bis-Schiff Base Ligand Research Articles

Novel Nickel(II) complex bearing acenaphthenequinone based thiosemicarbazone bis-Schiff Base: Synthesis, characterization, linkage isomers, antitumor activity, DFT, and DNA docking simulation

The synthesis of a new nickel(II) coordination complex bearing acenaphthenequinone bis(thiosemicarbazone), [NiL], a N2S2 tetradentate bis-Schiff base ligand (H2L), under reflux and sonochemical conditions is reported. These new compounds (H2L and [NiL]) have been characterized by using various techniques such as FT-IR, 1H NMR, ESI-Mass spectrometry, UV–Vis, TGA, and elemental analysis. In addition, molecular structure of the ligand, (H2L)2.4DMSO.H2O, and complexes [NiL]3.2.5CH3OH.0·5H2O (1) and [NiL].CH3CN (2) have been determined by single crystal X-ray diffraction studies. The molecular structures of the nickel(II) complexes (1 and 2) revealed that they are structural isomers differing in their chelate ring arrangements (symmetric 5–5–5-trichelate system for 1 and asymmetric 4–6–5-trichelation for 2). In addition, the anticancer activity of H2L and its nickel(II) complex, [NiL], have been evaluated against human breast cancer cell line (MCF-7) using colorimetric 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The cytotoxicity of both compounds was compared with two standard anticancer drugs, cisplatin and oxaliplatin. Density functional theory (DFT) calculations were done to predict the chemical reactivity of H2L and complexes 1 and 2. Furthermore, DNA binding with H2L and [NiL] was performed using docking simulation to reveal that acenaphthenequinone and amine groups in thiosemicarbazone moieties in both ligand and complex are responsible for the groove binding to DNA via the formation of hydrogen, pi-anion, and pi-sigma bonds.

Synthesis, Structural Characterization, Hirschfeld Surface Analysis, Density Functional Theory, and Photocatalytic CO2 Reduction Activity of a New Ca(II) Complex with a Bis-Schiff Base Ligand.

A new bis-Schiff base (L) Ca(II) complex, CaL, was synthesized by the reaction of calcium perchlorate tetrahydrate, 1,3-diamino-2-hydroxypropane, and 2-formyl phenoxyacetic acid in an ethanol-water (v:v = 2:1) solution and characterized by IR, UV-vis, TG-DTA, and X-ray single crystal diffraction analysis. The structural analysis indicates that the Ca(II) complex crystallizes in the monoclinic system, space group P121/n1, and the Ca(II) ions are six-coordinated with four O atoms (O8, O9, O11, O12, or O1, O2, O4, O6) and two N atoms (N1, N2, or N3, N4) of one bis-Schiff base ligand. The Ca(II) complex forms a tetramer by intermolecular O-H…O hydrogen bonds. The tetramer units further form a three-dimensional network structure by π-π stacking interactions of benzene rings. The Hirschfeld surface of the Ca(II) complex shows that the H…H contacts represent the largest contribution (41.6%) to the Hirschfeld surface, followed by O…H/H…O and C…H/H…C contacts with contributions of 35.1% and 18.1%, respectively. To understand the electronic structure of the Ca(II) complex, the DFT calculations were carried out. The photocatalytic CO2 reduction test of the Ca(II) complex exhibited a yield of 47.9 μmol/g (CO) and a CO selectivity of 99.3% after six hours.

Molecular docking and in vitro biological studies of a Schiff base ligand as anticancer and antibacterial agents

In this study, a bis-Schiff base ligand of N,N'-bis(4-dimethylaminobenzylidene)hexane-1,6-diamine (L) was obtained via a condensation reaction of N, N-dimethylaminobenzaldehyde and hexane-1,6-diamine. The ligand (L) was characterized by various analysis tools such as FT-IR, 1H and 13C NMR, Mass, DRS spectra, XRD, and thermal analyses. The ligand (L) inhibitory action was also assessed against two gram-negative and four gram-positive bacterial pathogens. Disk diffusion, MIC, and MBC test results indicate that the investigated ligand (L) has antibacterial activity against bacteria and can be employed as a therapeutic candidate after further research. The MTT assay was used to study the ligand (L) cytotoxicity on the MCF-7 cell line and calculate the IC50. Cell treatment with ligand (L) in various concentrations showed that the bis Schiff base ligand (IC50 = 6.27 ± 0.07 mgmL−1) is the most significant. Assessment of in silico ADMET ligand (L) properties illustrates that showed agreement with Lipinski’s rule of five. Lastly, the interaction between the ligand with 1STE, 1Z11, and 1AJ6 receptors was examined using docking experiments. The best conformation with the lowest affinity energy (−6.57 kcalmol−1) corresponds to the interaction of the ligand (L) with the active site of the 1Z11 receptor.

