•Newly synthesized lanthanides complexes of ferrocene-based Schiff base.•These metal complexes were characterized using different spectroscopic, elemental analysis and thermal analysis.•Biological ...and anticancer activities were tested and promising activities.•Molecular docking was studied on two different proteins receptors of breast cancer mutant oxidoreductase (3HB5) and colon cancer isomerase (2HQ6).•Yb(III) complex can be used as breast and colon cancer drugs.
Amino acids are the fundamental building blocks of proteins and are involved in all major biological activities. Schiff bases being active biological moieties and possessing diverse pharmacological activities. Herein, the previously synthesized Schiff base ligand (HL) underwent metal complex formation, to get their La(III), Er(III) and Yb(III) metal complexes. These metal complexes were characterized using different spectroscopic tools as elemental analysis, FT-IR, mass, UV-Vis spectra, thermal analysis (TG) and scanning electron microscope (SEM). According to the elemental analysis data, the complexes were found to have octahedral geometry with the formula M(L)(H2O)2ClCl.nH2O (M = La(III), n = 2; Er(III), n = 4 and Yb(III), n = 1). The ligand binds to the metal ions with mononegative tridentate mode through the carboxylic oxygen, imidazole nitrogen and azomethine nitrogen as deduced from the IR spectra. The complexes decomposed within two or three steps from room temperature to 1000 °C as elucidated from TG. Also, biological and anticancer activities were tested and promising activities. Molecular docking was studied on two different proteins, the receptor of breast cancer mutant oxidoreductase (3HB5) and the receptor of colon cancer isomerase (2HQ6). The results recommended that Yb(III) complex can be used as breast and colon cancer drugs.
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•Tetrathiacalix4arenes bearing 1,3-diketone groups are firstly synthesized.•Spatial structure for novel compounds was established.•1,3-Diketone calix4arene derivatives sensitize ...effectively Tb3+-luminescence.•Enhancement of Tb3+ luminescence is induced by tetrathiacalix4arene scaffold.
This is the first report on the synthesis and characterization of tetra-1,3-diketone derivatives of tetrthia- and calix4arenes substituted by acetylacetonyl or dipivaloylmethanyl moieties at the upper rim and bearing hydroxyl groups at the lower rim as ligands for Tb3+ complexes. The spatial structure and tautomeric content for the synthesized ligands have been determined by means of X-ray, IR and NMR spectroscopy. Comparison of the sensitizing properties of tetrathiacalix4arenes and their calix4arene analogues on the Tb3+-centered luminescence in DMF solutions has been performed. A substantial enhancement of the luminescent properties of Tb3+- complexes with tetra-1,3-diketone ligands promoted by the tetrathiacalix4arene scaffold was established.
The similar reactivity of lanthanides generally leads to statistically populated polynuclear complexes, making the rational design of ordered hetero‐lanthanide compounds extremely challenging. Here ...we report on the site selectivity in hetero‐lanthanide tetranuclear complexes afforded by the relatively simple ditopic pyterpyNO ligand (4’‐(4‐pyridil)‐2,2’:6’,2”‐terpyridine N‐oxide). The sequential room temperature reaction of RE2(tta)6(pyterpyNO)2 (where RE=Y, (1); Eu, (2), Dy, (3) Htta=2‐thenoyltrifluoroacetone) with La(tta)3dme (dme=dimethoxyethane) yielded Y2La2(tta)12(pyterpyNO)2 (4), Dy2La2(tta)12(pyterpyNO)2 (5) and Eu2La2(tta)12(pyterpyNO)2 (6). Single crystals X‐ray diffraction studies showed that 4, 5 and 6 are isostructural, featuring a tetranuclear structure with two different metal coordination sites with coordination numbers 8 (CN8) and 9 (CN9). The two smaller cations are mainly bridged by the O‐donor atoms of the NO groups of two pyterpyNO ligands (CN8), while the larger lanthanum centres are bound by a terpyridine unit (CN9). Size selectivity has been studied with structural and magnetic studies in the solid state and through 19F NMR and photoluminescence studies in solution, showing a direct dependence on the difference of ionic radii of the ions and yielding a 91 % selectivity for 4. Furthermore, 19F NMR, X‐ray and PL studies pointed out that the nature of the product is independent from the synthetic route for compound Eu2Y2(tta)12(pyterpyNO)2 (7), keeping the ion selectivity also for a self‐assembly reaction. Unexpectedly, these studies have evidenced that selectivity is not exclusively governed by electrostatic interactions related to size dimensions.
A size selectivity in the coordination of different lanthanides ions to the two donor sites of the ditopic pyterpyNO ligand has been evidenced in heteronuclear complexes of formula RE2RE*2(tta)12(pyterpyNO)2, where smaller (larger) ions normally display a higher affinity for the eight (nine)‐coordinated oxygen (nitrogen) site. The present results, obtained in solution and in the solid state with a multi‐technique approach (X‐ray diffraction, 19F NMR, magnetometry and photoluminescence), are independent of the employed synthetic route.
