Shining light on clay-chromophore hybrids: layered templates for accelerated ring closure photo-oxidation

Templates with specific microenvironments have been long employed to facilitate specialized reactions. From enzymes to metal organic frameworks (MOFs), various systems have exerted their prowess to affect specific chemical reactions. Here we report, for the first time, the acceleration of a ring closure photo-oxidation reaction due to the specific structural constraints provided by layered materials. A stilbene derivative has been used as a prototype reactant and the di-hydrophenanthrene intermediate has been isolated and characterized to the complete photo-oxidation. Combining the gathered evidence, a possible mechanism for the chemical transformation has been proposed. Kinetic analysis showed that layered materials help to manipulate the rate of the electrocyclic ring closure and, in turn, accelerate the complete reaction sequence. The structural microenvironment induced by layered materials could be a unique platform to probe and stabilize a plethora of photo-oxidative reactions and intermediates.