Novel terephthalaldehyde bis(thiosemicarbazone) Schiff base ligand and its transition metal complexes as antibacterial Agents: Synthesis, characterization and biological investigations

The synthesis and structural characterization of mixed ligand metal complexes from terephthalaldehyde bis(thiosemicarbazone) (TPTSC) (L1) and alanine (L2) by using ultrasonication are reported. The ligand and their transition metal complexes were characterized on the basis of their elemental, FT-IR, magnetic moment, molar conductance, mass spectra, and SEM analysis. The mixed ligand complexes are in the ratio 2:1:2 [M:L1:L2] ratio as found from the elemental analyses and found to have the formulae [M2L1(L2)2].nH2O where M = Co(II), Ni(II), Cu(II), Cd(II) and Zn(II), L1 = TPTSC and L2 = alanine. The molar conductance data show that complexes are non-electrolytes. FT-IR spectra show that the Schiff base is coordinated to the metal ions in a bidentate manner with N and S donor sites of the terephthalaldehyde bis(thiosemicarbazone) and second ligand alanine coordinated to the metal ions via its N and O of amino acid. The geometrical structure of these complexes is found to be tetrahedral. The antimicrobial activity of the synthesized Schiff base ligand and mixed-ligand metal complexes have been screened against gram-positive and gram-negative bacteria and two fungi species were tested. Mixed ligand complexes exhibited significant antibacterial activity against Klebsiella Pneumoniae, Salmonella typhi, Enterococcus Faecalis, Staphylococcus aureus, Escherichia coli and the fungi Aspergillus flavus and Aspergillus niger. Further, these compounds have been screened for their anticancer activity using Human Breast Cancer Cell Line MDA-MB-231.

Synthesis and antitumor activities of five Cu(II) complexes of bis(5-halosalicylidene)-1,3-propanediamine derivatives.

The development of metal complexes of Schiff base has attracted much attention due to their DNA binding properties and extensive biological activities. We reported here five copper(II) complexes [Cu(L1)] (1), [Cu(L2)] (2), [Cu(L3)] (3), [Cu2(L4)(OAc)] (4), and [Cu2(L5)(HCOO)] (5) bearing the bis-Schiff base ligands of bis(5-chlorosalicylidene)-1,3-propanediamine (H2L1), bis(5-chlorosalicylidene)-2-methyl-1,3-propanediamine (H2L2), bis(5-bromosalicylidene)-2-methyl-1,3-propanediamine (H2L3), bis(5-chlorosalicylidene)-2-hydroxyl-1,3-propanediamine (H3L4), and bis(5-bromosalicylidene)-2-hydroxyl-1,3-propanediamine (H3L5), respectively. The single crystal X-ray diffraction analysis results revealed that complexes 1-3 present mononuclear structures and complexes 4 and 5 show dinuclear structures. It was also shown that all of these complexes are stable under physiological conditions. The in vitro antitumor activities of the five complexes were evaluated. Anticancer selectivity was also found for complex 2 on different cell lines with the lowest IC50 value on Hela cells. Further mechanistic studies showed that the three mononuclear Cu(II) complexes can induce apoptosis through the mitochondrial pathway by decreasing mitochondrial membrane potential and increasing the reactive oxygen species (ROS) and Ca2+ levels. They can activate caspase-3 and caspase-9, and can also regulate the expression of pro-apoptotic protein and anti-apoptotic protein in cells. All of these results showed that complex 2 is a potential anticancer drug.

