Light‐Controlled Destruction and Assembly: Switching between Two Differently Composed Cage‐Type Complexes

We report on two regioisomeric, diazocine ligands 1 and 2 that can both be photoswitched between the E‐ and Z‐configurations with violet and green light. The self‐assembly of the four species (1‐Z, 1‐E, 2‐Z, 2‐E) with Co(II) ions was investigated upon changing the coordination vectors as a function of the ligand configuration (E vs Z) and regioisomer (1 vs 2). With 1‐Z, Co(2)(1‐Z)(3) was self‐assembled, while a mixture of ill‐defined species (oligomers) was observed with 2‐Z. Upon photoswitching with 385 nm to the E configurations, the opposite was observed with 1‐E forming oligomers and 2‐E forming Co(2)(2‐E)(3). Light‐controlled dis/assembly was demonstrated in a ligand competition experiment with sub‐stoichiometric amounts of Co(II) ions; alternating irradiation with violet and green light resulted in the reversible transformation between Co(2)(1‐Z)(3) and Co(2)(2‐E)(3) over multiple cycles without significant fatigue by photoswitching.