SYNTHESIS AND CHARACTERIZATION OF CHIRAL LUMINESCENT COORDINATION COMPOUNDS EXHIBITING A WHITE CIRCULARY POLARIZED LUMINESCENCE

Work package:
Chiral luminophores can emit light with a different intensity in the left and right circular polarization components. This property, called circularly polarized luminescence (CPL), is particularly interesting for applications in telecommunications, information storage or even to fight against counterfeiting. Luminophores involve organic, inorganic or hybrid as is the case with coordination networks.1,2 The compounds that we develop are of that latter type and are obtained in solvothermal conditions through association of chiral imidazolium ligands (noted as HL*), of oxalic acid and lanthanides ions. These synthesis conditions allow the formation of [Ln2(L*)2(ox)2(H2O)2] networks ions exhibiting at room temperature a green luminescence when Ln = Tb3+or a red luminescence when Ln = Eu3+. A yellow luminescence is observable when Tb3+ and Eu3+ are mixed at different ratio (see figure). The objective of this internship will be to achieve a material that emits a white light with large CPL activity. This will be obtained by adjusting the composition and ratio in lanthanides ions. The student in charge of this project will perform the synthesis and the characterization of these materials. This first part will be carried out at LCC. In a second part, the optical properties of these compounds will be studied. This part will be carried out at LPCNO and will include both the study of their luminescence properties and their CPL activities. This project aims at establishing a correlation between the optical properties, especially the CPL activity, and the chemical characteristics of the coordination compounds.