Chemistry in Progress

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Displaying theses 1-10 of 688 total
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L. Ram
Master programme: Chemistry - Analytical Sciences August 24th, 2018
Institute: HIMS Research group: Analytical Chemistry Graduation thesis Supervisor: Wim Kok
Theoretical model for flow modulated comprehensive two-dimensional gas chromatography
In this research a theoretical model has been developed for method development and optimization for reversed fill/flush modulation comprehensive two-dimensional gas chromatography (RFF-GC×GC). The theoretical model consists of a combination of equations for optimizing the instrumental parameters in RFF-GC×GC and optimization of columns and carrier gas flows to improve the GC×GC separation. The theoretical model needs column dimensions, carrier gas type and first-dimension column flow as input parameters and calculates all instrumental parameters, including dimensions of the collection channel and restriction capillary using resistance diagrams similar to Ohms law. It also calculates velocities and plate numbers in RFF-GC×GC separation using flow rate and plate height equations. The model described the configuration accurately enough to be a helpful tool in optimizing RFF-GC×GC analysis. With the newly developed model construction of the flow modulator is significantly simplified.
picture that illustrates the research done
Scientific abstract (pdf 2K)   Full text (pdf 1524K)

A.S. Abels
Master programme: Science for Energy and Sustainability - Physics / Chemistry August 22nd, 2018
Institute: Other Research group: none Graduation thesis Supervisor: prof. dr. Bas de Bruin
Heterobinuclear Organometallic Complexes: A Study of the Structure, Electronic Behaviour and Reactivity of New Low-Valent Compounds
Six new heterobimetallic Rh(I)Pt(II) complexes supported by a novel type of chelating tropPPh2 ligand were synthesised, characterised and tested in nitrous oxide activation. Heterobinuclear complex 13 proved to be the most efficient homogeneous catalyst for the hydrogenation of the greenhouse gas N2O up to date (TON = 430), producing benign water and nitrogen under mild reaction conditions. Ligand alteration at the rhodium centre led to fundamental insight into the nature of the bimetallic core: NMR and XRD studies revealed that cationic compounds contained a shorter metal-metal bond and stronger 103Rh-195Pt coupling in NMR, while neutral complexes demonstrated a longer intermetallic distance and weaker 1JRhPt coupling. Furthermore, a correlation between 195Pt satellites in 31P{1H} NMR and the intermetallic bond length was found. In these heterobimetallic systems, the platinum centre appeared to serve as a supporting ligand, donating electron density to the rhodium, which is suggested to be essential in the rhodium platinum bond.
picture that illustrates the research done
Scientific abstract (pdf 1K)   Full text (pdf 2930K)

R. Kools
Master programme: Chemistry - Molecular design, synthesis and catalysis August 15th, 2018
Institute: HIMS Research group: Industrial Sustainable Chemistry Literature thesis Supervisor: Prof. Gert-Jan Gruter
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CO2 sequestration and utilization in cement-based materials
To prevent human-induced climate change it is important to reduce the amount of CO2 that is emitted into the atmosphere. One way to reduce atmospheric carbon is by Carbon Capture and Utilization (CCU). When CO2 is used as a feedstock, the use of fossil feedstock (with associated emissions) is avoided. This report analyzes technologies that aim to convert CO2 into valuable cement-based building materials and assesses their potential of reducing atmospheric CO2. The analyses focus on the economic viability and the environmental impact of the methods. It is found that utilization of industrial wastes to produce cement-based construction materials could make a significant environmental and can be economically feasible.
picture that illustrates the research done
Scientific abstract (pdf 82K)   Full text (pdf 949K)

