Four novel mononuclear and polynuclear Cu(I) thiosaccharinates with triphenylphosphane and bis(diphenylposphino)methane. Synthesis and structural study of Cu(4)(tsac)(4)(PPh(3))(3), Cu(tsac)(PPh(3))(2), Cu(4)(tsac)(4)(dppm)(2), and Cu(2)(tsac)(2)(dppm)(2)

Four new ternary complexes of copper(I) with thiosaccharin and phosphanes were prepared. The reaction of [Cu(4)(tsac)(4)(CH(3)CN)(2)] (1) (tsac: thiosaccharinate anion) with PPh(3) in molar ratios Cu(I)/PPh(3) 1:075 and 1:2 gave the complexes [Cu(4)(tsac)(4)(PPh(3))(3)] center dot CH(3)CN (2) and Cu(tsac)(PPh(3))(2) (3), respectively. The reaction of 1 with Ph(2)PCH(2)PPh(2) (dppm) in molar ratios Cu(I)/dppm 2:1 and 1:1 gave the complexes [Cu(4) (tsac)(4)(dppm)(2)] center dot 2CH(2)Cl(2) (4) and [Cu(2)(tsac)(2)(dppm)(2)] center dot CH(2)Cl(2) (5), respectively. All the compounds have been characterized by spectroscopic and X-ray crystallographic methods. Complex 2 presents a tetra-nuclear arrangement with three metal centers in distorted tetrahedral S(2)NP environments, the fourth one with the Cu(I) ion in a distorted trigonal S(2)N coordination sphere, and the tsac anions acting as six electron donor ligands in mu(3)-S(2)N coordination forms. Complex 3 shows mononuclear molecular units with copper(I) in a distorted trigonal planar coordination sphere, built with the exocyclic S atom of a mono-coordinated thiosaccharinate anion and two P-atoms of triphenylphosphane molecules. With dppm as secondary ligand the structures of the complexes depends strongly on the stoicheometry of the preparation reaction. Complex 4 has a centrosymmetric structure. Two triply bridged Cu(2)(tsac)(2)(dppm) units are joined together by the exocyclic S-atoms of two tsac anions acting effectively as bridging tridentate ligands. Complex 5 is conformed by asymmetric dinuclear moieties where the two dppm and one tsac ligands bridge two Cu(I) atoms and the second tsac anion binds one of the metal centers through its exocyclic S-atom. (C) 2009 Elsevier B.V. All rights reserved.

Dithiocarbazate complexes with the [M(PPh(3))](2+) (M=Pd or Pt) moiety Synthesis, characterization and anti-Tripanosoma cruzi activity

New neutral Pd(II) and Pt(II) complexes of the type [M(L)(PPh(3))] (M Pd or Pt) were prepared in crystalline form in high-yield synthesis with the S-benzyldithiocarbazates and S-4-nitrobenzyldithiocarbazates derivatives from 2-hydroxyacetophenone, H(2)L(1a) and H(2)L(1b), and benzoylacetone, H(2)L(2a) and H(2)L(2b). The new complexes [Pt(L(1a))(PPh(3))] (1), [Pd(L(1a))(PPh(3))] (2), [Pt(L(1b))(PPh(3))] (3), [Pd(L(1b))(PPh(3))] (4), [Pt(L(2a))(PPh(3))] (5), [Pd(L(2a))(PPh(3))] (6), [Pt(L(2b))(PPh(3))] (7) and [Pd(L(2b))(PPh(3))] (8) were characterized on the basis of elemental analysis, conductivity measurements, UV-visible, IR, electrospray ionization mass spectrometry (ESI-MS), NMR ((1)H and (31)P) and by X-ray diffraction studies. The studies showed that differently from what was observed for the H(2)L(1a) and H(2)L(1b) ligands, H(2)L(2a) and H(2)L(2b) assume cyclic forms as 5-hydroxypyrazolinic. Upon coordination, H2L2a and H2L2b suffer ring-opening reaction, coordinating in the same manner as H(2)L(1a) and H(2)L(1b), deprotonated and in O,N,S-tridentate mode to the (MPPh(3))(2+) moiety. All complexes show a quite similar planar fourfold environment around the M(II) center. Furthermore, these complexes exhibited biological activity on extra and intracellular forms of Trypanosoma cruzi in a time- and concentration-dependent manner with IC(50) values ranging from 7.8 to 18.7 mu M, while the ligand H(2)L(2a) presented a trypanocidal activity on trypomastigote form better than the standard drug benznidazole. (C) 2010 Elsevier Inc. All rights reserved.

