title: Induction of Circularly Polarized Luminescence from Europium by Amino Acid Based Ionic Liquids.
abstract: Materials that emit circularly polarized light have application in several important industries. Because they show large optical activity and emit sharp visible light transitions, europium complexes are often exploited in applications that require circularly polarized luminescence (CPL). Chiral and coordinating ionic liquids based on prolinate, valinate, and aspartate anions are used to induce CPL from a simple achiral europium triflate salt. The sign of the induced CPL is dependent on the handedness (l vs d) of the amino acid anion. Comparison of the CPL spectra in ionic liquid with proline and valine vs aspartate shows that the number of carboxylate groups in the amino acid anion influences the europium coordination environment. DFT calculations predict a chiral eight-coordinate Eu(Pro)4-structure in the prolinate ionic liquid and a chiral seven- or eight-coordinate Eu(Asp)33-structure in the aspartate ionic liquid.
authors: Department of Chemistry, Butler University , 4600 Sunset Avenue, Indianapolis, Indiana 46208, United States.
authors: Ben
authors: B
authors: Zercher
authors: Department of Chemistry, Butler University , 4600 Sunset Avenue, Indianapolis, Indiana 46208, United States.
authors: Todd A
authors: TA
authors: Hopkins
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001224:Aspartic Acid / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry; D005063:Europium / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D008698:Mesylates / Q000737:chemistry*; D008958:Models, Molecular; D011392:Proline / Q000737:chemistry; D014633:Valine / Q000737:chemistry
chemical_list: D000596:Amino Acids; D056831:Coordination Complexes; D052578:Ionic Liquids; D049408:Luminescent Agents; D008698:Mesylates; D001224:Aspartic Acid; D005063:Europium; D011392:Proline; D014633:Valine