Understanding the orientation of small organic acid modifiers on metal oxide electrodes is important in advancing the field of organic photovoltaics (OPVs). In this work, the orientation of a group of these small organic acid modifiers will be investigated on indium zinc oxide (IZO). Polarization modulation-infrared reflectance-absorbance spectroscopy (PM-IRRAS) is the primary technique used to determine these orientations. In order to determine orientations from PM-IRRAS data, other chemical and physical properties of the modifiers, such as density and surface coverage, must be experimentally determined. Neutral buoyancy is used to determine the density of the modifiers, while X-ray photoelectron spectroscopy (XPS) is used to estimate surface coverage of these modifiers on IZO. These techniques are also used to determine binding mode of these modifiers on IZO. The tilt angles (θ) were found to be 50 ± 3°, 64 ± 2°, and 43 ± 3° for F₅BnPA, F₅BnCA, and F₅BnHA, respectively, meaning that the phenyl ring in F₅BnHA is more perpendicular to the surface while the phenyl ring in F₅BnCA more parallel to the surface. All three modifiers were also found to bind to IZO in a bidentate manner. In contrast, F₅BnSA etches away significant portions of the IZO substrate.

Comprendre les interactions réalisées entre un candidat médicament et sa protéine cible est un enjeu crucial pour orienter la recherche de nouvelles molécules. En effet, ce processus implique de nombreux paramètres qu’il est nécessaire d’analyser séparément pour mieux comprendre leurs effets.Nous proposons ici deux nouvelles approches observant les relations protéine/ligand. La première se concentre sur la comparaison de cavités formées par les sites de liaison pouvant accueillir une molécule. Cette méthode permet d’inférer la fonction d’une protéine mais surtout de prédire « l’accessibilité » d’un site de liaison pour un médicament. La seconde tactique se focalise sur la comparaison des interactions non-covalentes réalisées entre la protéine et le ligand afin d’améliorer la sélection de molécules potentiellement actives lors de criblages virtuels, et de rechercher de nouveaux fragments moléculaires, structuralement différents mais partageant le même mode d’interaction. / Understanding the interactions between a drug and its target protein is crucial in order to guide drug discovery. Indeed, this process involves many parameters that need to be analyzed separately to better understand their effects.We propose two new approaches to observe protein/ligand relationships. The first focuses on the comparison of cavities formed by binding sites that can accommodate a small molecule. This method allows to infer the function of a protein but also to predict the accessibility of a binding site for a drug. The second method focuses on the comparison of non-covalent interactions made between the protein and the ligand to improve the selection of potentially active molecules in virtual screening, and to find new molecular fragments, structurally different but sharing the same mode of interaction.