Sciencemadness Discussion Board - SnCl4:5H2O Solid or otherwise

SnCl4:5H2O Solid or otherwise

dann2 - 1-12-2007 at 21:36

Hello,

In an attempt to make SnCl4:5H20) or the equivalent (Sn(IV)) in solution I way going to try the following.
Dissolve Sn metal in HCl. (SnCl2 in solution)
Dillute with water slowly (untill tiny ppt seen, (Sn0 forming)) and bubble air through in order to convert the SnCl2 to hydrated Oxide of Tin(IV).
Filter out the insoluble Hydrated Oxide of Tin(IV).
Add to concentrated HCl to convet to SnCl4 (in solution).
Evaporate the HCl off to get SnCl4:5H2O (not to dryness, hopefully gettng ppt before dryness).

This is based on a post by 'not_important' (shown below as deleted off board) as (quite frankly) I don't have a clue about Tin Chem .

Will it work do ya think?

I cannot get the 'SnCl4 made from SnCl2 +H2O2 (all in solution)' to work for DTO (this line understood by DTO guru's only).

Dann2

___________________________________________________

You need to keep tin chlorides in fairly acid solutions. The hydrates can be made by evaporating the solutions (NOT to dryness) until crystals form, then cooling and collecting the tin salt on a filter. In the case of SnCl2 you will need to evaporate it almost to dryness, as it is very soluble in water, although strong HCl may reduce the solubility. If you do take the solution all the way to dryness, especially without enough HCl around, you likely will get some hydrolysis to basic chlorides.

SnCl2 is a fairly strong reducing agent. If you expose a solution of it to air, more quickly be bubbling filter air through the solution, the solution will grow cloudy as hydrated oxide of Sn(IV) is formed. Adding concentrated HCl will dissolve that forming a solution of SnCl4 in HCl. Evaporate solution to get crystals of SnCl4.5H2O

SnCl2 will go to SnO unless oxidised by air. As you are making a semiconducting film, not getting too much deviation from the actual stoichiometries would seem to be a good idea. Try Sn(II), but if things don't work quite right then switch to Sn(IV).

There will be a lot of HCl coming off those solutions during evaporation, you'll want to trap it to keep all the metals around from corroding. Same goes for SbCl3.
_____________________________________________-
End of Not_important post

YT2095 - 2-12-2007 at 02:22

you won`t get crystals of SnCl4 it`s a Covalent compound, and also a liquid, the SnCl2 will form crystals though (it`s Ionic), so I think you`re confusing the 2 here.

Rosco Bodine - 2-12-2007 at 03:00

Quote:

Originally posted by dann2

I cannot get the 'SnCl4 made from SnCl2 +H2O2 (all in solution)' to work for DTO (this line understood by DTO guru's only).

Dann2

possible and/or most likely reactions in mixture

2 SnCl2 + 4 H2O2 + 4 HCl ----> 2 SnCl4 + 6 H2O + O2

6 SnCl2 + O2 + 2 H2O ----> 2 SnCl4 + 4 Sn(OH)Cl

4 Sn(OH)Cl + 4 HCl ----> 4 SnCl2 + 4 H2O

Therefore :

4 SnCl2 + 4 H2O2 + 8 HCl ----> 4 SnCl4 + 8 H2O

simplest balanced expression for combined possible reactions

SnCl2 + H2O2 + 2 HCl -----> SnCl4 + 2 H2O

[Edited on 2-12-2007 by Rosco Bodine]

YT2095 - 2-12-2007 at 03:18

I`ve just a quick look up and there is a ~solid form of it, although it`s more like a wax, called "Butter of Tin".

might be a good searchword.

Rosco Bodine - 2-12-2007 at 03:38

The only way it wouldn't go all into solution is if there is too much water and/or the pH is too high . Maybe your problem
with using the reagents you make is that you don't really understand what you have made or how to change it to
what you want . If that is so , then maybe working with
already prepared reagents is better for you than improvising . Either that or get some of us to write a
recipe for you based on what materials you have . You
can't really guess at the chemistry because it is mathematical
in nature , there's no getting past the equations .

[Edited on 2-12-2007 by Rosco Bodine]

dann2 - 2-12-2007 at 05:23

Hello,

Ihave jar of SnCl4:5H2O. It is crystalline and not 'buttery'. I think if it has less water in it than 5H2O it is of a buttery consistency. Hard to nail down Tin compounds

Dann2

Rosco Bodine - 2-12-2007 at 12:43

Yeah Tin compounds are chemically reactive in solution
with both the water , and the oxygen of the atmosphere ,
and are also pH sensitive , as well as senstive to the concentration of the Sn in solution .....all of which makes
such a system inherently unstable . So the composition is variable , and it isn't going to be just one thing or another , but a mixture of things depending upon conditions including time and temperature also .

