Complexes based on the anionic octahedral rhenium chalcogenide clusters and [M(En)<Subscript>2</Subscript>]<Superscript>2+</Superscript> (M = Ni,Cu) cations

The compounds [Ni(H₂O)₂(En)₂][{Ni(En)₂}Re₆S₈(OH)₆] · 7H₂O (I), [{Cu(En)₂}Re₆S₈(H₂O)₂(OH)₄] · 4H₂O (II), and [Ni(H₂O)₂(En)₂]_0.5[Re₆Se₈(H₂O)₃(OH)₃] · 10H₂O (III) were synthesized by layering aqueous solutions of Ni(En)₂Cl₂ or Cu(En)₂Cl₂ (En is ethylenediamine) onto aqueous solutions of the potassium salts of the corresponding octahedral chalcohydroxo rhenium cluster complexes [Re₆Q₈(OH)₆]⁴⁻ (Q = S, Se). The structure of the obtained compounds was determined by X-ray diffraction analysis.     

Two novel four-coordinated zinc(II) complexes [Zn(dmatrz)<Subscript>2</Subscript>Cl<Subscript>2</Subscript>] and [Zn(dmatrz)<Subscript>2</Subscript>(SCN)<Subscript>2</Subscript>] exhibiting strong blue fluorescent properties

Two novel complexes, [Zn(dmatrz)₂]Cl₂ (1) and [Zn(dmatrz)₂(SCN)₂] (2), have been prepared and characterized by X-ray crystallography, absorption and luminescence spectrometries (dmatrz=3,5-dimethy-4-amino-1,2,4-triazole). The coordination environment of the zinc(II) ions in (1) and (2) has a distorted tetrahedral geometry completed via two independent nitrogen atoms of two triazole ligands and two anions, respectively. Both (1) and (2) show strong blue luminescence properties. Furthermore, (1) displays stronger blue photoluminescence than (2) as the result of different anions (Cl^- and SCN^-) coordinated to the zinc(II) ions.     

Synthesis, characterization and computational studies of zinc(II)-halide complexes with a bidentate schiff base ligand (2,5-MeO-ba)2En: The crystal structure of (2,5-MeO-ba)2En

In this study four coordinated complexes of zinc(II) halides with a new symmetrical bidentate Schiff base ligand (2,5-MeO-ba)₂En are synthesized and characterized. The metal to ligand ratio of the complexes is found to be 1:1 with the formula of Zn((2,5-MeO-ba)₂En)X₂ (X = Cl (1), Br (2), I (3)). The crystal structure of the Schiff base ligand (2,5-MeO-ba)₂En is determined by X-ray crystallography from single crystal data. Also, the optimized geometries of the Schiff base ligand (2,5-MeO-ba)₂En and its zinc(II) complexes are calculated using the density functional theory method (B3LYP/6-31G). The obtained structural parameters of (2,5-MeO-ba)₂En are in agreement with the experimental data.     

Complexes of podand-containing bis(dithiophosphonate) ligands with cobalt(II), nickel(II) and cadmium(II): recognition of CH<Subscript>2</Subscript>Cl<Subscript>2</Subscript>

Reaction of the potassium salts of podand-containing bis(dithiophosphonate)s [PhO(4-C₆H₄)P(S)(SH)OCH₂CH₂]₂O (H ₂ L) with Co(II), Ni(II) and Cd(II) in aqueous EtOH leads to complexes of formulae M₂(L-S,S′)₂. The structural formulae of the compounds were deduced by physico-chemical and spectroscopic methods. It was established that complex Ni ₂ L ₂ recognizes CH₂Cl₂.     

