Homobinuclear Complexes Research Articles

Cobalt and nickel homobinuclear metallomacrocycles based on the redox-active bis-semiquinonato ligands as potential functional absorbing materials

Recently obtained bis-o-quinone with resorcinol as a bridge was utilized for synthesis of cobalt and nickel homobinuclear complexes. Two bis-o-semiquinonato metal fragments are situated co-facially to each other forming metallomacrocycle. Metals in both fragments bond diethyl ether solvate molecules externally as well as internally in the cell. At 100 K one of two metal atoms in the macrocycle is five-coordinated whereas the other one is six-coordinated due to internal solvent molecule. Heating to room temperature results in disordering of internal solvent molecule in two positions: coordinated to different nickel atoms. Variable temperature magnetic measurements indicate both complexes to be bis-o-semiquinonato anion-radical adducts of high spin metals with magnetic interactions inside of bis-o-semiquinonato units. Sign and energy of interactions depend on the coordination number of metal. Exchange interactions between units are weak. UV–Vis absorption spectrum is determined by ligands centered bands. CV indicates reversible reduction processes involving redox active dioxolene ligands.

HOMO- AND HETERONUCLEAR Yb(III) AND Lu(III) COMPLEXES WITH CALIX[4]ARENE MODIFIED WITH PORPHYRIN SUBSTITUENTS.

In this work we describe the approaches for the synthesis of lanthanide-containing homo- and heteronuclear complexes using 5,11,17,23-tetra-tert-butyl-25,27-dihydroxy-26,28-bis[(N-meso-­(p-aminophenyl)-meso-triphenylporphyrincarbonyl)methoxy]-calix[4]arene (1). Such spatially preorganizedcalix[4]arene macrocycle facilitates lanthanide cation coordination, impacting the structure and analytical signal of porphyrin substituents. The study employs two synthesis stra­tegies resulting in mononuclear and homobinuclear complexes, influenced by steric effects and changes in hydrogen bonding. The complexes exhibit changes in fluorescence spectra due to intramolecular dimerization and hydrogen bonding during complex formation. Mononuclear complexes (Ln-1) are synthesized under mild conditions, while homobinuclear complexes (Ln2-1) require high-boiling solvents and specific reaction conditions, detailed synthesis procedures are described. The structural changes during complex formation were analyzed with the use of NMR analysis. The absorption spectra of lanthanide complexes demonstrate shifts in maxima, reflecting coordination changes, with notable variations between mononuclear and homobinuclear complexes. Additionally, heteronuclear compounds with copper(II), zinc(II), and palladium(II) exhibit distinctive absorption patterns, emphasizing the role of d-metal ions. Luminescence stu­dies reveal the sensitization of 4f-luminescence by both calix[4]arene and porphyrin fragments. The use of deuterated solvents enhances 4f-luminescence intensity, highlighting solvent effects. Furthermore, 4f-luminescence characteristics were investigated in both solid and solution states for heterometallic compounds, emphasizing differences between copper-containing and zinc/palladium-containing complexes. The results offer valuable insights into the design, synthesis, and spectral properties of these complexes, showcasing their potential applications in various fields, and the findings contribute to the understanding of lanthanide-porphyrin systems and their coordination behavior.

Synthesis and spectroscopic study of complex compounds of some 3D metals with the condensation product of 1-ferrocenylbutanedione-1,3 and succinic acid dihydrozide

We obtained by Claisen condensation β-diketone-1-ferrocenylbutanedione-1,3. The dicarboxylic acid dihydrazone of 1-ferrocenylbutanedione-1,3 (H4L) was synthesized by reacting succinic acid dihydrazide with ferrocenylacetone in a ratio of 2:1. Based on them, homobinuclear complex compounds with copper(II), zinc(II)and nickel(II) ions were obtained. The IR-, UV- and NMR spectra of the synthesized organic compounds were studied. The results of the studies showed that the H4L ligand in solution exists as a tautomeric mixture: diketone (A), keto-enol (B) and in dienol(C) forms. According to the results of spectroscopic studies, the complexes were assigned a square planar structure, where the four times deprotonated ligand residue is coordinated by each metal atom through two oxygen atoms and a nitrogen atom of the hydrazone fragment. The fourth position in the planar square of the trans-N2O2 coordination site is occupied by the ammonia molecule. Planar five- and six-membered metal cycles of synthesizers are practically coplanar with each other.

