Deoxyribonucleic acid binding and photocleavage studies of rhenium(I) dipyridophenazine complexes

The intercalative binding interaction of [Re(dppz)(CO)₃(py)][O₃SCF₃] (dppz = dipyrido[3,2-a:2′,3′-c]phenazine, py = pyridine) and [Re(dppn)(CO)₃(py)][O₃SCF₃] (dppn = benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine) with double-stranded calf thymus DNA, and synthetic oligonucleotides poly(dA)·poly(dT) and poly(dC)·poly(dG) has been studied with spectroscopic methods. The complexes have been found to promote cleavage of plasmid pBR322 DNA from the supercoiled form I to the open circular form II upon irradiation. The crystal structure of [Re(dppz)(CO)₃(py)][O₃SCF₃] has also been established.