Theis Ivan Sølling
Department of Chemistry
Universitetsparken 5, 2100 København Ø
The ultimate time scale in chemistry is the femtosecond time scale. Chemical bonding cannot cannot change any faster than that. With a time resolution on the femtosecond time scale it is possible to obtain information on the first decissive moments in a chemical reaction. The femto lab at the department of chemistry is achieving that resoltion with a pulsed laser: a femtosecond laserpulse initiates a "change" and a subsequent pulse measures the structural and electronic impact of the light excitation.
My focus is on mechanistic and physical problems in organic chemistry and photo chemistry. Both from a very fundamental angle but also more recently applied in Oil and Gas related contexts.
We have recently found that the outcome of many photo induced processes are determined by structural changes that take place immediately after excitation, i.e., in less than a picosecond. It is the mechanisms that drive the molecular motions in these first determining moments that are key to photophysical processes and fundamental for the photostability of for instance DNA and proteins. There is a clear link between structure and mechanism – thus we are also focusing on the interplay between organic chromophores and how they direct nuclear motions. My lab here at CHEM is built around a femtosecond laser with experimental setups for time-resolved photoelectron spectroscopy and time-resolved mass spectrometry for gas phase measurements, and absorption spectroscopy for solution phenomena. All experiments are supported by quantum mechanical calculations.
The problems in applied research rely on collaboration with industry research partners. The main focus here is on the understanding of flow in porous media and on how methods in organic chemistry can modify it. The experimental approach is tomography and scanning electron microscopy with simulation on the resulting images
Bachelor and Master projects: In the femtolab, we are currently investigating the mechanisms of internal conversion and intersystem crossing in a wide variety of organic molecules, and we have several interesting projects with this focus. It seems that we are at a breakthrough of understanding why transition from triplet states to singlets can sometimes be ultrafast, although it is formally a spin-forbidden process. These projects involve a combination of laser lab work and time spent in front of the computer both working on data and performing calculations.
In the case of the applied oil and gas related projects there are no lab facilities at HCØ yet. In due course the plan is to build a confocal microscopy setup for studies of the composition of organic species that are captured inside rocks and this involves plenty of project work. Currently, projects evolve around derivation of flow parameters from tomograms and how these parameters are impacted by the organic surface chemistry. The aim is to understand and modify the surface coverage and improve flow.
The group has a wide variety of internation partners and the projects can be designed so that they involve research at organizations abroad.
Primary fields of research
Reaction Dynamics and ultrafast processes in organic molecules
Pore scale phenomena