Abstract
Tetrapalladium clusters containing dppa or dppa and dppm bridging ligands were prepared by condensation of dinuclear units. Reaction of [Pd2Cl2(μ-dppa)2] with [Cu(PPh3)]PF6 (generated in situ in THF) yielded [Pd4(μ-Cl)2(μ-dppa)4] (PF6)2 (4) in a virtually quantitative yield but [Pd4(μ-Cl)2(μ-dppm)2(μ-dppa)2] (PF6)2 (6) was best prepared in CH2Cl2 from [Pd2Cl2(μ-dppm)2] and [Pd2(MeCN)2(μ-dppa)2](PF6)2 (2). The structure of 6·2(CH3)2CO·2H2O was determined by X-ray diffraction. It consists of a planar, centrosymmetric 10-membered ring structure. The four bridging diphosphine ligands are of two types: two dppa ligands support the Pd Pd bonds [2.6055(4) Å], whereas the two dppm ligands bridge between two palladium atoms separated by 3.722(4) Å, which are also bridged by a chloride ligand.
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Bachert, I., Braunstein, P., Guillon, E. et al. Synthesis of Palladium Clusters with the P--N--P Assembling Ligands (Ph2P)2CH2 (dppm) and (Ph2P)2NH (dppa). Crystal Structure of [Pd4(μ-Cl)2(μ-dppm)2(μ-dppa)2](PF6)2 . Journal of Cluster Science 10, 445–458 (1999). https://doi.org/10.1023/A:1022633211521
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DOI: https://doi.org/10.1023/A:1022633211521