•Novel Nd(III) complexes in NdL2NO3.nH2O structure were synthesized•Synthesized compounds were characterized by using (1H, 31P) NMR spectroscopy, FT-IR, thermal analysis, magnetic susceptibilities ...and elemental analysis•Catecholase-like enzymatic activity of the Nd(III) complexes were investigated
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The reaction of 2,4-diferrocenyl-1,3-dithiadiphosphetane disulfide dimer FcP(μ-S)S2 Ferrocenyl Lawesson: FcLR with two different alcohols (ROH) gave O-alkyl esters {FcPS(OR)SH, R= Me, Ph}, and the esters were converted to the ammonium salts, NH4L (1,2) where L is the ferrocenyl phosphonodithioate anion. Novel lanthanide complexes were prepared by the reaction of NH4L with the salts of Ln(NO3)3.6H2O in THF solvent LnL2NO3.nH2O, Ln: Nd (3,4). Synthesized compounds were characterized by using (1H, 31P) NMR spectroscopy, FT-IR, thermal analysis, magnetic susceptibilities and elemental analysis. The catecholase-like enzymatic activities of the synthesized and characterized Nd(III) complexes were investigated in methanol using 3,5-di-t-butylcatechol (3,5-DTBC) as substrate. The absorption of the oxidation product 3,5-di-t-butyl-o-benzoquinone (3,5-DTBQ) at maximum wavelength (400 nm) was measured spectrophotometrically. It was seen from the enzymatic activity studies that the synthesized novel complexes 3 and 4 have catecholase-like enzyme activity with a rate constants of 0.0441 and 0.0515 min−1, respectively.
Five binuclear complexes with rectangular topology have been synthesized using a nitronyl‐nitroxide ligand (L) functionalized with a pyrazole coordinating group: Ln2(hfac)2L2, with Ln=Eu (1), Gd (2 ...a, 2 b), Tb (3), Dy (4), Tm (5). The EuIII and TmIII complexes crystallize in the P21/n space group, while the GdIII, TbIII, and DyIII derivatives crystalize in P‐1 space group. The crystal structures for compounds 2 a, 3, 4, and 5 have been fully solved, while for compounds 1 and 2 b, the unit cell parameters have been measured and compared with crystals 3 and 5. Crystals 2 a (P21/n) and 2 b (P‐1) are polymorphic forms. In these complexes the nitronyl‐nitroxide ligand bridges two metal ions through one aminoxyl group and the pyrazole fragment. In the five complexes the LnIII ions show a coordination number of eight with a triangular dodecahedron geometry. The magnetic properties of all five complexes have been investigated. For compounds 2, 3, and 4 the LnIII‐Rad interaction was found to be ferromagnetic: JGdRad=2.09(1) cm−1 H=‐2JGdRad(SGd1SRad1+SGd2SRad2, JTbRad=1.93(14) cm−1, JDyRad=1.72(14) cm−1. The TmIII‐Rad coupling is antiferromagnetic (JTmRad=−0.53(1) cm−1). For the TbIII, DyIII, and TmIII complexes the effects of the crystal field have been taken into account in the fitting procedure.
A series of five binuclear 2p‐4f complexes has been obtained using as a bridging ligand a new nitronyl‐nitroxide radical functionalized with a N‐donor group. The magnetic properties of these rectangular‐shaped complexes have been investigated.
The enhanced luminescence of lanthanide complexes coordinated to antenna ligands has potential applications for developing devices like screens and lamps. Herein, three β -diketone antenna ligands ...were incorporated into Eu(III) and Tb(III) metals to synthesize five complexes. Their luminescence properties in solid state and the energy levels of the electronic states for the ligands and the metals were recorded and probed by UV–vis and fluorescence spectroscopies. Under UV light, a white-light emission powder was observed by mixing red-emission europium and green-emission terbium complexes, with blue-emission laundry powder. The powder composition was tuned by using spectroscopic analysis and CIE 1931 color diagram.
Ligand L and its nine complexes, LnL(NO3)2·(H2O)2NO3 were synthesized and characterized. Under the excitation, luminescence emission properties for Sm, Tb, and Eu complexes are observed. The ...antimicrobial activity of all complexes was studied against a number of pathogenic bacteria. Display omitted
► Ligand L and its nine complexes, LnL(NO3)2·(H2O)2NO3 were synthesized and characterized. ► Under the excitation, luminescence emission properties for Sm, Tb, and Eu complexes are observed. ► The antimicrobial activity of all complexes was studied against a number of pathogenic bacteria.