Unprecedented bi- and trinuclear palladium(II)-sodium complexes from a salophen-type Schiff base: Synthesis, characterization, thermal behavior, and in vitro biological activities

Novel bi- and trinuclear palladium(II)-sodium complexes, {[PdL]Na(NO3)(EtOH)} (1) and {[PdL]2Na}Cl (2) based on salophen-type Schiff base N,N'-(1,2-phenylene)-bis(3-methoxysalicylideneimine) (H2L) were synthesized under ambient and sonochemical conditions. Ultrasonication proved to be a more effective method for the rapid synthesis of these bi- and trinuclear complexes under mild conditions. On the basis of the molecular structure of complexes 1 and 2, each palladium atom is placed in the “inner” N2O2 compartment, and the sodium atoms are located in the “outer” O2O’2 compartment of the twofold deprotonated bis-Schiff base ligand. In both complexes, each Pd(II) ion is four coordinated showing square planar geometry, whereas the Na(I) ions in complexes 1 and 2 adopt two different geometries, namely hepta and octa coordination, respectively. In addition, the solventless thermolysis of both complexes at 500 °C was also studied by thermal gravimetric analysis (TGA). EDX and powder XRD data pointed out the presence of highly pure nanoscaled materials. Furthermore, the anticancer and antibacterial activities of bi- and trinuclear complexes were examined towards MCF-7 human breast cancer cell line and evaluated against one gram-negative strain (Escherichia coli ATCC 25922) and one gram-positive strain (Staphylococcus aureus ATCC 6538). The in vitro studies revealed that complex 2 exhibited higher anticancer activity against MCF-7 cell line as well as better antibacterial effect on the examined bacteria strains than complex 1.

Cyclic Carbonate Synthesis from Epoxides and CO2 Catalyzed by Aluminum-Salen Complexes Bearing a nido-C2B9 Carborane Ligand.

The active and well-designed Schiff base ligands are considered "privileged ligands". The so-called salen ligands, i.e., the tetradentate [O, N, N, O] bis-Schiff base ligands, have also found broad applications in many homogeneous catalytic reactions. Modification of the salen ligands has concentrated on altering the substituents in the phenolate rings and variations in the diamine backbones. Herein, o-carborane-supported salen ligands (2) were designed and prepared. A series of aluminum-salen complexes (3·(sol)2), which were supported by the nido-C2B9 carborane anions, were synthesized. These Al(III) complexes showed high activities (TOF up to 1500 h-1) in catalyzing the cycloaddition of epoxides and CO2 at atmospheric pressure and near room temperature. Complexes 3·(sol)2 are one of the rare examples of Al-based catalysts capable of promoting cycloaddition at 1 bar pressure of CO2. Density functional theory (DFT) studies combined with the catalytic results reveal that the catalytic cycles occur on two axial sites of the Al(III) center.

Anticancer activity of four trinuclear cobalt complexes bearing bis(salicylidene)-1,3-propanediamine derivatives

Schiff base and its complexes are being paid more and more interests for their great prospects in biological applications. We reported here four cobalt(II) complexes [Co3(L1)2(HCOO)2] (1), [Co3(L2)2(HCOO)2(CH3OH)2]·2CH3OH (2), [Co3(HL3)2(OAc)2(DMF)2] (3) and [Co3(HL4)2(HCOO)2(DMF)2]·2H2O (4) bearing the bis-Schiff base ligand of bis(5-bromosalicylidene)-1,3-propanediamine (H2L1), bis(5-bromosalicylidene)-2-methyl-1,3-propanediamine (H2L2), bis(5-chlorosalicylidene)-2-hydroxyl-1,3-propanediamine (H3L3) and bis(5-bromosalicylidene)-2-hydroxyl-1,3-propanediamine (H3L4), respectively. The anti-tumor activities of the four titled complexes were screened on a series of tumor cell lines. After an overall consideration of their cytotoxicity on cancer cells and normal cells in comparison to those for cisplatin, complex 3 shows the best anticancer effect among the four titled complexes. It revealed the influence of anti-cancer effects of the substitution groups of H, Me and OH, as well as Cl and Br. Anticancer selectivity was also found for complex 3 on different cancer cell lines with the lowest IC50 value on T-24 cells. Complex 3 induces cell apoptosis through mitochondrial pathway as demonstrated by increasing the level of reactive oxygen species, decreasing mitochondrial membrane potential, activating caspase 3/9 and arresting cell cycle in G1 phase.

