Scientists get the first glimpse of a chemical reaction's transition state
17 replies, posted
[QUOTE]Scientists have used an X-ray laser at the Department of Energy's SLAC National Accelerator Laboratory to get the first glimpse of the transition state where two atoms begin to form a weak bond on the way to becoming a molecule.
This fundamental advance, reported Feb. 12 in Science Express and long thought impossible, will have a profound impact on the understanding of how chemical reactions take place and on efforts to design reactions that generate energy, create new products and fertilize crops more efficiently.
"This is the very core of all chemistry. It's what we consider a Holy Grail, because it controls chemical reactivity," said Anders Nilsson, a professor at the SLAC/Stanford SUNCAT Center for Interface Science and Catalysis and at Stockholm University who led the research. "But because so few molecules inhabit this transition state at any given moment, no one thought we'd ever be able to see it."
Bright, Fast Laser Pulses Achieve the Impossible
The experiments took place at SLAC's Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility. Its brilliant, strobe-like X-ray laser pulses are short enough to illuminate atoms and molecules and fast enough to watch [URL="http://phys.org/tags/chemical+reactions/"]chemical reactions[/URL] unfold in a way never possible before.
Researchers used LCLS to study the same reaction that neutralizes [URL="http://phys.org/tags/carbon+monoxide/"]carbon monoxide[/URL](CO) from car exhaust in a catalytic converter. The reaction takes place on the surface of a catalyst, which grabs CO and oxygen atoms and holds them next to each other so they pair up more easily to form carbon dioxide.[/QUOTE]
[url]http://phys.org/news/2015-02-scientists-glimpse-chemical-bond-born.html[/url]
Behold! Another advancement once thought impossible.
What will be the next discovery I wonder? I really do feel blessed to be alive in a time like this.
[QUOTE=shingda;47148507]Behold! Another advancement once thought impossible.
What will be the next discovery I wonder? I really do feel blessed to be alive in a time like this.[/QUOTE]
Irrefutably break the Uncertainty Principle. That would probably be [I]the[/I] big thing in terms of "Okay guys, now we have to rewrite physics again."
[quote]This fundamental advance, reported Feb. 12 in Science Express and long thought impossible, will have a profound impact on the understanding of how chemical reactions take place and on efforts to design reactions that generate energy, create new products [b]and fertilize crops more efficiently.[/b][/quote]
is it just me, or does that last part stick out in a really weird way?
Oh, neat. Stuff like this is a huge step towards more effective catalytic converters and mass produced synthetic fuels of all types. I imagine a mastery of this branch of science would let us synthesize pretty much anything we want on any scale we need our of whatever random junk we have laying around. The first steps towards matter recombination?
[QUOTE=Jamsponge;47148611]Irrefutably break the Uncertainty Principle. That would probably be [I]the[/I] big thing in terms of "Okay guys, now we have to rewrite physics again."[/QUOTE]
I'd say it'd be more "The celestial speed limit is full of shit" than breaking the Uncertainty Principle. The latter? Yeah it's pretty groundbreaking, but it doesn't really push us forward quite like being able to fly faster than light itself.
Who knows, maybe the former and the latter can't happen seperately. Only time will tell.
i'm not exactly sold on how this will improve anything, its just like when electron microscopes got good enough to distinguish atoms, confirming that atomic theory is 100% correct, didn't exactly harold any breakthroughs in fusion or catalysts, it just allowed us to see that the theoretical framework of chemistry was correct, and similar finds with super-acids and carbocations, benzene ring observations, and chemical bond observations haven't radically changed the field, just confirmed what the wide body of evidence sugested.
who knows though, maybe knowing the order which individual atoms activate will allow for better chemistry after all. lotta science articles today though
[QUOTE=Jamsponge;47148611]Irrefutably break the Uncertainty Principle. That would probably be [I]the[/I] big thing in terms of "Okay guys, now we have to rewrite physics again."[/QUOTE]
The uncertainty principle has been proven to be true many times, and is actually fundamental to the way our physics work. I don't think that you can violate it.
[QUOTE=Sableye;47149731]i'm not exactly sold on how this will improve anything, its just like when electron microscopes got good enough to distinguish atoms, confirming that atomic theory is 100% correct, didn't exactly harold any breakthroughs in fusion or catalysts, it just allowed us to see that the theoretical framework of chemistry was correct, and similar finds with super-acids and carbocations, benzene ring observations, and chemical bond observations haven't radically changed the field, just confirmed what the wide body of evidence sugested.
who knows though, maybe knowing the order which individual atoms activate will allow for better chemistry after all. lotta science articles today though[/QUOTE]
All the things you mentioned are all very important advances. Electron microscopy has allowed us to image structures that we couldn't before. Proving the existence of carbocations was instrumental in their acceptance in the scientific community. I'm not sure what you mean by benzene ring observations and chemical bond observations.
