Synthesis, characterization and cytotoxic activity of substituted benzyl iminoether Pt(II) complexes of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}(2)] (R = Me, OMe, F). X-ray structure of trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}(2)]

New substituted benzyl iminoether derivatives of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}(2)] (R = Me (1a, 2a), OMe (3a, 4a), F (5a, 6a)) have been synthesized and characterized by elemental analyses, FT-IR spectroscopy and NMR techniques. The iminoether ligands are in the E configuration, which is stable in solution and in the solid state, as confirmed by the H-1 NMR data. Complex trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}(2)] (6a) was also characterized by an X-ray diffraction study. Complexes 1 a-6a have been tested against a panel of human tumor cell lines in order to evaluate their cytotoxic activity. cis-Isomers were significant more potent than the corresponding trans-isomers against all tumor cell lines tested; moreover, complexes la and 5a showed IC50 values from about 2-fold to 6-fold lower than those exhibited by cisplatin, used as reference platinum anticancer drug. (C) 2007 Elsevier Inc. All rights reserved.