T.R. Roose
Master programme: Chemistry - Molecular design, synthesis and catalysis August 10th, 2018
Institute: VU / Chem. & Pharm.Sc. Research group: VU Synthetic and Bio-Organic Chemistry Literature thesis Supervisor: prof. dr. R.V.A. Orru
Base-Metal Catalysed and Mediated Isocyanide Insertions
Isocyanides have demonstrated to be versatile C1 building blocks and reagents in combinatorial chemistry, medicinal chemistry, multicomponent (MCR) chemistry and organic chemistry. The ambivalent character of isocyanides has made these reagents useful in the formation of various N-heterocycles. Until this day research is predominantly focussed on the use of isocyanides in MCR chemistry for the synthesis of nitrogen-containing compounds. However, a rather underdeveloped, but extremely useful transformation is the insertion of isocyanides into various metal-element bonds. Isocyanides are isoelectronic to carbon monoxide (CO) and show similar reactivity towards metal centres and especially towards palladium. Until this day the migratory insertion of isocyanides into Pd-C or Pd-heteroatom bonds is well established and has been applied in the synthesis of various nitrogen-containing heterocycles and fine-chemicals. However, palladium is scarce and it is desired to utilize the more abundant base metals, such as Ti, Ni, Cu, Fe and Co in order to access nitrogen enriched fine-chemicals and heterocyclic scaffolds. Currently, no comprehensive overview of the chemistry of isocyanide insertion reactions involving base metals has been published. In this literature study, the use of base metals in imidoylative transformations will be investigated and discussed.
picture that illustrates the research done
Scientific abstract (pdf 3K)   For more info or full text, mail to: r.v.a.orru@vu.nl

Y. Djaidoen
Bachelor programme: Scheikunde August 9th, 2018
Institute: HIMS Research group: Homogeneous Catalysis Graduation thesis Supervisor: dr. Tiddo J. Mooibroek
Towards artificial carbohydrate receptors
Carbohydrates are one of the most abundant molecules in nature and they have a major role in biological regulation, such as the recognition of cells. They are also known to be involved in certain malignant processes like diabetes, cancer and infections. Understanding these molecular processes and interfering in them could be exploited in biomedical research. To achieve this, detection, separation, isolation and synthesis of different carbohydrates is required. Currently, this is accomplished by expensive methods, using lectins, enzymes and classic organic synthesis. This thesis describes the synthesis towards a biomimetic artificial carbohydrate receptor.
picture that illustrates the research done
Scientific abstract (pdf 1K)   For more info or full text, mail to: tiddo.uva@gmail.com

B. Weijers
Bachelor programme: Scheikunde August 2nd, 2018
Institute: VU / Chem. & Pharm.Sc. Research group: VU Synthetic and Bio-Organic Chemistry Graduation thesis Supervisor: Eelco Ruijter
A Novel NIS-Mediated Spirocyclization of Tryptamine Derived Isocyanides Towards Spiroindolines
Within the field of organic chemistry, scientists are always looking for new and efficient ways to create important medicines. Examples of these are compounds which may cure patients with cancer, heart diseases and viral infections. Nature is often the main source of inspiration for the design of these new medicines. Based on a molecule found in nature, a derivative is synthesized which has a biological activity similar to its natural counterpart. Thorough testing of the new compound is then performed to check if the compound contains the desired biological activity. For this research, we have made a small number of new compounds based on the amino acid tryptophan’s side chain. These compounds can, after some modifications, be used a cure for patients with thrombosis. Using a new reaction, we have successfully converted a small number of tryptophan-derivatives with moderate yield. The reaction also produced an interesting functional group in the product, which may be used in further modifications. Ultimately, we hope that our new reaction will be used by other organic and biochemists in the synthesis of natural products and new medicines.
picture that illustrates the research done
Scientific abstract (pdf 1K)   For more info or full text, mail to: e.ruijter@vu.nl

