I am sending some files along with structure and chromatogram's .
It is basically related to analysis of one sodium salt (disodium 2,2' bipyridine 4,4'-dicrboxylate)
This salt is only solurble in water or water with basic pH. We are analyzing it on ACN(0.1% H3PO4) : Water(0.1% H3PO4): : 20:80 wavelength 230nm. Flow 1.0 ml/min.
We I st dissolve the sample into 0.1N NaOH we got two sahrps peaks both have same UV spectra. II nd ly we dissolve this sample into 0.01N NaOH and analyze it on same conditiion as above we got one sharp peaks which has same UV sepctra which we got earlier .
Again we change the diluting solvent and take 0.1% TEA in water and analze it on same HPLC condition we got a single peak agin and its UV spectra is also same as Ist one .
I want to know why in the condition Ist we got two peaks of same UV spetra.? As I am thinking It is pi-pi conjugation change in basic pH and that's why we got cis and trans isomer both when we anlyzing it on 0.1N NaOH but when we change the condition (0.01N NaOH and O.1% TEA in water) we got only single peak i.e no swiching in conjugation.
We cant analyze this sample in acidic condition because of precipitate form. It is in soluble form only in basic or neutral condition (pH 7or above)
I want to know why these are happining?