Electronic synergism in [RuCl(2)(PPh(3))(2)(amine)] complexes differing the reactivity for ROMP of norbornene and norbornadiene

The reactivity of the new complex [RuCl(2)(PPh(3))(2)(3,5-Me(2)piperidine)], complex 1, was investigated for ring opening metathesis polymerization (ROMP) of norbornene (NBE) and norbornadiene (NBD) in the presence of ethyl diazoacetate (EDA) in CHCl(3). The aim is to observe the combination of PPh(3) and an amine as ancillary ligands concerning the steric hindrance and the electronic perturbation in the properties of the N-bound site when replacing the amines. Thus, the results with 1 were compared to the results obtained when the amine is piperidine (complex 2). Reaction with 1 provides 70% yield of isolated polyNBE (M(n) =8.3 x 10(4) g/mol; PDI = 2.03), whereas 2 provides quantitative reaction (M(n) = 1.2 x 10(5) g/mol; PDI = 1.90) with [NBE]/[Ru] = 5000, [EDA]/[Ru] = 48 and 1.1 mu mol of Ru for 5 min at 25 degrees C. The resulting polymers showed c.a. 62% of trans-polyNBE, determined by (1)H NMR, and T(g) = 32 degrees C, determined by DSC and DMTA. For ROMP of NBD, 1 showed quantitative yield with PDI =2.62 when [NBD]/[Ru] = 5000 for 20 min at 25 degrees C, whereas the reaction with 2 reached 55% with PDI = 2.16 in the same conditions. It is concluded that the presence of the two methyl groups in the piperidine ring provides an increase in the induction period to produce the Ru-carbene species justifying better polyNBE results with 2, and a greater amine(sigma)-> Ru(pi)-> monomer synergism which contributed to the best activation of less tensioned olefin as NBD. (C) 2010 Elsevier B.V. All rights reserved.

The influence of perhydroazepine and piperidine as further ancillary ligands on Ru-PPh(3)-based catalysts for ROMP of norbornene and norbornadiene

Polynorbornadiene and polynorbornene were synthesized via ring opening metathesis polymerization (ROMP) with [RuCl(2)(PPh(3))(2)(amine)] as catalyst precursors, amine = piperidine (1) or perhydroazepine (2) in the presence of 5 mu L of ethyl diazoacetate (EDA) ([monomer]/[Ru] = 5000; 40 degrees C with 1; 25 degrees C with 2). The effects of the solvent volume (2-8 mL of CHCl(3)) reaction time (5-120 min) and atmosphere type (argon and air) on the yields were investigated to observe the behavior of the two different precursors. Quantitative yields were obtained for 60 or 120 min regardless of the starting volumes, either in argon or air, with both Ru species. However, low yields were obtained for short times (5-30 min) when the reactions are performed with large volumes (6-8 mL). In argon, the yields were larger with 2, associated to a faster propagation reaction controlled by the Ru active species. In air, the yields were larger with 1, associated to a higher resistance to O(2) of the starting and propagating Ru species. The different activities between 1 and 2 are discussed considering the steric hindrance and electronic characteristics of the amines such as ancillary ligands and their arrangements with PPh(3) and Cl(-) ions in the metal centers. (c) 2009 Elsevier B.V. All rights reserved.

