Search results for " LIGANDS"

Hepta- and tetra-nuclear copper(II) clusters self-assembled by cyano- and azacyano-carbanions

2015

International audience; Two polynuclear copper(II) complexes with hydroxido-bridging ligands and polycyanide units, [Cu{Cu(tn)}6(μ2-OH)2(μ3-OH)4Cl2](tcm)4Cl2·2H2O (1) and [{Cu(bpy)}4(OH)4(dca)2](dca)2·bpy·2H2O (2) (tn = NH2(CH2)3NH2; tcm− = [C(CN)3]−, bpy = 2,2′-bipyridyl, dca− = [N(CN)2]−) have been prepared by one-pot reactions. The structure of 1 consists of a centrosymmetric heptanuclear ion [Cu{Cu(tn)}6(μ2-OH)2(μ3-OH)4Cl2]6+. The tcm− and the halide anions which appear as counter-ions in the formula unit, play an important role in the stabilization of the complex since the hydrogen bonding between nitrogen atoms of the tcm− anion and halide anions, and hydrogen atoms of the terminal wa…

Resolution of β-aminophosphines with chiral cyclopalladated complexes

2005

Abstract Resolution of the racemic chiral β-aminophosphines Ph 2 PCH 2 CH(Ph)NH(Ar) ( L 1 for Ar = C 6 H 5 and L 2 for Ar = 2,6-C 6 H 3 i Pr 2 ) has been investigated by use of different cyclopalladated complexes as chiral agents. The resulting complexes afford diastereomeric adducts in a 1:1 ratio. After successive crystallizations from ethanol, a d.e. of 98% was achieved for one aminophosphine palladium complex, while no significant d.e. was obtained after crystallizations from chlorinated solvents. The X-ray structure analysis has pointed out intermolecular hydrogen interactions N–H⋯Cl between the P,N ligand and the chloride ion, which are responsible for the formation and stabilization …

Assembly and encapsulation of coordination tectons driven by hydrogen-bondingand space-filling

2001

[FR] Le composé ¿Fe(LI)3¿2¿Fe(H2O)6¿(ClO4)6 (2), LI = 1,10-phénanthroline-5,6-dione, a été synthétisé et caractérisé. La structure cristalline 2 est définie par un assemblage bidimensionnel non covalent, peu commun, constitué par des tectons chiraux ¿Fe(LI)3¿2+, assemblés par des cations ¿Fe(H2O)6¿2+ encapsulés dans des cages. Ces cages sont formées par 12 liaisons hydrogène établies entre les molécules d¿eau coordinées et les groupes dione appartenant à six molecules chirales ¿Fe(LI)3¿2+ ¿, ¿ alternées.

Nickel precursors based on diamagnetic and paramagnetic di(imine)pyridine ligands for magnetic materials: Synthesis, X-ray structures and magnetic st…

2018

International audience; Structural characterization and spectroscopic studies of the (2-acetyl-6-(1-TEMPO-imino)ethyl)pyridine (pat) and the 2,6-bis(1-TEMPO-imino)ethyl)pyridine (pbtMe) ligands are presented. Their electrochemical properties are also discussed. Two new nickel complexes, [NiII(dip)(CH3CN)(H2O)2](BF4)2 (1) (dip = 2,6-(di-iminepyridine)) and [NiII(pbtMe)(CH3CN)3](BF4)2 (2) have been characterized by X-ray diffraction. The reaction of 1 with the tetraethyl ammonium pentacyanopropenide salt (Et4N)(pcp) affords the new compound [NiII(pcp)(dip)(CH3CN)](pcp) (3) for which X-ray diffraction studies evidence an usual bridging μ2 coordination mode for the pentacyanopropenide anion, le…

Single Molecule Magnet Features in the Butterfly [Co III 2 Ln III 2 ] Pivalate Family with Alcohol‐Amine Ligands

2021

Sequestering ability of some chelating agents towards methylmercury(II).

