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Characterizing a new compound having fluorescent properties

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Babcock_Hall:
https://global.oup.com/academic/product/spectrophotometry-and-spectrofluorimetry-9780199638123?cc=us&lang=en&
We are making two novel compounds that appear to be fluorescent.  Each one has a pyridine group, a phenolic group, and a vinyl group, and they are isomers of each other.  Based on one of the parent compounds, loss of the phenolic hydrogen as a proton will change the fluorescent properties.  I found a book chapter that was helpful in introducing me to both theory and practice.  This chapter was in the book Spectrophotometry and Spectrofluorimetry, a Practical Approach, edited by Michael G. Gore.

My question is how do we characterize the fluorescence for publication and for use of the compounds?  For example, how can we study the fluorescence as a function of pH.  By analogy to spectrophotometric studies, I envision making a series of buffers (probably Good's buffers) and using a stock solution of a compound dissolved in an organic solvent, but surely there are additional things one needs to know.  Maybe someone has a publication in mind that would serve as a model.

rolnor:

Is there conjugation between the pyridine and the vinyl group??

rolnor:
It would be nice to titrate a solution of the compound with base and meassure the flourescens spectrum and pH in real time and plot these as a curve

Babcock_Hall:

--- Quote from: rolnor on December 08, 2023, 05:30:26 AM ---
Is there conjugation between the pyridine and the vinyl group??

--- End quote ---
Yes, we converted an aldehyde into a vinyl group, and the aldehyde is known to be fluorescent.

Babcock_Hall:

--- Quote from: rolnor on December 08, 2023, 05:32:25 AM ---It would be nice to titrate a solution of the compound with base and meassure the flourescens spectrum and pH in real time and plot these as a curve

--- End quote ---
The absorption maximum will probably shift to longer wavelengths as pH is increased.  It seems to me that even if one kept the concentration constant, the absorbance will change, leading to differences in the inner filter effect from one pH to another.

BTW the book chapter by Arthur G. Szabo that I read, "Fluorescence Principles and Measurement," is very good in introducing the novice to things like the practical difference between Rayleigh and Raman scattering.

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