Here is a paper reporting a Stokes shift of 186 nm.

https://pubs.rsc.org/en/content/articlehtml/2017/ra/c6ra27547h

Here is one with 227 nm Stokes shift.

Article An organic dye with very large Stokes-shift and broad tunabi...

Thanks! Those are pretty big shifts.

I found an article claiming the largest shift of 252 nm.

Article Boranes with Ultra-High Stokes Shift Fluorescence

I understand the same shift in wavelength corresponding to the different energy in the different regions (UV, Vis, NIR), so maybe just comparing the wavelengths or energy may not be so meaningful, come to think of it. But it is interesting to see how large they could be (and more importantly, the mechanism).

Large Stokes shifts of 227 nm for dye is observed in in DMSO .

Excited-state processes like ESIPT can lead to very large distances between absorption and emission maxima. However, not sure if this should then still be called Stokes-Shift...

Thanks for the reply! ESIPT is a kind of the structural relaxations at excited states, so it is probably appropriate to call it Stokes shift.

I saw someone call the higher-energy emission by photon upconversion as "negative Stokes shift", which I think is debabtable...

Here , a Stokes shift of 312nm is reported, from a TICT compound:Article Phenothiazinyl Boranes: A New Class of AIE Luminogens with M...

Actually, when comparing Stokes shift values, it should be done in wavenumbers, as only those are linear in energy. On comparing wavelengths, the longer wavelength values would have an adavantage...

Mega Stokes shift! Thanks for this information.

I agree with you that the energy axis would be more appropriate to use to compare these shift (in cm-1 or eV) if you are interested in the comparison of the structural changes at the excited state. Wavelength may have practical importance for applications (whatever they could be). The wavelength range of FL would be also important (UV abs to vis FL or vis abs to NIR FL) for the applications.

Hi Keisuke Tajima , these are few of our research work with dyes which have Stokes’ shift over 200 nm.

https://pubs.rsc.org/--/content/articlelanding/2017/cc/c7cc00700k/unauth#!divAbstract

https://pubs.rsc.org/en/content/articlelanding/2021/nj/d1nj00044f#!divAbstract