Structural and photophysical studies of lamellar M(I)-thiophenolate coordination polymers (M = Au, Ag, Cu)
Résumé
Metal thiolate compounds represent a large family of materials including nanoparticles, self-assembled monolayers and oligomeric/polymeric species showing diverse properties and applications. Among them [M(I)(SR)]n coordination polymers have been studied for a long time, for example hybrid Au(I) compounds have been used as anti arthritic drugs; Ag(I) compounds are known for their antibacterial properties[1] and Cu(I) compounds were recently shown to be good electrical conductors.[2] Moreover, these materials present great interest due to their ability to form metalophilic interactions which often imply luminescence.[3] However, despite interesting properties and potential applications, little is known about their structures. Indeed, the high affinity of M(I) for sulfur atoms implies a high reactivity between thiols and metal precursors and the formation of insoluble products.
Metal thiolate phases, when the metal is Cu, Ag and Au, described in the literature can be classified according to the dimensionality of the -M(I)-S- motive into 0D, 1D and 2D-structures. The lamellar compounds are well-known, but only three structures are reported: [Au(pSPhCO2CH3)]n, [Ag(othiopyridine)]n, [Cu(pSPhOH)]n. The structure of [Au(pSPhCO2CH3)]n has been recently solved by powder X-Ray diffraction and exhibits an ultra-bright luminescence with a quantum yield over 70 % at room temperature in solid state.[4] From this result, we extended this study to other lamellar M(I)-thiophenolate coordination polymers. We will present the syntheses and structure resolutions by powder and single crystal X-Ray diffraction of series of 5 new M(I)-thiophenolate-based compounds [M(I)(pSPhCO2X)]n (M = Au, Ag, Cu and X = H and CH3). We will show how the presence of weak interactions can impact the structure and photophysical properties. In addition, some of these compounds show thermochromism with intrinsic dual emission. So, we will discuss their high potential as optical ratiometric thermometers exhibiting some of the best sensitivity parameters exceeding the performances of the lanthanide-based hybrid coordination polymers.
References:
[1] B. O. Leung, F. Jalilehvand, V. Mah, M. Parvez, Q. Wu, Inorg. Chem. 2013, 52, 4593-4602.
[2] H. Yan, J. N. Hohman, F. H. Li, C. Jia, D. Solis-Ibarra, B. Wu, J. E. P. Dahl, R. M. K. Carlson, B. A. Tkachenko, A. A. Fokin, Nature materials, 2016.
[3] H. Schmidbaur, A. Schier, Chem. Soc. Rev., 2012, 41, 370-412.
[4] C. Lavenn, N. Guillou, M. Monge, D. Podbevšek, G. Ledoux, A. Fateeva, A. Demessence, Chem. Commun., 2016, 52, 9063-9066.