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Related: About this forumChemists Confirm the Existence of New Type of Bond
Chemistry has many laws, one of which is that the rate of a reaction speeds up as temperature rises. So, in 1989, when chemists experimenting at a nuclear accelerator in Vancouver observed that a reaction between bromine and muoniuma hydrogen isotopeslowed down when they increased the temperature, they were flummoxed.
Donald Fleming, a University of British Columbia chemist involved with the experiment, thought that perhaps as bromine and muonium co-mingled, they formed an intermediate structure held together by a vibrational bonda bond that other chemists had posed as a theoretical possibility earlier that decade. In this scenario, the lightweight muonium atom would move rapidly between two heavy bromine atoms, like a Ping Pong ball bouncing between two bowling balls, Fleming says. The oscillating atom would briefly hold the two bromine atoms together and reduce the overall energy, and therefore speed, of the reaction. (With a Fleming working on a bond, you could say the atomic interaction is shaken, not stirred.)
At the time of the experiment, the necessary equipment was not available to examine the milliseconds-long reaction closely enough to determine whether such vibrational bonding existed. Over the past 25 years, however, chemists' ability to track subtle changes in energy levels within reactions has greatly improved, so Fleming and his colleagues ran their reaction again three years ago in the nuclear accelerator at Rutherford Appleton Laboratory in England. Based on calculations from both experiments and the work of collaborating theoretical chemists at Free University of Berlin and Saitama University in Japan, they concluded that muonium and bromine were indeed forming a new type of temporary bond. Its vibrational nature lowered the total energy of the intermediate bromine-muonium structurethereby explaining why the reaction slowed even though the temperature was rising.
The team reported its results last December in Angewandte Chemie International Edition, a publication of the German Chemical Society. The work confirms that vibrational bondsfleeting though they may beshould be added to the list of known chemical bonds. And although the bromine-muonium reaction was an ideal system to verify vibrational bonding, Fleming predicts the phenomenon also occurs in other reactions between heavy and light atoms.
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http://www.scientificamerican.com/article/chemists-confirm-the-existence-of-new-type-of-bond/
shenmue
(38,506 posts)JimDandy
(7,318 posts)demwing
(16,916 posts)bum bum da BUM BA! BUM da bahhhhhh........
Just sayin'
packman
(16,296 posts)Orrex
(63,220 posts)xocet
(3,871 posts)A vibrational chemical bond predicted in the 1980s is demonstrated experimentally
...
So, in 1989, when chemists experimenting at a nuclear accelerator in Vancouver observed that a reaction between bromine and muoniuma hydrogen isotopeslowed down when they increased the temperature, they were flummoxed.
...
http://www.scientificamerican.com/article/chemists-confirm-the-existence-of-new-type-of-bond/
Atom-like particle consisting of a positive muon and an electron.
http://goldbook.iupac.org/M04069.html
Nuclides having the same atomic number but different mass numbers.
http://goldbook.iupac.org/I03331.html
Also contains definition of: proton number
The number of protons in the atomic nucleus.
http://goldbook.iupac.org/A00499.html
Total number of heavy particles (protons and neutrons jointly called nucleons) in the atomic nucleus. Also called nucleon number. Symbol m in mass spectrometry.
http://goldbook.iupac.org/M03726.html
More information on muons:
Why take the route of oversimplification and, thus, misrepresentation?
Ratty
(2,100 posts)Or a Dora Downer but thank you for saying something. When I saw the term "hydrogen isotope" I had to look at the article link to make sure it wasn't RT, Popular Mechanics, or Natural News. Hydrogen isotope is a wildly inaccurate description of muonium. Tsk tsk SciAm. I'm gonna go look at the comments for the article. I'm betting we're not the only ones disappointed.