Hydrothermal synthesis and crystal structure of [Ni(Bptc)<Subscript>2</Subscript>(Bimb)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]

In the compound [Ni(Bptc)₂(Bimb)₂(H₂O)₂] (I), where H₄Bptc is 3,3′,4,4′-biphenyltetracarboxylic acid; Bimb is 4,4′-bis(1-imidazolyl)biphenyl), Ni(II) has a distorted octahedral coordination geometry, which was bonded with two N atoms from two Bimb ligands, two O atoms from two H₂Bptc²⁻ ligands and two water O atoms. The crystal structure of compound I is stabilized by the π-π-stacking and hydrogen bonds interaction.     

Synthesis and Structure of the Copper(II) Complex with <Emphasis Type="Italic">ortho</Emphasis>-Phthalic Acid and 1-Methylimidazole [Cu(HPht)<Subscript>2</Subscript>(1-CH<Subscript>3</Subscript>Im)<Subscript>2</Subscript>]

A new Cu(II) complex [Cu(HPht)₂(1-CH₃Im)₂] (I), where HPht is the monoanion of o-phthalic acid and 1-CH₃Im is 1-methylimidazole, is synthesized and characterized by IR spectroscopy, thermogravimetry, and X-ray diffraction analysis. Compound I contains molecular complexes in which the o-phthalic acid residue is monodeprotonated and linked to a metal through the carboxyl group in a 1,3-chelate mode. The cis-octahedral coordination of copper is formed by two HPht residues and two 1-CH₃Im molecules. The distances are Cu-N1.945(6) Å, Cu-O2.018(5) Å and 2.374(6) Å. Polymeric chains are formed in complex I due to intermolecular hydrogen bonds. The chains are unified into layers by the interactions between the 1-CH₃Im molecules of the adjacent complexes.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 8, 2005, pp. 630–635.Original Russian Text Copyright © 2005 by Gherco.     

A study of complexation between crystalline <Emphasis Type="Italic">trans</Emphasis>-[Pd(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>(NO<Subscript>3</Subscript>)<Subscript>2</Subscript>] and acetylacetone

Complexation between crystalline trans-[Pd(H₂O)₂(NO₃)₂] and acetylacetone was studied. The complexes Pd₂(Acac)₂(μ-NO₃)₂(I) and Pd₂(Acac)₂(μ-Acac)(μ-NO₃)(II) were obtained and examined by elemental analysis, X-ray powder diffraction analysis, differential scanning calorimetry, simultaneous thermal analysis, mass spectrometry, and vibrational spectroscopy.     

Crystal structure of dinuclear azide-bridged copper(II) complex [Cu2((3,4-MeO-Ba)2En)2(μ1,1-N3)2(N3)2]{(3,4-MeO-Ba)2En=N,N′-Bis(3,4-dimethoxybenzylidene)-1,2-ethanediamine}

New dinuclear copper(II)-azido complex [Cu₂((3,4-MeO-Ba)₂En)₂(μ_1,1-N₃)₂(N₃)₂] (I) ((3,4-MeO-Ba)₂En = N,N′-bis(3,4-dimethoxybenzylidene)-1,2-diaminoethane) has been synthesized and characterized by elemental analyses, FT-IR spectroscopy, and X-ray single-crystal diffraction. Complex I consists of a dinuclear unit that represents a new example of a copper(II)-azido compound and the Cu²⁺ ions are bridged by two azido ions in a double end-on fashion, consisting of two terminally bonded azido ligands. The Schiff base ligand (3,4-MeO-Ba)₂En is chelated by two imino nitrogen atoms.     

Zinc(II) complexes of 4-aminoantipyrine (AAP). Crystal structure of [Zn(AAP)<Subscript>2</Subscript>Cl<Subscript>2</Subscript>]

Zinc(II) complexes of 4-aminoantipyrine (AAP), [Zn(AAP)₂X₂] (X = Cl^–, I^–) and [Zn(AAP)(CN)₂] · 2H₂O were prepared and characterized by elemental analysis, IR and NMR (¹H & ¹³C) spectroscopy. The crystal structure of [Zn(AAP)₂Cl₂] (1) was determined by X-ray crystallography. The structural analysis of 1 shows that the complex exists as a monomeric nonionic molecule with zinc atom bound to two AAP ligands and two chloride ions adopting a distorted tetrahedral geometry. In [Zn(AAP)₂(CN)₂] · 2H₂O, the appearance of a band at 2162 cm^–1 in IR and resonances around 142 ppm in the ¹³C NMR spectra indicated the binding of cyanide to zinc(II).     

