Complexation and Electronic Spectra of Neodymium(III)–Amino Acid–1,10-Phenanthroline Systems in Aqueous Solution

Complexation of neodymium(III)-glutamate(glu)-phenanthroline(phen), neodymium(III)-aspartate(asp)-phenanthroline(phen) ternary systems and the corresponding binary systems in aqueous solution are discussed at various values of pH. Based on change regularity of hypersensitive transition intensities, the neodymium(III)-aspartate-phenanthroline ternary complex has a general formula of Nd(asp)₃phen, but the composition of the complex of Nd(III) with glutamate and phenanthroline is complicated and has not been determined. The electronic spectra of these complexes were studied, Slater-Condon parametersF _k ^s and the Lande parameter ξ_4f were obtained. The rms deviation between calculated and observed energy levels is less than 43 cm⁻¹. Bonding in these complexes are also investigated and bonding parameters calculated. The results show that Nd(III) and amino acids form complexes by ionic linkage with carboxylic oxygens, but with some weak covalency. Besides, the degrees of covalency in ternary complexes are larger than those in binary complexes.     

Structural and spectral studies of di-2-pyridyl ketone N(4)-methyl- and N(4)-dimethylthiosemicarbazone and their metal complexes

Cobalt(II), nickel(II) and copper(II) complexes of di-2-pyridyl ketone N(4)-methyl- and N(4)-dimethylthiosemicarbazone have been prepared and characterized by physical and spectral methods. Use of different ligand-to-metal chloride molar ratios in the preparation of the complexes has produced both mononuclear and polynuclear species for the three metal ions. Crystal structures of the uncomplexed di-2-pyridyl ketone N(4)-methylthiosemicarbazone and a nickel(II) complex, di-2-pyridyl ketone N(4)-dimethylthiosemicarbazone, have been determined and aid the assignments of the i.r., n.m.r., u.v.–vis.–n.i.r. and e.s.r. spectra.     

稀土与华法灵、水杨酸三元配合物的合成和抗凝血作用研究

用氯化稀土与华法灵钠、水杨酸钠在不同介质中制备了稀土三元配合物, 所试验各种制备方法均可获得恒定组成的配合物REL₂L'•2H₂O (HL＝华法灵离子; HL'＝水杨酸离子). 通过元素分析、红外光谱、核磁共振氢谱、X射线衍射、摩尔电导、电子吸收光谱和溶解性试验对配合物进行了表征. 抗凝血试验表明稀土三元配合物具有优良的抗凝血性质.     

Extraction-spectrophotometric study on the vanadium(V)-2,3-dihydroxynaphthalene — iodonitrotetrazolium chloride — water — chloroform system and its analytical application

The formation of a new ternary ion-associate complex of vanadium(V) with 2,3-dihydroxynaphthalene and iodonitrotetrazolium chloride with a composition ratio of 1:2:1 is reported. The complex is quantitatively extracted from water into chloroform. The molar absorptivity (ɛ) of the extract at λ _max=340 nm is 2.5 × 10⁴ dm³/mol cm, and Beer’s law is obeyed for concentrations ranging from 0.1 to 0.9 μg/cm³ V(V). The following constants are determined: the extraction constant, the association constant, the distribution constant, and the recovery factor. The effects of foreign ions and reagents are studied. A selective and sensitive method is developed for determination of vanadium in steels.     

混合配体、希土三元配合物的研究 Ⅳ.3,5二硝基水扬酸(H2DNSA)、邻菲咯啉(phen)、希土(RE)三元固体配合物的合成及性质

本文报道了十种希土元素与3,5-二硝基水扬酸、邻菲咯啉三元配合物的制备方法。通过元素和化学分析测定了化合物的化学组成,并用红外光谱、紫外光谱、差热分析、磁化率、X射线粉天衍射等对所合成的化合物进行了结构和性质的研究。     

Synthesis,characterization, crystal structure,and DNA binding of two copper(II)–hydrazone complexes

