Atmospherical oxidative coupling of amines by UiO-66-NH2 photocatalysis under milder reaction conditions

Abstract To assess the mechanism and milder conditions for amines to imines, UiO-66-NH 2 was chosen as an efficient photocatalyst for the transformation under light irradiation. A series of experiments for the catching of the active species were performed, and it was proved that holes (h + ) and superoxide radicals ( O 2 − ) were involved when the reaction was performed under air. The reaction also occurred because of the presence of nitrogen-centered radical cations and carbon-centered radicals, which were induced by photogenerated hole (h + ) with considerable conversion and selectivity under anaerobic conditions. Our experiments revealed that the catalyst can be recycled for four times.