Search results for "complexe"
showing 10 items of 920 documents
Two-dimensional assembling of 4,4'-bipyridine and 4,4'-azopyridine bridged iron(II) linear coordination polymers via hydrogen bond
1999
[EN] Novel two-dimensional polymers, [Fe(L-1)(H2O)(2)(NCX)(2)]. L-1 (L-1 =4.4'-bipyridine (bipy)) (1, 2) and [Fe(L-2)(CH3OH)(2)-(NCX)(2)]. L-2 (L-2 =4,4'-azopyridine (azpy)) (3) and X = S (1, 3), Se (2), have been synthesized and characterized by X-ray crystallography. The structures reveal the formation of tranzs-L-bridged [Fe(NCX)(2)(Y)(2)] where Y=H2O, CH3OH linear chains assembled into two-dimensional networks by hydrogen bonds between the uncoordinated ligand L and the coordinated solvent molecules.
Recognition of N-Alkyl- and N-Aryl-Acetamides by N-Alkyl Ammonium Resorcinarene Chlorides
2014
N-alkyl ammonium resorcinarene chlorides are stabilized by an intricate array of intra- and intermolecular hydrogen bonds that leads to cavitand-like structures. Depending on the upper-rim substituents, self-inclusion was observed in solution and in the solid state. The self-inclusion can be disrupted at higher temperatures, whereas in the presence of small guests the self-included dimers spontaneously reorganize to 1:1 host-guest complexes. These host compounds show an interesting ability to bind a series of N-alkyl acetamide guests through intermolecular hydrogen bonds involving the carbonyl oxygen (C=O) atoms and the amide (NH) groups of the guests, the chloride anions (Cl(-)) and ammoni…
Bridgehead isomer effects in bis(phosphido)-bridged diiron hexacarbonyl proton reduction electrocatalysts
2017
The influence of the substitution, orientation and structure of the phosphido bridges in [Fe2(CO)6(μ-PR2)2] electrocatalysts of proton reduction has been studied. The isomers e,a-[Fe2(CO)6{μ-P(Ar)H}2] (1a(Ar): Ar = Ph, 2′-methoxy-1,1′-binaphthyl (bn′)), e,e-[Fe2(CO)6{μ-P(Ar)H}2] (1b(Ar): Ar = Ph, bn′) were isolated from reactions of iron pentacarbonyl and the corresponding primary phosphine, syntheses that also afforded the phosphinidene-capped tri-iron clusters, [Fe3(CO)9(μ-CO)(μ3-Pbn′)] (2) and [Fe3(CO)9(μ3-PAr)2] (3(Ar), Ar = Ph, bn′). A ferrocenyl (Fc)-substituted dimer [Fe2(CO)6{μ:μ′-1,2-(P(CH2Fc)CH2)2C6H4}] (4), in which the two phosphido bridges are linked by an o-xylyl group, was al…
A novel mixed valent Cu(II)-Cu(I) 2D framework made of a hydrazone and μ-SCN bridged metallacyclic loops cross-linked by μ3-SCN chains.
2012
A mixed valent copper complex [Cu(II)Cu(I)(L)(μ-SCN)(μ(3)-SCN)](n) (LH = N'-((pyridin-2-yl)methylene)acetohydrazide) has been synthesized and characterized. It is a unique example of a 2D mixed valent Cu(II)-Cu(I) interlinked molecular assembly with a very unusual bridging property of the hydrazone ligand. An extraordinary in situ partial Cu(II)→ Cu(I) reduction is observed in this system at room temperature.
Slow magnetic relaxation in a hydrogen-bonded 2D array of mononuclear dysprosium(III) oxamates.
2013
The reaction of N-(2,6-dimethylphenyl)oxamic acid with dysprosium(III) ions in a controlled basic media afforded the first example of a mononuclear lanthanide oxamate complex exhibiting a field-induced slow magnetic relaxation behavior typical of single-ion magnets (SIMs). The hydrogen-bond-mediated self-assembly of this new bifunctional dysprosium(III) SIM in the solid state provides a unique example of 2D hydrogen-bonded polymer with a herringbone net topology.
Red-light-emitting electrochemical cell using a polypyridyl iridium(III) polymer.
2009
A deep-red phosphorescent ionic iridium(III) complex is prepared and incorporated into a polymer. Both the complex (1) and the polymer (2) were used as the single active material in solid-state light-emitting electrochemical cells (LECs). The devices built up using 1 and 2 emit in the deep-red region of the visible spectrum with CIE coordinates x = 0.710; y = 0.283 and x = 0.691; y = 0.289, respectively, making them one of the deepest-red emitting LECs reported. It is the first example of a polymeric LEC incorporating an ionic iridium complex, which exhibits increased stabilities compared with the device based on the small molecular weight complex.
Cluster dirhenium(III) cis-dicarboxylates with α-amino acids ligands as mighty selective G4s binders.
2021
The synthesis of four dirhenium(III) cis-dicarboxylates with the α-amino acids residues Asp (I), Glu (II), Phe (III) and Tyr (IV) is presented. The G-quadruplex stabilization potential was evaluated by fluorescence resonance energy transfer - melting analysis. All derivatives show specific binding to c-kit1 quadruplex, while II and IV have also strong stabilization activity to HTelo21 quadruplex. At the same time, the compounds do not show any stabilization activity for ds26 DNA, which suggests unique mechanisms of molecular DNA recognition for these complexes.
Pigment ligation to proteins of the photosynthetic apparatus in higher plants
1997
Ligation of pigments to proteins of the thylakoid membrane is a central step in the assembly of the photosynthetic apparatus in higher plants. Because of the potentially damaging photooxidative activity of chlorophylls, it is likely that between their biosynthesis and final assembly, chlorophylls will always be bound to protein complexes in which photooxidation is prevented by quenchers such as carotenoids. Such complexes may include chlorophyll carriers and/or membrane receptors involved in protein insertion into the membrane. Many if not all pigment-protein complexes of the thylakoid are stabilised towards protease attack by bound pigments. The major light-harvesting chlorophyll a/b prote…
Polymer supported synthesis of mixed ligand complexes
2003
A series of novel polymer-supported mixed ligand complexes were synthesized and studied. Two percent divinyl benzene (DVB)-crosslinked polystyrene supports were synthesized by the suspension copolymerization technique. An ethylene diamine group was anchored onto the support and the corresponding copper complexes were prepared. The ligating functions like phthalate, acetate, and oxalate groups were introduced, and mixed ligands complexes were synthesized. The resultant polymer supported mixed ligand complexes were characterized by UV-Vis, IR, and EPR methods. The stability constants dictate the formation of these complexes on polymer support. Spectral results gave information about the struc…
Manganese(III)-mediated oxidative carbon-carbon bond cleavage of the 1,10-phenanthroline-5,6-dione ligand
1999
[EN] A new manganese(III)-1,10-phenanthroline-5,6-dione (phendione) complex possessing a putative Mn-2(mu-O) (mu-O2CMe)(2) core has been found to undergo a Ligand-based oxidative cleavage of the C(5)-C(6) bond in weak acid aqueous MeOH under aerobic conditions at room temperature to yield 2,2'-bipyridyl-3,3'-dicarboxylate with co-reduction to the corresponding Mn-II-phendione species.