Synthesis, characterization, superoxide dismutase, and antimicrobial activities of Co (II) complexes with Schiff base ligand and their hybrid proteins

AbstractMetal complexes have been reported to possess excellent free radical scavenging and antimicrobial properties. In the present study, seven linear trinuclear complexes were synthesized based on bis Schiff base ligand and complexes 1, 3–7 are reported for the first time. Their structure was characterized by IR spectroscopy and single crystal diffraction. BSA was used as carrier to hybridize the synthesized complexes to construct hybrid proteins. The interaction between metal complex and BSA was studied by UV–Vis spectrophotometry and fluorescence spectroscopy. Static quenching was the main mechanism identified for the interaction between metal complex and BSA. In the superoxide dismutase (SOD) activity test, IC50 values of complexes and hybrid proteins range between 2.89 and 26.53 μM, with hybrid proteins demonstrating a stronger activity than the complexes. Among all the complexes studied, complex 5 exhibited the strongest inhibition against Candida albicans (MIC 12.5 μg ml−1) and Cryptococcus neoformans (MIC 6.5 μg ml−1).

Synthesis, Spectral Characterisation and Pharmacological Studies on Co(II), Ni(II), Cu(II) and Zn(II) Bis-Schiff Base Complexes Derived From 4-hydroxybenzohydrazide

The transition metal(II) chelates were prepared by the reactions of bis-Schiff base ligands derived from 4-hydroxy benzohydrazide and isophthalaldehyde / o-phthaldehyde in 1:1 metal to ligand ratio. The formed ligands and their metal complexes have been investigated by the following spectroscopic tools i.e, elemental analysis, FT-IR spectra, molar conductance, 1H NMR, ESI-mass, electronic spectra, magnetic moments, ESR and thermal analyses. The low molar conductance values give the non- electrolytic nature of the metal(II) chelates. From that the spectroscopic observations of complexes having the molecular formula [M(Ln)2Cl2] (where M= Co(II), Ni(II), Cu(II) and Zn(II), n=1and 2) and act as tetradentate N2O2 donor sites of ligands. The docking results predicts that the protein with ligands having good interaction energy. All formed complexes have efficient antibacterial activity than ligand of tested pathogens. The mode of binding interaction of ct-DNA and Cu(II) complexes gives the intercalative binding with hypochromism shifts using electronic titrations method. In electrophoresis, cleavages of PUC18DNA to cleave effectively with Cu(II) complexes in the presence of hydroxyl radicals. The antioxidant assay of DPPH radical scavenging activity of tested compounds shows good results, when compared to ascorbic acid as standard. The anticancer MTT assay of Cu(II) complexes tested against MCF-7 cancerous cells gives the promising therapeutic activity.

Mononuclear Erbium (III) Complex with Tetradentate N2O2 Schiff Base Ligand

The synthesis of a tetradentate Schiff-base ligand bis(salicylidene)ethylenediamine from salicylaldehyde and ethylenediamine , are important class of ligands . The results of the C.H.N study revealed the formation of a 1:1 [M:L] ratio. .[Er(Salen)(NO3)2]-, square antiprismatic geometry, is the proposed structure of lanthanide metal complex. 1H-NMR, FT-IR, UV-Visible spectral  mesurements, and molar conductance were used to estimate the synthesized Schiff-base ligand and its complex. The stoichiometry of the complex has been found to be 1:1 (Er:Salen) matching with C.H.N. analysis. After deprotonation, spectral studies revealed that the ligand was tetradentately coordinated to the metal ion (N2O2) through azomethine nitrogen and phenolic oxygen. The biological activities of the Schiff base (Salen , H2L) and Er(III) complex against E.coli and Staphylococcus bacteria were examined,  Schiff base ligand being less active than Erbium (III) complex.

A one‐dimensionalCd‐Eucoordination polymer with open‐chain ether Schiff base ligand and 4,4′‐bipyridine: Synthesis, structure, luminescence property, and antioxidation activities

AbstractA new Cd‐Eu coordination polymer (CP) with open‐chain ether Schiff base ligand bis(3‐methoxysalicylidene)‐3‐oxapentane‐1,5‐diamine (H2L) and 4,4′‐bipyridine (bipy), with composition [CdEuL(bipy)(NO3)3]n, has been synthesized by interfacial diffusion method and further performed structural characterization. The structure analysis revealed that Cd‐Eu CP is an infinite one‐dimensional zigzag coordination polymer formed by CdEuL secondary units through symmetrical coordination bridging bipy. Luminescence property of the Cd‐Eu CP in solid state was also studied. It has been found that the emission spectra of the Cd‐Eu CP exhibit corresponding Eu(III) ion characteristic emission peaks. Antioxidation activities of the ligand and the Cd‐Eu CP were also studied, showing that the antioxidant activities of the Cd‐Eu CP were better than that of H2L. All provide an irreplaceable reference for the study of the properties of one‐dimensional chain d–f coordination polymers.

