Search results for "Complexe"
showing 10 items of 920 documents
Preparation and structural characterization of Ph3Sn(IV)+ complexes with pyridinecarboxylic acids or hydroxypyridene, -pyrimidine and –quinoline.
2006
A number of [Ph3Sn(IV)](+) complexes formed with ligands containing -OH (-C=O), or -COOH group(s) and aromatic IN) donor atom have been prepared. The binding sites of the ligands were identified by FT-IR spectroscopic measurements. In the complexes containing hydroxy and carboxylate functions, the carboxylato group is coordinated to the organotin(IV) centres in monodentate or bridging bidentate manner. It was also found that in the hydroxypyridine and -pyrimidine complexes the [Ph3Sn(IV)]+ moiety in most cases reacts with the phenolic form of the ligands. The rationalisation of the experimental Sn-119 Mossbauer nuclear quadrupole splittings, vertical bar Delta(exp)vertical bar - according t…
A dinuclear rhodium(III) complex with the N,N′-ethylenebis(salicylideneiminato) (salen) ligand in a bridging bis-bidentate mode of coordination. Crys…
1990
In this communication we describe the synthesis and crystal structure of the complex [{Rh(η 2 -(C 6 H 4 )PPh 2 )(η 2 -P(o-ClC 6 H 4 )Ph 2 )} 2 (salen)]-(SbF 6 ) 2 , showing the bridging configuration of the salen ligand
Effects of preorganization in the chelation of UO22+ by hydroxamate ligands: cyclic PIPO– vs linear NMA–
2018
International audience; Many siderophores incorporate as bidentate chelating subunits linear and more seldomly cyclic hydroxamate groups. In this work, a comparative study of the uranyl binding properties in aqueous solution of two monohydroxamic acids, the prototypical linear N-methylacetohydroxamic acid (NMAH) and the cyclic analog 1-hydroxypiperidine-2-one (PIPOH), has been carried out. The complex [UO2(PIPO)(2)(H2O)] crystallized from slightly acidic water solutions (pH < 5), and its molecular structure was determined by X-ray diffraction. The uranyl speciation in the presence of both ligands has been thoroughly investigated in a 0.1 M KNO3 medium at 298.2 K by the combined use of four …
DNA binding, nuclease activity, DNA photocleavage and cytotoxic properties of Cu(II) complexes of N-substituted sulfonamides.
2013
Abstract Ternary copper(II) complexes [Cu(NST)2(phen)] (1) and [Cu(NST)2(NH3)2]·H2O (2) [HNST = N-(4,5-dimethylthiazol-2-yl)naphthalene-1-sulfonamide] were prepared and characterized by physico-chemical techniques. Both 1 and 2 were structurally characterized by X-ray crystallography. The crystal structures show the presence of a distorted square planar CuN4 geometry in which the deprotonated sulfonamide, acting as monodentate ligand, binds to the metal ion through the thiazole N atom. Both complexes present intermolecular π–π stacking interactions between phenanthroline rings (compound 1) and between naphthalene rings (compound 2). The interaction of the complexes with CT DNA was studied b…
New coordination polymer based on a triply bridged dicarboxylate ligand: Synthesis, structure, and magnetic properties of the adipato complex [Cu4(bp…
2007
International audience; One-pot reaction of copper(II) chloride dihydrate CuCl2 · 2H2O with 2,2′-bipyridyl (bpy = C10H8N2) in the presence of sodium adipate Na2adip (adip2− = [O2C(CH2)4CO2]2−) and potassium 1,1,3,3-tetracyano-2-ethoxypropenide (tcnoet− = [(NC)2CC(OEt)C(CN)2]−) gives the new compound [Cu4(bpy)4(adip)3](tcnoet)2 · 2H2O (1), which was characterized by single crystal X-ray diffraction analysis. The Cu(II) metal ion presents an elongated square pyramidal CuN2O3 environment, with an oxygen atom in apical position and a base plane involving almost equivalent bond lengths. The structure can be described as a pseudo dinuclear species in which two Cu(bpy) units are triply bridged by …
