Stable ion study of benzo[a]pyrene (BaP) derivatives: 7,8-dihydro-BaP, 9,10-dihydro-BaP and its 6-halo derivatives, 1- and 3-methoxy-9,10-dihydro- BaP-7(8H)-one, as well as the proximate carcinogen BaP 7,8-dihydrodiol and its dibenzoate, combined with a comparative DNA binding study of regioisomeric (1-, 4-, 2-) pyrenylcarbinolsElectronic supplementary information (ESI) available: Selected NMR spectra (Fig. S1 and Charts S1-S10) and DFT computed energies for carbocations (Table S1). See http://www.rsc.org/suppdata/ob/b2/b212412b/