Electra
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UV Frequencies for photochemistry?
I'm going to be doing some photocatalyzed reactions soon and am looking into purchasing an adequate UV lamp. The lamps I am looking at emit light in
the ranges of 315nm and upwards. Is this an adequate UV range for exciting various halide compounds? Most of these UV lights are either grow lights or
lights for UV curing. I haven't found much information on the frequency ranges of excitation of various halides.
One other question, that may have been asked before...Can I just shine UV light into the solution, if the top is open, or even through the glass? I've
seen many photochemical examples in which the light is immersed in the solution. Then again I've seen UV done in which the sunlight is utilized,
albiet, sunlight is much more powerful than any lamp.
[Edited on 23-4-2014 by Electra]
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Mildronate
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There is only one problem you need quartz glassware!
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Electra
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The reactions I am running are going to be run at room temperature with an open top. I wouldn't need quartz glass if the light is shining directly on
the reaction mixture, correct?
Even still, UV light should pass through normal glass, although some of it will be filtered. Many people have been sun-burned by sunlight radiating
through the windshields of cars during long drives, and windshields are designed to filter light somewhat.
If I can just shine UV light on the top of the open stirring reaction, that would make life so much more simple.
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Mildronate
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borsilicate absorb uv.
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forgottenpassword
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You don't need quartz glass for 300nm and upwards. You will find a lot of good information here: http://www.google.com/url?q=http://www-oc.chemie.uni-regensb...
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jwpa17
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I'm not sure how much interesting photochemistry you're going to do with wavelengths longer than 315 nm, but as forgottenpassword said, ordinary glass
passes 300 nm and longer.
You can probably blast organo-iodides, and maybe bromides, but I doubt many organochlorides absorb significantly in that range.
Usually, one records the UV-visible absorption spectrum and irradiates at a wavelength corresponding to an absorption in the spectrum. That ensures
that the energy is being delivered into the target molecule. And typically the higher the excitation energy used, the more "chemistry" the excited
species does.
You should give some thought to how you're going to characterize the product(s) of your photochemical reactions.
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Texium
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Thread Moved
21-11-2023 at 13:54 |
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