Synthesis and Characterization of a Conjugated Metallopolymer Complexed with Terbium Ions.

Metallopolymers are hybrid structures in which metallic centers are linked to some of the repeating units, in order to obtain advantages from both parts: the properties from the metallic centers (optical, magnetic, electronic) and from the organic structure. Apart from the well-known mechanical features such as flexibility, easy processing and low cost of production other characteristics (electric conductivity, electrochromism, luminescence, high rate of carrier mobility), are added to the final material. In this line of pursuit, the synthesis of a metallopolymer was performed in two steps: first, the synthesis of the conjugated polymer poly[(9,9’-diexylfluorene-2,7-il)-alt-6,6”-(2,2’:6’,2”-terpyridine)] (LaPPS75) composed of fluorene (flu) and terpyridine (tpy) units, synthezised by Suzuki coupling, and in the second, the synthesis of the metallopolymer by in-situ reaction by adding to the polymer (LaPPS75), organic ligand acetylacetonate (acac) and terbium salt respecting the proportions 1:3:1, originating the LaPPS75Tb, (LaPPS75 complexed with Tb ions in the tpy sites). The structural and photophysical characterizations were performed 1H and 13C NMR, FTIR, UV-Vis and emission measurements in solution. The metallopolymer (LaPPS75Tb) showed photophysical behavior dependent on the chemical environment, in particular it was observed that the emission of the metal occurs only in DMSO solution. Curiously, all other solvents act as quenching agents in the emission of the metal, as shown in the Figure. With such characteristics this structure becomes potentially applicable in OLED’s devices, chemical sensor, photoconductors, electrocatalysts, etc.