2013

A study on the interactions between CH3Hg+ and some S, N and O donor ligands (2-mercaptopropanoic acid (thiolactic acid (H2 TLA)), 3-mercaptopropanoic acid (H2 MPA), 2-mercaptosuccinic acid (thiomalic acid (H3 TMA)), d,l-penicillamine (H2 PSH), l-cysteine (H2 CYS), glutathione (H3 GSH), N,N′-bis(3-aminopropyl)-1-4-diaminobutane (spermine (SPER)), 1,2,3,4,5,6-benzenehexacarboxylic acid (mellitic acid (H6 MLT)) and ethylenediaminetetraacetic acid (H4 EDTA)) is reported. The speciation models in aqueous solution and the possible structures of the complexes formed are discussed on the basis of potentiometric, calorimetric, UV spectrophotometric and electrospray mass spectrometric results. For t…

Anion template effect and the polymerization degree

2005

Two 2D (M1 and M2) and one 1D (M3) metal‐organic frameworks (MOFs) have been prepared from pyridine functionalized tetradentate ligand tetrakis(nicotinoxymethyl)methane TNM with silver tetrafluoroborate, nickel chloride, and copper hexafluorophosphate. M1 manifests a previously unpresented mode of 4,4 threefold parallel interpenetration for 2D MOFs. Large channels (vdW diameter 9.4 Å) through eclipsed 2D layers of M2 were observed. While the open space percentage in the noninterpenetrated M2 was 38.0 %, the triple interpenetration of the sheets of M1 reduced the void to 10.8 %. With the same ligand and a similar, weakly coordinating anion as that in M1, the structure M3 was rendered one‐dim…

High oxidation state aqueous organometallics: synthesis and structure of a dinuclear oxo(pentamethylcyclopentadienyl)acetato complex of molybdenum(IV…

2003

International audience; The zinc reduction of Cp*2Mo2O5 in a MeOH–H2O mixture in the presence of acetic acid affords the diamagnetic dinuclear compound [Cp*MoO(O2CCH3)]2. An X-ray structural investigation reveals a novel dioxo- and diacetato-bridged structure, with a relatively strong metal–metal bond [2.5524(3) Å]. The compound exhibits a reversible one-electron oxidation process in the cyclic voltammogram. A comparison with other related structures reveals the effect of the electric charge on the mononuclear or dinuclear structural choice.Zinc reduction of Cp*2Mo2O5 in water–methanol in the presence of acetic acid affords compound Cp*2Mo2O2(O2CCH3)2, whose dinuclar tetrabridged structure …

mGluR2/3 agonist LY379268, by enhancing the production of GDNF, induces a time-related phosphorylation of RET receptor and intracellular signaling Er…

2011

In the present study we aimed to verify if the enhancement of glial cell line-derived neurotrophic factor (GDNF) production in mouse striatum following treatment with LY379268 may also induce in the nigrostriatal system a time-related activation of RET receptor and its specific intracellular signaling. For this purpose, we have investigated the effects of LY379268 treatment on RET phosphorylation at the Tyr1062 and on downstream signaling Erk1/2, Akt and PLCγ1 pathway activation. The results showed that treatment with LY379268 (3 mg/kg) induces a significant increase of GDNF levels and time-related RET and Erk1/2 phosphorylation in the striatum. These increases were detected at 24 h and 48 …

Bright Blue Phosphorescence from Cationic Bis-Cyclometalated Iridium(III) Isocyanide Complexes

2012

We report new bis-cyclometalated cationic indium(III) complexes [((CN)-N-boolean AND)(2)Ir(CN-tert-Bu)(2)](CF3SO3) that have tert-butyl isocyanides as neutral auxiliary ligands and 2-phenylpyridine or 2-(4'-fluoropheny1)-R-pyridines (where R is 4-methoxy, 4-tert-butyl, or 5-trifluoromethyl) as (CN)-N-boolean AND ligands. The complexes are white or pale yellow solids that show irreversible reduction and oxidation processes and have a large electrochemical gap of 3.58-3.83 V. They emit blue or bluegreen phosphorescence in liquid/solid solutions from a cyclometalating-ligand-centered excited state. Their emission spectra show vibronic structure with the highest-energy luminescence peak at 440-…