Synthesis,characterization and antibacterial activity of palladium(II) bromide complexes of thioamides; X-ray structure of [Pd(tetramethylthiourea)<Subscript>4</Subscript>]Br<Subscript>2</Subscript>

Palladium(II) bromide complexes of thioamides having the general formulae [PdL₂Br₂] and [PdL₄]Br₂ where L = Thiourea (Tu), Methylthiourea (Metu), Dimethylthiourea (Dmtu), Tetramethylthiourea (Tmtu), Imidazolidine-2-thione (Imt), Mercaptopyridine (Mpy), Mercaptopyrimidine (Mpm) and Thionicotinamide (Tna) were prepared by reacting K₂[PdCl₄] with KBr and the corresponding thioamides. The complexes were characterized by elemental analysis, IR and NMR spectroscopy, and one of them, [Pd(Tmtu)₄]Br₂ (1) by X-ray crystallography. The crystal structure of 1 shows a square-planar coordination environment around the Pd(II) atoms with the average cis and trans S–Pd–S bond angles of 90.0° and 180.0°, respectively. The synthesized complexes were screened for antibacterial effects, and the results showed that the complexes exhibit significant activities against both gram positive and gram negative bacteria.     

Thermal study of cyclopalladated complexes of the type [Pd<Subscript>2</Subscript>(dmba)<Subscript>2</Subscript>X<Subscript>2</Subscript>(bpe)]

The synthesis, characterization and thermal analysis of the novel cyclometallated compounds [Pd₂(dmba)₂Cl₂(μ-bpe)] (1), [Pd₂(dmba)₂(N₃)₂(μ-bpe)] (2), [Pd₂(dmba)₂(NCO)₂(μ-bpe)] (3), [Pd₂(dmba)₂(SCN)₂(μ-bpe)] (4), [Pd₂(dmba)₂(NO₃)₂(μ-bpe)] (5) (bpe=trans-1,2-bis(4-pyridyl)ethylene; dmba=N,N-dimethylbenzylamine) are described. The thermal stability of [Pd₂(dmba)₂X₂(μ-bpe)] complexes varies in the sequence 1>4>3>2>5. The final residues of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.     

Crystal structures of [Hg(<Emphasis Type="Italic">N</Emphasis>-ethylthiourea)<Subscript>2</Subscript>(CN)<Subscript>2</Subscript>] and [Hg(<Emphasis Type="Italic">N</Emphasis>-propylthiourea)<Subscript>2</Subscript>(CN)<Subscript>2</Subscript>]

Two mercury(II) cyanide complexes of N-ethylthiourea (Ettu) and N-propylthiourea (Prtu) ligands, [Hg(Ettu)₂(CN)₂] (1) and [Hg(Prtu)₂(CN)₂] (2), were prepared and their crystal structures were determined by X-ray crystallography. In both structures, the mercury atom is coordinated to two sulfur atoms of thioureas and two cyanide carbon atoms in a pseudo-tetrahedral mode with the bond angles in the range of 90.52(11)–162.2(3)°. The structures are stabilized by N-H—S, N-H—N, and C-H—N intramolecular and intermolecular hydrogen bonds.     

