Two new cyano-bridged Cu(II)-Fe(II) complexes: Synthesis and crystal structures

Two new cyano-bridged Cu(II)-Fe(II) binuclear complexes, [Cu(L¹)Fe(CN)₅(NO)] (I) [L¹ = 1,3,6,8,11,14-hexaazatricyclo[12.2.1.1^8,11]octadecane and [Cu(L²)Fe(CN)₅(NO)] · 2H₂O (II) L² = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1^6,9]octadecane, have been assembled and structurally characterized by spectroscopy and X-ray crystallography. Complex I crystallizes in the monoclinic crystalline system of space group P2₁/c, while complex II crystallizes in the monoclinic crystalline system of space group P2₁/n. These two complexes assume a binuclear structure in which the Fe²⁺ ion is in an octahedron environment and the Cu²⁺ ion is in a square-prism geometry environment.     

Synthesis of binuclear complexes of PdCl2 with chiral α,α′-diamino-meta-xylene dioximes H2L1, H2L2, and H2L3, the derivatives of the terpenes (+)-3-carene, (R)-(+)-limonene, and (S)-(−)-α-pinene. Crystal structure of [Pd2(H2L1)Cl4]

Chiral α,α′-diamino-meta-xylene dioximes H₂L¹, H₂L², and H₂L³ were obtained from the naturally occurring terpenoids (+)-3-carene, (R)-(+)-limonene, and (S)-(?)-α-pinene, respectively. Reactions of these ligands with PdCl₂ gave the diamagnetic complexes Pd₂(H₂L¹)Cl₄ (I), Pd₂(H₂L²)Cl₄ (II), and Pd₂(H₂L³)Cl₄ (III). According to X-ray diffraction data, the crystal structure of complex I consists of acentric binuclear molecules [Pd₂(H₂L¹)Cl₄]. The coordination polyhedron PdN₂Cl₂ is a square distorted in a tetrahedral manner (trapezium) made up of two N atoms of the tetradentate bridging cyclic ligand H₂L¹ and two Cl atoms. The fragments PdCl₂ in the complex are cis to each other. According to the ¹H NMR spectra of complexes I–III in CDCl₃, the organic ligands are coordinated through the N atoms; in solution, the complexes exist in several forms.     

Synthesis, characterization and catalytic activity of three palladium(II) complexes containing Schiff base ligands

Three new Pd(II) complexes of Schiff base ligands, namely, [Pd₄(L¹)₄] (1), [Pd₂(L²)₂Cl₂] (2) and [Pd(L³)₂Cl₂] (3) [HL ¹ ?=?N-(benzylidene)-2-aminophenol; L ² ?=?N-(2,4-dichlorobenzylidene)-2,6-diethylbenzenamine, L ³ ?=?4-(2,4-dichlorobenzylide-neamino)phenol] have been synthesized using solvothermal methods and characterized by elemental analysis, spectroscopy and single crystal X-ray diffraction. The crystal structures of the free ligands were also determined. The ??-oxygen-bridged tetranuclear cyclometallated Pd(II) complex (1) contains four nearly planar units, in which Pd^II is four-coordinate. Complex 2 is a ??-chloro-bridged dinuclear cyclometallated Pd(II) complex, whereas complex 3 is mononuclear. The Heck reactions of bromobenzene with acrylic acid catalyzed by complexes 1?C3 have also been studied.     

Hydrothermal synthesis, crystal structures, and properties of two Co(II) complexes based on 4-bromoisophthalic acid and N-donor ligands

Two new Co(II) complexes, [Co₂(H₂O)(Bipy)₂(Bript)₂] _n (I) and [Co(H₂O)(Phen)(Bript)] · H₂O (II), where H₂Bript = 4-bromoisophthalic acid, Bipy = 2,2??-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co²⁺ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ????? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investigated.     

Crystal and molecular structure of [RuNO(NO2)4OHCuPy n ] heterometallic complexes

Heterometallic complexes [RuNO(NO₂)₄OHCuPy₂(H₂O)] (I) and [RuNO(NO₂)₄OHCuPy₃] (II) are described structurally for the first time. In complex I, the ruthenium anion is coordinated to the copper atom by the bridging OH group and two bridging nitro groups; in complex II, by the bridging OH group and one bridging nitro group. Dimers are formed in the crystal lattice of complex II due to the interaction of the copper atom and the nitro group of the ruthenium anion in trans position to the bridging NO₂ group.     

