We report on a new compound composed of a phenanthroline network in which emerging channels are alternately occupied by selenous acid (H2SeO3) and dioxane molecules. The material undergoes a variety of structural changes due to both its redox activity as well as its thermal decomposition. We investigate an internal redox system of the incorporated selenous acid and the aldehyde groups of the phenanthroline framework. The reduction process of the selenium species was further elucidated by cyclic voltammetry, while the oxidation process was also monitored by 1H NMR spectra. The thermal behavior reveals that the material can undergo a reversible, topotactic transition due to dioxane and water (de)intercalation.