Heterobimetallic compounds [Ru(eta(5)-Cp)(dppf)X] (X = Cl, Br, I and N(3)): synthesis, electrochemical analysis, and the crystal structure of [Ru(eta(5)-Cp)(dppf)I] [dppf=1,1`-bis(diphenylphosphino)ferrocene]

A series of new ruthenium-iron based derivatives [Ru(eta(5)-Cp)(dppf)Cl] (1), [Ru(eta(5)-Cp)(dppf)Br] (2), [Ru(eta(5)-Cp)(dppf)I] (3) and [Ru(eta(5)-Cp)(dppf)N(3)] (4) were obtained by reactions of [Ru(eta(5)-Cp)(PPh(3))(2)Cl] with 1,1`-bis(diphenylphosphino) ferrocene (dppf) and characterized by IR, NMR ((1)H, (13)C and (31)P), (57)Fe Mossbauer spectroscopy and cyclic voltammetry. Additionally, the compound (3) was structurally characterized by X-ray crystallography, and the results were as follows: orthorhombic, Pbca, a = 18.2458(10), b = 20.9192(11), c = 34.4138(19) a""<<, alpha = beta = gamma = 90A degrees, V = 13135.3(12) a""<<(3) and Z = 16.

Synthesis and Structural Analysis of New Palladium(II) Thiosaccharinates with Triphenylphosphane or Diphosphanes

A series of palladium(II) thiosaccharinates with triphenylphosphane (PPh(3)), bis(diphenylphosphanyl)methane (dppm), and bis(diphenylphosphanyl)ethane (dppe) have been prepared and characterized. From mixtures of thiosaccharin, Htsac, and palladium(II) acetylacetonate, Pd(acac)(2), the palladium(II) thiosaccharinate, Pd(tsac)(2) (tsac: thiosaccharinate anion) (1) was prepared. The reaction of I with PPh(3), dppm, and dppe leads to the mononuclear species Pd(tsac)(2)(PPh(3))(2)center dot MeCN (2), [Pd(tsac)(2)(dppm)] (3), Pd(tsac)(2)(dppm)(2) (4), and [Pd(tsac)(2)(dppe)]center dot MeCN (5). Compounds 2, 4, and 5 have been prepared also by the reaction of Pd(acac)(2) with the corresponding phosphane and Htsac. All the new complexes have been characterized by chemical analysis, UV/Vis, IR, and Raman spectroscopy. Some of them have been also characterized by NMR spectroscopy. The crystalline structures of complexes 3, and 5 have been studied by X-ray diffraction techniques. Complex 3 crystallizes in the monoclinic space group P2(1)/n with a = 16.3537(2), b = 13.3981(3), c = 35.2277(7) angstrom, beta = 91.284(1)degrees, and Z = 8 molecules per unit cell, and complex 5 in P2(1)/n with a = 10.6445(8), b = 26.412(3), c = 15.781(2) angstrom, beta = 107.996(7)degrees, and Z = 4. In compounds 3 and 5, the palladium ions are in a distorted square planar environment. They are closely related, having two sulfur atoms of two thiosaccharinate anions, and two phosphorus atoms of one molecule of dppm or dppe, respectively, bonded to the Pd(II) atom. The molecular structure of complex 3 is the first reported for a mononuclear Pd(II)-dppm-thionate system.

Syntheses, crystal structure and theoretical investigation of novel heteroleptic complexes of nickel(II) with N-R-sulfonyldithiocarbimate and phosphine ligands