Synthesis,crystal structures,and properties of copper(II) dicarboxylate complexes with [bis(2-pyridylcarbonyl)amido]

Four new complexes, [Cu₂(Bpca)₂(L¹)(H₂O)₂] · 3H₂O (I), [Cu₂(Bpca)₂(L²)(H₂O)₂] (II), [Cu₂(Bpca)₂(L³)] · 2H₂O (III), [Cu₂(Bpca)₂(L¹)(H₂O)] · 2H₂O (IV) (Bpca = bis(2-pyridylcarbonyl)amido, H₂L¹ = glutaric acid, H₂L² = adipic acid, H₂L³ = suberic acid, H₂L⁴ = azelaic acid) have been synthesized and characterized by single-crystal X-ray diffraction methods (CIF files CCDC nos. 1432836 (I), 1432835 (II), 817411 (III), and 817412 (IV)), elemental analyses, IR spectra. Structural analyses reveal that compounds I, II, and IV have similar structures [Cu(Bpca)]⁺ units bridged by dicarboxylate forming dinuclear units, whereas the dinuclear of compound III are edge-shared through two carboxylate oxygen atoms of different suberate anions. Hydrogen bonds are response for the supramolecular assembly of compounds I to IV. The temperature-dependent magnetic property of III was also investigated in the temperature range of 2 to 300 K, and the magnetic behaviour suggests weak antiferromagnetic coupling exchange.     

Reactions of nitrosoarenes containing electron-withdrawing substituents with coordinated CO. Synthesis and structure of complexes Pd2(OAc)2(p-ClC6H4N[p-ClC6H3NO])2 and Pd2(OAc)2(o-ClC6H4N[o-ClC6H3NO])2

The reaction of tetranuclear Pd₄(μ-COOCH₃)₄(μ-CO)₄ cluster (1a) with p- and o-chloronitrosobenzenes was found to give dinuclear nitrosoamide complexes, Pd₂(OAc)₂(p-ClC₆H₄N[p-ClC₆H₃NO])₂ (4) and Pd₂(OAc)₂(o-ClC₆H₄N[o-ClC₆H₃NO])₂ (5), respectively. The formation of complexes 4 and 5 is accompanied by evolution of CO₂, resulting from oxidation of CO coordinated in cluster 1. Complexes 4 and 5 were characterized by elemental analysis and IR and ¹H NMR spectroscopy; their structures were studied by EXAFS. The reactions of dinuclear complex 4 with molecular hydrogen and CO were studied. The major products of reduction of 4 with hydrogen include metallic palladium, acetic acid, cyclohexanone, and molecular nitrogen. Treatment of complex 4 with CO under mild conditions (1 atm, 20 °C) affords p-chlorophenyl isocyanate.     

Synthesis and crystal structures of the dioxovanadium complexes [VO2L1] and [VO2L2]2

Two new oxovanadium complexes, [VO₂L¹] (I) and [VO₂L²]₂ (II), where L¹ and L² are the deprotonated forms of 4-bromo-2-[(2-diethylaminoethylimino)methyl]phenol (HL¹) and 4-bromo-2-{[2-(2-hydroxyethylamino)ethylimino]methyl}phenol (HL²), respectively, have been synthesized and characterized by IR spectra and single crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/n, a = 14.300(3), b = 7.010(2), c = 15.460(2) ?, ?? = 107.401(2)°, V = 1478.7(5) ?³, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 7.270(2), b = 15.373(3), c = 11.893(3) ?, ?? = 99.302(2)°, V = 1311.8(5) ?³, Z = 2. Complex I is a mononuclear dioxovanadium(IV) complex. Complex II is a centrosymmetric dinuclear dioxovanadium(V) complex with a V...V distance of 3.117(2) ?. The Vatom in I is in a distorted square-pyramidal coordination, and that in II is in an octahedral coordination. The difference in the structures of the complexes is largely induced by the hydrogen bonds during the self-assembly process.     

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 structure of palladium(II) and copper(II) complexes with chiral bis-α-aminooximes containing (+)-3-carene or (+)-limonene fragments and 4,4′-methylenedianiline linker. Crystal structure of the complex [Cu(i-PrOH)Cl2(μ-H2L3)CuCl2·H2O]

Coordination compounds Pd₂(H₂L²)Cl⁴ (I), Cu₂(H₂L²)Cl₄ (II), Pd₂(H₂L³)Cl₄ (III), and Cu₂(H₂L³)Cl₄ (IV), where H₂L² and H₂L³ are chiral bis-α-aminooxime ligands consisting of (+)-3-carene or (+)-limonene fragments and 4,4′-methylenedianiline linker, were synthesized and examined by NMR, ESR, and IR spectroscopy. The structure of [Cu(i-PrOH)CL₂(μ-H₂L³)CuCL₂·H₂O] (V) was determined by X-ray analysis.     

