Dicarbonyl chelates from 1-cymantrenylalkylamides with the dendrite structure: formation, photochromism, and kinetics of dark reaction with carbon monoxide

Abstract

Photolysis of carboxamides of the dendrite structure with aminomethyland 1-aminoethylcymantrenes leads to the formation of six-membered dicarbonyl chelates with the Mn—O bond which are stable in solutions. The chelates in the reversed dark reaction with carbon monoxide give the starting tricarbonyl complexes. The formation of the chelates and their dark reaction are accompanied by the reversible change of color by the compounds. The rate determining step of the thermal reaction of chelates with CO is a chelate ring opening with the ligand substitution by the SN1 mechanism. A possibility of solvent-free photoinduced ligand-exchange reaction in a number of cymantrene derivatives was demonstrated.