A zirconium atom can switch easily between two different bonding patterns in an unusual molecule created by Japanese scientists.
The molecule’s odd behavior is the first example of this particular type of chemical bonding shift, according to Noriyuki Suzuki of RIKEN's Advanced Science Institute in Wako, and his colleagues at Saitama University and Saitama Institute of Technology. “These complexes have very unique structures and show interesting movement,” says Suzuki.
The team discovered the phenomenon when they were experimenting with a molecule (hexapentaene) made from a chain of six carbon atoms, all doubly bonded to each other. The chain is surrounded by a long cloud of delocalized electrons, which can bond with a zirconium-based compound to create a new complex.
Once the new complex has formed, the zirconium atom normally tends to bridge between carbon atoms in different parts of the chain, creating a five-membered ring. But when very bulky groups were added to each end of the chain, the zirconium switches its allegiance so that it sticks to just the central carbon–carbon double bond.
The complex could be toggled between its two bonding modes by adding or removing other chemical groups such as phosphines around the zirconium atom. Further experiments showed that this sort of shift was the first step in a reaction the scientists had previously studied, where adding an isocyanide chemical to the zirconium complex created a compound with a small ring of four carbon atoms at its heart.
This switching behavior is well known in certain ring-shaped organic molecules, but is much rarer in these molecular chains, and is unprecedented with this particular compound. “It suggests the possibility of a molecular motion like scissors or tongs,” says Suzuki. The research is published in the Journal of the American Chemical Society (1).
Suzuki’s team has spent several years investigating a range of such zirconium complexes, which were long assumed to be too unstable to isolate2,3.
Although there are no immediate applications for this family of complexes, Suzuki suggests that it may be possible to use the scissoring action identified in their latest research to capture another molecule or ion. “We might be able to achieve a molecular machine that catches a certain target,” says Suzuki.
1. Suzuki, N., Hashizume, D., Yoshida, H., Tezuka, M., Ida, K., Nagashima, S. & Chihara, T. Reversible haptotropic shift in zirconocene–hexapentaene complexes. Journal of the American Chemical Society 131, 2050-2051(2009) .
2. Suzuki, N., Nishiura, M. & Wakatsuki, Y. Isolation and structural characterization of 1-zirconacyclopent-3-yne, five-membered cyclic alkynes. Science 295, 660–663 (2002).
3. Suzuki, N., Hashizume, D., Koshino, H. & Chihara, T. Transformation of a 1-zirconacyclopent-3-yne, a five-membered cycloalkyne, into a 1-zirconacyclopent-3-ene and formal “1-zirconacyclopenta-2,3-dienes”. Angewandte Chemie International Edition 47, 5198–5202 (2008).
The corresponding author for this highlight is based at the RIKEN Chemical Analysis Team
Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
26.04.2017 | Materials Sciences
26.04.2017 | Agricultural and Forestry Science
26.04.2017 | Physics and Astronomy