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

Abstract

Abstract 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.