The investigation of a photochemical behavior of imino derivatives of cymantrene reveals a possibility of formation of four-membered hemilabile chelate complexes. In the presence of external ligands, such as CO, MeCN, or PPh3, the ligand exchange between imino groups at the Mn atom in dicarbolyl chelates and the external ligand is observed. It is shown that MeCN or PPh3 can be substituted for CO under dark conditions, resulting in intermolecular photochromic systems between tricarbonyl complexes and dicarbonyl derivatives with MeCN and PPh3 ligand, respectively.