So in a very real sense the simplest balanced equation
is an oversimplification for the system which is unstable by nature . But it gives you a place to start . And in concentrated solutions , having a bit excess HCl and a bit excess H2O2 having reacted with the metal , the reaction
would / should go virtually complete to the right producing
the SnCl4 . The complication arises in manipulations
seeking to isolate it , where boiling down to concentrate
for example might cause hydrolysis , yet a gentle evaporation at a lower temperature may not cause the same hydrolysis . So differences in how you go about isolating the product can end you up with what you want ,
or something else entirely , or a mixture . That is one good reason to avoid attempted isolation of unstable materials if there is no reason for the isolation of something which is simply an intermediate in a lengthier
process . No reason to try to isolate something from solution that involves a difficult isolation , only to reform
a solution of the same thing to continue a process where
it is needed in solution .

not_important - 2-12-2007 at 17:37

Quote:

Originally posted by YT2095
you won`t get crystals of SnCl4 it`s a Covalent compound, and also a liquid, the SnCl2 will form crystals though (it`s Ionic), so I think you`re confusing the 2 here.

Not true, SnCl4 . 5H2O is a crystalline solid when pure, small amounts of impurities leave it less obviously crystalline and in a form once called "butter of tin".

Couple of old books that might be useful

http://books.google.com/books?id=txUNAAAAYAAJ&pg=PA449&a...

http://books.google.com/books?id=OgI5AAAAMAAJ&pg=PA94&am...

Towards the MVIP!

dann2 - 3-12-2007 at 22:52

Hello,

@Roscoe,
I dissolved 5g SnCl4:5H2O in 5g water and added 0.3g Sb metal, in the hope that the Sb will dissolve.
Should I add some HCl to this?

Also refluxing an Sn/Sb homemade alloy (15% Sb) in HCl.
All Tin dissolved and I am now left with powdered Sb on bottom of flask.
Now starting to add portions of H2O2 to get Sb to dissolve.

HCl + H2O2 is WOEFULL hard stuff on the fingertips!!

Cheers,
Dann2

Rosco Bodine - 4-12-2007 at 02:06

Quote:

Originally posted by dann2
Hello,

@Roscoe,
I dissolved 5g SnCl4:5H2O in 5g water and added 0.3g Sb metal, in the hope that the Sb will dissolve.
Should I add some HCl to this?

You can , as you are going to boil out the excess HCl later anyway if you are going for the polymer . You are still way heavy on the Sb .

Quote:

Also refluxing an Sn/Sb homemade alloy (15% Sb) in HCl.
All Tin dissolved and I am now left with powdered Sb on bottom of flask.
Now starting to add portions of H2O2 to get Sb to dissolve.

HCl + H2O2 is WOEFULL hard stuff on the fingertips!!

Cheers,
Dann2

If I was running into that separation problem , I would decant off the Sn portion that is done , and work with the Sb residue separately , to get it over that hump . Whatever excess of HCl and H2O2 you use in pushing the Sb reaction , will then function to advance the SnCl2 to SnCl4 when you mix the separately formed solutions back together .

You want to save out some of the undissolved material anyway , about half of it .

You probably don't really need the Sb anyway , since the Co has arrived

, and you are using way more than needed . You are probably going to end up with even more in the coating than before , since indeterminate amounts aren't going to be volatilizing , but will stay put when baked . The Sb content you are trying to use is not justified and it will trash what you are trying to do when it drops out of solid solution as a separate phase on baking . You have four times what you need for doping SnO2 .

dann2 - 9-12-2007 at 20:03

Hello,

Dissolved a quattity of Sn + Sb in HCl. Did not have the time to keep adding H2O2 to the solution to dissolve the Antimony metal (very finely devided as it was originally alloyed with the Tin). Took out the Sb, weighed, it was still all there. I added some Antimony Trioxide (ceramic) to the SnClx where is dissolved. (7%Sb to 93%Sn).
Continued to reduce volume of mix and added some H2O2 now and then. A small amount of black suspended solid appeared in the solutioin. Continued to reduce volume and adding some H2O2. Cooled and the whole lot crystallize into a mostly solid mass.

@ Whoever it may concern:
My experiments with Mixed Tin/Antimony Variable Valency Inorganic Polymer are now officially at an end.

