Date/Time Date(s) - 29/05/20262:30 pm - 3:30 pm
Categories
Prof. Iwona Nierengarten
Université de Strasbourg et CNRS
Interlocked molecular ensembles such as rotaxanes and catenanes are fascinating systems in which large amplitude molecular motions are possible. Chemists became rapidly interested in controlling the conformation of such molecules and the pioneering work of Sauvage and Stoddart in this area gave rise to the field of molecular machines.[1] The possible applications of such systems in various fields including biology, nanotechnology or catalysis have been a strong driving force to further improve the synthetic strategies allowing to efficiently produce mechanically interlocked molecules. Their preparation remains often challenging as pre-organization of separate molecular units into a well-defined supramolecular structure is mandatory. For example, the most classical approach to prepare rotaxanes is based on the grafting of bulky stoppers onto a linear building block associated to a macrocyclic moiety in an inclusion complex. This strategy is efficient as long as the reaction conditions are compatible with the formation of the supramolecular complex. This requirement is however often problematic, in particular when weak intermolecular interactions are used to assemble the two components. This is for example the case when pillar[5]arene is used as the macrocyclic component for the preparation of rotaxanes.[2] The direct preparation of rotaxanes from pillar[5]arene-based inclusion complexes is highly dependent on the nature of the reagents even when similar reactions are used for their synthesis and yields are often quite moderate. To solve this problem, we have developed the preparation of pillar[5]arene-containing [2]rotaxane building blocks allowing their efficient post-modification by a stopper exchange reaction.[3] The latest advances in this particular field will be presented.
Iwona Nierengarten studied chemistry at the University of Wroclaw (Poland) and obtained her Ph.D. in coordination chemistry under the supervision of Krystyna Bukietynska (2005). She worked as a postdoctoral fellow with Anne-Marie Albrecht-Gary in Strasbourg (France) where she gained experience in physical organic chemistry for the characterization of supramolecular assemblies. She joined the group as a post-doctoral fellow in 2011 and obtained a permanent CNRS position in 2019. She worked on the synthesis of fullerene-based glycoclusters and on the preparation of luminescent copper(I) complexes. She also played a major role in the development of pillar[5]arene chemistry within the group. Her current research interests are concerned with supramolecular systems based on pillar[5]arene-containing rotaxanes for applications in materials science and biology. Other research interests include the chemistry of copper complexes and the development of molecular machines.
In-Person: ABB 102
Online: Echo360