(2-hydroxy-1-naphthylmethylidene)-glycine and bpy = 4,4'-bipyridine]. These two compounds have been characterized using single-crystal X-ray diffraction, infrared, powder X-ray diffraction, thermogravimetric analysis, optical spectra analysis, and magnetic measurement. Complex 1 features an unprecedented threefold interpenetrated diamond network based on the fan-shaped Co(II)(4)(μ(2)-napala)(4) molecular square node and bpy linker, which represents the first example of 3D framework among the amino-acid-based Schiff base complexes with salicylaldehyde or its derivatives. In 2, adjacent Co(II) ions are bridged by μ(2)-napgly(2-) to form left- and right-handed [Co(II)(μ(2)-napgly)](n) helical chains. These two types of helical chains are sustained alternately by a symmetrical bpy co-ligand into a 2D grid-based layer. The solid-state fluorescence of complexes 1 and 2 are quenched almost completely compared with free mixed-ligands at room temperature. Moreover, magnetic studies show the dominant antiferromagnetic coupling between the Co(II) centers mediated by the syn-anti-COO(-)-bridges in both complexes.

Two dioxidovanadium(V) complexes, [VO2LH] (1) and [{VO2L}K(H2O)3] (2), containing a tridentate O, N, O donor Schiff base ligand salicylaldehyde–isonicotinoylhydrazone (H2L), have been synthesized. The synthesized ligand and corresponding complexes were structurally characterized by elemental analyses, FT-IR, UV–visible, and 1H NMR spectroscopy. Single crystal X-ray diffraction studies of the complexes (1, 2) show a distorted square pyramidal coordination environment around the metal centre. The synthesized dioxidovanadium(V) complexes were found to bind with CT-DNA in intercalative mode, with binding constant values for 1 and 2 calculated to be 1.16 × 104 M−1 and 1.08 × 104 M−1, respectively. The complexes show photocatalytic activity under visible light in the degradation of toxic cationic and anionic dyes, viz., methylene blue (MB) and rhodamine B (RhB), brilliant blue (BB), Congo red (CR), methyl orange (MO), and xylenol orange (XO) in aqueous medium.

Novel Schiff base ligand was prepared by the condensation of 2,2-(ethylenedioxy)bis(ethylamine) and imidazole-2-carboxaldehyde in a 1:2 ratio, and its complexes with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Cd(II) metal ions were synthesized in a 1:1 ratio. Various methods were used to identify the Schiff base ligand and complexes. Characterization techniques such as infrared, UV, and 1H NMR spectral tests, elemental analysis, molar conductivity, magnetic properties, thermal analysis, BET surface area, and theoretically by DFT were used to help further understanding of the complex structures. For all complexes, the ligand behaved as a neutral tetradentate ligand with NOON donor atoms and spectroscopic studies indicated an octahedral structure. The electrolytic behavior of the complexes was revealed by the molar conductivity measurements. In addition, thermogravimetric analysis was used to investigate the decomposition of the complexes and Schiff base ligand. According to the results obtained, the antibacterial activity of the metal complexes is higher than that of the Schiff base ligand against one or more bacterial species. The results showed that Cd(II) complex exhibits enhanced activity against Aspergillus flavus and Ni(II) complex against Candida albicans than the standard drug ketoconazole. The Mn(II) complex had stronger activity against human breast cancer cell line (MCF-7) than the other complexes. Antiviral drug development is critical in the latest outbreak of a novel coronavirus (SARS-CoV-2). The new coronavirus was screened using molecular docking.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13738-021-02359-w.