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Topic: Unexplained blue shift in UV-Vis experiment  (Read 1982 times)

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Offline _Espard_

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Unexplained blue shift in UV-Vis experiment
« on: March 01, 2015, 06:51:30 PM »
I am running a UV-Vis spectroscopy experiment and witnessed slight blue shift in my spectra that I cannot explain.

The experiment consists of a mixture of a metal salt and an organic compound in water. The s#*$ is only witnessed when the two are mixed together, as individual UV-Vis spectra show the correct (unshifted) peaks.

My assumption was that blue shifts are typically seen due to the effects of solvents and do not typically arise for same-solvent (i.e. water) experiments. My first thought would be some sort of charge-transfer complex - but doesn't this typically lead to lower-energy red shifts?

Offline Corribus

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Re: Unexplained blue shift in UV-Vis experiment
« Reply #1 on: March 02, 2015, 10:26:37 AM »
More details about what you're doing are needed. Also, seeing the actual spectra would be helpful, because what you call "slight" may be different from what I call "slight". Spectral shifts can be due to lots of things.
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

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