摘要:
The synthesis of palladacyclopentadiene derivatives with the mixed-donor bidentate ligands o-Ph2PC6H4-CH=NR (N <^> P) has been achieved. The new complexes of general formula [Pd{C-4(COOMe)(4)}(o-Ph2PC6H4-CH=NR)] [R = Me (1), Et (2), Pr-1 (3), Bu-1 (4), NH-Me (5)] have been prepared by reaction between the precursor [Pd{C-4(COOMe)(4)}](n) and the corresponding iminophosphine. The polymer complex [Pd{C-4(COOMe)(4)}](n) also reacts with pyridazine (C4H4N2) to give the insoluble dinuclear complex [Pd{C-4(COOMe)(4)}(mu-C4H4N2)](2) (6), which has been successfully employed as precursor in the synthesis of pyridazine-based palladacyclopentadiene complexes. The reaction of 6 with tertiary phosphines yielded complexes containing an N,P-donor setting of formula [Pd{C-4(COOMe)(4)}(C4H4N2)(L)J (L=PPh3 (7), PPh2Me (8), P(P-MeOC6H4)(3) (9), P(p-FC6H4)(3) (10)). The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, H-1, (19) and (31) NMR). The molecular structure of complex 3 has been determined by a single-crystal diffraction study, showing that the iminophosphine acts as chelating ligand with coordination around the palladium atom slightly distorted from the square-planar geometry. (C) 2002 Elsevier Science B.V. All rights reserved.