Simultaneous Enhancement of Near-Infrared Emission and Dye Photodegradation in a Racemic Aspartic Acid Compound via Metal-Ion Modification

Changing functionalities of materials using simple methods is an active area of research, as it is "green" and lowers the developing cost of new products for the enterprises. A new small molecule racemic N , N -dimethyl aspartic acid has been prepared. Its structure is determined by single-crystal X-ray diffraction. It is characterized by FTIR, XPS, 1 H NMR, and mass spectroscopy. Its near-infrared luminescence can be enhanced by the combination of metal ions, including Dy 3+ , Gd 3+ , Nd 3+ , Er 3+ , Sr 3+ , Y 3+ , Zn 2+ , Zr 4+ , Ho 3+ , Yb 3+ , La 3+ , Pr 6+ /Pr 3+ , and Sm 3+ ions. An optical chemistry mechanism upon interaction between the sensitizer and activator is proposed. Furthermore, the association of Ca 2+ , Sr 2+ , or Zr 4+ ions to the molecule enhanced its photodegradation for dyes under white-light irradiation. Specifically, rhodamine 6G can be degraded by the Ca 2+ -modified molecule; rhodamine B, rhodamine 6G, and fluorescein sodium salt can be degraded by the Sr 2+ - or Zr 4+ -modified molecule. This surprising development opens a way in simultaneously increasing NIR luminescence and the ability of dye photodegradation for the investigated molecule.