Be careful, consider what conditions you are working under. If it is under aqueous conditions then you need the pKa of H2CO3 and HCO3-.

If the Cs2CO3 is in water then I would expect that the pKas for the base are the same as those for K2CO3, Na2CO3 and Rb2CO3.

Li2CO3 could be a funny one as the Li+ ions can in aqueous media act as quite a strong acid through hydroylsis. If you want to read at length about hydrolysis then I know that Christain Ekberg is writing a book on the subject, I am not sure when the book will be published. I think it is coauthors with Paul Brown who lives in Auz.

But if you are using it under non aqueous conditions then it may well behave in a different way. One problem I see is if you are using a suspension of Cs2CO3 instead of a solution, this will make things more complex.

Thanks Mark, you are absolutely right. I am using DCE as a solvent, I see a high difference in reactivity compared with sodium carbonate and potasium carbonate. I have hear about the "cesium effect" and the creation of a naked ion that would make it more reactive compared to other alkaline metal bases ( due to high polarizability and size)

However I would like to know pkb values of those bases in organic solvents

Hi Guillermo,

Did you have any luck finding out the answer to your question, about the pKaH of Cs2CO3? I am looking for the same system, ie, Cs2CO3 or K2CO3 in DCE.

Thanks