Palladium(II) and platinum(II)-C(3)-substituted 2,2′-bipyridines

Reaction of Pd(OAc)(2) with HL1 and HL2 (HL1=6-iso-propyl-2,2'-bipyridine; HL2=6-neo-pentyl-2,2'-bipyridine), followed by treatment with LiCl or KI gives [PdCl(L-1)](2), (1), [PdCl(L-2)](2), (2), [PdI(L-2)](2), (3), respectively. The chloride bridge in complexes 1 and 2 is split by PPh3 to give the mononuclear species PdCl(L-1)(PPh3), (4), and PdCl(L-2)(PPh3), (5). Spectroscopic data provide evidence for coordination of the deprotonated ligands through a nitrogen and the C((3)) atom of the B-substituted pyridine. An analogous platinum complex PtCl(L-3)(SMe2), (6), (HL3=6-tert-butyl-2,2'-bipyridine) was obtained from trans-PtClMe(SMe2)(2) and HL3. The crystal structures of compounds 1 and 6 have been solved by X-ray diffraction analysis.