Search results for "N ligand"
showing 10 items of 46 documents
Heterobimetallic single-source precursors for MOCVD. Synthesis and characterization of volatile mixed ligand complexes of lanthanides, barium and mag…
1999
Several heterobimetallic complexes of general formula [(M 1 Q) m M 2 (dik) n ], where (M 1 Q) is Cu(salen) or Ni(salen) and M 2 (dik) n is a lanthanide tris(β-diketonate) or an alkali-earth element bis(β-diketonate) with more or less fluorinated diketonato(-) ligands, have been prepared and structurally characterized. Some of them were submitted to thermal and mass spectrometry analyses, and to isothermal vacuum sublimation tests, in view of their potential use as MOCVD single-source precursors for the deposition of heterobimetallic materials. The study stresses upon the influence of the nature of the diketone. of the M 2 cation, and of chemical modification of the salen ligand on the therm…
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 …
Complejos NHC–Metal en la funcionalización de hidrocarburos; procesos en batch y en flujo
2017
Desde hace muchos años, la catálisis juega un papel fundamental en distintas áreas, tanto del ámbito académico como del industrial, ya que facilita la síntesis de productos de gran impacto para la sociedad. Actualmente, industrias como la petroquímica, la farmacéutica, la cosmética, o la alimentaria, entre otras, dependen en gran medida de la catálisis. En la búsqueda de sistemas catalíticos óptimos que permitan llevar a cabo transformaciones eficientes, selectivas y que minimicen el costo energético y la producción de residuos, surgió la catálisis metálica, principalmente basada en complejos de metales de transición como catalizadores. Estos complejos han tenido una importante evolución, d…
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…
Extended dipyrrin ligands : candidates for optical metal ion detection under competitive conditions
2017
Acylhydrazone based extended dipyrrins L1-H and L2-H are introduced as complexometric ppb sensitive metal ion detectors. The binding of lanthanide, transition as well as post-transition metal ions is followed by UV-Vis measurements. The carbohydrate based ligand L2 is water soluble and thus can act as a metal ion sensor in this medium.
Neuroglobin and Other Hexacoordinated Hemoglobins Show a Weak Temperature Dependence of Oxygen Binding
2004
AbstractMouse and human neuroglobins, as well as the hemoglobins from Drosophila melanogaster and Arabidopsis thaliana, were recombinantly expressed in Escherichia coli, and their ligand-binding properties were studied versus temperature. These globins have a common feature of being hexacoordinated (via the distal histidine) under deoxy conditions, as evidenced by a large amplitude for the alpha absorption band at 560nm and the Soret band at 426nm. The transition from the hexacoordinated form to the CO bound species is slow, as expected for a replacement reaction Fe-His → Fe → FeCO. The intrinsic binding rates would indicate a high oxygen affinity for the pentacoordinated form, due to rapid…
A novel dimer of oxo-di(acetato)-bridged manganese(III) dimers complex of potential biological significance
2000
[EN] Assembly of the tetranuclear oxomanganese(III) acetato cluster [Mn4O2(O2CMe)(7)(phen)(2)](BF4) from the dinuclear oxo-di(acetato)bridged manganese(III) species [Mn2O(O2CMe)(2)(H2O)(2)(phen)(2)](BF4)(2) . 3H(2)O in aqueous/acetic acid MeOH solution occurs via the new 'dimer of dimers' Mn-III complex [Mn2O(O2CMe)(3)(H2O)(phen)(2)](BF4) . MeOH possesing an unprecedent [Mn-4(mu-O)(2)(mu-O2Me)(4) (mu-(OH2O2CMe)-O-...)(2)] core.
Biochips for cell biology by combined dip-pen nanolithography and DNA-directed protein immobilization.
2013
A general methodology for patterning of multiple protein ligands with lateral dimensions below those of single cells is described. It employs dip pen nanolithography (DPN) patterning of DNA oligonucleotides which are then used as capture strands for DNA-directed immobilization (DDI) of oligonucleotide-tagged proteins. This study reports the development and optimization of PEG-based liquid ink, used as carrier for the immobilization of alkylamino-labeled DNA oligomers on chemically activated glass surfaces. The resulting DNA arrays have typical spot sizes of 4-5 μm with a pitch of 12 μm micrometer. It is demonstrated that the arrays can be further functionalized with covalent DNA-streptavidi…
Pharmacophore Models Derived from Molecular Dynamics Simulations of Protein-Ligand Complexes: A Case Study
2018
A single, merged pharmacophore hypothesis is derived combining 2000 pharmacophore models obtained during a 20 ns molecular dynamics simulation of a protein-ligand complex with one pharmacophore model derived from the initial PDB structure. This merged pharmacophore model contains all features that are present during the simulation and statistical information about the dynamics of the pharmacophore features. Based on the dynamics of the pharmacophore features we derive two distinctive feature patterns resulting in two different pharmacophore models for the analyzed system – the first model consists of features that are obtained from the PDB structure and the second uses two features that ca…