| Pages:
1
2 |
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
You do need the ligroin, because if you don't have that, then the complex indeed forms, but it is oxidized very quickly and you'll not be able to keep
it around for more than a few hours. When the solution is shaken in contact with air, it even is gone in a minute or so!
Things of course become totally different if you have the apparatus to work under a protective atmosphere (nitrogen or argon).
|
|
|
kmno4
International Hazard
Posts: 1495
Registered: 1-6-2005
Location: Silly, stupid country
Member Is Offline
Mood: No Mood
|
|
I prepared Na2[Ni(CN)4]x3H2O at first, simply dissolving hydrated Ni(CN)2 in NaCN solution.
[Literature says that hydrated Ni(CN)2 is green-gray powder, but my product (made accordingly to IS pocedure and I did it twice)] was pale-blue, just
like the sky.]
After evaporation, I got very nice crystals of Ni(II) complex (on the picture).This compound is similar to K4[Fe(CN)6]x3H2O: orange colour of larger
crystals, yellow in powdered form and easily losing water in the air, leaving white powder.
Its solution also on the picture.
Next I added some (~100g) Na amalgam to this solution: lots of H2 bubbles but solution almost immediately turn blood-red (on the picture), something
like Fe(III)/SCN complexes.
As time went by, this colour was fading (starting from the surface) and after ~24h I got again orange-yellow solution of Ni(II) complex. Unfortunately
I was not able to isolate Ni(I) compound.
Probably its concentration is relatively low, although colour of the solution is very intensive.
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Nice work with the synthesis of the nickel(II) complex. The crystals have a nice orange color. I would not call its appearance similar to the
appearance of potassium hexacyanoferrate(II), the latter has a much paler color, the solid is pale yellow and not so nicely orange as the crystals you
made.
Isolating the nickel(I) complex is much more complicated though. You need to separate it from the reductor if zinc is used (using Na-amalgam is a good
idea, no additional ions are introduced besides sodium ions) and you need to keep it away from air when evaporating to dryness.
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