L. Kooij
Bachelor programme: Scheikunde July 22nd, 2018
Institute: VU / Other Research group: Department of Environment and Health Graduation thesis Supervisor: dr. M. H. Lamoree
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WRISTBANDS AS PERSONAL PASSIVE SAMPLERS TO ASSESS THE EXPOSURE TO ORGANOPHOSPHORUS FLAME RETARDANTS AND PER- AND POLYFLUORINATED ALKYL SUBSTANCES
Chemical exposure is not avoidable anymore. Individuals are exposed during their daily routines because most chemicals used in products are also found in the environment. Some of them may be harmless others hazardous. Measurement of those chemicals found in the environment is often done with a passive sampling device (PSD), such as silicone. Monitoring for the chemicals humans are exposed to, silicone wristbands are applied as personal passive samplers. The wristband is cost friendlier, however, the outcome is different. The wristband provides a blueprint of exposure outside the human body, not the chemicals that entered the body. In this study, non-polar materials such interfered with obtaining clear extracts for later chemical analysis for the determination of organophosphorus flame retardants (OPFRs) and per- and polyfluorinated alkyl substances (PFASs). Once a wristband cleaning and extraction procedure were optimized, the wristbands could be worn by volunteers. The aim of this research is to determine human exposure to OPFRs and PFASs by wristband sampling. Analysis after a seven-day wear-period of showed peaks for all OPFRs and some PFASs, for all volunteers. It is to be expected that these results will create more public awareness.
picture that illustrates the research done
Scientific abstract (pdf 67K)   For more info or full text, mail to: marja.lamoree@vu.nl

Y.T.H. Tio
Bachelor programme: Scheikunde July 19th, 2018
Institute: HIMS Research group: Computational chemistry and physics Graduation thesis Supervisor: Dr. ir. Bernd Ensing
Water splitting on Ruthenium Oxide: A first principle Study
An arising challenge is the large-scale production of sustainable energy. To tackle this problem, excess energy produced during peak production time is used to split water into oxygen and a CO2-neutral fuel: hydrogen gas. This method is based on two half-reactions: the rate-determining oxygen evolution reaction (OER) that splits water via four successive Proton-Coupled Electron Transfers (PCET's), followed by hydrogen evolution reaction (HER). A new generation of OER-catalysts are metal-oxides of which RuO2 has proven experimentally to be the most active. However, recent research revealed that theoretical calculations predict lower activities of RuO2 than experimentally proven, additionally the scientific community has not reached a consensus on pinpointing the rate determining PCET and therefore the origin of the overpotential. By combining Ab Initio Molecular Dynamic simulations and the implementation of explicit solvation effects these issues were addressed. The results revealed surprising new insights and a deeper understanding of the OER-mechanism on RuO2.
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Scientific abstract (pdf 2K)   For more info or full text, mail to: b.ensing@uva.nl

D.P. Kooi
Master programme: Chemistry - Molecular Simulation and Photonics July 19th, 2018
Institute: VU / Chem. & Pharm.Sc. Research group: VU Division of Theoretical Chemistry Literature thesis Supervisor: Prof. P. Gori-Giorgi
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The exact functional in Natural Orbital Functional theory and the N-representability of the 2-body Reduced Density Matrix
In the development of new chemicals and materials a lot of experiments can be potentially be replaced by computer simulations. One of the methods that can be used is Natural Orbital Functional Theory. In this thesis we look at the formal properties of the so-called Reduced Density Matrices (RDMs) and the corresponding functional theories. In particular we look at constraints on these functionals.
picture that illustrates the research done
Scientific abstract (pdf 2K)   For more info or full text, mail to: p.gorigiorgi@vu.nl

D.P. Kooi
Master programme: Chemistry - Molecular Simulation and Photonics July 19th, 2018
Institute: VU / Chem. & Pharm.Sc. Research group: VU Division of Theoretical Chemistry Graduation thesis Supervisor: Prof. P. Gori-Giorgi
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Testing Local Interpolations along the Adiabatic Connection in Density Functional Theory
When developing new drugs and new materials a lot of experiments have to be done in the lab. It would be preferable to reduce the number of experiments that have to be done by utilizing simulations. One of the most important methods used for these simulations is Density Functional Theory (DFT). It provides a good balance between cost and accuracy, also for large systems. However, certain types of systems cannot be treated by DFT, especially ones in which so-called correlation effects are strong. In this thesis we test new ways to solve these problems.
picture that illustrates the research done
Scientific abstract (pdf 2K)   For more info or full text, mail to: p.gorigiorgi@vu.nl

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