Synthesis, structural characterisation and biological studies of new mononuclear platinum(II) complexes with sterically hindered heterocyclic ligands

Abstract Three novel cisplatin analogues were synthesized, designed according to an approach which violates the “classical” structure–activity relationship, by replacing the diamine ligands with a planar N donor heterocycle giving a sterically hindered complex. Moreover, the sterical hindrance of antitumor drug candidates potentially makes them less susceptible to deactivation by sulphur-containing proteins and helping to overcome resistance mechanisms. The resulting mononuclear complexes of sterically hindered polidentate heterocyclic N ligands [PtCl(bbp)]Cl ( 1 ) [bbp = 2,6-bis(2-benzimidazolyl)pyridine], [PtCl 2 (dptdn)](H 2 O) ( 2 ) [dptdn = sodium 5,6-diphenyl-3-(2′-pyridyl)-1,2,4-tria…