25-Jun-2020 - Albert-Ludwigs-Universität Freiburg

Breaking the limit

Researchers introduce new transition metal carbonyl complexes relevant to textbooks and applications

Since the end of the 19th century, transition metal carbonyls have been an important and familiar class of compound in coordination chemistry and organometallic chemistry. In these materials, carbon monoxide molecules (CO) are bound to transition metals as the central atom. In this subject area, the team of Prof. Dr. Ingo Krossing and Wiebke Unkrig of the Institute of Inorganic and Analytical Chemistry at the University of Freiburg has succeeded in synthesizing brand-new transition metal carbonyl complexes – Ta2(CO)12 and M(CO)7+, where the metal atoms M are Niobium (Nb) and Tantalum (Ta). In many aspects, these substances go beyond current compound limits. As a result, they transcend new chemical frontiers that are relevant for practical use as well as basic science.

They have synthesized the dinuclear compound Ta2(CO)12 – which is considered the first new, neutral carbonyl complex to be synthesized in the 21st century. What is more, they managed to “bottle” positively charged carbonyl complexes with seven CO ligands by combination with a weakly-coordinating anion as a stable substance. No matter which of the thirty known transition metals were used, until now, complex compounds with more than six CO molecules were not accessible in  substance. Evidence for such molecules was observed only in the gas phase.

The bonding modes of these types of complexes is not fully explained. Many of the compounds in the new, positively-charged class of substances are as yet unknown. For many years, Krossing and Unkrig’s working group has been investigating weakly-coordinating anions that allow them to approximate the conditions of the gaseous state. They now aim to synthesize such prototypical, positively-charged molecules as “bottleable” substances in condensed form, in order to investigate them using a variety of methods. The researchers would then be able to demonstrate that these substances can play a role in applied chemistry in addition to serving as examples in textbooks.

Facts, background information, dossiers
  • transition metal complexes
  • carbonyl complexes
  • transition metals
More about Uni Freiburg
  • News

    Funding for renewable energy startups in Germany and East Africa

    Challenges like climate change and dwindling natural resources require permanent, global innovations. However, to be able to make the greatest impact, these solutions must also be adjusted for local conditions. That is why the University of Freiburg and the Solar Energy Foundation (Stiftung ... more

    From Biopaste to Bioplastic

    A viscous biopaste that is easy to process, solidifies quickly and is suitable for producing even complex structures using the 3D printing process has been developed by a research team headed by Prof. Dr. Marie-Pierre Laborie from the Chair of Forest Biomaterials at the University of Freibu ... more

    Innocent and highly oxidizing

    Chemical oxidation, the selective removal of electrons from a substrate, represents one of the most important transformations in chemistry. However, most common oxidants often show disadvantages such as undesired side reactions. The chemist Marcel Schorpp and colleagues from the group of Pr ... more