Here, I am changing the polarity of the solvent by adjusting the concentration of the Toluene and DMF. There are some changes in the UV and fluorescence emission of the molecules also enhancing. All are in same concentration Kindly help me to interoperate this data. The results are attached in attachment.
I got some Problems with your data:
Why did you normalize Absorption to Absorption at 300nm ?
In my opinion you should have no fluorescence at 0% fluorophore. If the secound component got a fluorescence Emission to, the shape of the spectrum has to Change by reducing the amount of the first component.
Hi,
Among the many reasons mentioned in the discus, we should note one objective reason. Namely, when the concentration of the polar solvent increases and the solute concentration is the same, there is a dependence of the fluorescence intensity observed you adding DMF in toluene. It follows from my theory. For small additions deviations from my theory are possible, because the concentration of solvent surrounded solute molecules do not coincide with that in bulk solution. I think you understand what I want to say. My poor English does not allow discussing this issue in detail. Perhaps you can help literature references:
Article: Solvatochromism and Nonradiative Decay of Intramolecular Charge-Transfer Excited States: Bands-of-Energy Model, Thermodynamics, and Self-Organization
Vladimir S Pavlovich
[Show abstract]
Article · Dec 2012 · ChemPhysChem
PDF possible on request via RG.
Article: Solvent polarity effect on excited-state lifetime of carotenoids and some dyes
Vladimir S Pavlovich
[Show abstract]
Article · Jul 2006 · Biopolymers
PDF possible on request via RG.
Article: Nonradiative Transitions in Media of Different Polarities and Their Modeling for 12′-Apo-β-Caroten-12′-Al and 8′-Apo-β-Caroten-8′-Al
V. S. Pavlovich
[Show abstract]
Full-text available · Article · Sep 2014 · Journal of Applied Spectroscopy
Russian PDF available on RG, but English only from Springer.
With best wishers
Vladimir
Thank you all now I update the UV without normalization. all are in same concentration. I used HPLC solvents (Toluene and DMF). Kindly Update me more information on this.
I think you will help my theory. In any case, it would be useful to get acquainted with it. To even be a little bit to understand the causes of the dependence observed by you, you need to read more articles.
I got the reference for similar molecules. Now I am interpreting the data not yet come to the conclusion. after getting the conclusion i will update you.
The absorbance spectra for high toluene content looks like being near the solvent cutoff. However Toluene should be usable beyond 300 nm, according to here: http://www.chem.fsu.edu/~shatruk/docs/Solvent-UV-cutoffs.pdf
So, might be solvent impurities? How does a toluene only solvent spectrum look,like? Did you try another batch of toluene?
Thank you for your response, The solubility of compound in toluene is not very good that will be the reason.
Yes, that's an even better explanation. So, we see basically the effect of scattering by undissolved compound! Like explained here: http://www.fluortools.com/software/ae/documentation/tools/scatter
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