Synthesis, structure and biological activity of diphenyltin complexes based on O,N,O-tridentate ligands

Abstract Three new diphenyltin complexes, {[p-t-Bu-C6H4(O)C=N-N=C(Me)COO](MeOH)Ph2Sn}2 (C1), {[p-MeO-C6H4(O)C=N-N=C(Me)COO](MeOH)Ph2Sn}2 (C2) and {[C4H3O(O)C=N-N=C(Me)COO]Ph2Sn}n (C3), were synthesized by the reactions of diphenyltin dichloride with the corresponding hydrazones. All the complexes were characterized by IR; 1H, 13C, and 119Sn NMR spectroscopy; HRMS; elemental analysis; single-crystal X-ray diffraction and TGA. To test their in vitro antitumour activities, the complexes were evaluated by an MTT assay, and that C3 exhibited better antitumour activity than C1 or C2. The interaction between C3 and DNA was studied by UV-visible absorption spectroscopy and fluorescence spectroscopy. The complex intercalated into DNA, which is consistent with the results of molecular docking.