Ruthenium(III) chalconate complexes containing PPh3/AsPh3 and their use as catalysts

Ruthenium(III) complexes of the type [RuX(EPh₃)(L)₂] (X?=?Cl or Br; E?=?P or As; L?=?2-hydroxychalcone) have been prepared by reacting [RuX₃(EPh₃)₃] with 2-hydroxychalcones in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (infrared, electronic, electron paramagnetic resonance, and mass) methods. Redox potential studies of the complexes have been carried out to elucidate the electronic structure, geometry, and electrochemical features. On the basis of data obtained, an octahedral structure has been assigned for all the complexes. The new complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide as co-oxidant and they were also found to be efficient catalyst for the transfer hydrogenation of ketones.     

SYNTHESIS,PROPERTIES AND BIOLOGICAL ACTIVITY OF RARE EARTH COMPLEXES OF 5-FLUOROURACIL-1-PROPIONIC ACID

Abstract

Seven new solid complexes of 5-fluorouracil-1-propionic acid with rare earth metals have been synthesized. Elemental analyses, molar conductance, TG-DTA, IR, UV-Vis, fluorescence, XPS and ¹H NMR spectra have been used to characterize these complexes. The general formula of the complexes is RE(FPA)₃. nH₂O where RE = Y(III), La(III), Pr(III), Sm(III), Eu(III), Dy(III), Er(III); n=3 or 5. Prooxidative and antitumor activity of these complexes was tested. The results showed that these complexes augment free radical generation; especially the Pr³+ complex which obviously increased the O₂ ^? and OH^? radicals. It was also found that La³+ and Y³+ complexes possess antitumor effects on human colon bladder HCT-B and human leukemia HL-60 cells in vitro.     

Theoretical study of inner and outer mononuclear complexes of Co(II), Ni(II), and Cu(II) with a compartmental hexadentate Schiff base derived from 3-formylsalicylic acid

Density functional theory (B3LYP/6-31G(d)) has been applied for optimization and calculation of the vibrational spectra of the compartmental hexadentate Schiff base derived from 3-formylsalicylic acid and 4,5-dichloro-1,2-phenylenediamine and 12 of its mononuclear complexes with Co(II), Ni(II), and Cu(II). Six of these complexes have the metal ion occupying the inner, N₂O₂, or the outer, O₂O₂, coordination sites in square planar geometry. The other six complexes possess octahedral geometry, occupying the inner or the outer coordination sites coordinating, additionally, to two waters. Significant changes in the ligand geometry have been observed in all complexes to permit efficient complexation with the metal. Assignments of the infrared bands are proposed based on calculations. Vibrational frequencies that are important for assignment and confirmation of the coordination sites are reported. Comparison of the total energies of the complexes reveals that inner complexes are more stable than corresponding outer complexes. Selectivity of metal ions to the coordination sites is also discussed.     

Tb(III) complexes with 1-phenyl-3-methyl-4-stearoyl-pyrazol-5-one as a material for luminescence Langmuir–Blodgett films

Abstract

Synthesis and properties of new luminescent amphiphilic Tb(III) complexes [TbL₃·2H₂O]·3H₂O, TbL₃·bipy, [H₃O][TbL₄]·6H₂O and [H₃O][TbL′₃L]·H₂O, where HL is 1-phenyl-3-methyl-4-stearoylpyrazolone-5 and HL′ is 1-phenyl-3-methyl-4-formylpyrazolone-5, are reported. The complexes have been characterized by elemental and thermal analysis, FTIR and luminescence spectroscopy methods. Formation and properties of Langmuir–Blodgett films of the complexes are described.     

