In his element

150 years periodic table

For laymen it is a huge collection of letters and numbers, for experts it is an important basis to foresee chemical reactions: the periodic table of elements. This year it is celebrating its 150th birthday. LANXESS employee, Hermann Sicius, is among the most renowned experts worldwide within this field.

Mr. Sicius, 150 years of the periodic table – how did this chart, which everyone knows from chemistry lessons, actually come into being?

Two researchers, the Russian Dmitri Mendeleev and the German Lothar Meyer, were working almost simultaneously on the model. Mendeleev was, however, quicker in publishing his results and is therefore considered the founder of the periodic table. The essential features of the system he developed 150 years ago are still applicable today. In his chart, he even left space for elements that had not yet been discovered during his lifetime or could not be generated with the technical measures available at the time. The periodic table can theoretically be indefinitely continued.

What features must an element fulfill for it to be added to the chart?

Most important criteria: The element’s representation method or its nuclide must be reproducible. There are few laboratories worldwide that specifically research the discovery of new elements – one of which is the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. There are others in Russia, USA, and Japan. In brief, in an accelerator facility, a “target” arising from atoms of a defined chemical element is “shot at” with nuclides of another element until nuclides of a new element arise through nuclear fusion. This experiment must be carried out using the same nuclides whilst maintaining the same conditions in another nuclear physics laboratory. If reproduction is a success, the element is deemed to be discovered.

And where do the partly extraordinary element names come from?

For several years now, it has been the general consensus that the laboratory that discovers the material is allowed to name it. Darmstadtium, for example, is named after the GSI site. Sometimes, elements are named after famous chemists – for example, meitnerium is named after the Austrian physicist Lise Meitner.

Which elements are of particular importance to LANXESS?

LANXESS has developed in the direction of synthesis chemistry; therefore, base chemicals are used less and less. We have just completed an inventory control and determined that of the current 118 elements, around 25 play an important role for LANXESS. For example, phosphorous is very important in the production of base materials for synthesis of plant protection products and flame retardants. Without iron, there would be no Bayferrox®, while chromium plays a large role in leather chemicals and even in the production of anorganic green pigmentation.

You have dealt with the periodic table in-depth for a great number of years. Have you got a favorite element?

I actually find all of them exciting! I have been creating my own collection of elements since 1974 – my passion reaches that far back. From a scientific point of view, I think lanthanides are very interesting. They can also be found under the name “rare earth metals” and play an ever greater role in current technical developments. Elements such as dysprosium and holmium have been attributed huge potential in the future in high-performance magnets – for example, in wind power systems. Other areas of application for rare earth metals are in smartphones and plasma screens.

You know the periodic table like the back of your hand – is this the same for all chemists?

No, probably not. A lot of passion can be attributed to learning the entire system by heart. Chemists generally know the properties of the elements with which they frequently work. In spite of my passion, the periodic table is only a component of chemistry. In order to really get enthusiastic about chemistry, you need to feel and see it – and that happens best through experimenting. This is, above all, an important approach for chemistry lessons in schools, in my opinion.

What does the anniversary year of the periodic table mean for you?

I am currently working on an amended new version and summary of my previous books to generate a large handbook. This entails a lot of research and collation of new research results. The date of publication is set for late fall. My free time is therefore currently well occupied!