The synthesis, spectroscopic and thermal properties of the novel five-membered [N,O] metallocyclic complexes of palladium(II) with monoethyl (HL1) and monobutyl (HL2) esters of (alpha -amino-N-benzyl)phosphonic acid are reported. Binuclear complexes Pd(2)L(4) (L = L1, L2) were obtained by reaction of sodium salts of monoalkyl phosphonates with PdCl(4)(2-) in aqueous solution. Four organophosphorus ligands bridge two palladium atoms by coordination through the aniline nitrogen and the deprotonated phosphonic acid oxygen. The complexes were identified and characterized by elemental analysis, magnetic and conductance measurements, as well as by spectroscopic (ESI-MS, IR, UV-VIS, (1)H and (31)P NMR) and thermal (TG, DTA) studies. The properties of the complexes are discussed with respect to those of palladium(II) metallocyclic complexes reported for monoalkyl 4-azobenzene-substituted anilinobenzylphosphonates
