Heterodi‐ (Fe, Pd/Pt) and Heterotrimetallic (Fe 2 , Pd) Complexes Derived from 4‐(Ferrocenylmethyl)‐ N ‐(2‐methoxyethyl)‐3,5‐diphenylpyrazole as Potential Antitumoral Agents

The study of the reactivity of the pyrazole derivative 1‐[MeO(CH 2 ) 2 ]‐3,5‐Ph 2 ‐4‐(CH 2 Fc)–(C 3 N 2 ) ( 1 , Fc = ferrocenyl) with Na 2 [PdCl 4 ], Pd(OAc) 2 , and [MCl 2 (dmso) 2 ] (M = Pd or Pt, dmso = dimethyl sulfoxide) has allowed us to isolate trans ‐[Pd{κ‐ N ‐(1‐{MeO(CH 2 ) 2 }‐3,5‐Ph 2 ‐4‐{CH 2 Fc}–{C 3 N 2 })} 2 Cl 2 ] ( 2 ), [Pd{κ 2 ‐ C , N (1‐{MeO(CH 2 ) 2 }‐3‐{C 6 H 4 }‐5‐Ph‐{C 3 N 2 })}{κ‐ N ‐(1‐{MeO(CH 2 ) 2 }‐3,5‐Ph 2 ‐4‐{CH 2 Fc}–{C 3 N 2 })}Cl] ( 3 ), [Pd{κ 2 ‐ C , N (1‐{MeO(CH 2 ) 2 }‐3‐{C 6 H 4 }‐4‐{CH 2 Fc}‐5‐Ph‐{C 3 N 2 })}Cl(PPh 3 )] ( 4 ), and the trans ( 5 ) and cis ( 6 ) isomers of [Pt{κ‐ N ‐(1‐{MeO(CH 2 ) 2 }‐3,5‐Ph 2 ‐4‐{CH 2 Fc}–{C 3 N 2 })}Cl 2 (dmso)]. Compound 1 acts as a N (in 2 , 5 , and 6 ) or (C,N) – donor ligand (in 4 ) and shows both binding modes in 3 . The cytotoxic assessment of 1 – 6 against MCF7, MDA‐MB231 (breast), and HCT‐116 (colon) cancer cell lines reveal that (1) 1 is more potent than 1‐[MeO(CH 2 ) 2 ]‐3,5‐Ph 2 ‐(C 3 HN 2 ) ( V ), (2) 2 – 6 have cytotoxic activity, (3) 2 and 3 are less active than 4 – 6 , and (4) 6 is the most potent compound against the three cancer cell lines.