The photochemical stability of the synthesized PHOTACs was then tested by rapidly switching them between the cis-and the trans-state and measuring the absorbance at 370 nm. All three PHOTACs showed no change in absorbance at both states over the course of 20 cycles ensuring the stability of the photoswitch (Figure ). Lastly the amount of cis-and trans-isomers at the photostationary states (PSSs) were measured photometrically. All three PHOTACs showed a photostationary state containing 63-80% of the cis-isomer after irradiation at 390 nm and could be switched back to >94% of trans-isomer following irradiation at 505 nm (Figure ).