Prof. Dr. Klaus Köhler

Prof. Dr. Klaus Köhler

Associate Professorship of Inorganic Chemistry

Which research topics are you focused on in your working group?

The research group is mainly concerned with surface chemistry and heterogeneous catalysis, but also works on molecular topics, for example how catalysts, mainly solid catalysts, are produced and how metal complexes or organometallic compounds can be attached to such surfaces and thereby immobilized. All this is in line of sight to an application in heterogeneous catalysis.

How is the schedule and content of a research internship designed at your working group?

We have no preference for when the research internships should take place. If I receive enquires, I pass them onto the staff and they then check when the time is available. But it is often easier to contact the doctoral students directly. Then you come the laboratory and get explained what it would be about. The schedule is of course, like everywhere else, set at four weeks in the lecture-free period, etc. The practical work, which is normal for the AC, is primarily preparative. Characterization methods are of course also part of this, especially of transition metal compounds, complexes or organometallic compounds, but mostly in relation to surfaces. But it is also possible that we are only trying to synthesize certain precursors.

Which synthetical methods are used for the respective topics?

It depends a lot on the system. It can be a pure solid-state synthesis, which is the classic way of producing catalysts. But if, for example, you work on the immobilization of organometallic compounds, then there are even more demanding inert preparations than with other metal organics.
But of course, these are also techniques that, at least those who have completed the synthesis practical course, are familiar with. We also work with Schlenk technology or in the glovebox. Perhaps a special feature that arises due to the surfaces is that we often do this in combination with high temperatures and vacuum. But the precursor is a classic complex. And it is also not always so easy to create a defined structure of a compound on a surface and then simply characterize it because everything that is traditionally known in terms of characterization methods no longer works. You cannot hand in the NMR tube, you have to do solid-state NMR. The elemental analysis becomes critical, depending on how much you have on the surface. You always have the dilution, I say 90% SiO2 or carbon and what interests you is only the smallest area.
So it’s classic inorganic chemistry with some specific applications.

Is a progress/final talk about the research internship planned?

We do it sometimes, but not always. This is not a requirement, but we would be happy to do it if necessary. But it is more the candidates‘ wish than pressure or coercion. It has to be noted, that the student has to do the lab work, then present the work in a final talk, write the report and a short communication, as well as create a poster. Therefore, it is almost a bit exaggerated.

With which working groups are overlapping topics possible?

We have cross-chair projects, but mainly with chairs from other areas. For example, we work together with our colleague Prof. Heiz on several such projects.
In technical chemistry, we are more intensively involved with Prof. Hinrichsen. This is often useful, for example, for certain measurements that we would never or could never make here. In such cases, it is usually clarified beforehand that interesting things are being investigated in which the physical-chemists say that the preparation effort is too great for them, but they would like to see, for example, what a chiral surface looks like and would do the CD-spectroscopy.

How and in what way can one apply for a research internship at your working group?

There is not a directive or regulation, simply because it is straightforward. Of course, you can always express your interest, but it is not always possible to plan so precisely too long in advance. But it makes sense to ask and if it doesn’t work out right away, you can come back again. I don’t think we have ever rejected anyone before, only when the schedule didn’t work out at all. There is always a phase in which we supervise several bachelor theses with chemical engineers. Then it is always difficult to supervise someone else at the same time because it we are not a chair, but a small working group.

What kind of previous knowledge is required for a research internship at your working group?

For the understanding of the connections in catalysis, it helps of course if you would choose catalysis as a minor subject, but this is by no means a requirement because it is simply more about preparation and less about catalysis. But catalysis usually plays a role. Nevertheless, this is more of a courtesy to the students, because one is usually happy, when you understand what the whole thing is used for. The most important thing is the synthetic practical course, but in principle, everyone has done that. Everything else you learn during the internship.
I mean it makes sense for you as a student to try out as many different directions as possible before deciding on a master’s thesis or doctorate.

Can a research intership be expanded to a master’s thesis?

This is not usual, which contradicts a bit what I just said. Of course, you can say that with the last research internship I found exactly what I would enjoy. Then, of course, you can expand it to you master’s thesis, but it is usually difficult to link them directly.
But such more or less accidental, almost flowing transitions have already existed.

How much cake does your chair expect?

It doesn’t expect one at all. I know that it has become common. As long as I have been here, it has been like this, mostly on your last labor day or at the beginning or some other time. Whenever it fits, at some point, any cake is welcome that you can then cut as small as you like. We are a small group, a small cake is enough.

Is it an advantage of small working groups, that there is more cake for everyone?

(laughs) Yes, but there are other advantages. You are a little bit more integrated into the life of the group, you might see the boss more often than in a large group. Of course, you don’t always have so many alternatives, there’s almost always someone looking for someone else at a large chair.