The other contained that I dissilved SnCl4:5H2O + Some finely divided Sb metal + some HCl is still sitting there. The Sb does not appear to be dissolving. Will leave for a few months as it requires none of my time or energy.

Dann2

dann2 - 14-1-2008 at 18:01

Hello,

Received the following method for SnCl4:5H2O from RongPeng.
Thought I would post here for completness.
The SnCl4 (anhydrous) is old hat to the board.

SnCl4 (anhydrous) can be manufactured by applying Chlorine gas to Tin metal. The formed SnCl4 (liquid) should be allowed to drip onto the Tin metal in the apparatus. The reaction is exothermic. The Tin metal should be OK if cut into small pieces or powdered.

Anhydrous SnCl4 will dissolve in cold water ( warm/hot will decompose it). Saturate a water solution of SnCl4 with Chlorine gas. The solution is then evaporated and condened. When this solution is cooled, deposits of SnCl4:5H20 will form.

Dann2

chloric1 - 14-1-2008 at 18:30

What? No man we do not need to make spirit of Libavious for these experiments. Just oxidize stannous chloride in solution. If not with H2O2 then with Chlorine gas if you wish. I would evaporate on a steam bath as the heat transfer is tremendous but gentler than hardboiling directly on the hotplate. If hydrolsis occurs add tiny amounts of conc HCl until solution is clear. Evaporate until crystals separate when cooled.

Rosco Bodine - 21-2-2008 at 11:47

Quote:

Originally posted by not_important

Quote:

Originally posted by YT2095
you won`t get crystals of SnCl4 it`s a Covalent compound, and also a liquid, the SnCl2 will form crystals though (it`s Ionic), so I think you`re confusing the 2 here.

@not_important &
@chloric1

Look at that second reference linked above a few pages back beginning the last paragraph of page 88 and top paragraph of page 89 . In Gmelins era the stannic chloride was erroneously called "bichloride of tin" and shown as SnCl2
while the stannous chloride of tin was called the "hydrochlorate" or perhaps the "protochloride" and assigned the formula SnCl ........*one half* the chlorine contents assigned today . But you may *perhaps* place more confidence in the verbal descriptions of certain reactions for these misidentified materials , while keeping
the more modern understanding of the actual count for the chlorines involved . It would seem there was confusion about the quantitative analyses interpretation , leading to
inconclusive specification of reaction equations assigned as
describing what was observed . In hindsight from todays
more accurate knowledge of the chlorine count for the stannous and stannic compounds , the observations reported
in the past may be interpreted differently and assigned
different equations which seem more plausible .

See the Lowenthal article which I have brought up in the following thread , here:
http://www.sciencemadness.org/talk/viewthread.php?goto=lastp...

The assistance of someone who may translate the German ,
hopefully with an understanding simultaneously of this
discrepancy involving the archaic terminology of "bichloride"
as applied to the stannic salt , may shed light on this matter .

[Edited on 21-2-2008 by Rosco Bodine]

S.C. Wack - 21-2-2008 at 16:00

Chlorine, one way or another. http://tinyurl.com/2pat7z

Fleaker - 21-2-2008 at 16:03

I would just use aqua regia, I recall that makes stannic chloride.

Rosco Bodine - 21-2-2008 at 16:24

Quote:

Originally posted by S.C. Wack
Chlorine, one way or another. http://tinyurl.com/2pat7z

That's excellent .

Thanks . Relevant pages have been
excerpted and attached .
Several paths are now clear for working from tin metal
to produce the (+IV) stannic chloride required for various uses .
Particularly of interest to me is simply a soluble
stannic precursor which can be neutralized by ammonia
to provide the alpha stannic acid , which can be converted
to any desired stannic oxide , stannic salt or stannate with
ease .

[Edited on 21-2-2008 by Rosco Bodine]

Attachment: SnCl4 and SnCl2 Preparations.pdf (242kB)
This file has been downloaded 986 times

Baphomet - 13-7-2008 at 18:11

Cl2 gas appears to be the most straightforward method from SnCl2 to relatively pure SnCl4, whereupon the purity would be dependant upon SnCl2 purity.

I've attempted H2O2 + SnCl2. This produces a gelly of hydrated SnO2, which I suppose could be chlorinated and evaporated, but why bother?

On the subject of DTOs I spent two weeks barking up the wrong tree attempting to form SnO2 from SnCl2, using a paper from Okeke et. al. and assuming that air oxidation was responsible for Sn4+ production. Not so.

I guess that's why Okeke's work is not featured in any of the 'real' journals (he must have been using SnCl4 and thought it was dichloride)