ERC FUNDED PROJECTS

Most of the developments in catalyst are still based on serendipitous and trial-and-error approaches, in which potential systems can be overlooked simply because of the sub-optimal conditions of the initial activity assessment. Mechanistic and kinetic studies could provide a framework for a more adequate assessment of new catalysts, but such rigorous experiments are not practical for general catalyst discovery. Modern chemical theory and computations hold a promise to be employed in new efficient theory-guided approaches for rational catalyst and process development. The main aim of DeLiCat is to formulate a hierarchical computational strategy for the design and synthesis of new non-critical metal-based catalysts for sustainable chemical transformations. New, durable and cheap, yet, highly active and selective tailor-made catalyst for hydrogenation of carboxylic acids and their esters as well as for acceptorless dehydrogenation of alcohols will be developed. The research will follow an innovative strategy combining advanced chemical theory, computational screening and experimental approaches from the fields of homogeneous and heterogeneous catalysis in an efficient knowledge exchange loop. Computer simulations will reveal complex reaction networks that determine the “death” and the “life” of catalyst systems. These insights will be used in targeted design of novel multifunctional catalyst systems to direct the selectivity of the reaction network and to prevent deactivation paths. Complementary experimental studies will guide and validate the theoretical predictions. DeLiCAT represents a leap forward in unified first principles-guided catalyst design for liquid phase chemical transformations. The new theoretical concepts, methodological advances as well as the novel superior catalyst systems developed here will be applicable in various areas including biomass valorization, homogeneous and heterogeneous catalysis as well as hydrogen technology.

1 999 524 €

Start date: 2017-05-01, End date: 2022-04-30

This proposal aims to understand and control glycosylation reactions. In a glycosylation reaction a “donor” glycoside and an “acceptor” (the nucleophile) are united to form an oligosaccharide. Although it is the central reaction in carbohydrate chemistry, our understanding of this reaction, in terms of stereoselectivity and productivity is still limited. The structural variation in the building blocks leads to a complex continuum of SN2-SN1 mechanisms that operates and it is currently impossible to predict where in the continuum the reaction exactly takes place. This proposal provides fundamental insight into the outcome of glycosylations by studying both the activated donor glycoside and the acceptor nucleophile. Activation of a donor glycoside leads to different reactive intermediates, covalent anomeric species (most often triflates) and oxocarbenium ion-like species. The relative reactivity of these species is quantified to generate novel reactivity charts. The covalent species are studied by innovative competition experiments, kinetic studies and NMR spectroscopy. The (fleeting) oxocarbenium ion-like intermediates are probed by a computational approach and by “super-acid NMR” studies in which stable glycosyl cations are generated and studied in super-acid media. The reactivity of glycosyl acceptors is systematically studied in a set of SN2 or SN1-type glycosylations. Using kinetic studies and competition reactions charts of acceptor nucleophilicity are compiled. The reactivity of the donors and acceptors is matched using a family of tailor made “reactivity modulators”, spanning a broad reactivity window bridging the reactivity gap between the building blocks leading to predictable glycosylations. The developed methodology is employed in automated solid phase syntheses of libraries of oligosaccharides featuring multiple cis-glycosidic linkages. The proposal is a major step forward in the development of a general glycosylation procedure.

2 000 000 €

Start date: 2017-05-01, End date: 2022-04-30

This proposal is concerned with the mathematical theory of inverse problems. This is a vibrant research field at the intersection of pure and applied mathematics, drawing techniques from PDE, geometry, and harmonic analysis as well as generating new research questions inspired by applications. Prominent questions include the Calderón problem related to electrical imaging, the Gel'fand problem related to seismic imaging, and geometric inverse problems such as inversion of the geodesic X-ray transform. Recently, exciting new connections between these different topics have begun to emerge in the work of the PI and others, such as: - The explicit appearance of the geodesic X-ray transform in the Calderón problem. - An unexpected connection between the Calderón and Gel’fand problems involving control theory. - Pseudo-linearization as a potential unifying principle for reducing nonlinear problems to linear ones. - The introduction of microlocal normal forms in inverse problems for PDE. These examples strongly suggest that there is a larger picture behind various different inverse problems, which remains to be fully revealed. This project will explore the possibility of a unified theory for several inverse boundary problems. Particular objectives include: 1. The use of normal forms and pseudo-linearization as a unified point of view, including reductions to questions in integral geometry and control theory. 2. The solution of integral geometry problems, including the analysis of convex foliations, invertibility of ray transforms, and a systematic Carleman estimate approach to uniqueness results. 3. A theory of inverse problems for nonlocal models based on control theory arguments. Such a unified theory could have remarkable consequences even in other fields of mathematics, including controllability methods in transport theory, a solution of the boundary rigidity problem in geometry, or a general pseudo-linearization approach for solving nonlinear operator equations.

920 880 €

Start date: 2018-05-01, End date: 2023-04-30

About half of the elements heavier than iron have been produced via the rapid neutron capture process, the r process. Its astrophysical site has been one of the biggest outstanding questions in physics. Neutrino-driven winds from proto-neutron stars created in core-collapse supernovae were long considered as the most favourable site for the r process. Recently, neutron-star mergers have become the most promising candidates, and new exciting observations from these compact objects, such as gravitational waves, are expected in the coming years. In order to constrain the astrophysical site for the r process, nuclear binding energies (i.e. masses) of exotic neutron-rich nuclei are needed because they determine the path for the process and therefore have a direct effect on the final isotopic abundances. In this project, high-precision mass measurements will be performed in three regions relevant for the r process, employing novel production and measurement techniques at the IGISOL facility in JYFL-ACCLAB. Long-living isomeric states, which also play a role in the r process, will be resolved from the ground states to obtain accurate mass values. Post-trap decay spectroscopy will be performed to confirm which state has been measured in order to avoid systematic uncertainties in the mass values. The new data will be compared with theoretical mass models and included in r-process calculations performed for various astrophysical sites. MAIDEN will advance our knowledge of nuclear structure far from stability and reduce nuclear data uncertainties in the r-process calculations, which can potentially constrain the astrophysical site for the r process and lead to a scientific breakthrough in our understanding of the origin of elements heavier than iron in the universe.

1 999 575 €

Start date: 2018-06-01, End date: 2023-05-31