SCHIFF-BASES DERIVED FROM BENZOYLFERROCENE AND THEIR CYCLOPALLADATED DERIVATIVES - X-RAY CRYSTAL-STRUCTURE OF [PD((ETA(5)-C5H5)FE[(ETA(5)-C5H3)-C(C6H5)=N-C6H5])CL(PPH3)]

We report the synthesis, characterization, and study of cyclopalladated complexes derived from ferrocenylimines [(eta5-C5H5)-Fe{(eta5-C5H4)-C(C6H5)=N-R'}] (R' = C6H5 (1a), C6H4-2-CH3 (1b), C6H4-4-CH3 (1c), CH2-C6H5 (1d), CH2-C6H4-2-CH3 (1e), or CH2-C6H4-2-Cl (1f). Addition of these ferrocenylamines to methanolic solutions of Na2[PdCl4] and sodium acetate trihydrate in a 1:1 molar ratio results in the formation of the di-mu-chloro-cyclopalladated complexes [Pd{(eta5-C5H5)Fe[(eta5-C5H3)-C(C6H5)=N-R]}(mu-Cl)]2 (2a-2f). More soluble complexes [Pd{(eta5-C5H5)Fe[(eta5-C5H3)-C(C6H5)=N-R]}Cl(PPh3)] (3a-3f) were obtained by the reaction of compounds 2a-2f with triphenylphosphine. H-1, C-13, and 31P-NMR spectroscopic studies of these complexes reveal that cyclometallation occurs on the ferrocynyl-moiety, producing five-membered metallacycles which contain the > C=N bond (endo-type structures). The X-ray crystal structure of [Pd{(eta5-C5H5)Fe](eta5-C5H3)-C(C6H5)=N-C6H5]}Cl(PPh3)] . 2H2O (3a) is also reported. This complex is monoclinic with a = 18.184(3), b = 11.631(2), c = 19.499(3) angstrom, beta = 112.55(2)-degrees, space group P2(1)/c, and its crystal structure confirms the formation of a five-membered metallacycle, which contains a sigma{Pd-C(sp2(ferrocene))} bond.