14:15-14:40: Sanna Stenfors
Title: Rigid medium-sized rings: applications and synthesis
Abstract: The literature review section of this master's thesis discusses the applications and synthesis of medium-sized rings. The synthesis of medium-sized rings is very challenging in organic chemistry: smaller rings are formed faster than medium-sized rings and macrocycles with larger ring sizes are thermodynamically more stable. Despite the difficulties associated with synthesis, medium-sized rings are very interesting structural units in the design of pharmaceuticals. This feature has increased interest in the development of synthesis methods. In addition, medium-sized rings, such as 9-membered rings, are found in several natural products. An example is the sesquiterpene caryophyllene, which was synthesized for the first time in 1963. The development of synthetic methods for medium-sized rings continues today. In current research, humilisin E, a macrocycle containing a 9-membered ring is a target of total synthesis in the research group of Petri Pihko.
The literature review focuses on the structures of medium-sized ring-structured compounds, the most common synthesis strategies, their occurrence in nature, and utilization in medicinal chemistry. In the experimental part of the thesis, a functionalized starting material for medium-sized ring synthesis was prepared using a photochemical isomerization reaction as the key step. The carbon backbone of the starting material was synthesized by alkylation and Weinreb ketone synthesis. The photochemical isomerization was successful, but the reaction was not completely stereoselective, and a functionalized trisubstituted Z-alkene was obtained as the major product.
Supervisors: Aino Rolig, Pradip MondaI, Petri Pihko
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14:40-15:05: Emmi Pirttijärvi
Title: Study of the surface chemistry of activated carbon through the Boehm titration and spectroscopic methods
Abstract:
Activated carbon is an effective adsorbent for the removal of a wide range of organic and inorganic contaminants from aqueous and gaseous substances. The global demand for activated carbon has increased in line with the emergence of new applications, including the treatment of drinking water, the utilization of energy storage technology and the development of environmental technology for example in controlling the emissions of power plants.
The adsorption efficiency is influenced by a combination of factors, including the materials exceptionally high surface area (500-1 500 m² g⁻¹), well-developed intrinsic microporosity, and a wide range of surface functional groups and their broad spectrum. It is crucial to gain an understanding of the factors that influence the adsorption of activated carbons. With this knowledge, the physical and chemical properties of activated carbon can be further tailored. The affinity of activated carbon for metals, inorganic and organic substances can be improved.
This thesis focused on the surface chemistry of activated carbon and the study of surface functional groups. The research was carried out at the request of Neova. A significant part of the work involved the introduction and development of analytical methods in relation to surface chemistry. In particular, these studies provided an insight into Neova Carbons activated carbons and by utilizing this knowledge, the development of activated carbons can be optimized.
Supervisors: Jarmo Louhelainen JYU and Hannu Lamberg Neova Oy
