Synthesis, characterization, and DNA-binding studies of ruthenium complexes [Ru(tpy)(ptn)]2Â + and Ru(dmtpy)(ptn)]2Â +

► Synthesis of two new Ru(II) complexes [Ru(tpy)(ptn)]2+ and Ru(dmtpy)(ptn)]2+. ► Two Ru(II) complexes bind to DNA in an intercalative mode. ► Two complexes induce B-Z transition in CT-DNA at low ionic strength (0.05 M NaCl). ► The induced Z-DNA conformation keeps intact from 25 to 90 °C.