Synthesis of cis-[Cr(diimine)2(1-methylimidazole)2](3+) Complexes and an Investigation of Their Interaction with Mononucleotides and Polynucleotides.

A protocol is presented for the synthesis of chromium(III) complexes of the type cis-[Cr(diimine)2(1-methylimidazole)2](3+). These compounds exhibit large excited-state oxidizing powers and strong luminescence in solution. Emission is quenched by added guanine, yielding rate constants that track the driving force for guanine oxidation. The cis-[Cr(TMP)(DPPZ)(1-MeImid)2](3+) species binds strongly to duplex DNA with a preference for AT base sites in the minor groove and may serve as a precursor for photoactivated DNA covalent adduct formation.