Pancake bonding as a new tool to construct novel metal based magnetic materials

Date:
August 13, 2020
Source:
University of Jyva"skyla" - Jyva"skyla"n yliopisto
Summary:
New research has led to the discovery of a novel magnetic compound
in which two magnetic dysprosium metal ions are bridged by two
aromatic organic radicals forming a pancake bond. The results of
this study can be utilized to improve the magnetic properties of
similar compounds.



FULL STORY ==========================================================================
A Canadian-Finnish collaboration has led to the discovery of a novel
magnetic compound in which two magnetic dysprosium metal ions are bridged
by two aromatic organic radicals forming a pancake bond. The results of
this study can be utilized to improve the magnetic properties of similar compounds. The theoretical investigation of the study was carried out
by the Academy Research Fellow Jani O. Moilanen at the University
of Jyva"skyla", whereas the experimental work was performed at the
University of Ottawa in the groups of Profs. Muralee Murugesu and Jaclyn
L. Brusso. The research results were published in the well-recognized
chemistry journal -- Inorganic Chemistry Frontiers in July 2020 --
with the cover art.


========================================================================== Magnets are used in many modern electronic devices ranging from mobile
phones and computers to medical imaging devices. Besides the traditional metal-based magnets, one of the current research interests in the field
of magnetism has been the study of single-molecule magnets consisting of
metal ions and organic ligands. The magnetic properties of single-molecule magnets are purely molecular in origin, and it has been proposed that in
the future, single- molecule magnets could be utilized in high-density information storage, spin- based electronics (spintronics), and quantum computers.

Unfortunately, most of the currently known single-molecule magnets only
exhibit their magnetic properties at low temperatures near absolute zero (-273DEGC), which prevents their utilization in electronic devices. The
first single- molecule magnet that retained its magnetization over the
boiling point of liquid nitrogen (-196 DEGC) was reported in 2018. This
study was a considerable breakthrough in the field of magnetic materials
as it demonstrated that single- molecule magnets functioning at higher temperatures can be also realized.

Excellent magnetic properties of the reported compound at the elevated temperatures originated from the optimal three-dimensional structure
of the compound. In theory, similar design principles could be used
for single- molecule magnets containing more than one metal ion but
controlling the three- dimensional structure of multinuclear compounds
is much more challenging.

Bridging organic radicals were utilized in the novel compound Instead
of fully controlling the three-dimensional structure of the reported
compound, a different design strategy was utilized in this study.

"Like dysprosium ions, organic radicals also have unpaired electrons
that can interact with unpaired electrons of metal ions. Thus, organic
radicals can be used to control the magnetic properties of a system
along with metal ions.

Particularly interesting organic radicals are bridging ones as they can interact with multiple metal ions. We employed this design strategy in
our study, and surprisingly, we synthesized a compound where not only
one but two organic radicals bridged two dysprosium ions as well as
formed a pancake bond through their unpaired electrons," Prof. Muralee
Murugesu from the University of Ottawa clarifies.

"Even though the formation of the pancake bond between two radicals is
well known, this was the first time that the pancake bond was observed
between two metal ions. The interaction between organic radicals is often referred to as pancake bonding because the three-dimensional structure of interacting organic radicals resembles a stack of pancakes," Prof. Jaclyn
L. Brusso from the University of Ottawa tells.

The pancake bond in the novel compound was very strong. Therefore, the
unpaired electrons of the organic radicals did not interact strongly with
the unpaired electrons of the dysprosium ions and the compound functioned
as a single- molecule magnet only at low temperatures. However, the
study paves the way for the new design strategy for novel multinuclear single-molecule magnets and has initiated further research.

"Computational chemistry methods provided important insights into the electronic structure and magnetic properties of the compound that can
be utilized in future studies. By choosing the right kind of organic
radicals we can not only control the nature of the pancake bond between
the radicals but also enhance the magnetic properties of the compound
overall," Academy Research Fellow Jani O. Moilanen from the University
of Jyva"skyla" comments.


========================================================================== Story Source: Materials provided by University_of_Jyva"skyla"_-_Jyva"skyla"n_yliopisto. Note: Content may
be edited for style and length.


========================================================================== Journal Reference:
1. Maykon A. Lemes, Niki Mavragani, Paul Richardson, Yixin Zhang, Bulat
Gabidullin, Jaclyn L. Brusso, Jani O. Moilanen, Muralee Murugesu.

Unprecedented intramolecular pancake bonding in a {Dy2}
single-molecule magnet. Inorganic Chemistry Frontiers, 2020; 7
(14): 2592 DOI: 10.1039/ D0QI00365D ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200813144916.htm

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