Binding forms of gold(III) from solutions by cadmium diethyl dithiocarbamate: Thermal behavior and role of secondary interactions in the supramolecular self-assembly of polymeric complexes ([Au{S2CN(C2H5)2}2][AuCl4]) n and [Au{S2CN(C2H5)2}Cl2] n

The chemisorption interaction between the binuclear cadmium diethyl dithiocarbamate (EDtc), [Cd₂{S₂CN(C₂H₅)₂}₄], (chemisorbent I) and AuCl₃ solutions in 2 M HCl results in the formation of polymeric gold(III) complexes: ([Au{S₂CN(C₂H₅)₂}₂][AuCl₄]) _n (II) and [Au{S₂CN(C₂H₅)₂}Cl₂] _n (III) with the same Au : EDtc : Cl ratio (1 : 1 : 2). The alternating centrosymmetric cations and anions of complex II are structurally self-assembled to form linear polymeric chains: the gold atom in [Au{S₂CN(C₂H₅)₂}₂]⁺ forms secondary Au(1)?Cl(1) bonds (3.7784 Å) with two neighboring [AuCl₄]^? anions. This binding is additionally strengthened by secondary S(1)?Cl(1) interactions (3.4993 Å). The mixed-ligand complex III comprises two structurally non-equivalent molecules [Au{S₂CN(C₂H₅)₂}Cl₂]: A—Au(1) and B—Au(2), each being in contact with two nearest neighbors through pairs of unsymmetrical secondary bonds: Au(1)?S(1)^a/b 3.4361/3.6329; and Au(2)?S(4)^c/d 3.4340/3.6398 Å. At the supramolecular level, this gives rise to independent zigzag-like polymeric chains, (?A?A?A?) _n and (?B?B?B?) _n along which antiparallel isomeric molecules of III alternate. The chemisorption capacity of cadmium diethyl dithiocarbamate calculated from the gold(III) binding reaction is 963.2 mg of gold per 1 g of the sorbent. The recovery conditions for the bound gold were elucidated by simultaneous thermal analysis of II and III. The DSC curves reflect different sets of heat effects, because thermolysis occurs for complex molecules (III) or for cations and anions (II). Nevertheless, the patterns of experimental TG curves are similar despite different structures of the complexes. The final product of thermal transformations is reduced gold.     

Fe(II) complex with chiral pyrazolylquinoline L and Fe(II), Co(II), and Cu(II) complexes with achiral pyrazolylquinoline L1: Synthesis and properties. The crystal structures of [ML1Cl2] (M = Fe, Co, and Cu)

The complexes FeLCl₂ (I), [FeL¹Cl₂] (II), [CoL¹Cl₂] (III), and [CuL¹Cl₂] (IV) (where L and L¹ are chiral and achiral pyrazolylquinolines, respectively) were obtained. Complexes II–IV were structurally characterized by single-crystal X-ray diffraction analysis. Crystals of complexes II and III are triclinic (space group P $ \bar 1 The complexes FeLCl₂ (I), [FeL¹Cl₂] (II), [CoL¹Cl₂] (III), and [CuL¹Cl₂] (IV) (where L and L¹ are chiral and achiral pyrazolylquinolines, respectively) were obtained. Complexes II–IV were structurally characterized by single-crystal X-ray diffraction analysis. Crystals of complexes II and III are triclinic (space group P ) and crystals of complex IV are monoclinic (space group P2₁/n). Structures II–IV are built from discrete mononuclear acentric molecules. In these complexes, the M²⁺ ion (M = Fe, Co, and Cu) coordinates two N atoms of the bidentate chelating ligand L¹ and two Cl atoms. The coordination cores MCl₂N₂ are distorted tetrahedra. For complexes I and II, μ_eff = 5.05 and 5.07 μ_B, respectively, correspond to the high-spin configuration d ⁶. For complex III, μ_eff = 4.51 μ_B (high-spin configuration d ⁷) and for complex IV, μ_eff = 1.80 μ_B (configuration d ⁹). Original Russian Text ? Z.A. Savel’eva, L.A. Glinskaya, R.F. Klevtsova, S.A. Popov, A.V. Tkachev, N.V. Semikolenova, V.A. Zakharov, S.V. Larionov, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 4, pp. 285–292.     

