Tunable Luminescent Heterometallic Zn₂Ln₂ Edge-Defective Molecular Cubane with Stimuli-Responsive Properties

Abstract

Heterometallic Zn 2 Ln 2 [Ln = Gd ( 1 ), Eu ( 2 ), Tb ( 3 ), Dy ( 4 )] discrete molecules with edge-defective cubane structure are assembled from a multifunctional fluorescent conjugate ligand and Ln III /Zn II mixed-metal ions; they exhibit the tunable luminescence, including ligand-based yellow-green light emission for 1 and 4 and lanthanide-center emission for 2 and 3 . The multiple stimuli-responsive photoluminescences were investigated to show a two-step thermal-responsive luminescence increase in the intensity upon cooling and piezochromic luminescence.