Interaction of phenazine with water and DNA bases.

The fluorescence spectrum of aqueous phenazine (PZ), an N-heterocyclic compound, shows some interesting features that indicate the formation of PZ-water complex in the excited state. Two types of complexes are postulated; Type I, formed by the association of water molecule with one of the nitrogen of PZ and Type II, formed by the association of water molecules with both the nitrogen of PZ. In addition, PZ also interacts with the DNA bases, adenine and thymine and the corresponding nucleosides, adenosine and thymidine. Fluorescence and laser flash photolysis studies indicate that the mode of interaction may be photoinduced electron transfer.