RT info:eu-repo/semantics/doctoralThesis
T1 Desarrollo de pinzas y máquinas moleculares con capacidad de establecer interacciones supramoleculares con fullerenos
A1 Sacristán Martín, Adriana
A2 Universidad de Valladolid. Escuela de Doctorado
K1 Química analítica
K1 Fullerenes
K1 Fullerenos
K1 Química
K1 23 Química
AB The doctoral thesis, built as a set of three article, focuses on the design, development and study of different molecular tweezers and molecular machines capable of establishing supramolecular interactions with fullerenes.Chapter 1 is divided in two different sections coinciding with the published Articles I and II and describes the development of several molecular machines capable of modulating their affinity for fullerenes by means of different external stimuli. First, a molecular machine, based on the 2,2'-bipyridine core functionalized at the 4 and 4' positions with the non-planar polyaromatic organic corannulene moiety is described. Its activity as a molecular receptor is modulated by copper (I) coordination/discoordination. The molecular machine was able establish supramolecular interactions with fullerenes when the coordination complex was formed and to cease its activity upon ligand release acting as an ON/OFF molecular machine. Second, two molecular machines with electrochemical-stimuli responsive properties were described. The first one bases its structure on the thiophenol functionalized in the para positions with the corannulene moiety. Its oxidation and consequent dimerization resulting in a disulfide bridge provided a molecular tweezer suitable for fullerene reception. Reduction of the disulfide bond and return to the corresponding thiols deactivated this functionality, thus obtaining a bistable ON/OFF molecular machine. The addition of a further restriction on the oxidized molecular tweezer (introducing a C-C bond between phenyl groups) provided further pre-organization in the host. This molecular machine showed modulated affinity for fullerenes, and, in addition, a dual behavior of the machine was observed depending on the aerobic or anaerobic environment. Under inert atmosphere the molecular machine showed two switchable and reversible states while in the presence of atmospheric oxygen the molecular machine oxidized spontaneously over the time from thiol to disulfide without additional external stimuli.Chapter 2 develops Article III and describes a large family of molecular tweezers derived from the fluorene core. The effect of varying the electronic nature of the bridgehead atom of the fluorene-like core on interactions with fullerenes has been studied. It was observed that the dibenzothiophene-derived tweezer showed extraordinary properties against the association of fullerenes establishing equilibria of 2:1 stoichiometry for C70. Finally, it was concluded that supramolecular interactions in polyaromatic compounds are dominated by dispersion forces and the electronic changes introduced to the corannulene moiety did not substantially affect the supramolecular interaction.
YR 2022
FD 2022
LK https://uvadoc.uva.es/handle/10324/59754
UL https://uvadoc.uva.es/handle/10324/59754
LA spa
NO Escuela de Doctorado
DS UVaDOC
RD 18-nov-2024