NATURAL ACID-CATALYZED SYNTHESIS OF 6,6'-(((3,3'- DIMETHOXY-[1,1'-BIPHENYL]-4,4'- DIYL)BIS(AZANYLYLIDENE))BIS(METHANYLYLIDENE))BIS( 2,4-DICHLOROPHENOL), ITS CONVENTIONALLY SYNTHESIZED METAL COMPLEXES AND THEIR POTENTIAL AS BIOLOGICAL AGENTS

Organic research has recently focused on the development of a more environmentally friendly process that uses alternate reaction media in place of harmful and expensive catalysts. So here a facile protocol was developed for the green synthesis of a novel Schiff base ligand, and the synthesized ligand was characterized using physicochemical techniques. The homobinuclear complexes of synthesized ligands made of Iron (II), Cobalt (II), Manganese (II), Nickel (II), Zinc (II), and Copper (II) were characterized through the FTIR technique after synthesizing them conventionally. The in-vitro antimicrobial and antioxidant activities were examined for all the synthesized compounds

A Deeper Insight in Metal Binding to the hCtr1 N-terminus Fragment: Affinity, Speciation and Binding Mode of Binuclear Cu2+ and Mononuclear Ag+ Complex Species.

Ctr1 regulates copper uptake and its intracellular distribution. The first 14 amino acid sequence of the Ctr1 ectodomain Ctr1(1-14) encompasses the characteristic Amino Terminal Cu2+ and Ni2+ binding motif (ATCUN) as well as the bis-His binding motif (His5 and His6). We report a combined thermodynamic and spectroscopic (UV-vis, CD, EPR) study dealing with the formation of Cu2+ homobinuclear complexes with Ctr1(1-14), the percentage of which is not negligible even in the presence of a small Cu2+ excess and clearly prevails at a M/L ratio of 1.9. Ascorbate fails to reduce Cu2+ when bound to the ATCUN motif, while it reduces Cu2+ when bound to the His5-His6 motif involved in the formation of binuclear species. The histidine diade characterizes the second binding site and is thought to be responsible for ascorbate oxidation. Binding constants and speciation of Ag+ complexes with Ctr1(1-14), which are assumed to mimic Cu+ interaction with N-terminus of Ctr1(1-14), were also determined. A preliminary immunoblot assay evidences that the anti-Ctr1 extracellular antibody recognizes Ctr1(1-14) in a different way from the longer Ctr1(1-25) that encompasses a second His and Met rich domain.

Synthesis, Structural Investigations and Antimicrobial Activities of Homo Binuclear Complexes Derived from 2-Amino-4-chlorophenol

Co(II), Ni(II) and Cu(II) homo binuclear Schiff base metal complexes were synthesized from terephthalaldehyde and 2-amino-4-chlorophenol in methanol using template method. The structure of the ligand and its metal complexes were established by elemental, molar conductance, UV, magnetic moment, IR, 1H & 13C NMR, EPR, mass, thermal and PXRD. Molar conductance values showed that all complexes were non-electrolytic in nature. The IR spectral data provides the coordination of azomethine nitrogen and oxygen with central metal ion. UV, ESR and magnetic moment values suggest square planar geometry for Co(II), Ni(II) and Cu(II) complexes. TGA and DSC analysis data show the thermal stability of the ligand and its metal complexes. The crystalline nature of ligand and its metal complexes were investigated by powder-XRD. The DNA cleavage activities of all the complexes assayed on PUC18 DNA shows nuclease ability.