Five new complexes of general formula: [Ni(RSO(2)N=CS(2))(dppe)], where R = C(6)H(5) (1), 4-ClC(6)H(4) (2), 4-BrC(6)H(4) (3), 4-IC(6)H(4) (4) and dppe = 1,2-bis(diphenylphosphino) ethane and [Ni(4-IC(6)H(4)SO(2)N=CS(2))(PPh(3))(2)] (5), where PPh3 = triphenylphosphine, were obtained in crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate K(2)(RSO(2)N=CS(2)) and dppe or PPh(3) with nickel(II) chloride in ethanol/water. The elemental analyses and the IR, (1)H NMR, (13)C NMR and (31)P NMR spectra are consistent with the formation of the square planar nickel(II) complexes with mixed ligands. All complexes were also characterized by X-ray diffraction techniques and present a distorted cis-NiS(2)P(2) square-planar configuration around the Ni atom. Quantum chemical calculations reproduced the crystallographic structures and are in accord with the spectroscopic data. Rare C-H center dot center dot center dot Ni intramolecular short contact interactions were observed in the complexes 1-5. (C) 2011 Elsevier B. V. All rights reserved.

Rhenium chelate complexes with maltolate or kojate

Novel rhenium complexes containing the maltolate (mal) or kojate (koj) anions as chelating ligands have been synthesized: [ReOCl(mal)(2)] (1), [ReOCl(2)(mal)(PPh(3))] (2), [ReOBr(2)(mal)(PPh(3))] (3), [ReOCl2(koj)(PPh(3))] (4) and [ReOBr(2)(koj)(PPh(3))] (5). The products have been characterized by MR, (1)H, (13)C, and (31)P NMR spectroscopies and elemental analysis. The crystal and molecular structures of all complexes were determined. Complex I crystallizes monoclinic, space group C2/c, Z = 8. It contains two O, O`-bidentate maltolate ligands and one chloro ligand at the (ReO)(3+) unit, so that a distorted octahedral geometry is adopted by the six-coordinated rhenium(V) center. The chloro ligand occupies a cis position to the oxo ligand. Complexes 2 and 3 are isostructural and crystallize orthorhombic, space group Pbca and Z = 8. The isostructural complexes 4 and 5 crystallize monoclinic, space group P2(1)/n and Z = 4. In complexes 2-5, the (ReO)(3+) unit is coordinated by a monoanionic O,O-bidentate unit of the maltolate (2 and 3) or kojate (41 and 5) ligand, one triphenylphosphine and two halogeno ligands (Cl in 2 and 4; Br in 3 and 5), with the rhenium(V) center in a distorted octahedral environment. The halide ligands are in cis positions to each other. (c) 2008 Elsevier Ltd. All rights reserved.

Oxorhenium(V) Complexes with 2,3-Dihydroxynaphthalene

2,3-Dihydroxynaphthalene (H(2)dhn) reacts with [ReOCl(3)-(PPh(3))(2)] or [ReOBr(3)(PPh(3))(2)] in a 1:1 molar ratio with formation of the isostructural complexes [ReOCl(2)(PPh(3))(2)(Hdhn)] (4) and [ReOBr(2)-(PPh(3))(2)(Hdhn)] (5). They have distorted octahedral coordination spheres with the halide and the triphenylphosphine ligands arranged in equatorial trans positions to each other. The Hdhn-ligand coordinates monodentately in trans position to the oxo ligand. Intramolecular hydrogen bonds between the Hdhn and the halogeno ligands stabilize this coordination mode. The products represent the first examples of oxorhenium(V) complexes with monodentate catecholate-type ligands.

Ruthenium (II) phosphine/picolinate complexes as antimycobacterial agents

The synthesis, characterization and the anti-Mycobacterium tuberculosis (MTB) activities of three ruthenium complexes containing the 2-pyridinecarboxylic acid anion (picolinate), with formulae cis-[Ru(pic)(dppm)(2)]PF(6) (1), Cis- [Ru(pic)(dppe)(2)]PF(6) (2) and [Ru(pic)(2)(PPh(3))(2)] (3) [pic = 2-pyridinecarboxylate; dppm = bis(diphenylphosphino)methane: dppe = 1,2-bis(diphenylphosphino)ethane; PPh(3) = triphenylphosphine] are reported in this article. The complexes were characterized by elemental analysis, spectroscopic and electrochemical techniques. Their in vitro anti mycobacterial activity was determinated as the Minimum Inhibitory Concentration (MIC) for MTB cell growth, measured by the REMA method. The best MICs were found for complexes (1) and (2), with values of 0.78 and 0.26 mu g/mL, respectively. The results are comparable to or better than ""first line"" or ""second line"" drugs commonly used in the treatment of TB. (C) 2009 Elsevier Masson SAS. All rights reserved.