Pd(II) and Au(I) chloride complexes with tetrakis(butylthiomethyl)calix[4]arene: Synthesis and crystal structures

Two novel complexes, (AuCl)₄L³(I) and (PdCl₂)₂L³(II) (L³ is calix[4]arene-thioether), were synthesized and their structures were determined. In complex I, one thioether group of molecule L³ is coordinated to every Au atom. In complex II, the bidentate coordination of L³ to the Pd atoms is observed; two thioether groups are in the trans-positions in the Pd square surrounding. Both complexes have the layered crystal lattices. In the Au complex, the layers are more stable due to the short contacts Au-Au (3.19–3.23 Å).     

Urease inhibition of oxovanadium(V) complexes with hydrazone and hydroxamate ligands

Two new oxovanadium(V) complexes, [VOL¹(SHA)] (I) and [VOL²(BHA)] (II), were prepared by the reaction of [VO(Acac)₂] (Acac = acetylacetonate) with N′-(2-hydroxybenzylidene)isonicotinohydrazide (H₂L¹) and salicylhydroxamic acid (HSHA) and 4-chloro-N′-(2-hydroxy-3-methoxybenzylidene)benzohydrazide (H₂L²) and benzohydroxamic acid (HBHA), respectively, in methanol. Crystal and molecular structures of the complexes were determined by elemental analysis, infrared spectra and single crystal X-ray diffraction (CIF file CCDC nos. 978238 (I) and 978392 (II)). The V atoms are in octahedral coordination. Thermal stability and the inhibition of urease of the complexes were studied.     

Synthesis, characterization, electrochemical studies, and antibacterial activities of cobalt(III) complexes with Salpn-Tipe Schiff base ligands. Crystal structure of trans-[CoIII(L1)(Py)2]ClO4

The synthesis, characterization, spectroscopic and electrochemical properties of trans-[Co^III(L¹)(Py)₂]ClO₄ (I) and trans-[Co^III(L²)(Py)₂]ClO₄ (II) complexes, where H₂L¹ = N,N′-bis(5-chloro-2-hydroxybenzylidene)-1,3-propylenediamine and H₂L² = N,N′-bis(5-bromo-2-hydroxybenzylidene)-1,3-propylenediamine, have been investigated. Both complexes have been characterized by elemental analysis, FT-IR, UV-Vis, and ¹H NMR spectroscopy. The crystal structure of I has been determined by X-ray diffraction. The coordination geometry around cobalt(III) ion is best described as a distorted octahedron. The electrochemical studies of these complexes revealed that the first reduction process corresponding to Co(III/II) is electrochemically irreversible accompanied by dissociation of the axial Co-N(Py) bonds. The in vitro antimicrobial activity of the Schiff bse ligands and their corrsponding complexes have been tested against human pathogenic bacterias such as Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. The cobalt(III) complexes showed lower antimicrobial activity than the free Schiff base ligands.     

Complexes of Cu(II) and Co(II) nitrates with 3-Phenyl-5,5-dimethyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinoline

Complexes of Cu(II) and Co(II) nitrates with 3-phenyl-5,5-dimethyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinoline (L⁰) of the composition [CuL ₂ ⁰ (NO₃)₂] (I) and [CoL ₂ ⁰ (NO₃)₂] · CH₃CN (II) are synthesized and their crystal structures are determined by X-ray diffraction. The L⁰ ligand is coordinated to the metal atoms through the N atom in position 2 of triazole fragment. The coordination polyhedron of the Cu(II) atom is a square with two additional axial vertices, while that of the Co(II) atom is a tetrahedron with two additional vertices. The NO ₃ ^? groups in the structures of I and II perform similar anisobidentate function. Complexes I and II are studied by IR and electronic spectroscopy.     

Structure of the products formed in the reaction of cobalt chloride with 1,2-cyclohexanedione dioxime

Cobalt(II) and Cobalt(III) chloride compounds with 1,2-cyclohexanedione dioxime, [CoCl₂(NioxH₂)₂] (I), and H₃O[CoCl₂(NioxH)₂] · H₂O (II), are prepared and studied by X-ray diffraction. In acidic media without oxidants, cobalt(II) and 1,2-cyclohexanedione dioxime form a cis-octahedral complex, whereas in the presence of oxygen, cobalt is oxidized, which is accompanied by cis-trans transition of the complex and the formation of two typical intramolecular hydrogen bonds in the equatorial plane. The “acidic” proton in II is shown to be located on the solvating H₂O molecule.     

