A novel guanidine-containing polyoxotantalate with reversible thermochromism property

Abstract

A novel guanidine-containing polyoxotantalate (POTa), H12[CN3H6]12Na2(H2O)6[Cu(en)2(H2O)]3[Ta6O19]4·32H2O (1) has been synthesized by adding the CH6N3+ as counter cations. The [Ta6O19]8− clusters in compound 1 are connected by sodium ions to form a 2-D layered structure, which is further connected through [Cu(en)2(H2O)]2+ to form a 3-D supramolecular framework structure. Moreover, it is demonstrated that compound 1 exhibits reversible thermochromism behavior, changing from purple to dark blue upon heating and dehydration, which endows it with potential application in the field of anti-counterfeiting functional materials.