Synthesis and crystal structure of 〚PdMe{PPh2NHC(O)Me}{O=C(NH2)Me}〛〚BF4〛, a palladium complex containing the acetamide ligand

Abstract

The synthesis of a square planar cationic Pd(II) complex containing the acetamide ligand is described. The complex has been characterised by X-ray diffraction, leading to one of the rare examples of a crystal structure showing an acetamide molecule coordinated to a metal centre and, to the best of our knowledge, the first one with palladium. This complex may be relevant to catalytic reactions, such as the palladium-catalysed amidocarbonylation, in which transient species with O-coordinated acetamide can be formed. To cite this article: P. Braunstein et al., C. R. Chimie 5 (2002) 131-135 © 2002 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS acetamide / acetamidophosphine / crystal structure / palladium Résumé -Synthèse et structure cristallographique de [PdMe{PPh 2 NHC(O )Me}{O=C(NH 2 )Me}][BF 4 ], un complexe du palladium comportant le ligand acétamide. Nous décrivons la synthèse d'un complexe cationique du palladium (II) avec le ligand acétamide. Ce complexe a été caractérisé par diffraction des rayons X, conduisant à l'une des rares structures cristallographiques montrant la coordination de NH 2 C(O)Me à un centre métallique par l'atome d'oxygène et, à notre connaissance, la première dans le cas de complexes du palladium. Il est probable que des complexes similaires se forment de manière transitoire dans des processus catalytiques impliquant l'acétamide, comme par exemple les réactions d'amidocarbonylation catalysées par des complexes du palladium.

An Oriented 1D Coordination/Organometallic Dimetallic Molecular Wire with AgPd Metal–Metal Bonds

“…The O1C10 and N2C10 bond lengths of 1.273(9) and 1.353(9) Å, respectively, are consistent with C${^{\underline{.....}}}$ O and N${^{\underline{.....}}}$ C bond orders intermediate between single and double bonds 7. 9, 14…”

Factors Controlling Metal-Ion Selectivity in the Binding Sites of Calcium-Binding Proteins. The Metal-Binding Properties of Amide Donors. A Crystallographic and Thermodynamic Study

“…One can illustrate these two bonding extremes in Figure , where the structures of the highly ionic [Li(acetamide)] + cation and highly covalent [BH 3 ·acetamide] complex, calculated using the HyperGauss module of HyperChem at the 6-31G** level, are shown. In support of these calculations, which suggest that with very covalent M−O bonding the M−OC angle should be small, the M−OC angles in complexes of the very soft 35 (≈ covalent) metal ions Pd(II) and Hg(II) with unidentate amide ligands are 122.5° and 108.5°, respectively. In contrast, as noted below, with the ionically bound Ca(II), the Ca−OC angles in unidentate acetamide-like complexes average 161.5°.…”

An Oriented 1D Coordination/Organometallic Dimetallic Molecular Wire with AgPd Metal–Metal Bonds

“…The O1ÀC10 and N2ÀC10 bond lengths of 1.273(9) and 1.353 (9) , respectively, are consistent with CPO and NPC bond orders intermediate between single and double bonds. [7,9,14] A solution of 3 in THF was then treated with pure, acidfree AgSO 3 CF 3 in a 1:1 stoichiometry, and slow crystallization afforded high yields of a beige product 5·SO 3 CF 3 [Eq. (2)], which was shown by X-ray diffraction studies to be an unprecedented Ag-Pd coordination polymer (Figure 2 and see the Supporting Information).…”