|
| ||
|
|
||
Cationic Ligands (cationic + ligand)
Selected AbstractsPlatinum and Palladium Complexes Containing Cationic Ligands as Catalysts for Arene H/D Exchange and Oxidation,ANGEWANDTE CHEMIE, Issue 34 2010Marion Kationische Komplexe aus Palladium(II) oder Platin(II) und Bipyridinliganden mit Pyridiniumsubstituenten sind hoch aktive und beständige Katalysatoren für den H-D-Austausch und die Oxidation der C-H-Bindungen von aromatischen Substraten mit Umsatzzahlen bis 3200 und Umsatzfrequenzen bis 0.1,s,1. [source] An Atropo-Stereogenic Diphosphane Ligand with a Proximal Cationic Charge: Specific Catalytic Properties of a Palladium Complex ThereofEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2008Nathalie Debono Abstract A class of cationic diphosphane ligands combining phosphane and amidiniophosphane moieties is illustrated on the N -methyl,N -naphthylbenzimidazolium framework. The palladium(II) complex thereof is described and compared to the corresponding complex of the analogous neutral diphosphane. Contrary to first-level expectations, the N2C,P and N2CP,Pd bonds in the cationic diphosphane complex are not longer than those occurring in its neutral counterpart. In the cationic ligand, the proximal positive charge is indeed conjugated to one phosphanyl group, and the coordination scheme is tentatively interpreted by resonance of the phosphane,metal dative bond (+N2C,P:,[Pd]) with a carbene,phosphenium dative bond (N2C:,[+P:,Pd]). Despite this peculiar structural feature, the electronic , donation (vs. , acceptation) towards the palladium centre remains lowered in the cationic ligand. This specific property can be a priori valuable in a catalytic process where oxidative addition is not the limiting step. It is indeed shown that although the neutral complex is more active in Suzuki coupling reactions, the cationic complex is more active in Sonogashira-type coupling reactions involving predissociated halide substrates, namely an acyl chloride. These likely atropo-chiral ligands deserve to be resolved for application in asymmetric catalysis.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Complexes of AgI with cationic ligands: bis[(pyridylmethyl)ammonio]silver(I) saltsACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2001Sunkari Sailaja Bis[(2-pyridylmethyl)ammonio]silver(I) trinitrate, [Ag(C6H9N2)2](NO3)3, (I), and bis{bis[(4-pyridylmethyl)ammonio]silver(I)} hexakis(perchlorate) dihydrate, [Ag(C6H9N2)2]2(ClO4)6·2H2O, (II), are rare examples of complexes with cationic ligands. In (I), the Ag+ cation has a T-shaped [2+1] coordination involving the pyridine N atoms and a nitrate O atom, while in (II) there are three independent two-coordinate Ag complex cations (two with the Ag atoms on independent inversion centres) and disordered ClO4, ions. The crystal structures reveal the role of hydrogen bonding in stabilizing these complexes. [source] | ||||||||||