Polypyridyl-functionalizated alkynyl gold(i) metallaligands supported by tri- and tetradentate phosphanes
2017
A series of alkynyl gold(I) tri and tetratopic metallaligands of the type [Au3(CuC-R)3(μ3-triphosphane)] (R = 2,2'-bipyridin-5-yl or C10H7N2, 2,2':6',2''-terpyridin-4-yl or C15H10N3; triphosphane = 1,1,1-tris(diphenylphosphanyl) ethane or triphos, 1,3,5-tris(diphenylphosphanyl)benzene or triphosph) and [Au4(CuC-R)4 (μ4-tetraphosphane)] (R = C10H7N2, C15H10N3; tetraphosphane = tetrakis(diphenylphosphanylmethyl)methane or tetraphos, 1,2,3,5-tetrakis(diphenylphosphanyl)benzene or tpbz, tetrakis(diphenylphosphaneylmethyl)-1,2- ethylenediamine or dppeda) were obtained in moderate to good yields. All complexes could be prepared by a Q4 reaction between the alkynyl gold(I) polymeric species [Au(Cu…
Designing dicyanamide bridged 1D molecular architecture from a mononuclear copper(II) Schiff base precursor: Syntheses, structural variations and mag…
2009
International audience; A new tridentate N2O donor Schiff base ligand [(C6H5C(OH)CHC(CH3)NCH2C5H4N)LH] was obtained by 1:1 condensation of benzoylacetone with 2-picolylamine and has been used to synthesise a mononuclear [CuLCl] (1) and an end-to-end dicyanamide bridged polynuclear {[Cu2(μ-L)2(μ2-1,5-(CN)2N)]ClO4}n (2) copper(II) complexes. The ligand, 1 and 2 were clearly characterised by elemental analysis, FT-IR, 1H NMR, UV–Vis spectral studies, electrochemical studies and in addition single crystal X-ray diffraction studies were performed for 1 and 2. The Schiff base ligand [LH] shows a significant variation in its coordination behaviour with copper(II) ion in absence and in presence of …
Multiple Roles of Isocyanides in Palladium-Catalyzed Imidoylative Couplings: A Mechanistic Study
2016
International audience; Kinetic, spectroscopic and computational studies examining a palladium-catalyzed imidoylative coupling highlight the dual role of isocyanides as both substrates and ligands for this class of transformations. The synthesis of secondary amides from aryl halides and water is presented as a case study. The kinetics of the oxidative addition of ArI with RNC-ligated Pd-0 species have been studied and the resulting imidoyl complex [(ArC=NR)Pd(CNR)(2)I] (Ar=4-F-C6H4, R = tBu) has been isolated and characterized by X-ray diffraction. The unprecedented ability of this RNC-ligated imidoyl-Pd complex to undergo reductive elimination at room temperature to give the amide in the p…
Mononuclear Perfluoroalkyl-Heterocyclic Complexes of Pd(II): Synthesis, Structural Characterization and Antimicrobial Activity
2020
Two mononuclear Pd(II) complexes [PdCl2(pfptp)] (1) and [PdCl2(pfhtp)] (2), with ligands 2-(3-perfluoropropyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfptp) and 2-(3-perfluoroheptyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfhtp), were synthesized and structurally characterized. The two complexes showed a bidentate coordination of the ligand occurring through N atom of pyridine ring and N4 atom of 1,2,4-triazole. Both complexes showed antimicrobial activity when tested against both Gram-negative and Gram-positive bacterial strains.
White-light phosphorescence emission from a single molecule: application to OLED.
2009
A simple mononuclear cyclometallated iridium(III) complex exhibits white photo- and electro- luminescence in the wavelength range from 440 to 800 nm, which originates from a single emitting excited state of mixed character. Bolink Henk, Henk.Bolink@uv.es ; Coronado Miralles, Eugenio, Eugenio.Coronado@uv.es