Sustainable dipolar homo-dicopper (II) dihydrazone complex as a catalyst for Sonogashira cross couplings

A novel dicopper (II) complex, Cu2L, was prepared form the complexation of the new polydentate ligand (H4L), bis(sodium 3-formyl-4-hydroxybenzenesulfonate)succinylhydrazone, with copper acetate. The novel homobinuclear complex was quite characterized by various physico-chemical tools and employed as a homogeneous and efficient-green catalyst for Sonogashira cross-couplings of phenylacetylene with halobenzenes under sustainable conditions. Cu2L exhibited very good catalytic performance with excellent chemoselectivity. The catalytic efficiency of Cu2L was improved by using ionic liquids–aqueous media (1: 1, binary mixture). A mechanistic pathway was also proposed for Cu(II)-catalyzed Sonogashira cross-coupling reactions for the reported finding. DFT for H4L and Cu2L were studied. Electronic configurations, energy of HOMO and LUMO orbitals, energy gap between orbitals (ΔE), electronegativity, hardness and softness were also calculated and compared with the applicable catalytic findings of Cu2L, which are in good conformity.

Pharmacologically bio-relevant N-functionalized homo-binuclear macrocyclic complexes: synthesis, spectral studies, biological screening, HSA binding, and molecular docking

The bio-efficient homobinuclear macrocyclic complexes, [Co2LCl4] · 2H2O (1), [Ni2LCl4] · 2H2O (2), [Cu2LCl4] (3) and [Zn2LCl4] · H2O (4); Tetrachloro[1,1' biphenyl bis(1,6,9,14-tetrahydro-3,4;11,12-diphenyl-1,6,9,14-tetraazacyclohexadecane)] di metal(II).nH2O, were synthesized via metal ion controlled reaction using 3,3′-diaminobenzidine, 1,2-bis(bromomethyl)benzene and ethane-1,2-diamine. The stoichiometry, geometry, thermal stability and morphology of the synthesized compounds were inferred by analytical and spectral data. The complex 3 showed substantial radical scavenging potency. The metal complexes were also screened for comparative antibacterial analysis against different pathogenic microbes. XTT reduction assay further certified this observation to resist biofilm formation. Further, various biophysical measurements were performed for the assessment of human serum albumin-binding affinity of complexes 1-4.

Novel series of nanosized mono- and homobi-nuclear metal complexes of sulfathiazole azo dye ligand: Synthesis, characterization, DNA-binding affinity, and anticancer activity

Novel five nanosized mono- and homobi-nuclear complexes of 4-(2,4-dihydroxy-5-formylphen-1-ylazo)-N-thiazol-2-yl-benzenesulfonamide (H2L) ligand were synthesized for developing new anticancer agents. H2L was prepared by coupling the diazonium salt of 2-(p-aminobenzenesulfonamido)thiazole with 2,4-dihydroxybenzaldehyde in order to integrate the bio-effectiveness of both azo group and sulfonamide part in the synthesized metal chelates which strongly increase their bio-activities. H2L and synthesized Cu, Co, Ni, Mn and Zn complexes were characterized applying different analytical and spectral methods. The obtained results revealed that H2L coordinated with divalent metal ions of copper, cobalt and nickel in a monobasic bidentate mode through the azo group nitrogen, and deprotonated phenolic oxygen whereas H2L coordinates with Mn(II), and Zn(II) in dibasic tetradentate mode via the azo group nitrogen, deprotonated phenolic oxygen, sulfonamide oxygen, and N-atom of thiazole ring. All metal complexes had a tetrahedral geometry around the metal centers. XRD patterns denoted the ligand crystalline and the complexes amorphous natures. TEM images proved the nanosized range of all complex's particles. UV–Vis spectra and viscosity techniques revealed that H2L and complexes exhibited groove binding mode interactions with DNA. Anticancer efficiency of the ligand and complexes were examined against breast carcinoma cells (MCF-7) and human liver carcinoma cells (HepG-2). Co(II) and Zn(II) complexes displayed the greatest anticancer activity and are very promising candidates for future applications in cancer therapy.

