Engineering N-salicylidene aniline derivatives : from solid-state molecular switches to multifunctional organic-inorganic architectures
(2010)
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- Authors
- Supervisors
- Garcia, Yann
- Abstract
- (en) In a world involving large amounts of new technologies, the search for new molecular switches for the optimisation of information storage and display setups becomes very challenging. In this context, N-salicylidene aminopyridines have revealed a more complicated structure-properties relationship than the one previously reported because of the combination of structural (associated to the molecular packing) and electronic factors, induced by the molecular architecture itself. A study of the influence of the molecular flexibility has led to consider new conditions needed to observe thermo- and photochromism (with short or long lifetimes). This study was performed with fluorimetry (observation of new radiative relaxations) and supported by a computational approach in order to simulate the thermo- and photo-induced phenomena appearing in the solid state materials. A second step of rationalisation and control of involved parameters was then investigated by using a supramolecular engineering approach based on 1,10-phenanthroline, 1,2,4-triazole and tetrazole moieties. These molecules allowed studying the role of each type of supramolecular interactions in the crystal structure. It also gave access to novel phenomena such as a ‘spring type’ effect involving a photo-switchable material which resists to applied light-induced constraints. These organic molecules were also studied after incorporation as ligands in inorganic complexes. The impact of the coordination as well as the nature of complexes components on the optical behaviours (tuning of the intensity of the thermo- and the photochromism and of the fluorescence of materials) was demonstrated experimentally and supported by a theoretical approach. Moreover, the use of spin transition ions paves interesting way to the observation of thermo- and/or photo-induced magnetic phenomena. We were also able to follow a thermo-induced spin crossover by temperature dependent fluorimetry via the use of a ligand acting as a local probe. N-salicylidene aniline derivatives were also presented as excellent precursors for complex self-assemblies formation as demonstrated by the synthesis of magnetic and asymmetric nanogrids. Finally, N-salicylidene aminobenzenesulfonates were inserted as non coordinated anionic units in organic-inorganic hybrid materials. These molecules have shown a strong sensitivity to the molecular environment and the preservation of their chromic behaviours after insertion. This study paves the way to the synthesis of materials with magnetic properties tuned by the thermo- and/or the photo-sensitivity of the inserted anions.
- Affiliations
Citations
Robert, F. (2010). Engineering N-salicylidene aniline derivatives : from solid-state molecular switches to multifunctional organic-inorganic architectures. https://hdl.handle.net/2078.5/131220