Synthesis and characterization of N,N'-diarylformamidino complexes of palladium(II)

Trans-Pd(PPh3)2Cl2 reacts with Li(p-RC6H4N:CHNC6H4R-p) (R = MeO, Me, H and Cl) in THF to yield the deeply colored complexes Pd(PPh3)2(p-RC6H4NCH:NC6H4R-p)Cl (I), stable in the solid state. The main decompn. products in EtOH were identified when R = Me, as trans-Pd(PPh3)2Cl2 and [Pd(p-MeC6H4N:CHNC6H4Me-p)2]2 (II). Dimeric complexes of type II can be synthesized also by reacting Li(p-MeC6H4N:CHNC6H4Me-p) with Pd(NCMe)2Cl2 in THF. Structures for all the new complexes are proposed on the basis of uv, ir, and nmr data