Two new Cu(II)–hydrazone complexes, [Cu(L)(Hbpe)ClO₄]·ClO₄·[Cu(L)Cl] (1) and [Cu(HL)₂]·1.5ClO₄·0.5OH (2) (where HL?=?(E)-N′-(1-(pyridine-2-yl)ethylidene)benzohydrazide and bpe = trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene), have been synthesized and characterized by physicochemical methods. The structures of the complexes have been established by single-crystal X-ray diffraction direct methods, which reveal that the metal ions have distorted square-pyramidal and square-planar geometries in 1, and a distorted octahedral geometry in 2. DNA binding of HL, 1, and 2, performed by UV–vis titration in tris-buffer medium, yielded binding constants, which are 9.5 × 10³, 1.88 × 10⁴, and 4.66 × 10⁴ M^?1, respectively. Viscosity measurements suggest a surface or groove-binding mode of interaction between CT-DNA with HL, 1, and 2.     

N-(2-吡啶基)-伯胺·二甲基合镓(Ⅲ)的制备及表征

通过2-甲酰基吡啶与胺缩合制得Schiff碱,经NaBH₄还原得到四个N-(2-吡啶甲基)芳胺(芳基=苯基,邻甲氧基苯基,对甲苯基及2-吡啶基),得到的芳胺及N-(2-吡啶乙基)甲胺与三甲基镓反应生成相应的N-(2-吡啶基)伯胺·二甲基合镓(Ⅲ)配合物。用元素分析、红外光谱、质子核磁共振、质谱等手段对配合物进行了结构鉴定和表征。     

Syntheses,crystal structures and antibacterial activities of two new Mn(II) complexes based on triaryltriazoles

Two new Mn(II) complexes, trans-[Mn(L1-L2)₂(NCS)₂] (1–2) with triaryltriazole (1, L1 = 3-(p-bromophenyl)-4-phenyl-5-(2-pyridyl)-1,2,4-triazole; 2, L2 = 3,4-bis(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole), have been synthesized and structurally characterized by elemental analysis, FT-IR, ESI-MS, and single-crystal X-ray crystallography. Crystallographic studies revealed that both 1 and 2 contain a distorted octahedral [MnN₆] core with two trans-disposed NCS^? ions. The L1 ligand, 1 and 2, together with four known homologous Mn(II) complexes, trans-[Mn(L3-L6)₂(NCS)₂] (3–6) (3, L3 = 3-(p-methoxyphenyl)-4-(p-chlorophenyl)-5-(2-pyridyl)-1,2,4-triazole; 4, L4 = 3-(p-methoxyphenyl)-4-(p-bromophenyl)-5-(2-pyridyl)-1,2,4-triazole; 5, L5 = 3-(p-chlorophenyl)-4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole; 6, L6 = 3,5-bis(2-pyridyl)-4-(p-methylphenyl)-1,2,4-triazole), were tested in vitro for their antibacterial activities against two Gram-positive bacterial strains and two Gram-negative bacterial strains by the MTT method. The results indicate that 1 exhibited better activity than Penicillin and Kanamycin against Pseudomonas aeruginosa and also better than its free L1 ligand.     

Preparation of soluble ternary heteroazo dye complexes for the spectrophotometric determination of trace uranium(VI)

The complexing ability of typical pyridylazo, quinolylazo and thiazolylazo dyes with uranium(VI) in aqueous ethanol media are investigated in the presence and absence of aromatic carboxylic acid. Uranium(VI) forms solubilized ternary complexes with PAN, PAR, TAM, 5-Br-PADAP, 3,5-diBr-PADAP and QADAP in 48% ethanol solution containing sufficient amounts of sulfosalicylic acid and triethanolamine buffer (pH 7.8). Aromatic carboxylic acids contribute to expel the coordinated water molecules from the uranium (VI) moiety and their chelating effects have been explained by ternary complex formation. An increase in molar absorptivity and no shift in the wavelength of maximum absorbance are observed for all uranium(VI) complexes investigated. The 11 stoichiometry of uranuim(VI) and heteroazo dye in the binary complex does not change through ternary complex formation. The molar absorptivity of the uranium(VI)-3,5-diBr-PADAP-sulfosalicylic acid ternary complex at 595 nm is 8.4×10⁴l mol^–1 cm^–1 and Beer's law is valid up to 2.5gmg ml^–1 of uranium(VI). The interferences due to coexisting metal ions can be effectively masked by addition of CyDTA or Ca-CyDTA.     