STRUCTURES OF COPPER(I) AND ZINC(II) COMPLEXES WITH N,N′-BIS(2-PYRIDINYL)THIOUREA (BPT)

Abstract

Copper(I) and zinc(II) complexes with N,N′-bis(2-pyridinyl)thiourea (BPT), [Cu(BPT)₂]ClO₄ (1) and [Zn(BPT)₂](ClO₄)₂ (2) were synthesized by reaction of M(ClO₄)₂ (M = Cu, Zn) with BPT in methanol solution. The crystal structures of complexes (1) and (2) were characterized by X-ray diffraction: (1) is triclinic, space group P, with a = 10.162(2), b=14.483(6), c = 9.496(2) Å, α = 105.80(2)°, β = 106.94(2)°, γ = 82.71(3)°, V = 1284.4(7) ų, Z = 2, and final R = 0.047, R _w = 0.061; (2) is monoclinic, space group C2/c, with a = 15.15(1), b = 6.299(3), c = 30.16(1)Å, β = 93.49(7)°, V = 2872(2)ų, Z=4, and final R = 0.049, R_w = 0.070. Both of the complexes exhibit novel structures. Two N atoms and two S atoms from two BPT groups coordinate to one M atom. The M atom shows distorted tetrahedral geometry. IR spectra and ther-moanalyses of BPT and its complexes (1) and (2) are briefly discussed.     

FORMATION OF 2-PYRIDINYL-2-OXAZOLINES AND PYRIDINE-2-CARBOXAMIDINE IN THE COORDINATION SPHERE OF COPPER(II)

Abstract

The reaction of pyridine-2-carbonitrile (2-CNpy) with 2-amino-2-hydroxymethyl-1,3-propanediol (L¹) and 2-amino-2-methyl-1-propanol (L²) in methanolic solutions of anhydrous copper(II) chloride at room temperature led to the formation of solid complexes containing 2-(2-pyridinyl)-4,4-bis(hydroxynmethyl)-2-oxazoline (pyoxaL¹) and 2-(2-pyridinyl)-4,4-dimethyl-2-oxazoline (pyoxaL²), respectively. With copper(II) bromide instead of copper(II) chloride, along with the oxazoline complexes, the complex dibromo-bis(pyridine-2-carbox-amidine)copper(II) was isolated. Under several hour reflux, the complexes dihalogenobis(pyridine-2-carboxamidine)copper(II) are the only isolable products both for chloride and bromide starting salts. The stereochemistry of the complexes and the mode of ligand coordination have been determined by spectroscopic and conductometric measurements. The crystal structure of bromobis[(2-(2-pyridinyl)-4,4-dimethyl)-2-oxazoline]copper(II) bromide hydrate was solved by X-ray diffraction techniques. The mechanism of 2-CNpy transformation to the final products is proposed.     

A one-dimensional assembly of a Keggin tungstogermanate and sodium-pyridine-2-carboxylic acid: NaH3(C6H5N2)4[GeW12O40] · 7H2O

A hybrid inorganic-organic assembly, NaH₃(C₆H₅NO₂)₄[GeW₁₂O₄₀] ·?7H2O (1), has been synthesized and characterized by IR, UV, ¹H NMR and single crystal X-ray diffraction. Crystal data: orthorhombic, P2₁2₁2₁, a =?12.819(2) Å, b =?19.326(3) Å, c =?24.164(4) Å, V =?5986.4(18) ų, Z =?4, R ₁ =?0.0541 (I >?2σ). The structure of 1 is based on a 1D zigzag infinite chain assembled by alternating [GeW₁₂O₄₀]^4? and sodium-pyridine-2-carboxylic complex [Na(C₆H₅NO₂)3(H₂O)₂]⁺ via W–O_d–Na–O_d–W.     

Pyrazine-2,3-dicarboxylate-bridged polymeric and dinuclear complexes involving decameric water clusters

Two copper(II) complexes of pyrazine-2,3-dicarboxylate (H₂pzdc) with 2-aminopyridine (apy), {(Hapy)₂[Cu(μ-pzdc)₂]} _n (1) and 1,10-phenanthroline (phen), [Cu₂(μ-pzdc)(phen)₄][N(CN)₂]₂?·9H₂O (2) have been synthesized and structurally characterized. Complex 1 consists of a pyrazine-2,3-dicarboxylate bridging across a double chain, while 2 exists as a dinuclear complex in which two Cu(II) ions are bridged by pzdc via different coordination modes. One Cu(II) ion in the binuclear complex is a distorted octahedron, while the other Cu(II) is a distorted trigonal bipyramid. A chair-like decameric water cluster composed of two pentamers and a shared-edge tetramer is detected, which further associate into a 1-D tape with dicyanamide anions by hydrogen bonds.