The reactions between [Pd2{(C,N)eC6H4CH2NH(Et)}2(m-X)2] (X ¼ Cl or Br) and 1,2-
bis(diphenylphosphino)ethane (dppe) in the 1:1 molar ratio resulted in the dppe-bridged Pd(II) complexes,
[Pd2{(C,N)eC6H4CH2NH(Et)}2(m-dppe)(Cl)2] (1) and [Pd2{(C,N)eC6H4CH2NH(Et)}2(m-dppe)(Br)2]
(2), respectively, which were characterized by elemental analyses, infrared (IR), 1H- and 31P{1H} NMR
spectroscopy. The molecular structure of 1 was determined by single-crystal X-ray diffraction. In vitro
cytotoxicity of 1, 2, dppe, PhCH2NH(Et) and cisplatin were carried out against four human tumor cell
lines. The interactions of complexes towards DNA and protein are investigated. The results suggested that
both complexes could interact with FS-DNA through the intercalation mode. Moreover, the reactivity
towards BSA revealed that the microenvironment and the secondary structure of BSA were changed in
the presence of Pd(II) complexes.