Sciencemadness Discussion Board - Modulating electromagnetic frequencies to interact with specific compounds in big ways

Modulating electromagnetic frequencies to interact with specific compounds in big ways

CrimpJiggler - 31-12-2014 at 09:51

Learning about all the different forms of spectroscopy really opened my mind up to this and has been giving me ideas. In case you don't know, modulation of EM waves just means varying the frequency (or amplitude in the case of AM) over time in a controlled manner. Also, you can use more than one frequency at a time, the word for that is a pulse (thats why they use Fourier Transform in spectroscopy).

So we all know that each compound has its own unique IR, UV-Vis, microwave, whatever spectrum which we can use to analyse the compound. But what about using this principle for things other than analysis, like causing reactions to occur. For example, if you used multiple IR frequencies to target specific bonds of a molecule and make them vibrate faster, then used UV-Vis frequencies to excite electrons in or around those specific bonds, I reckon you could increase the odds of a reaction happening, involving those particular bonds. So by adding EM frequencies to the reaction mix, you increase the selectivity towards specific reactions. I reckon the more large and complex the molecule, the more useful this principle would become.

I doubt I'm the first person to think of this, does anyone know the name of this field of chemistry? I reckon its only in its infancy (or in the womb might be a better analogy) because I have never come across it being used, and in uni, they didn't even cover the topic.

There are so many possibilities, this has to be a whole new frontier for chemistry. x-rays for exciting inner electrons would likely come into use here. Not sure if inducing rotation with microwaves would have any application here. So by knowing exactly what resonant properties (i.e. the vibration of bonds, valence electrons, inner electrons etc.) to target, at exactly what time, we could add a whole new dimension to controlling chemical reactions. And thats just the tip of the iceberg. I bet it can come into use in separation methods like chromatography. I don't know how exactly that could work, I just intuitively know it can. By exciting a molecule in a very specific way, we could influence how it travels through a chromatographic matrix. How well it travels through an electrophoresis matrix. The more aspects of one molecule we target, the more selective the EM waves become for that specific molecule.

[Edited on 31-12-2014 by CrimpJiggler]

forgottenpassword - 31-12-2014 at 09:54

http://en.wikipedia.org/wiki/Photochemistry

https://www.google.com/search?q=photochemistry&btnG=Sear...

[Edited on 31-12-2014 by forgottenpassword]

CrimpJiggler - 31-12-2014 at 10:06

I've learned about photochemical reactions, its the process of modulating EM pulses in order to target specific molecules/parts of molecules in a specific way over time that I haven't come across. This falls under the category of photochemistry, in the same way electronics falls under the category of physics. Its such a vast field, electronics deserves a category of its own.

forgottenpassword - 31-12-2014 at 10:09

Quote: Originally posted by CrimpJiggler

This falls under the category of photochemistry, in the same way electronics falls under the category of physics.

No it doesn't. Learn about photochemistry first, then come back and tell us that you've come up with something completely new. Read some of the books: what you are suggesting is precisely what they are doing.

[Edited on 31-12-2014 by forgottenpassword]

CrimpJiggler - 31-12-2014 at 10:18

Just came across this:
http://www.crcpress.com/product/isbn/9780824757106
Chiral photochemistry. Thats pretty cool. Looks like they're only using frequencies that interact with valence electrons though. Just came across talk of magnetochiral anisotropy too, interesting stuff. Looks like they're using modulated magnetic fields to influence the stereoselectivity of reactions.
http://www.tandfonline.com/doi/abs/10.1080/00268970110109826
Again, pretty cool but not what I'm talking about. All these things don't take time into consideration, not to the extent I'm talking about anyway. Magnetic fields I'm sure will be a useful component of this when this field advances enough that it becomes commonly used. Electrical fields too. Then then theres electron bombardment, neutron bombardment etc. I suppose the motion of large groups of molecules can be exploited too, so ultrasound, microwaves, radio waves etc. will come into play here.

CrimpJiggler - 31-12-2014 at 10:21

Quote: Originally posted by forgottenpassword

Quote: Originally posted by CrimpJiggler

This falls under the category of photochemistry, in the same way electronics falls under the category of physics.

I've only learned the basics, probably the historical stuff (like Norrish reactions), if you're saying the field has advanced and now covers exactly what I have in mind, then I'll take your word for it for the time being. It'd be helpful if you mentioned some terminology to help narrow searches.

forgottenpassword - 31-12-2014 at 11:21

Quote: Originally posted by CrimpJiggler

Just came across this:
http://www.crcpress.com/product/isbn/9780824757106
Chiral photochemistry. Thats pretty cool. Looks like they're only using frequencies that interact with valence electrons though.

You've read that book, have you? That was quick! Yes, they're talking about valence electrons because that is what determines the chemistry of a molecule. If you are interested in electron and neutron bombardment, then perhaps you're more interested in nuclear physics rather than chemistry?

I'm afraid that I cannot give you any terms to look up because you are not expressing yourself very clearly at all. I have worked in photochemistry for a good portion of my career, so I have no doubt that I will be able to help you: but vague references to 'time' as well as other seemingly-stimulant-induced grandiose ideas do not help me to give you specific recommendations. Sorry about that, but I don't know what you have in mind. I suspect that what you have in mind is simply modern photochemistry, but since you've only just learned the basics and haven't read any books or reviews on the subject, I cannot say for sure. Perhaps you could get back to me once you have; if you're still interested in it then.

Marvin - 2-1-2015 at 06:14

Traditionally microwave bands are associated with rotation of groups, IR bending and stretching and mostly far UV for electronic excitation. With electronic excitation an electron can be moved from a bonding orbital to an antibonding orbital causing the parts to move apart and leading to reactions with the radicals. I don't see how you could reasonably stimulate a reaction with IR or below, the energy is too close to regular thermal energy and human time scales are so long compared to molecular interactions.

IR has been used in conjunction with sharp UV decompositions for isotope enrichment. In MLIS the IR frequency is chosen for a particular isotope in the molecule and the UV is tuned so that only excited molecules absorb.

For chromatography or electrophoresis, I think the main barrier would be how much energy would be required to keep a high proportion of molecules in the excited state. I'm also not sure what information you would get from it if it worked that isn't in an IR spectrum.

deltaH - 2-1-2015 at 06:23

CrimpJiggler, I've started a thread a long time ago in the 'whimsy' section of SM called 'The Pandora Device' that deals exactly with this idea. Get access to whimsy from an Administrator, write like Bert.

The idea requires that one use a very broad portion of the spectrum, from UV to IR and extremely intense light sources, all discussed.

Quantum mechanical molecular modelling these days has progressed to the stage where one can get an accurate predictive spectra for any reasonably smallish organic molecule, so some day, one might be able to simple draw the molecule and get a few mg's synthesised this way from stock gases that supply the elements to the reaction chamber.

...scary thought, hence the name the 'Pandora Device'

[Edited on 2-1-2015 by deltaH]