A Dynamic Heterometal-Organic Rhomboid Exhibiting Thermochromic and Piezochromic Luminescence

Heterometallic grids or rhomboids, in which two or more different metal ions are periodically segregated throughout a lattice, can give rise to emergent synergistic multifunctionalities but are typically static in nature because of strong metal-ligand binding. Here, a heterobimetallic C₂-symmetric rhomboid, [Zn₂Dy₂] (1), was self-assembled from a naphthol-containing asymmetric ligand and 3d/4f mixed-metal ions. We show that a heavy structural twist of bridge ligands around the heterometallic centers can induce a translation ("stretch-elastic phase" behavior) related to the shape of the metallorhomboid and facilitates a luminescence response to external stimuli, such as temperature, mechanical pressure, etc.