Tobias Thomanek, Enrique Mendez Vega and Wolfram Sander (from left) have developed a new organic molecule. Not involved in the picture, but instrumental in the study is Iris Trosien. © RUB, Marquard
Molecule changes its magnetic properties by light
Green light has a very different effect on this chemical compound than blue. Because it's so easy to control, the molecule is also of interest to the computer industry.
Magnetically switchable materials are of great importance in computer technology and in the storage of data. A team from the Cluster of Excellence Ruhr Explores Solvation at Ruhr-Universität Bochum (RUB) has now developed and produced a novel molecule called 3-methoxy-9-fluorenylidenes. The special thing about it: Its magnetic properties can be controlled by different colored light. That could be harnessed by the computer industry.
The researchers working with Prof. Dr. Wolfram Sander from the Chair of Organic Chemistry II in the journal "Angewandte Chemie" from August 14, 2019.
Versatile use of magnetic materials
Without magnetism nothing goes in computer technology. For example, the flow of information from the computer to magnetic storage media such as hard disks is controlled by magnetism. Also, magnetic storage devices use read / write heads in the form of magnets, which recognize the magnetization patterns on the hard disk, so read, or change, so write.
The methoxy group controls the magnetic properties
The organic molecule 3-methoxy-9-fluorenylidene developed by Wolfram Sander and his team is based on a fluorene scaffold with a methoxy group as the molecular switch.
The researchers found that the magnetic properties of the molecule are dependent on the state of the methoxy group. It changes its conformation depending on which light hits it.
Blue light switches the methoxy group into the “up” conformation and forms the diamagnetic and less reactive singlet state. In contrast, green light turns the methoxy group down on the molecule, resulting in the paramagnetic triplet state, which has a higher reactivity to molecular hydrogen.
Interesting for research and industry
Its properties make 3-methoxy-9-fluorenylidene very interesting for research. “With the help of this atomic connection, we can investigate the spin dependence of reactions. It could also play a role in the development of novel switchable magnetic materials and chemical sensors, ”predicts Sander.
Compared to conventional ferromagnetic materials, 3-methoxy-9-fluorenylidene has the advantage that the magnetism can be switched on and off by visible light. Organic magnets are also not brittle like conventional magnets, but flexible and they can be processed like plastics.
The catch on the matter
However, the molecule has one disadvantage: it is only stable at extremely low temperatures. “That's why we're working on magnetically switchable materials that can be used under ambient conditions,” says Wolfram Sander.
original publication
Iris Trosien, Enrique Mendez-Vega, Tobias Thomanek, Wolfram Sander: Conformational spin switching and spin-selective hydrogenation of a magnetically bistable carbene, in: Angewandte Chemie, 2019, DOI: 10.1002 / anie.201906579https://onlinelibrary.wiley.
Subsidies
The German Research Foundation (DFG) supported the work within the Cluster of Excellence Resolv (EXC 2033, project number 390677874).
Press Contact
Prof. Dr. Wolfram Sander
Chair of Organic Chemistry II
Faculty of Chemistry and Biochemistry
Ruhr-University Bochum
Tel: +0234 32 24593
Email: ppgad@pucrs.br