Theoretical and experimental investigations of new bis (amino triazole) schiff base ligand: Preparation of its UO2(II), Er (III), and La (III) complexes, studying of their antibacterial, anticancer, and molecular docking

UO2(II), Er (III), and La (III) complexes were prepared from new bis (amino triazole) Schiff base ligand. The ligand was synthesized by condensation of 1,3‐bis(4‐amino‐5‐phenyl‐1,2,4‐triazol‐3‐ylsulfanyl)propane with benzaldehyde. The structure of the prepared compounds was confirmed by some spectroscopic tools such as1H‐NMR, UV‐Vis, and IR, as well as molar conductance, mass spectrometry, elemental analysis, thermogravimetric analysis (TG), differential thermogravimetric (DTG), and differential thermal analysis (DTA) studies. The data revealed coordination of the complexes with tetradentate Schiff base. All complexes were octahedral. Computational studies for the prepared ligand by using DFT/B3LYP method were reported. The theoretical results described its bond lengths, angles, and dipole moment, and other parameters were calculated. The theoretical studies were supported the experimental data of the ligand and confirmed its successful preparation. Also, their antibacterial activities against four types of bacteria species (Pseudomonas aeruginosa,Escherichia coli,Bacillus subtilis, andStaphylococcus aureus) were investigated. The prepared complexes were biologically active compounds. The synthesized compounds were estimated for their anticancer activities against two cell lines (MCF‐7 and HepG2). The lowest IC50values were 17.6 and 23 μM for uranyl complex against MCF‐7 and ligand against HepG2 cell lines, respectively, which make them very important materials as anticancer drugs in the future researches. Finally, molecular docking studies were checked up for all prepared compounds with different protein receptors (3HB5 and 2GYT) to confirm their anticancer activities data.

Crystal Engineering of Schiff Base Zn(II) and Cd(II) Homo- and Zn(II)M(II) (M = Mn or Cd) Heterometallic Coordination Polymers and Their Ability to Accommodate Solvent Guest Molecules.

Based on solvothermal synthesis, self-assembly of the heptadentate 2,6-diacetylpyridine bis(nicotinoylhydrazone) Schiff base ligand (H2L) and Zn(II) and/or Cd(II) salts has led to the formation of three homometallic [CdL]n (1), {[CdL]∙0.5dmf∙H2O}n (2) and {[ZnL]∙0.5dmf∙1.5H2O}n (3), as well as two heterometallic {[Zn0.75Cd1.25L2]∙dmf∙0.5H2O}n (4) and {[MnZnL2]∙dmf∙3H2O}n coordination polymers. Compound 1 represents a 1D chain, whereas 2–5 are isostructural and isomorphous two-dimensional structures. The entire series was characterized by IR spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction and emission measurements. 2D coordination polymers accommodate water and dmf molecules in their cage-shaped interlayer spaces, which are released when the samples are heated. Thus, three solvated crystals were degassed at two temperatures and their photoluminescent and adsorption–desorption properties were recorded in order to validate this assumption. Solvent-free samples reveal an increase in volume pore, adsorption specific surface area and photoluminescence with regard to synthesized crystals.

One Nanoscale Zn(II)-Nd(III) Complex With Schiff Base Ligand: NIR Luminescent Sensing of Anions and Nitro Explosives.

One Zn-Nd complex [Zn2Nd4L2(OAc)10(OH)2(CH3OH)2] (1) was synthesized from Schiff base ligand bis(3-methoxysalicylidene)ethylene-1,2-phenylenediamine (H2L). 1 shows nanoscale rectangular structure with sizes of about 0.8 × 1.1 × 2.8 nm. 1 exhibits typical near-infrared luminescence of Nd(III) under the excitation of UV-visible light. Further study shows that the complex displays luminescent response behavior to anions and nitro explosives, especially with high sensitivity to H2 and 2,4,6-trinitrophenol.

