Synthesis and characterization of organopalladium(II) complexes of N,N,S?tridentate sulfur-containing Schiff bases derived from 2-(2-pyridyl)benzothiazolines.

The synthesis of mononuclear Pd(II) complexes of type [Pd(Ln)Me] (n = 1?4, 1a?4a) and dinuclear (?3?allyl)palladium(II) dichloro complexes [Pd2(Ln)(?3-C3H5)Cl2] (n = 1?3, 1b?3b) derived from 2-R-(2-pyridyl)benzothiazolines used as Schiff bases precursors (R = H, 1; R = Me, 2; R = Ph, 3; R = C5H4N-2, 4) is reported. The formation of the trinuclear complex [Pd3(L4)(?3-C3H5)2Cl3] (4c) and its behavior in solution is also described. Complexes 1a?4a, 1b?3b and 4c were obtained from the thiazole ring-opening reaction of precursors 1?4 in presence of the [Pd(tmeda)Me2] and [Pd(? -Cl)(?3-C3H5)]2 starting materials. The {Ln}? anionic Schiff bases obtained showed a versatile behavior towards coordination to Pd(II) ion; in 1a?4a the ligand acted as tricoordinate whilst in 1b?3b and 4c, {Ln}? acted as mono- and tridentate ligand, respectively.