Reactions of Tris(acetonitrile)tricarbonylchromium with Trimethylsilylarenes

The reactions of tris(acetonitrile)tricarbonylchromium 1 with trimethylsilyl derivatives 2–5 of phenalene, indene, 1,2-dihydronaphthalene and trans-β-methylstyrene gave products 10-13, respectively, containing no trimethylsilyl groups. The reactions of 1 with trimethylsilyl derivatives 6–8 of benzene, toluene and cycloheptatriene gave products 14–16, respectively, containing trimethylsilyl groups. The reaction of 1 with 1,2-bis(trimethylsily-1,2-dihydro)naphthalene 9 gave product 17 in which only trimethylsilyl at the allylic position was cleaved. Compound 10 crystallizes in the orthorhombic system, space group Pbca, with a = 12.228(4), b = 14.288(1), c = 15.128(3) Å, Z = 8, R_F= 0.046, and R_w = 0.047. X-ray crystallographic data confirm that the Cr(CO)₃ moiety is bonded to phenalene in a η⁶-mold.     

Reactions of bis(diphenylphosphine)acetylene with metal carbonyl complexes

The reaction of [Co₂(CO)₈] with DPPA at room temperature yields a diphosphine bridged product [Co₄(CO)₁₂(μ-Ph₂-P-C≡C-P-Ph₂)₂] 1. Heating of 1 at 45°C promoted cleavage of the P-C_sp bond with the formation of binuclear, phosphido-bridged σ-π-acetylide isomer complexes [Co₂(CO)₅(μ-PPh₂) (μ-σ-π-C≡C-PPh₂ )] 2a, 2b. Heating (60°C) of the complex [CpFe(CO)₂CH₃] and DPPA affords mono and binuclear acetyl, P-coordinated diphenylphosphinoalkyne metal complexes [CpFe(Ph₂P-C≡C-PPh₂)CO(COCH₃)] 3, [CpFeCO(COCH₃)]₂-μ-(Ph₂P-C≡C-PPh₂) 4.     

Mononuclear copper(I) complexes with triphenylphosphine and N,N′-disubstituted thioureas: synthesis,characterization, and biological evaluation

Abstract

Twelve new complexes, of the general formula CuCl(TPP)₂Tu^1–12 (Tu?=?thiourea), were synthesized by the reaction of CuCl(TPP)₃ (TPP?=?triphenylphosphine) and various N,N′-disubstituted thioureas. The structures of the synthesized complexes were characterized by different techniques such as Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy (¹H, ¹³C, ³¹P, and ¹⁹F), and the representative complexes (1, 2 and 12) were analyzed via single crystal X-ray diffraction. The single crystal X-ray analysis revealed that copper(I) is coordinated with chlorine, two TPP, and the thiourea ligands through the sulfur atom in a mononuclear distorted tetrahedral mode. The compounds were tested for antibacterial, antifungal, cytotoxicity, antileishmanial, and antioxidant activities. The results showed that the synthesized complexes are significantly more active than the free ligands and the commercial reference compounds. The high biological activities of the complexes versus free ligands can be attributed to the copper(I) chloride complexation with thiourea ligands. The synthesized complexes were also evaluated, both experimentally and theoretically, for DNA binding studies. The UV-visible spectroscopic and molecular docking studies demonstrated that the complexes are conjugating with DNA through a groove binding mode.     

Complexation of N-tris[(1,2-dicarboxyethoxy)ethyl]amine with Ca(II), Mn(II), Cu(II) and Zn(II) in aqueous solution

In a search for environmentally friendly metal chelating ligands for industrial applications, the protonation and complex formation equilibria of N-tris[(1,2-dicarboxyethoxy)ethyl]amine (TCA6) with Ca(II), Mn(II), Cu(II) and Zn(II) ions in aqueous 0.1?M NaCl solution were studied at 25°C by potentiometric titration. A model for complexation and stability constants of the complexes were determined. With all of the metals, complex formation was dominated by ML^4?. Comparison of TCA6 and six other chelating agents showed TCA6 to be suitable for applications where strong calcium binding is essential.     