Nano-synthesis, Biological Efficiency and DNA Binding Affinity of New Homo-binuclear Metal Complexes with Sulfa Azo Dye Based Ligand for Further Pharmaceutical Applications

Five novel nanometric homo-binuclear complexes have been synthesized by the reaction of Cu(II), Co(II), Ni(II), Mn(II) and Zn(II) salts with a new azo dye 4-(2,4-dihydroxy-phenylazo)-N-thiazol-2-yl-benzenesulfonamide (H2L) with the aim to develop neoteric antitumor drugs. H2L has been prepared by coupling of sulfathiazole with resorcinol in order to comprise the bioactivities of sulfonamide part and azo group in the formed metal complexes which greatly enhance their bio-efficiencies. The ligand and complexes have been fully characterized using various spectral and analytical techniques. The obtained data indicated a dibasic tetradentate nature of ligand which coordinated via deprotonated phenolic oxygen, one azo group nitrogen, N-atom of thiazole ring, and sulfonamide oxygen forming tetrahedral geometry around the central metal ions. XRD data confirmed the crystalline nature of ligand and amorphous nature of the complexes. TEM images proved nanometeric size of complexes particles. The data of antimicrobial screening revealed that metal complexes are more potent than the azo dye ligand against varies micro-organisms. Anticancer activities of all compounds were evaluated against human liver carcinoma cells (HepG-2) and breast carcinoma cells (MCF-7). Cu(II) complex showed the highest anticancer activity (IC50 = 23.6 µg/ml) against HepG-2 cells. Co(II) complex displayed the greatest anticancer activity (IC50 of 7.67 µg/ml) contra MCF-7 cells. Electronic absorption and viscosity studies proved that H2L and complexes interact with DNA by intercalation binding and electrostatic force groove binding modes, respectively. The results of this study ascertain that Cu(II) and Co(II) complexes are very favorable candidates for further applications in cancer therapy.

Iridium(I) homobinuclear complexes containing salen-type ligands as bridge

New binuclear iridium(I) complexes with general formula [Ir2(η4-cod)2(μ-SB)] (1–12) derived from the reactions of tetradentate Schiff bases ligands [N,N′-ethylenebis(5-R-salicylideneimine)] (5,5′-R-salenH2), [N,N′-1,3-propylenebis(5-R-salicylideneimine)] (5,5′-R-salpenH2), and [N,N′-o-phenylenebis(5-R-salicylideneimine)] (5,5′-R-salphenH2) (R = H, MeO, Cl, NO2) with [Ir(cod)(μ-Cl)]2 were synthesized. The homobinuclear nature of this iridium complexes was supported by elemental analysis, FAB-Mass and 1H NMR spectrometry. Full characterization was accomplished by IR spectroscopy, 13C NMR and bidimensional NMR experiments (COSY, HSQC, HMBC and NOESY). In addition, iridium complex [(Ir(η4-cod)2(μ-5,5′-MeO-salen)] (2) was characterized by X-ray crystallography, showing that ethylene bridge is a s-trans conformation, and that the Schiff base ligand act as a bridging N,O-bidentate ligand toward two iridium atoms, and 1,5-cyclooctadiene (cod) ligand complete the coordination sphere of metal center. The effect of the substituent groups on salicylaldiminate fragments has been studied by 13C{1H} NMR shift and Hammett sigma correlations for each series of complexes.

Homo- and Heterobinuclear Cu and Pd Complexes with a Bridging Redox-Active Bisguanidino-Substituted Dioxolene Ligand: Electronic Structure and Metal-Ligand Electron-Transfer.

