DNA binding and biological activity of some platinum(ii) intercalating compounds containing methyl-substituted 1,10-phenanthrolinesElectronic supplementary information (ESI) available: Binding data determined for platinum complexes bound to calf thymus DNA, linear dicroism spectra, Absorption spectra of the DNA alone and of the platinum complexes with DNA and solubilities of complexes in water. See http://www.rsc.org/suppdata/dt/b3/b316511f/