Sciencemadness Discussion Board

Preparation of transition metal nitrites

symboom - 11-7-2018 at 23:00

Conversion to nitrates Edit
NO2 is used to generate anhydrous metal nitrates from the metal oxide and metal nitrites from the metal iodide

TiI4 and NO2 forms titanium nitrite and iodine gas
I think this reaction proceeds due to volatility

Vandium nitrate
Same as titanium

Chromium nitrite
Same as titanium

Manganese nitrite
Not possible?

Copper nitrite?
Not possible

Zinc nitrite
Havnt found any sources

Nickel nitrite
For nickel nitrite the sensitivity only vacuum stable
Photocatalyic decomposes

Properties
Brooker claims that intense light photocatalyses the destruction of the ionic nitro complexes, leaving only Ni(NO2)2(H2O)4

potassium hexanitronickelate
nitronickelates
formed from KNO2 and NiCl2 mix in water; orange brown; stable in vacuum

I cant find any info on any of the other transition metal salts
Have anyone else worked on transition metal nitrites

Source
https://en.m.wikipedia.org/wiki/Nickel(II)_nitrite
https://en.m.wikipedia.org/wiki/Nitronickelate
https://en.m.wikipedia.org/wiki/Nitrogen_dioxide

[Edited on 12-7-2018 by symboom]

[Edited on 12-7-2018 by symboom]

[Edited on 12-7-2018 by symboom]

woelen - 11-7-2018 at 23:43

Cobalt forms a hexanitritocobaltate(III) ion, [Co(NO2)6](3-). The potassium salt is available as a yellow/ochre pigment and the sodium salt is available as a reagent for detection of potassium ions (the potassium salt is insoluble in water and it is one of the rare insoluble potassium salts).

If you have a cobalt salt and you have sodium nitrite, then try adding the cobalt salt to a solution of acetic acid in water and then add the sodium nitrite and allow to stand in contact with air for a few hours. Your solution will turn golden yellow. Then add a potassium salt. This will give a precipitate of K3Co(NO2)6.

AJKOER - 12-7-2018 at 05:48

I have not tested this idea, but it may work for some metal nitrite formation, assuming one does NOT have access to the metal iodide.

I am suggesting simply dissolving NO2 in water (see https://pubs.acs.org/doi/abs/10.1021/ie402417p?journalCode=i... ) and adding the targeted metal hydroxide or carbonate. For example, with zinc:

NO2 + H2O = 2 H+ + NO2- + NO3-

2 Zn(OH)2 + 2 HNO2 + 2 HNO3 = Zn(NO2)2 + Zn(NO3)2 + 4 H2O

Now, zinc nitrate is very soluble in water and alcohol, per Wikipedia. No reference for the nitrite, but I would speculate the nitrite is solubility is different as is observed in Wikipedia solubility table (see https://en.wikipedia.org/wiki/Solubility_table) where the difference (large + or -) from the nitrate is usually significant for the limited number of nitrites listed. It is assumed for zinc nitrite that it does not decompose in solution, which should have previously boiled to remove any dissolved oxygen, and kept out of air contact. The reason for the latter general procedure is that many transition metals (Fe, Cu,..) in lower valence states together with O2 and H+ may form an electrochemical cell leading to basic salts (see http://www.sciencemadness.org/talk/viewthread.php?tid=75921#... ).

In general, nitrite ions can be light sensitive so prepare and store in the dark (see, for example, https://www.sciencedirect.com/science/article/pii/0304420379... ).

[Edited on 12-7-2018 by AJKOER]

symboom - 12-7-2018 at 10:33

Thanks i tried it once i didnt know allow to stand in contact with air for a few hours. Your solution will turn golden yellow. Then add a potassium salt. This will give a precipitate of K3Co(NO2)6.

Nitrites are stablized by the other ion such as potassium stabilizing cobalt nitrite

Google does not like me. searching nitrites it keeps saying you
mean nitrides

Thank you
AJKOER
That really helps
Wiki sats for calcium nitrite
From sodium nitrite and calcium nitrate

Besides lead nitrite and silver nitrite anyone know of any other nitrite








[Edited on 13-7-2018 by symboom]

DraconicAcid - 12-7-2018 at 10:45

I made K4[Ni(NO2)6] once. Someone here gave me the prep.