C1-symmetrical titanium(IV) complexes of salan ligands with differently substituted aromatic rings: enhanced cytotoxic activity

Diaminobis(phenolato) ("salan") titanium(IV) complexes of differently substituted aromatic rings were synthesized, and their hydrolytic stability and cytotoxicity were analyzed and compared to those of the C2-symmertrical analogues and their equimolar mixtures. The hydrolytic stability of the asymmetrical complexes was in between those of the symmetrical analogues, implying an additive influence of the ligand structural parameters. Most mixed halogenated/nitrated complexes showed a marked improvement of cytotoxic activity relative to the symmetrical analogues and their mixtures, with IC50 values as low as