Metal derivatives of thiosemicarbazones: crystal structure of [chloro bis(triphenylphosphino) (thiophene-2-carbaldehyde thiosemicarbazone) copper(I)] complex

Reactions of copper(I) halides (X = Cl, Br, I) with thiophene-2-carbaldehyde thiosemicarbazone and triphenylphosphine in 1 : 1 : 2 molar ratio yield tetrahedral mononuclear complexes, [CuX(η¹-S-Httsc)(Ph₃P)₂] (X = Cl, 1; Br, 2; I, 3), characterized by elemental analysis, IR, NMR (¹H, ¹³C, ³¹P), and single crystal X-ray crystallography (1). The unit cell of 1 has two independent distorted tetrahedral molecules (1a and 1b) with different bond parameters. One acetonitrile is entrapped between them. Crystal data: C₈₆H₇₇Cl₂Cu₂N₇P₄S₄ 1: triclinic, P-1, a = 12.8810(9), b = 18.5049(13), c = 18.7430(13) Å, α = 63.7130(10), β = 89.0960(10), γ = 85.5010(10)°, V = 3992.4(5) ų, Z = 2, R _(int) = 0.0314. Bond parameters: 1a, Cu(1A)–Cl(1A), 2.3803(5); Cu(1A)–S(1A), 2.3822(5); Cu(1A)–P(1A), 2.2498(5) Å; P(1A)–Cu(1A)–P(2A), 124.294(19)°; 1b, Cu(1B)–Cl(1B), 2.3975(5); Cu(1B)–S(1B), 2.3756(5); Cu(1B)–P(1B), 2.2777(5) Å; P(1B)–Cu(1B)–P(2B), 127.156(19)°.     

Rh(III), Pd(II), Pt(IV) and Au(III) complexes of 2-thiopyrimidine derivatives

Some news thiopyrimidine derivatives and complexes [4-amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidine (TANH), its 2-methylthio derivative (MTH), the ammonium salt ofTANH (sTANH) and six new complexes of formulas: Rh(MT)₂Cl · 2H₂O, Pd(MTH)₂Cl₂, Pt(MTH)₂Cl₄, Au(MTH)Cl₃ Pd(TANH)₂Cl₂ and Au(TAN ^–)Cl] have been synthesized and characterized by elemental analysis, IR and¹H-NMR spectroscopy techniques. The thermal behaviour of all compounds has also been studied.

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Rh(III), Pd(II), Pt(IV) und Au(III) Komplexe von 2-Thiopyrimidin Derivaten

Zusammenfassung Es wurden einige neue Thiopyrimidinderivate und deren Komplexe synthetisiert und mittels Elementaranalyse, IR und¹H-NMR charakterisiert: 4-Amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidin (TANH), dessen 2-Methylthio-Derivat (MTH), das Ammoniumsalz vonTANH (sTANH) und sechs neue Komplexe der Formeln Rh(MT)₂Cl · 2H₂O, Pd(MTH)₂Cl₂, Pt(MTH)₂Cl₄, Au(MTH)Cl₃, Pd(TANH)₂Cl₂ und Au(TAN ^–)Cl. Das thermische Verhalten der Verbindungen wurde ebenfalls untersucht.

     

Group 6 metal carbonyl complexes of 3′H-spiro[indole-3,2′-[1,3]benzothiazole-2(1H)]-one

The spiro-compound 3′H-spiro[indole-3,2′-[1,3]benzothiazole-2(1H)-one (IBTH₂) was synthesized and its structure was determined using spectroscopic techniques (FTIR, ¹H NMR and mass) and X-ray crystallography. This ligand possesses different centers for coordination. Reactions of [M(CO)₆], M = Cr, Mo or W with IBTH₂ in THF under reduced pressure were studied. For chromium a complex with molecular formula [Cr(ITP)₂] was isolated; where ITP is the opened form of the ligand which occurred through C_spiro–S bond, while [Mo(CO)₅(IBTH₂)] and [W(CO)₅(IBTH₂)] were isolated from the reaction of IBTH₂ with molybdenum and tungsten carbonyls, respectively. All complexes were characterized by elemental analysis, IR, mass and ¹H NMR spectroscopy. The biological activity of the ligand and its complexes were studied and compared with the parent compound isatin.     

