Heterobimetallic ferrocenylthiosemicarbazone palladium(II) complexes: Synthesis, electrochemistry and antiplasmodial evaluation

Heterobimetallic ferrocenylthiosemicarbazone palladium(II) complexes (3–5) were prepared through the cleavage of a chlorido-bridged palladium ferrocenylthiosemicarbazone intermediate (2) using various P-donor ligands. These compounds were screened for antiplasmodial activity against chloroquine-sensitive (NF54) and chloroquine-resistant (Dd2) Plasmodium falciparum strains, exhibiting biological activity in the low micromolar range. The compounds generally display well-resolved electrochemically reversible one-electron transfer processes for the ferrocenyl group. The half-wave potential for the Fe(II)/Fe(III) couple is electronically influenced by the type of P-donor group through the palladium(II) centre.