Bis(Salicylidene)Ethylenediamine(Salen) and Bis(Salicylidene)Ethylenediamine-Metal Complexes: from Structure to Biological Activity

Nworie, Felix Sunday

doi:10.15406/japlr.2016.03.00076

Cited by 16 publications

(12 citation statements)

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“…From the large number of oxidation states observed for the aforementioned actinides, the tetravalent oxidation state is most stable for the elements under reducing conditions, lending itself to a systematic comparison. The Schiff base salen has been a versatile ligand system for industrial, biological, and medicinal purposes in combination with metals across the periodic table − and is also used for benchmarking high-level computational methods. − Moreover, it contains N and O as coordinating atoms, which allows a comparison of these donor atoms of differing hardness in the same molecule, while a previous study had focused on the amidines as a well-established N-donor ligand system, i.e., ( S , S )- N , N ′-bis(1-phenylethyl)benzamidine. The salen ligand can also be considered to approximate the binding motifs of natural complexing agents, e.g., amino acids or humic substances …”

Section: Introductionmentioning

confidence: 99%

Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)₂]

et al. 2021

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Key questions for the study of chemical bonding in actinide compounds are the degree of covalency that can be realized in the bonds to different donor atoms and the relative participation of 5f and 6d orbitals. A manifold of theoretical approaches is available to address these questions, but hitherto no comprehensive assessments are available. Here, we present an in-depth analysis of the metal–ligand bond in a series of actinide metal–organic compounds of the [M(salen)2] type (M = Ce, Th, Pa, U, Np, Pu) with the Schiff base N,N′-bis(salicylidene)ethylenediamine (salen). All compounds except the Pa complex (only included in the calculations) have been synthesized and characterized experimentally. The experimental data are then used as a basis to quantify the covalency of bonds to both N- and O-donor atoms using simple electron-density differences and the quantum theory of atoms in molecules (QTAIM) with interacting quantum atoms. In addition, the orbital origin of any covalent contributions was studied via natural population analysis (NPA). The results clearly show that the bond to the hard, charged O-donor atoms of salen is consistently not only stronger but also more covalent than bonds to the softer N-donor atoms. On the other hand, in a comparison of the metals, Th shows the most ionic bond character even compared to its 4f analogue Ce. A maximum of the covalency is found for Pa or Np by their absolute and relative covalent bond energies, respectively. This trend also correlates with a significant f- and d-orbital occupation for Pa and Np. These results underline that only a comprehensive computational approach is capable of fully characterizing the covalency in actinide complexes.

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Section: Introductionmentioning

confidence: 99%

Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)₂]

et al. 2021

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“…The 1 HNMR spectra (Figs. [7][8][9][10][11][12] were recorded for the Schiff base ligand (H 2 L) and its metal complexes in DMSO as the solvent and showed the following chemical shifts; multiple signal chemical shifts between 6.97-7.89 ppm belong to the protons in aromatic rings, the singlet chemical shift at 9.01-9.10 ppm is attributed to the proton attached to C=N group. 27 The 1 H NMR spectrum of the ligand (H 2 L) showed the hydroxyl protons appeared at δ = 13.27 ppm.…”

Section: Hnmr Spectramentioning

confidence: 99%

“…Imine compounds containing the azomethine (C=N) group are considered good coordinating ligands when they bear a functional group such as the hydroxyl, amine or thiol due to the formation of a five-or six-membered chelate with a metal ion. 1,2 Imine compounds and their transition metal complexes have attracted considerable interest due to their antibacterial, 3 antifungal, 4 antiviral, 5 antimalarial, 6 anticancer, 7 and antitumour 8 activities. Benzidine compounds form a variety of Schiff bases with aldehydes/ ketones and are reported to be superior reagents in biological, pharmacological, clinical and analytical applications which are improved by complexation with transition metal ions.…”

Section: Introductionmentioning

confidence: 99%

Anomalous Sorption of Neodymium and Praseodymium Ions by Intergel System Polyacrylic Acid Hydrogel – Poly-4-Vinylpyridine Hydrogel