Synthesis,characterization and spectroscopic studies of pyrazinamide metal complexes

The present paper deals with the synthesis and characterization of Schiff base complexes of pyrazinamide an antitubercular drug. Metals selected for complexation are copper, silver, gold, zinc, mercury, iron and cobalt. The complexes have been suitably synthesized and isolated in pure powdered form. Analytical data agrees with the compositions M(L), M′(L)₂ and M″(L)₂·2H₂O, respectively where M = Ag, M′ = Cu, Au, Zn and Hg and M″ = Fe and Co, ligand metal ratios were also confirmed by monovariation method and Job’s method of continuous variation. Molar conductance values suggest the non ionic nature of the complexes. The tentative structure assigned to the complexes on the basis of stoichiometry and analytical data were further supported by spectral studies viz; IR, NMR, magnetic susceptibility and electronic spectra. A preliminary attempt has also been made to compare the potencies of metal complexes with parent drug. The Cu and Ag complexes are giving encouraging results. Particle size studies further suggest that the drug molecule undergoes reduction in size on complexation.     

Some Tris[(triorganophosphine)gold(I)]-oxonium and -Organoimonium Tetrafluoroborates with Bulky Substituents

Tris{[tri(2-methylphenyl)phosphine]gold(I)}-, tris{[tri(2,4,6-trimethylphenyl)phosphine]gold(I)}- and tris{[tri(cyclohexyl)phosphine]gold(I)}-oxonium tetra-fluoroborate ( 1?3 ) have been prepared from the corresponding (phosphine)gold(I) chlorides, silver oxide, and sodium tetrafluoroborate in acetone. These oxonium salts are excellent aurating agents for primary amines. Thus in the reaction with 1, t -butylamine ^tBuNH₂ and aniline PhNH₂ are readily converted into the tri nuclear imino complexes {[(2-MeC₆H₄)₃P]Au}₃N^tBu⁺BF₄^? ( 4 ) and {[(2-MeC₆H₄)₃P]Au}₃NPh⁺BF ( 5 ) in high yields. With 3 , both aniline and 8-amino-quinoline also give the tri nuclear complexes, i.e. {[(c-C₆H₁₁)₃P]Au}₃ NPh⁺BF ( 6 ) and {[(c-C₆H₁₁)₃P]Au}₃N(C₉H₆N)⁺BF ( 7 ). Auration of aniline with the most sterically hindered reagent 2 yields only the bi nuclear complex {[2,4,6-Me₃C₆H₂)₃P] · Au}₂N(Ph)H⁺BF ( 8 ). The reagents 1?3 and the Products 4 – 8 have been characterized by analytical and NMR spectroscopic data, and the crystal structures of compounds 4 and 6 have been determined by single crystal x-ray diffraction. In the cations of 4 , a triangle of gold atoms with short Au — Au contacts [3.036(1), 3.107(1), and 3.214(1) Å] forms a steep pyramid with the nitrogen atom, in which the angles Au? N? Au are all much smaller than the tetrahedral standard of 109.7°: 94.8(4), 98.1(4), and 103.0(4)°. This triangular Au₃ unit is staggered relative to the three methyl groups of the ^tBu substituent at nitrogen. The results for 6 are similar [Au — Au: 3.037(1), 3.071(1), and 3.222(1) Å; Au? N? Au: 95.3(3), 96.5(3), and 103.6(3)°]. Variable temperature NMR studies of compounds 3 and 8 show hindered rotation of the mesityl groups about the P? C bonds of the ligands originating from the steric congestion within each tertiary phosphine.