A new redox-active 4,5-bisguanidino-substituted o-benzoquinone ligand L is synthesized, which allows rational access to heterobinuclear complexes through the sequential coordination of two metals. In the examples discussed in this work, mononuclear Cu and Pd complexes are prepared in a first coordination step, and these complexes are then used as precursors to homobinuclear [CuII -L0 -CuII ] and heterobinuclear [PdII -L0 -CuII ] complexes. In the heterobinuclear complex, the PdII is coordinated by the softer bisguanidine side of L and the CuII by the harder dioxolene side (in line with the HSAB concept). The heterobinuclear complex is in a temperature-dependent equilibrium with its dimer, with two unsymmetrical Cu-Cl-Cu bridges. The redox-chemistry of the [CuII -L-CuII ] and [PdII -L-CuII ] complexes is studied. One-electron oxidation of both complexes was found to be quasi-reversible in CV experiments, and chemical one-electron oxidation was achieved with NO+ (SbF6- ). In the case of the homobinuclear complex [L(CuCl2 )2 ]+ , intramolecular ligand-metal electron-transfer, triggered by coordination of a CH3 CN solvent molecule, leads to a temperature-dependent equilibrium between the form [CuII -L0 -CuIII ] at low temperatures (with CH3 CN coordinated to the CuIII atom) and [CuII -L⋅+ -CuII ] at higher temperatures (without CH3 CN).

Syntheses, crystal structures, spectral and DFT studies of copper(II) and nickel(II) complexes with N′-(pyridine-2-ylmethylene)acetohydrazide

Three new metal(II) complexes (copper(II)/nickel(II)) with N’-(pyridine-2-ylmethylene) acetohydrazide [Cu(HL)2]·(ClO4)21, [Ni(HL)2]·NO3·ClO4·0.5H2O 2 and [Cu(μ-CH3COO)(L)]2·4H2O 3 have been synthesized form N′-(pyridine-2-ylmethylene) acetohydrazide (HL/L). The synthesized complexes were characterized by means of elemental analysis, spectroscopic, magnetic susceptibility and cyclic voltammetric measurements. Single crystal X-ray analysis of complexes has revealed the presence of a distorted octahedral geometry around mononuclear copper(II) and nickel(II) complex (1 and 2) and distorted square pyramidal geometry around copper(II) centers of complex 3. In the solid state Schiff base remains in its keto-tautomeric form. On complexation with Cu(II)/Ni(II) ions in natural or slightly acidic medium it coordinates through ketonic oxygen (keto form, HL) whereas in basic medium it acts as monoprotic (enol form, L) ligand. Variable-temperature magnetic susceptibility data of the compound 3 indicates the presence of weak antiferromagnetic interaction with J = −12.3 cm−1. The cyclic voltammograms of homobinuclear complex 3 in DMSO gave two irreversible waves which correspond to the Cu(II,II)/Cu(II,I) and Cu(II,I)/Cu(I,I) redox processes. On the other hand, the mononuclear complex 1 exhibited M(II)/M(I) quasireversible wave E1/2 = 0.06 V vs Ag/AgCl. X-band electron paramagnetic resonance (epr) data of copper(II) mononuclear and binuclear complexes 1 and 3 have been collected to investigate magnetic properties of the complexes in detail. The electronic structures, spectral properties of the ligands and the complexes have been explained by DFT and TD-DFT calculations. In addition, biological activity ranking of present complexes 1–3 are investigated theoretically. Complexes catalyzed the dismutation of superoxide (O2▪─) at biological pH in alkaline nitroblue tetrazolium chloride assay and IC50 values were evaluated.

Spectroscopic methods (IR, EPR and Electronic) for characterization of Homobinuclear 3D complexes

Spectroscopic methods (IR, EPR and Electronic) for characterization of Homobinuclear 3D complexes

Classical hydrogen bonding and stacking of chelate rings in new copper(ii) complexes.

