The Simplistic
Beauty of a Free Radical
- Korean scientists
conduct experiments with highly reactive nitric oxide (NO) to form
N-heterocyclic carbine nitric oxide radicals (NHCNOs)
June 18 , 2015
By Neil Mannix
The study was conducted at the Center for Self-Assembly and Complexity
within the Institute for Basic Science (IBS) in South Korea. Director
Kimoon
Kim and his team experimented with nitric oxide, a highly stable
molecule of supreme importance in science. NO is highly reactive and a free
radical, meaning a single, unpaired electron is present in its molecule.
Put simply NO plays the role of a mediator between elements and helps
them combine. Radicals are regularly generated in many metabolic pathways. Some
of these radicals can exist in a free form and subsequently interact with
various tissue components resulting in dysfunction. The potential role of free
radicals in the pathology of several human
diseases has resulted in extensive research. However, because free
radical-mediated changes are pervasive and often poorly understood, the
question of whether free radicals are a major cause of tissue injury and human
disease remains unanswered
Only a few organic compounds have been utilized to react with NO to
form radical nitric oxide compounds and the development of such reactivity with
NO using N-heterocyclic carbenes (NHCs) has not been reported to date. NHCs are
not well known to react with or stabilize main group radicals and radical ions.
Main group radicals, along with nitrogen, include carbon and oxygen.
The Creation of NHCNOs
N-heterocyclic carbine nitric oxide radicals were prepared for the
first time by direct addition of nitric oxide to two readily available
N-heterocyclic carbenes in solution phase. The compounds, stable in air and in
water, were fully characterized using X-ray crystallography and by a technique
called EPR which is used to study
chemical species with unpaired electrons. A functioning group of molecules from
the solid molecules obtained can be thermally transferred to another NHC,
suggesting potential applications to NO delivery. A light orange solid was the result of the
experiment.
Although nitrous oxide was dominantly formed during chemical
decomposition of the experiment, nitric oxide was also found to be thermally
transferred to other N-heterocyclic carbenes. This suggests potential
biological applications for NO delivery. Furthermore, this study adds another
example of stable singlet carbenes acting as mimics for transition metal
centers
Notes for editors
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References
Junbeom Park, Hayoung Song, Youngsuk Kim, Bit
Eun, Yonghwi Kim, Dae Young Bae, Sungho Park, Young Min Rhee, Won Jong Kim,
Kimoon Kim, and Eunsung Lee, (2015), “N-Heterocyclic Carbene Nitric Oxide Radicals”, JACS, DOI:
10.1021/jacs.5b01976
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For further information or to request
media assistance, please contact: Mr. Shi Bo Shim, Head of Department of
Communications, Institute for Basic Science (+82-42-878-8189; sibo@ibs.re.kr)
or Ms. Sunny Kim, Department of Communications, Institute for Basic Science
(+82-42-878-8135; Sunnykim@ibs.re.kr)
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About the Institute for Basic Science
(IBS)
IBS was founded in 2011 by the government of the Republic of Korea with the
sole purpose of driving forward the development of basic science in Korea It
comprises a total of 50 research centers in all fields of basic science,
including mathematics, physics, chemistry, life science, earth science and interdisciplinary
science. IBS has
launched 24 research centers as of January 2015.There are eight physics, one
mathematics, six chemistry, seven life science, and two interdisciplinary
research centers.
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