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Lecture

Molecular Topology: Catenanes and Rotaxanes

In course

CH-424: Supramolecular chemistry

The course provides an introduction to supramolecular chemistry. In addition, current trends are discussed using recent publications in this area. ...

Description

This lecture explores the world of molecular topology, focusing on the design and synthesis of interlocked molecules such as catenanes and rotaxanes. Starting with the definition and formation of catenanes, it delves into the transition from tetrahedral to octahedral templates for their synthesis. The formation and characterization of metallacatenanes are discussed, along with paraquat-based systems and cyclodextrin-based catenanes. The lecture then moves on to strategies for the synthesis of rotaxanes, including early approaches and examples like paraquat-based and cucurbituril-based rotaxanes. Knots, trefoil knots, Borromean rings, and DNA-based Borromean rings are also covered, highlighting their structural and symbolic significance.

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Instructor

Kay Severin

Kay Severin was born in Germany in 1967. He obtained his Ph.D. in 1995 with a thesis in the group of Prof. W. Beck, University of Munich. Subsequently, he joined the group of Prof. M. R. Ghadiri as a postdoctoral fellow. In 1997, he started independent research projects ("Habilitation") at the Department of Chemistry, University of Munich. In 2001, he became assistant professor at the Institute of Chemical Sciences and Engineering at the Swiss Federal Institute of Technology, Lausanne (EPFL). Since 2009, he is full professor at the same institute. Awards: Bayerischer Habilitations Förderpreis (1997), ADUC award of the year (2001), Heinz Maier-Leibnitz award of the DFG (2001), award of the Karl-Ziegler foundation (2001), Arnold Sommerfeld award of the Bavarian Academy of Science (2001), Werner Prize of The Swiss Chemical Society (2003), Otto Roelen Medal of the DECHEMA (2005), award for chemistry of the Academy of Sciences, Göttingen (2007), Dalton Transactions European Lectureship (2008).

Official source

Ontological neighbourhood

Chemical engineering

Nanotechnology: Topics in nanotechnology

Related concepts (32)

Mechanically interlocked molecular architectures

In chemistry, mechanically interlocked molecular architectures (MIMAs) are molecules that are connected as a consequence of their topology. This connection of molecules is analogous to keys on a keychain loop. The keys are not directly connected to the keychain loop but they cannot be separated without breaking the loop. On the molecular level, the interlocked molecules cannot be separated without the breaking of the covalent bonds that comprise the conjoined molecules; this is referred to as a mechanical bond.

Molecular knot

In chemistry, a molecular knot is a mechanically interlocked molecular architecture that is analogous to a macroscopic knot. Naturally-forming molecular knots are found in organic molecules like DNA, RNA, and proteins. It is not certain that naturally occurring knots are evolutionarily advantageous to nucleic acids or proteins, though knotting is thought to play a role in the structure, stability, and function of knotted biological molecules.

Supramolecular chemistry

Supramolecular chemistry refers to the branch of chemistry concerning chemical systems composed of a discrete number of molecules. The strength of the forces responsible for spatial organization of the system range from weak intermolecular forces, electrostatic charge, or hydrogen bonding to strong covalent bonding, provided that the electronic coupling strength remains small relative to the energy parameters of the component.

Rotaxane

A rotaxane () is a mechanically interlocked molecular architecture consisting of a dumbbell-shaped molecule which is threaded through a macrocycle (see graphical representation). The two components of a rotaxane are kinetically trapped since the ends of the dumbbell (often called stoppers) are larger than the internal diameter of the ring and prevent dissociation (unthreading) of the components since this would require significant distortion of the covalent bonds.

Molecular machine

Molecular machines are a class of molecules typically described as an assembly of a discrete number of molecular components intended to produce mechanical movements in response to specific stimuli, mimicking macromolecular devices such as switches and motors. Naturally occurring or biological molecular machines are responsible for vital living processes such as DNA replication and ATP synthesis. Kinesins and ribosomes are examples of molecular machines, and they often take the form of multi-protein complexes.

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