Jumadilov¹,

Kondaurov²,

Imangazy³

et al. 2022

ChChT

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This paper is devoted to study of sorption properties (sorption degree, polymer chain binding degree) of intergel system hydrogel of polyacrylic acid (hPAA) – hydrogel of poly-4-vinylpyridine (hP4VP) in relation to neodymium and praseodymium ions. It was found that remote interaction of the polymers in intergel pairs provides significant changes of the electrochemical and volume gravimetric properties. Strong increase of the swelling degree of hPAA is observed at the ratio 17%hPAA-83%hP4VP; significant increase of swelling degree of hP4VP is observed at the ratio 83%hPAA-17%hP4VP. Individual hydrogels of PAA and P4VP do not have sufficiently high sorption properties – sorption degree of neodymium and praseodymium ions is not higher than 65 %, polymer chain binding degree is not higher than 55 %. High ionization of hPAA and hP4VP due to remote interaction effect provides significant increase (up to 30 %) of the sorption properties. Maximum sorption of neodymium and praseodymium ions occurs at the ratios 83%hPAA-17%hP4VP and 50%hPAA-50%hP4VP (sorption degree is 93.5 % and 93.6 %, respectively). The highest values of polymer chain binding degree (in relation to neodymium and praseodymium ions) are observed at the ratios 83%hPAA-17%hP4VP and 50%hPAA-50%hP4VP – binding degree is 73.2 % and 75.4 %, respectively. Remote interaction provides possibilities for creation of innovative sorption technologies for selective sorption of aimed rare-earth elements.

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“…Over the past few decades, transition metal complexes containing N 2 O 2 coordination sites, such as salicylidenes [ 1 ], have aroused the increased interest of researchers due to their multiple applications in topical fields such as non-linear optics [ 2 ], molecular magnetism [ 3 ], functional materials and organic electronics [ 4 ], light-emitting diodes (OLEDs) [ 1 , 5 ], and display magnetic properties [ 6 ]. Among them, salen-like ligands ( Figure 1 a) were studied for their properties and applications in biology [ 7 ], catalysis [ 8 ], and electrocatalysis [ 9 ]. They are diimines prepared from differently substituted aldehydes and various 1,2 diamines.…”

Section: Introductionmentioning

confidence: 99%

Ni(II)-Salophen—Comprehensive Analysis on Electrochemical and Spectral Characterization and Biological Studies

Ngounoue Kamga,

Hrubaru,

Enache

et al. 2023

Molecules

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New aspects of the Ni(II)-salophen complex and salophen ligand precursor were found during deep electrochemical and optical characterization, as well as biological studies for new pharmacological applications. Physicochemical and spectroscopic methods (1H- and 13C-NMR, FT-IR and UV-Vis, electrospray ionization mass spectroscopy, thermogravimetric analysis, and molar conductance measurements) were also used to prove that the salophen ligand acts as a tetradentate and coordinates to the central metal through nitrogen and oxygen atoms. The electrochemical behavior of the free Schiff salophen ligand (H2L) and its Ni(II) complex (Ni(II)L) was deeply studied in tetrabutylammonium perchlorate solutions in acetonitrile via CV, DPV, and RDE. Blue films on the surfaces of the electrodes as a result of the electropolymerization processes were put in evidence and characterized via CV and DPV. (H2L) and Ni(II)L complexes were tested for their antimicrobial, antifungal, and antioxidant activity, showing good antimicrobial and antifungal activity against several bacteria and fungi.

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Bis(Salicylidene)Ethylenediamine(Salen) and Bis(Salicylidene)Ethylenediamine-Metal Complexes: from Structure to Biological Activity

Cited by 16 publications

References 0 publications

Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)₂]

Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)₂]

Anomalous Sorption of Neodymium and Praseodymium Ions by Intergel System Polyacrylic Acid Hydrogel – Poly-4-Vinylpyridine Hydrogel

Ni(II)-Salophen—Comprehensive Analysis on Electrochemical and Spectral Characterization and Biological Studies

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Bis(Salicylidene)Ethylenediamine(Salen) and Bis(Salicylidene)Ethylenediamine-Metal Complexes: from Structure to Biological Activity

Cited by 16 publications

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Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)2]

Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)2]

Anomalous Sorption of Neodymium and Praseodymium Ions by Intergel System Polyacrylic Acid Hydrogel – Poly-4-Vinylpyridine Hydrogel

Ni(II)-Salophen—Comprehensive Analysis on Electrochemical and Spectral Characterization and Biological Studies

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Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)₂]

Comprehensive Bonding Analysis of Tetravalent f-Element Complexes of the Type [M(salen)₂]