Pyrazolato-bridged binuclear palladium(II) compounds: synthesis and crystal structure
Abstract
Pyrazolato-bridged binuclear palladium(II) complexes of the type [Pd2X2(µ-L–L)2(PR3)2][L–L = pz (pyrazolate) or dmpz (3,5-dimethylpyrazolate); X = Cl, Br or I; PR3= PBu3, PMe2Ph or PMePh2] have been prepared. They were characterized by elemental analysis, 1H and 31P NMR data and in the case of [Pd2Cl2(µ-dmpz)2(PMe2Ph)2] by single-crystal X-ray diffraction methods. The structure determination shows two Pd atoms bridged by two dmpz ligands which form asymmetric Pd–N bond distances, an observation that may be correlated with the different trans influences associated with the Cl and P atoms which complete the square-planar geometries about the Pd atoms: monclinic, space group P21/c, a= 20.164(1), b= 10.140(1), c= 16.129(3)Å, β= 111.71(1)°, and Z= 4. The structure was refined to final R= 0.027 for 2906 reflections with I 2.5 σ(I).