Achievement of ligand-field induced thermochromic luminescence via two-step single-crystal to single-crystal transformations.

We report here a new approach to achieve thermochromic luminescence through thermally induced ligand-field transformations. A one-dimensional chain manganese(ii) complex exhibits thermochromic luminescence from blue-green (502 nm) to red (617 nm) emission in a wide range of temperatures (480-80 K), ascribed to the conversion of a tetrahedronal to trigonal bipyramidal ligand-field via two-step single-crystal to single-crystal transformations.