Template syntheses of diverse haloargentates with reversible photochromism behaviors and efficient photocatalytic properties

By virtue of the template synthesis strategy, a series of haloargentates [Me-hmta][AgI₂]·H₂O (1), [Me-hmta][Ag₂I₃] (2) and [Me-hmta][Ag₂Br₃] (3) (hmta = hexamethylenetetramine), have been successfully prepared. Compounds 1–3 feature diverse infinite chains with in situ methylated Me-hmta cations serving as the templates and structure-directing agents. The syntheses, crystal structures and characterizations have been investigated for the compounds. Interestingly, compounds 1 and 2 exhibit the reversible photo-induced chromic behaviors. The solid samples can be colored with light illumination and further decolored in the presence of heat. Moreover, photocatalysis tests have been performed on 2 and 3, which display that the compounds can be considered as promising photocatalysts with high efficiency toward the degradation of organic dye pollutants.