Three new copper(ii) complexes, viz., [Cu(L)(NO3)(H2O)]H2O 1, [Cu(L)(H2O)2]NO32 and [Cu2(L)2(pyrazine)](ClO4)2·4H2O 3, were prepared using a biomimetic synthesis strategy [HL = 4-chloro-2-{(E)-[2-(pyridin-2-yl)hydrazinylidene]methyl}phenol]. Structural characterization revealed very different local geometries around copper(ii) ions, being square pyramidal for mononuclear complexes (τ5 = 0.021 for 1 and τ5 = 0.13 for 2) and square planar for homobinuclear pyrazine bridged complex 3 (τ4 = 0.06). In complex 3, stacking of chelate rings was observed. This insight was thought to provide new structural evidence for the stacking of the planar chelate rings. These π-interactions provide stability to the crystal structure of homobinuclear complex 3. Magnetic measurements of bulk materials 1, 2 and 3 revealed weak antiferromagnetic coupling in all complexes. The EPR spectra of complexes 1, 2 and 3 in polycrystalline state exhibited broad signals at g ≅ 2.15 owing to spin-spin interactions between two copper ions. The cyclic voltammograms of mononuclear complexes (1 and 2) in DMSO gave one CuII/CuI irreversible wave. On the other hand, pyrazine bridged binuclear complex 3 exhibited two waves, which correspond to CuIICuII/CuIICuI and CuIICuI/CuICuI redox processes. Differential pulse voltammetry (DPV) experiments also exhibited the same reduction behavior. These complexes displayed effective antioxidant SOD activity and exhibit the outlines of a structure-based cyclic mechanism. On the basis of experimental and theoretical DFT studies, the structure-activity relationships of these complexes have also been discussed.

Homo- and heterobimetallic 1,4-divinylphenylene- and naphthalene-1,8-divinyl-bridged diruthenium, diosmium and ruthenium osmium complexes

Heterobimetallic 1,4-divinylphenylene- and 1,8-divinylanthracene-bridged ruthenium/osmium complexes 1-RuOs and 2-RuOs were prepared via stepwise hydroruthenation of the parent dialkynes with first the ruthenium and then the osmium hydride complexes HM(CO)Cl(PiPr3)2. They are compared with their homobimetallic diruthenium and diosmium analogs with respect to their electrochemical and spectroscopic properties. Trends in redox potentials and changes in the vibrational and electronic spectra on oxidation point to strongly delocalized electronic ground states for the radical cations of the homobinuclear complexes and for heterobinuclear 1-RuOs+ but a significant charge localization at the more electron-rich {Os} site for 2-RuOs+ and a generally less efficient coupling of the alkenyl metal moieties to the π-conjugated bridge for the dinuclear 1,8-anthracenediyl complexes. The latter is due to a significant torsion of the alkenyl metal entities as a consequence of steric congestion around the closely spaced alkenyl ruthenium moieties as indicated by X-ray crystallography and by quantum chemical calculations.

Mononuclear, homo- and hetero-binuclear complexes of 1-(5-(1-(2-aminophenylimino)ethyl)-2,4-dihydroxyphenyl)ethanone: synthesis, magnetic, spectral, antimicrobial, antioxidant, and antitumor studies

