Bifunctional N–P ligands as building blocks for construction of multilayered metallodendrimers

The synthesis of 4-amino(N-methylendiphenylphosphino)pyridine (1a) and its reaction with [PdCl2(cod)], [PtCl2(cod)], [AuCl(tht)], [RuCl2(p-cymene)]2, [RhCl(cod)]2 and [Pd(η3-2-MeC3H4)Cl]2 to give [PdCl2(1a)2] (2), [PtCl2(1a)2] (3), [AuCl(1a)] (4), [RuCl2(p-cymene)(1a)] (5), [RhCl(cod)(1a)] (6) and [Pd(η3-2-MeC3H4)Cl(1a)] (7) respectively are described. The new chelate complex [Pd(η3-2-MeC3H4)(py–N(CH2–PPh2)2)](OTf) (8) is also reported. Compounds 5 and 8 were characterized by single crystal X-ray diffraction. In all complexes prepared the metal atoms appear to be bonded through the P atom of 1a. The metalloligands 4, 5 and 8 have been reacted with the ruthenocarbosilanedendrimer 10 to afford new Ru–Au and Ru–Pd concentric metal layered dendrimers 11, 12 and 13.