Syntheses,crystal structures,and spectral properties of Mn(II) and Co(II) complexes with 3-(p-chlorophenyl)- 4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole

Two new complexes, trans-[MnL₂(NCS)₂] (1) and trans-[CoL₂(H₂O)(EtOH)](ClO₄)₂?·?H₂O (2) with asymmetrical triaryltriazole ligands [L?=?3-(p-chlorophenyl)-4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole], have been synthesized and characterized by elemental analysis, FT-IR, ESI-MS, and single-crystal X-ray diffraction. In the complexes each L adopts a chelating bidentate mode via the nitrogen of pyridyl and triazole. Both complexes have a similar distorted octahedral core with two NCS^? ions in the trans position in 1, while one H₂O and one EtOH are present in the axial sites in 2.     

Greener solid state synthesis of a ternary lanthanum complex at room temperature

Wet chemical synthesis of rare-earth complexes often requires large amounts of solvents to dissolve reactants, and the use of base to neutralize acidic solution. We have explored a green alternative route that involves solid-state synthesis of ternary lanthanum complex at room temperature by using lanthanum chloride hydrate (LaCl_3?·?6H₂O), sodium p-hydroxybenzoate (PBA), and 8-hydroxyquinoline (8-hq). The structure and composition of the ternary lanthanum complex were confirmed by microanalysis, Fourier transform infrared (FT-IR), UV-Vis, X-ray diffraction (XRD), electron diffraction, and thermogravimetric analysis. UV-Vis and FT-IR spectra confirms coordination of lanthanum ion with two ligands and XRD results show that signals of the product are not from the three reactants, and are believed to originate from the ternary lanthanum complex prepared by solid-state reaction. Effects of reaction conditions such as molar ratios and synthetic method on the formation of ternary lanthanum complex were also investigated. The structure and composition of the ternary lanthanum complex are independent of molar ratios of reactants. Compared to the ternary lanthanum complex prepared via solution-phase synthesis, although the ternary lanthanum complex prepared by solid-state reactions has the same composition and structure, the synthesis is scalable and greener.     

稀土与半胱氨酸、枸橼酸钠三元配合物的合成和抗凝血作用研究

用氯化稀土与枸橼酸钠、半胱氨酸制备了三种组成恒定的稀土三元配合物. 通过元素分析、红外光谱、X射线衍射、摩尔电导、TG-DTA和1H NMR对配合物进行了表征, 并进行了抗凝血试验, 表明稀土三元配合物具有优良的抗凝血性质.     

Structural modulation of Cd(II) supramolecular frameworks with a versatile 2,4-dipyridyl-type building block and different dicarboxylate ligands

A series of Cd(II) coordination complexes with an elongated 2,4-dipyridyl-type building block trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (bpe) and different dicarboxylate ligands have been presented. Generally, bpe shows the unidentate coordination mode and serves as the terminal pendant, whereas the dicarboxylate ligands display various binding fashions to interlink the metal centers to form 1-D comb-like chain, ribbon, and fishbone arrays, as well as 2-D 4⁴ and 4.8² layered networks. Notably, the bpe building block is also involved in secondary interactions such as hydrogen bonding and aromatic stacking to construct the resulting supramolecular architectures. Thermal stability of these complexes has been studied by TG-DTA technique.     

Ternary Complexes in Solution: Mixed Ligand Pb(II) Complexes with 2,2′-Bipyridyl or 1,10-Phenanthroline and Some Bivalent Mercapto Acid Amides

Abstract

The stability constants of ternary Pb(II) complexes containing 2,2′-bipyridyl (Bipy) or 1,10-phenanthroline (phen) as the first ligand and N-phenyl-2-mercapto acid amide, N-(p-chloro)phenyl-2-mercapto acid amide, N-(p-tolyl)-2-mercapto acid amide, N-(p-anisyl)-2-mercapto acid amide, or N-phenyl-2-mercapto-propionamide as the second ligand were determined in 70% v/v dioxane-water medium at 30 ± 1°C and constant ionic strength (0.1 M NaClO₄) in a nitrogen atmosphere. The results give evidence that all these complexes have the same structure and therefore the binding sites of the ligands have to be the imino nitrogen and sulfur of the sulfhydryl group. The stability difference between the ternary and the binary complexes are in good agreement with this interpretation. It is of interest to note that these ternary complexes are significantly more stable than expected from statistical reasons, i.e., the difference; Δ log K_M = log K^MA _MAL - log K^M _ML is positive (except for PMP) (where A = Bipy or phen and L is the second ligand). In addition, the enhanced stability of the ternary complexes is suggested on the basis of the π-accepting qualities of the hetero aromatic N-base. The effect of the chelate ring size is discussed.     