Synthesis, Structural Characterization, and Biological Evaluation of Oxorhenium(V) Complexes with a Novel Type of Thiosemicarbazones Derived from N-[N `,N `-Dialkylamino(thiocarbonyl)]benzimidoyl Chlorides

Reactions of N-[N`,N`-diethylamino(thiocarbonyl)]benzimidoyl chloride with 4,4-dialkylthiosemicarbazides give a novel class of thiosemicarbazides/thiosemicarbazones, H(2)L, which causes a remarkable reduction of cell growth in in vitro experiments. These strong antiproliferative effects are also observed for oxorhenium(V) complexes of the general composition [ReOCl(L)], which are formed by reactions of the potentially tridentate ligands with (NBu(4))[ReOCl(4)]. A systematic substitution of the alkyl groups in the thiosemicarbazone building blocks of the ligands do not significantly influence the biological activity of the metal complexes, while the replacement of the chloro ligand by a PPh(3) ligand (by the replacement of the oxo unit by a nitrido ligand) completely terminated the cytotoxicity of the metal complexes.

Mixed-Ligand Complexes of Technetium and Rhenium with Tridentate Benzamidines and Bidentate Benzoylthioureas

Mixed-ligand complexes of technetium(V) or rhenium(V) containing tridentate N-[(dialkylamino)(thiocarbonyl)]benzamidine (H(2)L(1)) and bidentate N,N-dialkyl-N`-benzoylthiourea (HL(2)) ligands were formed in high yields when (NBu(4))[MOCl(4)] (M = Tc or Re) or [ReOCl(3)(PPh(3))(2)] was treated with mixtures of the proligands. Other approaches for the synthesis of the products are reactions of [MOCl(L(1))] complexes with HL(2) or compounds of the-composition [ReOCl(2)(PPh(3))(L(2))] with H(2)L(1). The resulting air-stable [MO(L(1))(L(2))] complexes possess potential for the development of metal-based radiopharmaceuticals. [TcO(L(1))(L(2))] complexes are readily reduced by PPh3 with formation of [Tc(L(1))(L(2))(PPh(3))]. The resulting Tc(III) complexes undergo two almost-reversible oxidation steps corresponding to one-electron transfer processes. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Ability of Ru complexes for ROMP tuned through a combination of phosphines and amines

Polynorbonerne with high molecular weight was obtained via ring opening metathesis polymerization using catalysts derived from [RuCl(2)(PPh(2)Bz)(2) L] (1 for L = PPh(2) Bz; 2 for L = piperidine) type of complexes when in the presence of ethyl diazoacetate in CHCl(3). The polymer precipitated within a few minutes at 50 degrees C when using 1 with ca. 50% yield ([NBE]/[Ru] = 5000). Regarding 2, for either 30 min at 25 C or 5 min at 50 degrees C, more than 90% of yields are obtained; and at 50 C for 30 min a quantitative yield is obtained. The yield and PDI values are sensitive to the [NBE]/[Ru] ratio. The reaction of 1 with either isonicotinamide or nicotinamide produces six-coordinated complexes of [RuCl(2)(PPh(2)Bz)(2)(L)(2)] type, which are almost inactive and produce only small amounts of polymers at 50 C for 30 min. Thus, we Concluded that the novel complexes show very distinct reactivities for ROMP of NBE. This has been rationalized on account of a combination of synergistic effects of the phosphine-amine ancillary ligands. (C) 2009 Elsevier B.V. All rights reserved.