Optical Spectra of Phenazine, 5,10-Dihydrophenazine, and the Phenazhydrins

The optical properties of phenazine, 5,10-dihydrophenazine, 1: 1 phenazhydrin, and 3: 1 phenazhydrin have been investigated, and ir, uv, and diffuse reflectance spectra are reported. The ir data indicate that the structures of the phenazhydrins resemble those of the parent compounds. The uv spectrum of 5,10-dihydrophenazine has a Λmax at 350 nm, which is not in agreement with a previously reported value of 325 nm. Absorption spectra of the reduced phenazine were also obtained via diffuse reflectance and a subtraction technique. Absorption in the visible region which is not present in the solution spectra is observed in the diffuse reflectance spectra of the phenazhydrins. The optical spectra of the four related compounds are collectively presented and discussed.