Construction of a Nano‐rectangular Zn(II)‐Yb(III) Complex with Near‐Infrared Luminescent Response towards Metal Ions

Summary of main observation and conclusionOne six‐metal Zn(II)‐Yb(III) complex [Zn2Yb4L2(OAc)10(OH)2(CH3OH)2] (1) was constructed from Schiff base ligand bis(3‐methoxysalicylidene)ethylene‐1,2‐phenylenediamine (H2L). 1 shows a nanoscale rectangular structure with dimensions of approximately 0.8 nm × 1.1 nm × 2.8 nm. Excited by ligand‐centered absorption bands, 1 shows typical near‐infrared emission of Yb3+ ion. Interestingly, 1 exhibits lanthanide luminescent response towards metal ions, especially to Cd2+ at ppm level.

Synthesis and antitumor activities of transition metal complexes of a bis-Schiff base of 2-hydroxy-1-naphthalenecarboxaldehyde

The complexes of Schiff base have attracted much attention for their potential biological activities. In this research, five transition metal complexes TM3L2(OAc)2 (TM = Cu, 1; Ni, 2; Co, 3; Mn, 4; Fe, 5) were prepared using a bis-Schiff base of N,N′-bis[(2-hydroxy-1-naphthalenyl)methylene]-propane-1,3-diamine (H2L), which present similar linear trinuclear structures with their three metal ions consolidated by two bis-Schiff base ligands and two acetate ligands. Their antitumor activities in vitro were screened through seven human cancer cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. It revealed that complexes 1, 2 and 5 show much higher antitumor activities than the bis-Schiff base ligand and complexes 3 and 4, and even than cisplatin. Among them, complex 1 has the highest inhibitory effects on tumor cells with its IC50 value (half-inhibitory concentration) being less than 0.5 μM for human bladder cancer cell line T-24, at which concentration complex 1 shows nearly no toxicity to the normal cell HL-7702 as revealed by flow cytometry. All of these demonstrate a potential anti-cancer candidate for complex 1, which induces tumor cell apoptosis by blocking T-24 tumor cells at the G2/M phase of the cell cycle, reducing mitochondrial membrane potential, increasing the concentration of reactive oxygen species and Ca2+ in the cell, and changing the expression of proteins.

Construction of a nano-rectangular Zn-Nd complex with near-infrared luminescent response towards metal ions

One 6-metal Zn-Nd complex [Zn2Nd4L2(OAc)10(OH)2(CH3OH)2] (1) with Schiff base ligand bis(3-methoxysalicylidene)ethylene-1,2-phenylenediamine (H2L) was constructed, and it has nanoscale rectangular structure (8 × 11 × 28 Å). Excited by ligand-centered absorption bands, 1 shows NIR emission of Nd3+ ion. Interestingly, 1 exhibits lanthanide luminescent response towards metal ions, especially to alkali metal ions (Li+, Na+ and K+) at ppm level.

Nickel(II) Complexes Derived from Bis-Schiff Bases: Synthesis, Crystal Structures, and Antimicrobial Activity

Nickel(II) complexes derived from the bis-Schiff bases N,N'-bis(5-methylsalicylidene)-1,2-diaminocyclohexane (H2La), N,N'-bis(5-methylsalicylidene)-1,2-diaminoethane (H2Lb) and N,N’-bis(3,5-difluorosalicylidene)-1,2-diaminoethane (H2Lc), respectively, have been prepared and characterized by elemental analyses, IR, UV−Vis and single crystal XRD (CIF files CCDC nos. 1912770 (I), 1912771 (II), and 1912772 (III)). The bis-Schiff base ligands coordinate to the nickel atoms through phenolate O and imine N atoms. Each metal atom in the complexes is in square planar coordination. The effects of the complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans were studied, which indicate that the fluoro-substituted groups are essential for the biological process.

The near-infrared luminescence and magnetism of dinuclear complexes with different local symmetries constructed from a β-diketonate co-ligand and bis-Schiff base ligand

A DyIII-complex based on a β-diketonate co-ligand and bi-Schiff base ligand displays slow magnetic relaxation behavior.