A new Schiff base, H2L, was prepared by condensation of 4,6-diacetylresorcinol with o-phenylenediamine in molar ratio 1 : 1. The ligand reacted with copper(II), nickel(II), cobalt(II), iron(III), zinc(II), oxovanadium(IV), and dioxouranium(VI) ions in the absence and presence of LiOH to yield mononuclear and homobinuclear complexes. The mononuclear dioxouranium(VI) complex [(HL)-(UO2)(OAc)(H2O)]·5H2O was used to synthesize heterobinuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, 1H-, and 13C-NMR, electronic, ESR and mass spectra, conductivity, and magnetic susceptibility measurements as well as thermal analysis. In the absence of LiOH, mononuclear complexes (1, 4, and 9) were obtained; in the presence of LiOH, binuclear complexes (3, 5, 7, and 10) as well as mononuclear complexes (2, 6, and 8) were obtained. In the mononuclear complexes, the coordinating sites are the phenolic oxygen, azomethine nitrogen, and amino nitrogen. In addition to these coordinating sites, the free carbonyl and phenolic OH are involved in coordination in binuclear complexes. The metal complexes exhibited octahedral, tetrahedral, and square planar geometries while the uranium is seven-coordinate. The antimicrobial and antioxidant activities of the ligand and its complexes were investigated. The ligand and the metal complexes showed antitumor activity against Ehrlich Acites Carcinoma.

Metallathiacrown Ethers: Synthesis and Characterization of Transition-Metal Complexes Containing α,ω-Bis(phosphite)-Polythioether Ligands and an Evaluation of Their Soft Metal Binding Capabilities

The metallathiacrown ethers cis-Mo(CO)4{2,2′-(C12H8O2)PO(CH2CH2S)nCH2CH2OP(2,2′-(O2H8C12))} (n = 2, 3) and cis-Mo(CO)4{2,2′-(C12H8O2)POCH2CH2S-1-(C6H4)-2-SCH2CH2OP(2,2′-(O2H8C12))} have been prepared as soft metal selective molecular receptors. Multinuclear NMR spectroscopy and X-ray crystallography have been used to show that byproducts formed during the syntheses of the metallathiacrown ethers cis-Mo(CO)4{2,2′-(C12H8O2)PO(CH2CH2S)nCH2CH2OP(2,2′-(O2H8C12))} (n = 2, 3) are homobinuclear complexes with cis-Mo(CO)4(P-donor)(S-donor) centers. The abilities of the metallathiacrown ethers to bind PdCl2 and PtCl2 have been assessed using 31P{1H} NMR spectroscopy and X-ray crystallography. The complexes showed null results with PdCl2; however, the PtCl2 experiments showed that the complexes cis-Mo(CO)4{2,2′-(C12H8O2)PO(CH2CH2S)nCH2CH2OP(2,2′-(O2H8C12))} (n = 2, 3) formed heterobinuclear cis,cis-{[Mo(CO)4{2,2′-(C12H8O2)PO(CH2CH2S)nCH2CH2OP(2,2′-(O2H8C12))}]PtCl2} (n = 2, 3) complexes. The 31P{1H} NMR spectra of t...

Four homobinuclear lanthanide complexes with 3-D coordination networks based on 3-methyloxysalicylaldoxime: syntheses, crystal structures, and properties

Four new homobinuclear lanthanide(III) complexes of multidentate 3-methyloxysalicylaldoxime (MeOsaloxH2), [Ln2(MeOsaloxH)4(PhCOO)2(CH3OH)2] (Ln = Pr, 1; Nd, 2; Sm, 3) and [Gd2(MeOsaloxH)4(CH3COO)2(H2O)2]·2H2O (4), have been synthesized and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. In these complexes, the two LnIII ions are bridged by two phenolate oxygens from two η1 : η2 : η1 : μ2-[MeOsaloxH]− ligands and two carboxylate groups to form a [Ln2O2(RCOO)2] binuclear structure (R = Ph, 1–3; CH3, 4). The noncovalent interactions (hydrogen bonds and weak C–H···O interactions) led to two types of 3-D supramolecular architectures. Magnetic and luminescence properties of these complexes have also been studied.

Visual Threshold Detection of Iron(III) at ppb Level Based on Homo-binuclear Complex Formation System Equipped with Ion-exchanger Colorimetry

Visual Threshold Detection of Iron(III) at ppb Level Based on Homo-binuclear Complex Formation System Equipped with Ion-exchanger Colorimetry