Scission of DNA with Bis(1,10‐phenanthroline)copper without Intramolecular Hydrogen Migration

C-1′H and not C-2′H is the initial site of oxidative cleavage of DNA with the chemical nuclease [Cu(phen)2]+/H2O2. This is the result of experiments with DNA containing C-1′-deuterated thymidine groups (the first step of the reaction sequence is shown below). If C-2′H is extracted in the first step, a one-electron oxidation and H/D migration should take place; there is no evidence of this.