Luminescence switching upon thermally-induced solid-state amorphous-to-crystalline phase transition in gold(I)-thiophenolate coordination polymer
Résumé
Polynuclear hybrid Au(I) compounds exhibit a very large domain of applications such as electronic devices, contrast agents, sensors or photocatalysts. All these applications are related to the ability of gold(I) to form aurophilic interactions which give luminescent materials.[1] Among hybrid gold species, gold(I) thiolate compounds are an important class of materials due to the high affinity of gold for sulfur atoms that can generate molecular complexes, extended polymers, stabilized gold nanoparticles or self-assembled monolayers. So to explain the luminescence of gold thiolate coordination polymers, we will present the syntheses and the first structure resolutions, by powder X-Ray diffraction, of gold(I)-thiophenolate, [Au(SPh)]n, compounds. It has been synthetized either by employing hydrothermal conditions at 120 °C or by a two-step synthesis which is a thermally-induced solid-state amorphous-to crystalline isomerization. The crystalline compound forms double interpenetrated helical chains stabilized through C-H? and aurophilic bonds. This cristalline solid is phosphorescent at room temperature and in the solid-state with a quantum yield of around 5 % but the amorphous one is not. [2]
[1] H. Schmidbaur, A. Schier, Chem. Soc. Rev., 2012 (41) 370.
[2] C. Lavenn, L. Okhrimenko, N. Guillou, M. Monge, G. Ledoux, C. Dujardin, R. Chiriac, A. Fateeva, A. Demessence, J. Mater. Chem. C, 2015 (3) 4115.