Destruction of the propylenediamine ring upon the chlorination of the platinum(IV) tetramine complex [PtpnPy2Cl2]Cl2

The chlorination of an aqueous solution of [PtpnPy₂Cl₂]Cl₂ affords the platinum(IV) dichloroamine complex [PtPy₂(NCl₂)₂Cl₂](I), as the major reaction product formed due to the complete destruction of the five-membered chelate ring. Complex I is obtained in the pure state from acetonitrile. In addition, the [PtPy(NH₂-CH(CH₃)-CH(CH₃)-NH₂)Cl₃]Cl · 1/2 H₂O complex (II) is isolated from the mother liquor upon chlorination. Complex I reacts rapidly with concentrated HCl to form the tetramine complex [PtPy₂(NH₃)₂Cl₂](CF₃SO₃)₂ · 1/2 H₂O(III). The X-ray diffraction study is carried out for complexes I, II, and III. Complex I crystallizes in the monoclinic crystal system: space group C2/c, a = 7.4529(4), b = 15.2143(9), c = 14.9965(8) Å, β = 99.866(1)°, V = 1675.3(2) ų, Z = 4; R _hkl = 0.040. The crystals of complex II are triclinic: space group P $ \bar 1 The chlorination of an aqueous solution of [PtpnPy₂Cl₂]Cl₂ affords the platinum(IV) dichloroamine complex [PtPy₂(NCl₂)₂Cl₂](I), as the major reaction product formed due to the complete destruction of the five-membered chelate ring. Complex I is obtained in the pure state from acetonitrile. In addition, the [PtPy(NH₂-CH(CH₃)-CH(CH₃)-NH₂)Cl₃]Cl · 1/2 H₂O complex (II) is isolated from the mother liquor upon chlorination. Complex I reacts rapidly with concentrated HCl to form the tetramine complex [PtPy₂(NH₃)₂Cl₂](CF₃SO₃)₂ · 1/2 H₂O(III). The X-ray diffraction study is carried out for complexes I, II, and III. Complex I crystallizes in the monoclinic crystal system: space group C2/c, a = 7.4529(4), b = 15.2143(9), c = 14.9965(8) ?, β = 99.866(1)°, V = 1675.3(2) ?³, Z = 4; R _hkl = 0.040. The crystals of complex II are triclinic: space group P , a = 8.163(2), b = 8.656(2), c = 10.638(2) ?, α = 78.30(3)°, β = 83.95(3)°, γ = 84.68(3)°, V = 730.0(3) ?³, Z = 2; R _hkl = 0.026. The crystals of complex III are monoclinic: space group C2/c, a = 11.946(2), b = 19.624(4), c = 10.034(2) ?, β = 95.96(3)°, V = 2339.5(8) ?³, Z = 4; R _hkl = 0.043. The IR spectra of all the compounds synthesized are studied. Original Russian Text ? I.B. Baranovskii, M.D. Surazhskaya, M.A. Golubnichaya, G.G. Aleksandrov, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 12, pp. 2000–2007.     

Reaction of trans-[RuNO(NH3)4(OH)]Cl2 with nitric acid and synthesis of ammine(nitrato)nitrosoruthenium complexes

The reaction of trans-[RuNO(NH₃)₄(OH)]Cl₂ with nitric acid has been studied. Reaction products have been identified by IR spectroscopy, NMR, mass spectrometry, powder and single-crystal X-ray diffraction, and chemical analysis. Synthesis methods have been developed for amminenitrosoruthenium complexes containing outer-sphere and coordinated nitrate ions: trans-[RuNO(NH₃)₄(H₂O)](NO₃)₃ (I), trans-[RuNO(NH₃)₄(NO₃)](NO₃)₂ (II), and fac-[RuNO(NH₃)₂(NO₃)₃] (III). Complex II has two polymorphs: monoclinic and tetragonal. The latter has been studied by X-ray crystallography.     

Supramolecular ensembles with intermolecular hydrogen bonds: The synthesis and structure of (H2Phda)[SnF3]2 and (H2Bipy)[SnF6]

The structures of the compounds (H₂Phda)[SnF₃]₂ (I) and (H₂Bipy)[SnF₆] (II) have been determined. The main structural elements of I are anionic ([SnF₃] _n ^n? ) polymer chains and 1,4-phenylenediamine ([C₆H₄(NH₃)₂]²⁺) cations. The coordination polyhedron of Sn²⁺ is a trigonal bipyramid with a stereochemically active lone pair in the equatorial plane. The [SnF₃E] _n ^n? chains are crosslinked by phenylenediamine cations through N-H...F hydrogen bonds, resulting in supramolecular ensembles. The structure of II is built of separate [SnF₆]^2? complexes and 4,4′-bipyridinium ((C₁₀H₁₀N₂)²⁺) cations linked by bifurcate N-H...F hydrogen bonds. These bonds combine the [SnF₆]^2? complexes into supramolecular layers alternating along the [100] direction with a period of 1/2a.