We have used DFT to determine the photophysical properties and thermal stabilities of four bis-diazoarene photoswitches. We predict that the thermal half-lives of the isomeric Z-isomers range from hours to years. The (3,3)-substituted isomers (2 and 4) have cross-conjugated πsystems, significantly affecting the photophysical and thermal properties. This truncated πconjugation leads to large optical gaps, thus requiring UV light for photoswitching (300 nm for 2-E and 314 nm for 4-E). Those with fully π-conjugated systems (1-E and 3-E) contain relatively small optical gaps, which enable visible light photoswitching (376 nm and 391 nm, respectively). The extent of π-conjugation strongly influences the transition structures and thermal half-lives of the Z-isomers. 1-Z and 3-Z have a small ΔG ‡ , which translates to a t1/2 of one hour. 2-TS and 4-TS are higher in energy due to the limited π-delocalization, and the t1/2 is in the range of 40-230 years.