It's really quite important that we can characterise the transition state of a reaction directly. This technique also allows time-resolved observations of atomic positions along the reaction coordinate. That said, it's still an indirect observation process as they are measuring time-resolved X-ray absorption spectra, but I doubt we would ever get to image the transition state directly like you would with electron microscopy or X-ray diffraction.
[QUOTE=Headhumpy;47152288]All the things you mentioned are all very important advances. Electron microscopy has allowed us to image structures that we couldn't before. Proving the existence of carbocations was instrumental in their acceptance in the scientific community. I'm not sure what you mean by benzene ring observations and chemical bond observations.
It's really quite important that we can characterise the transition state of a reaction directly. This technique also allows time-resolved observations of atomic positions along the reaction coordinate. That said, it's still an indirect observation process as they are measuring time-resolved X-ray absorption spectra, but I doubt we would ever get to image the transition state directly like you would with electron microscopy or X-ray diffraction.[/QUOTE]
For the benzene ring, everyone knew that there was a compound C6H6, but no one could come up with a structure that made sense, until Kekule imagined a snake eating itself and proposed the ring structure without the continuous pi electron ring (1,3,5-cyclohex-tri-ene ). This structure has 2 difference C-C bond lengths, where as benzene's C-C bonds are all the same length. Kekule's structure also didn't correspond to the change in enthalpy when brominating the double bonds. I think it was only until someone did x-ray crystallography and some fancy ass calculations that they came up with a structure that matched the physical observations.
[QUOTE=Jamsponge;47148611]Irrefutably break the Uncertainty Principle. That would probably be [I]the[/I] big thing in terms of "Okay guys, now we have to rewrite physics again."[/QUOTE]
Not possible until we can develop an observation method that doesn't use energy.
Which itself would be impossible.
Huh, I was just learning about Michaelis-Menten equation in my Biochem class too. Really cool discovery. My professor was just saying in Office Hours a week ago that he doubt this would happen in our life times and he runs a biophysics lab.
[QUOTE=Jamsponge;47148611]Irrefutably break the Uncertainty Principle. That would probably be [I]the[/I] big thing in terms of "Okay guys, now we have to rewrite physics again."[/QUOTE]
The uncertainty principle is due to the Fourier transform, which is how wave equations are manipulated in quantum mechanics. It's a mathematical feature of how position and momentum wave equations are related, so unless we're entirely wrong about particles being representable as waves (unlikely), uncertainty is pretty impossible to disprove.
Is this the actual thing or just an illustration?
[t]http://cdn.phys.org/newman/gfx/news/hires/2015/scientistsge.jpg[/t]
[QUOTE=BFG9000;47153470]Not possible until we can develop an observation method that doesn't use energy.
Which itself would be impossible.[/QUOTE]
The uncertainty principle has nothing to do with measurement. You are thinking of the observer effect. The results of the uncertainty principle are inherent to all systems and do not change with observation technology.
[editline]17th February 2015[/editline]
[QUOTE=eirexe;47153675]Is this the actual thing or just an illustration?
[t]http://cdn.phys.org/newman/gfx/news/hires/2015/scientistsge.jpg[/t][/QUOTE]
Illustration. The caption is admittedly misleading.
[editline]17th February 2015[/editline]
The full paper presents the actual data, consisting of time-resolved X-ray absorption spectra, along with calculated free energy diagrams for the minimum energy pathway, the wavefunctions of the states associated with that potential, and calculated spectra of the various states. The paper also includes a pictorial interpretation of what is happening on the surface of the ruthenium catalyst, although nowhere near as dramatised as the illustration in the article.
It's reasons like this that science is based around [U]theories.[/U] Because something completely off the wall like this, can entirely re-write our laws of the universe
[QUOTE=Tmaxx;47155599]It's reasons like this that science is based around [U]theories.[/U] Because something completely off the wall like this, can entirely re-write our laws of the universe[/QUOTE]
I don't see how this is completely off the wall, we always knew there were transition states?
It'd be amazing if we could actually observe (even indirectly) transition states in solution, which is where most reactions occur, especially for organic chemistry. Right now we rely mainly on Hammond's postulate to make conjectures about the structure of the transition state. Even observing intermediates is a bit of a challenge sometimes.
[QUOTE=eirexe;47153675]Is this the actual thing or just an illustration?
[t]http://cdn.phys.org/newman/gfx/news/hires/2015/scientistsge.jpg[/t][/QUOTE]
[media]http://www.youtube.com/watch?v=cYUVeKDR6qE[/media]
[editline]18th February 2015[/editline]
[QUOTE]Since its opening in 1962, SLAC has been helping create the future. We built the world's longest particle accelerator, discovered some of the fundamental building blocks of matter and created the first website in North America.
Our top-notch research facilities attract thousands of scientists from all over the world each year. Along with our own staff scientists, they're working to discover new drugs for healing, new materials for electronics and new ways to produce clean energy and clean up the environment.
Six scientists have been awarded Nobel prizes for work done at SLAC, and more than 1,000 scientific papers are published each year based on research at the lab. As our second half-century unfolds, we're just getting started.[/QUOTE]
This is awesome. People like that deserve more recognition!
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