Thesis (M.Sc. (Organic Chemistry))--Mahidol University, 1978. / Supported by the University Development Commission.

La performance des dispositifs moléculaires, tels que les cellules solaires ou des diodes électroluminescentes, peut être optimisée en contrôlant l’organisation des composantes des couches actives. Les fullerènes et leurs dérivés sont souvant utilisés dans des dispositifs photovoltaïques pour leurs propriétés électro-acceptrices et conductrices. Il est donc important de concevoir des structures moléculaires pouvant interagir avec les unités fullerène et ainsi de diriger leur organisation. Le caractère électro-accepteur et la forme convexe des fullerènes favorisent le choix d’un partenaire de surface complémentaire : électro-donneuse et concave. Le phosphangulène, une triarylphosphine hexacyclique qui répond à ces critères et est aisément fonctionnalisable, a été choisi comme structure de base pour la synthèse des cibles. La présente thèse décrit la synthèse et la structure des dérivés du phosphangulène et des cocristaux obtenus avec les fullerènes au travers de quatre articles soumis au courant de ce doctorat. Le premier article décrit la synthèse des dérivés chalcogénures du phosphangulène. Ces dérivés-ci présentent de nombreux polymorphes, résultant en de bons candidats pour la cocristallisation. Le second article se concentre sur les cocristaux de ces dérivés chalcogénures avec le C60 et le C70. Dans le troisième article, nous décrivons les complexes obtenus par la coordination du phosphangulène sur des métaux de transition. Enfin, dans le quatrième article, nous parlons des sels du µ-nitrido-bis(phosphangulène), un cation organique où deux unités phosphangulène sont pontées par un atome d’azote, ainsi que des cocristaux résultant de la combinaison de ce ligand pontant et du C60. / The performance of molecular devices such as solar cells or light-emitting diodes can be optimized by controlling how the active-layer components are organized. Fullerenes and their derivatives are often used in photovoltaic devices for their electron-accepting and conductive properties. It is therefore important to design molecular structures that can interact with fullerene units and thus direct their organization. The electron-accepting character and convex shape of fullerenes favor the choice of a partner with a complementary surface that is electron-donating and concave. Phosphangulene, a hexacyclic triarylphosphine that meets these criteria and is easily functionalizable, was chosen as the basic structure for synthesizing targets. This thesis describes the synthesis and structure of phosphangulene derivatives and their cocrystals obtained with fullerenes through four articles submitted during this doctorate. The first article describes the synthesis of chalcogenide derivatives of phosphangulene. These derivatives have many polymorphs, resulting in good candidates for cocrystallization. The second article focuses on cocrystals of these chalcogenide derivatives with C60 and C70. In the third article, we describe the complexes obtained by the coordination of phosphangulene with transition metals. Finally, in the fourth article, we talk about the salts of μ-nitrido-bis (phosphangulene), an organic cation where two phosphangulene units are bridged by a nitrogen atom, as well as the crystals resulting from the combination of this bridging ligand and C60.

The influence of seven additives on the crystallization ability of polylactide (PLA), melt flow index (MVR) and mechanical tensile properties was studied. Pressed plates with a thickness of 0.8 mm were tested. Selected additives added in amounts of 0.5 and 1.0% were as follows: talc, sodium benzoate, mixtures of organic salts with amorphous SiO2 and zinc stearate, metal salt, phosphate salt, and potassium salt of 5-dimethylsulfoisophthalate (LAK-301 - nucleating agent developed for PLA). Non-isothermal crystallization measurements were performed at different cooling rates (0.3; 0.5; 0.7; 1.0 and 1.5 ° C). All nucleation agents increased the MVR of PLA except talc; the largest increase (9-fold and 24-fold) was the addition of metal salt. The additives did not fundamentally change the mechanical properties. All samples were rather brittle (the most brittle with LAK-301), the modulus of elasticity was around 1.2 GPa for all samples, the strength of PLA was increased the most by the addition of 1% talc (by 12%) and the elongation at break was increased by organic salt with SiO2. All samples with nucleating agents content of 1% were amorphous (crystalline content did not exceed 2%). Thus, the addition of reagents did not support the crystallization process during rapid cooling, even in the case of LAK-301. However, LAK-301 was acting as an excellent nucleating agent at slow cooling rates (1.5 °C / min and below). The nucleation activity of the additives decreased in the following order: LAK-301, organic salt with zinc stearate, talc, organic salt modified with amorphous SiO2 and phosphate salt. Samples with sodium benzoate and metal salt were crystallizing on cooling in several steps and it was not possible to use the method of Dobrev and Gutzow to evaluate the nucleation activity.