Synthesis and Characterization of Some Ruthenium Mixed-Ligand Complexes

The complexation reaction of trans-[RuCl₂(Dpte)₂] (Dpte – (diphenylthio)ethane) with mixed diimine ligands 2,2"-bipyridine, pyridylquinoline, 4,6-dichloro-2-(2-pyridyl)pyrimidine, 4,6-dichloro-5-methyl-2-(2-pyridyl)pyrimidine, and 4,6-dichloro-5-phenyl-2-(2-pyridyl)pyrimidine produces new Ru(II) mixed-ligand complexes. These complexes exhibit maximum photo- and chemical stability and high absorptivity. The above complexes have been characterized using IR, ¹H and ¹³C NMR, electronic absorption spectroscopy, and elemental analysis.     

UV/VIS Spectral Studies of Catecholase Activity of Binuclear Copper(II) Complexes [Cu2REP(μ-X)(Y)2]

By means of ultraviolet and visible spectroscopy we have studied the catecholase activity of two binuclear copper(II) complexes of general formula [Cu₂REP(u-X)(Y)₂] (1, X=OH and Y=ClO₄; 2, X=Y=CI), REP =deprotonated 2, 6-bis(1′-(4′-(2″-pyridyl)-2′-thiabutyl))-4-methylphenol. Both complexes promote catalytic autoxidation of 3, 5-di-tert-butylcatechol (3, 5-DTBC) to 3, 5-di-tert-butylquinone (3, 5-DTBQ) in methanol, but not in acetonitrile.     

Rhodium carbonyl complexes of thetrans-[RhCl(CO)(PR3)2] type with pyridylphosphines

Summary Trans-[RhCl(CO)(PR₃)₂] complexes [PR₃=tris-(2-pyridyl)phosphine {P(2-pyl)₃}, phenylbis(2-pyridyl)phosphine {PPh(2-pyl)₂} or tris(3-pyridyl)phosphine {P(3-pyl)₃}] have been synthesized and examined by spectroscopic methods (i.r., u.v.-vis,³¹P{¹H} n.m.r.,¹H n.m.r.). In solution the P(2-pyl)₃ and PPh(2-pyl)₂ complexes exhibit equilibrium between the pentacoordinate state, with one of the phosphine molecules coordinated via nitrogen and phosphorus, and complexes with the phosphine coordinated only through nitrogens.     

Synthesis,Spectral, Characterization,and Anticancer Activity of Some Binary and Mixed Ligand Complexes of 4-Methyl-2-Pentanone Thiosemicarbazone and Some Amino Acids

The Schiff base ligand 4-methyl-2-pentanone thiosemicarbazone (MPTSC) (HL) has been synthesized by the interaction of 4-methyl-2-pentanone (MP) and thiosemicarbazone (TSC). The Ni(II), Cu(II), and Fe(III) binary complexes of this ligand have been prepared. The ternary complexes of VO(IV) and Mn(II) ions with HL and glutamine (Glu) as a secondary ligand, in addition to VO(IV), Mn(II), and La(III) with HL and glycine (Gly) as a secondary ligand, have also been synthesized. The binary and ternary complexes have been characterized based on elemental analysis, IR, UV-VIS, molar conductance, mass spectra, magnetic moment, and ESR measurements. The magnetic moment, UV, and ESR studies suggest that Ni(II) and Cu(II) complexes are square planar, whereas Fe(III), Mn(II), and La(III) complexes have octahedral geometry, but VO(IV) ternary complexes have square pyramidal geometry. The analytical data indicate that the metal-to-ligand ratio in binary complexes is 1:1, except HL-Cu(II) chloride complex where the metal-to-ligand to secondary ligand ratio in ternary complexes is 1:1:1. The anticancer studies showed that the anticancer activity is in the decreasing order: ternary complexes > binary complexes > free ligand (HL).

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