Formation of Cu<Superscript>I</Superscript>(CH<Subscript>3</Subscript>CN)<Subscript>4</Subscript>ClO<Subscript>4</Subscript> in the reactions of copper(II) perchlorate with acetonitrile in the presence of sulfur-containing organic compounds

Cu(ClO₄)₂·6H₂O was shown to react with 2,2′-[propane-1,3-diylbis(thio-2-phenylnemethylidene]-bis(3-pyridylamine) (I) or (5Z)-2-ethoxycarbonylmethyl-(2-pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-one (II) in the presence of CH₃CN with the reduction of copper(II) to copper(I) and the formation of the tetrahedral complex Cu^I(CH₃CN)₄ClO₄ (III). In the course of the reaction the organic ligands I and II were oxidized to the corresponding sulfoxides.     

A Novel Coordinated Polymer [Cu(En)<Subscript>2</Subscript>][(PzTp)Fe(CN)<Subscript>3</Subscript>]<Subscript>2</Subscript>: Synthesis,Crystal Structure,and Inhibiting Left Atrial Myxoma Cell Activity in vitro

A new cyanide-bridged neutral centrosymmetric cluster [Cu(En)₂][(PzTp)Fe(CN)₃]₂ (I), where En = ethylenediamine, PzTp = tetra(pyrazol-1-yl)borate) was synthesized by a programmed self-assembly of preformed building blocks. Characterization with single crystal X-ray diffraction (CIF file CCDC no. 1555334) showed that the Cu²⁺ center was located in a large distorted octahedral environment due to the obvious Jahn–Teller effect, which was demonstrated by continuous shape measures with the SHAPE program. Furthermore, no coordinated or free solvent molecules existed in the clusters, showing good roomtemperature stability. In addition, in vitro anticancer activity of compound I on three human cancer cells (SKOV3, A2780, and OVCAR) was further determined.     

Synthesis,structure, and electrochemistry of <Emphasis Type="Italic">trans</Emphasis>-[Co<Superscript>III</Superscript>{(BA)<Subscript>2</Subscript>pn}(L)<Subscript>2</Subscript>]ClO<Subscript>4</Subscript> complexes

The structure, spectroscopic, and electrochemical properties of [Co{(BA)₂pn}(L)₂]ClO₄ complexes, where (BA)₂pn = N,N′-bis(benzoylacetone)-1,3-propylenediimine dianion and the two ancillary ligands (L) are pyridine, py (1), and 4-methylpyridine, 4-Mepy (2), have been investigated. These complexes have been characterized by elemental analyses, IR, UV–Vis and ¹H-NMR spectroscopy. The crystal structure of [Co{(BA)₂pn}(py)₂]ClO₄ (1) has been determined by X-ray diffraction. The coordination geometry around cobalt(III) is best described as a distorted octahedron. The electrochemical reduction of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Co^III–Co^II is electrochemically irreversible, which is accompanied by the dissociation of the axial N(py)–cobalt bonds. This process becomes quasi-reversible upon the addition of excess py ligands. The second reduction step of Co^II/I shows reversible behavior and is not influenced by the nature of the axial ligands. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

New complex of mercury(II) with Schiff base derived from A-methylcinnamaldehyde and ethylenediamine

The new mononuclear mercury(II) complex [Hg((Me-Ca)₂En)Br₂] (I), where (Me-Ca)₂En = N, N,N′-bis[(E)-2-benzylidenepropylidene]ethane-1,2-diamine, has been synthesized and characterized. The crystal and molecular structure of I was determined by X-ray crystallography from single-crystal data. The complex I crystallizes in the monoclinic system, having one symmetry-independent Hg²⁺ ion coordinated in distorted tetrahedral geometry by two N atoms of the Schiff base ligand and by two Br atoms. This structure contains intermolecular non-classical hydrogen bonds of the type C-H...Br.     

