[EpicLauren]

Hello everyone
I'm currently doing a project where I analyze the Spin-Crossover phenomena in 4 different iron complexes. I managed to synthesis 3 complexes with: iron (II)-iodide, bromide and chloride. (I used l-ascorbic acid to prevent the oxidation of iron (+ N2)  and I used 4-amino-1,2,4-tirzole as ligand and methanol as the solvent). Now I stuck with Iron(II)-fluoride. It never really worked; the beige powder never dissolved in the solution. I used 4 different solvents, first I used methanol like the others, then I used distilled water, then I used Dimethyl sulfoxide (DMSO) (it was organic so obviously it didn’t work) and at the end I used Tetrahydrofuran (THF). None of these worked and my last guess would be to use HF (hydrofluoric acid). Though my school does not have this chemical right now. Does anybody of you guys maybe know how to dissolve iron(II)-fluoride, maybe heat it or something?
Regards,
Laurin

[mjc123]

From Wikipedia article;
"The anhydrous salt (FeF₂) can be prepared by reaction of ferrous chloride with anhydrous hydrogen fluoride.[11] It is slightly soluble in water (with solubility product Ksp = 2.36×10−6 at 25 °C)[12] as well as dilute hydrofluoric acid, giving a pale green solution.[1] It is insoluble in organic solvents.[4]

The tetrahydrate can be prepared by dissolving iron in warm hydrated hydrofluoric acid and precipitating the result by addition of ethanol.[1] It oxidizes in moist air to give, inter alia, a hydrate of iron(III) fluoride, (FeF3)2·9H2O."


Be very careful if you use HF!

[Corribus]

Rather than using HF, I wonder if you can generate the needed HF in situ using HBF4, which is safer to work with. This is commonly done in acid digestions.

[EpicLauren]

Thank you two for the reply. The problem is I don't really want to work with HF. My teacher wouldn't allow me to anyway. So I need another way but I don't know if there is another good way than with HF. And my guess is HF would do harm to the other chemicals anyway.

[EpicLauren]

I tried water now again, because I though this might work with the ligand. But it just doesn't dissolve even though wikipedia sais ''slightliy dissolvable in water''. I also tried heating it simultaneously but I don't get it done. Any suggestions with water?