Sciencemadness Discussion Board

Ion exchange resin for converting CsCl to CsSCN

Bezaleel - 16-11-2020 at 10:54

H.L. Wells describes Cs4[Mn(SCN)6] as magnificent massive crystals, pale yellowish-green (American Chemical Journal, 1902, 28, p 261-262). I'd like to see those, but I don't have any CsSCN, nor any Cs2CO3 to make it from HSCN solution.

So I thought that maybe CsSCN can be made through ion exchange. Can anyone refer me to a document or site which describes what resin could be used for this? Starting material is preferably CsCl.

I found some basic knowledge about ion exchange resins, like here, but I'm interested in more detailed or practical knowledge, like column size, flow speed, preparation and regeneration conditions, etc.

Thanks!

Bedlasky - 16-11-2020 at 12:21

I think, that this salt will precipitate from solution containing Mn2+, SCN- and Cs+. Double salts of Cs are in most cases insoluble.

Tsjerk - 16-11-2020 at 13:39

You don't really need a column, you can just stir a suspension of resin for a while and repeat the process a couple of times to make sure you get out most of the chloride. The equilibration of chloride/thiocyanate is fast, a couple of minutes should be more than sufficient.

Bezaleel - 16-11-2020 at 13:41

Quote: Originally posted by Bedlasky  
I think, that this salt will precipitate from solution containing Mn2+, SCN- and Cs+. Double salts of Cs are in most cases insoluble.

The Cs Tutton salts are all very well soluble.
So, there's only one way to find out - to the lab! :D

Boffis - 20-11-2020 at 03:34

Hi Bezaleel, Yes I am sure it will work. When you have got/chosen your resin find the data sheet for this specific product. It will usually give a figure for exchangable ions in millimoles per gram and the wet packing density. From these figures you can calculate the amount you require. I have done similar preps using other ions. Larger ions like the thiocyanate ion may diffuse into the resin more slowly than smaller ones like chloride so I would soak your resin in a large excess of thiocyanate say x2 by running this through a column first then clean water. Saturate the column with deionised water and then run your CsCl solution through slowly. I used a 40% excess of resin over what was theoretically required.

Bezaleel - 20-11-2020 at 14:36

Quote: Originally posted by Boffis  
Hi Bezaleel, Yes I am sure it will work. When you have got/chosen your resin find the data sheet for this specific product. It will usually give a figure for exchangable ions in millimoles per gram and the wet packing density. From these figures you can calculate the amount you require. I have done similar preps using other ions. Larger ions like the thiocyanate ion may diffuse into the resin more slowly than smaller ones like chloride so I would soak your resin in a large excess of thiocyanate say x2 by running this through a column first then clean water. Saturate the column with deionised water and then run your CsCl solution through slowly. I used a 40% excess of resin over what was theoretically required.
Thanks so much, Boffis!
Q: You said: "When you have got/chosen your resin find the data sheet for this specific product." Do you mean the data sheet for the resin, coming from the supplier? Or do you mean a specific data sheet for that resin for SCN- exchange?
I'm still very new to this, so I'm trying to find my way in a dark room...