Diiodo{N,N′-Bis(2,3,4-trimethoxybenzaldehyde)-ethylenediimine}mercury(II): Synthesis and crystal structure

Mononuclear mercury(II) complex [Hg((2,3,4-MeO-Ba)₂En)I₂] (I), where (2,3,4-MeO-Ba)₂En = N,N′-bis(2,3,4-trimethoxybenzaldehyde)ethylenediimine, has been synthesized and characterized by elemental analysis (C, H, and N) and confirmed by single-crystal X-ray diffraction analysis. The complex I crystallizes in the monoclinic system, with space group C2/c, having one symmetry-independent Hg²⁺ ion coordinated in distorted tetrahedral geometry by two N atoms of the Schiff base ligand and by two I atoms. The Schiff base ligand (2,3,4-MeO-Ba)₂En acts as a chelating ligand and coordinates via two N atoms to the mercury center and adopts an (E,E) conformation.     

Structure of heteroassociates formed in the HF-(C<Subscript>2</Subscript>H<Subscript>5</Subscript>)<Subscript>2</Subscript>O liquid system

The aim of this work was to determine the structure of stable heteroassociates (HAs) with the stoichiometric ratios 1:2, 2:1, and 4:1 of molecules formed in the HF-(C₂H₅)₂O binary liquid system. The stretching frequencies of HF molecules found for each HA using a special procedure for processing IR spectra were compared with the calculated frequencies V HF of the stable molecular complexes (HF)_m ((C₂H₅)₂O)_n (m = 1, 2, 4, 8; n = 1, 2) with different topologies by the density functional method (B3LYP/6-31++G(d,p)). As a result, it was shown that the most stable (among H-bonded complexes with the same stoichiometric ratio of molecules) HAs HF((C₂H₅)₂O)₂, (HF)₄ ((C₂H₅)₂O)₂, and (HF)₈-((C₂H₅)₂O)₂ formed in HF solutions in diethyl ether. All of them had a cyclic structure and a common peculiarity of structure: only one lone electron pair of the oxygen atom of the (C₂H₅)₂O molecules is involved in hydrogen bonding.     

Iron(II) complexes [Fe(DfgH)<Subscript>2</Subscript>(3-CONH<Subscript>2</Subscript>-Py)<Subscript>2</Subscript>] and [Fe(DfgH)<Subscript>2</Subscript>(4-COOC<Subscript>2</Subscript>H<Subscript>5</Subscript>-Py)<Subscript>2</Subscript>]: Synthesis and structures

The complexes [Fe(DfgH)₂(3-CONH₂-Py)₂] (I) and [Fe(DfgH)₂(4-COOC₂H₅-Py)₂] (II), where DfgH₂ is α-benzyl dioxime, were obtained and examined by X-ray diffraction analysis. The equatorial planes of the coordination octahedra of the metal ions consist of two monodeprotonated α-benzyl dioxime residues united through intramolecular hydrogen bonds O-H…O into a pseudomacrocyclic system. The neutral molecules 3-CONH₂-Py and 4-COOC₂H₅-Py are coordinated to the Fe²⁺ ion through the N atom of the heterocycle. Structure I is layered and structure II is molecular. Intermolecular interactions N-H…O are responsible for the formation of layers in crystal structure I.     

Synthesis and characterization of manganese(II), nickel(II), copper(II) and zinc(II) Schiff-base complexes derived from 1,10-phenanthroline-2,9-dicarboxaldehyde and 2-mercaptoethylamine

The synthesis of a new Schiff base containing 1,10-phenanthroline-2,9-dicarboxaldehyde and 2-mercaptoethylamine is described. The reaction of 1,10-phenanthroline-2,9-dicarboxaldehyde with 2-mercaptoethylamine leads to 2,9-bis(2-ethanthiazolinyl)-1,10-phenanthroline (I) which undergoes rearrangement when reacted with manganese, nickel, copper or zinc ions to produce complexes of the tautomeric Schiff base 2,9-bis[2-(2-mercaptoethyl)-2-azaethene]-1,10-phenanthroline (L). The [M(L)Cl₂] complexes [where M = Mn(II), Ni(II), Cu(II) and Zn(II) ions] were characterized by physical and spectroscopic measurements which indicated that the ligand is a tetradentate N₄ chelating agent.