A series of lanthanide complexes with a Schiff base ligand, L (N,N′-bis(2-hydroxy-1-naphthylidene)-1,6-hexadiimine) are presented. The ligand and its complexes were synthesized and characterized based on elemental analyses, molar conductance, IR, 1H and 13C NMR, UV–Vis, and TGA studies. These analytical and spectral data reveal that the ligand L coordinates to the central Ln(III) ion by its two imine nitrogen atoms and two phenolic oxygen atoms and the general formula of the complex is LnL(NO3)2·2H2ONO3, Ln=Ln=La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III) and Er(III) Under the excitation at 396nm, the luminescence emission properties for Sm, Tb, and Eu complexes are observed. These observations show that the ligand favors energy transfers to the emitting energy level of these lanthanide ions. Furthermore, the antimicrobial activities of all complexes were studied against a number of pathogenic bacteria. The antimicrobial activity results show that most of the synthesized Ln(III) complexes possessed good antibacterial activity and in most cases higher than that of the corresponding ligand L.
A Schiff base L 2-thiophenecarboxylic acid, 2-（2-pyridinylmethylene）hydrazide with its lanthanide metal complexes was synthesized. These complexes were characterized by elemental analysis, molar ...conductivity measurements, spectral analysis（NMR, FT-IR, and UV-Vis）, luminescence and thermal gravimetric analysis. The Schiff base ligand was a tridentate chelate and coordinates to the central lanthanide ion with 1：2 metal：ligand ratio. The conductivity data showed a 1：1 electrolytic nature with a general formula LnL_2（NO_3）_2NO_3. The luminescence emission properties for Sm, Tb, and Eu complexes were observed and showed that the ligand L could absorb and transfer energy to Sm（III）, Tb（III） and Eu（III） ions. The complexes possessed a good antibacterial activity against different bacterial strains. In addition, the scavenging activity of the Ln（III） complexes on DPPH was concentration dependant and the complexes were significantly more efficient in quenching DPPH than the free Schiff base ligand.
Four Na-involving lanthanide phosphonate complexes, featuring new 3D topological frameworks and luminescence, were constructed by pyridyl-N-oxide phosphonate ligand. Display omitted
To investigate ...the synthesis and structure of pyridyl-N-oxide phosphonate ligand based lanthanide complexes, a series of four complexes, namely, NaLn2(pmpa)(C2O4)2.5(H2O)4·2H2O {Ln=Sm (1), Eu (2), Gd (3), and Tb (4); H2pmpa=2-(pyridyl-N-oxide)methylphosphonic acid; H2C2O4 =oxalic acid}, were hydrothermally synthesized and characterized by elemental analyses, FT-IR, powder and single-crystal X ray diffraction analyses, and thermogravimetric analyses. In the preparation of complexes 1–4, the pH value of reaction system exhibited a significant impact on the product structures. Complexes 1–4, which are isomorphic, exhibited Na ions involving a three-dimensional 4-nodal topological framework with the point symbol of {42·52·62·73·8}{42·5}{43·5·62}{43·5·63·73}. This framework can be further simplified to a 2-nodal topology with the point symbol of {318·436·533·64}{33}2. Photoluminescence studies of complexes 1, 2 and 4 exhibited characteristic luminescence of Sm(III), Eu(III), and Tb(III) ions, while complex 3 exhibited a Gd(III) ions disturbed ligand emissions.
Rare metals have been used in pharmaceuticals and for medicinal purposes for long time. Currently, the link between some specific medicinal and biological properties of inorganic drugs has been ...established. Ln(NO
3
)
3
complexes with
N
-(2-hydroxynaphthalen-1-yl) methylene) isonicotinohydrazide Schiff base, Ln(NHIso)
2
(NO
3
)
2
NO
3
, complexes
1–8
, were prepared and characterized using different techniques. The expected coordination for prepared complexes is ten, six from the tri-dentate NHIso ligand, and four from the two bi-dentate nitrate groups. DFT calculations on La and its cationic La(NHIso)
2
(NO
3
)
2
+
complex were carried out at the B3LYP level of theory. The NHIso ligand and its lanthanide complexes were screened for antimicrobial activity, in vitro activity against four gram-negative bacteria
Ec
:
Escherichia coli
;
Kp
:
Klebsiella pneumonia
;
Pm
:
Proteus mirabilis
;
Pa
:
Pseudomonas aeruginosa
, with two gram-positive bacteria
En: Enterococcus faecalis
and
Sa: Staphylococcus aureus
. Complexes
1
,
2
,
4
,
7
and
8
showed excellent and higher activity against
En
and
Sa
Gram-positive bacteria than the free ligand, especially complex
2
with a MIC value of 4 μg/mL. The reported complexes have greater and significant efficiency in quenching DPPH than that of free NHIso ligand, with a scavenging activity between 39 and 65%.
Graphic Abstract
Ln (III) nitrate complexes with N-(2-hydroxynaphthalen-1-yl) methylene) isonicotinohydrazide Schiff base, Ln(NHIso)2(NO3)2NO3, were prepared and characterized. They showed very promising antimicrobial and antioxidant activities. Their molecular geometries have been examined using DFT calculations and the obtained results are in good agreement with the experimental data.
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