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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: lutesium on March 22, 2008, 05:55:34 PM

Title: Phosphorus And Sulphur
Post by: lutesium on March 22, 2008, 05:55:34 PM

As all we know HI/RP is a very powerful Reducing and Ether Cleaving agent which is frequently employed in organic chemistry... Adding Al to the RXN mixture causes AlI3 formation which is further destroyed by H2O to form further HI.

But how does HI reduce the alcoholic groups or cleave ethers??? Is it done by the further dissasociation of HI ---Heat---> H+  +  I-

Can simply Al be employed instead of P??? (I've never ever heard of it in any journal) If not why???

And Sulphur??? Can it be employed instead of P??? SI2 + H20 => HI + SO???


Lutesium...

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 24, 2008, 07:12:55 PM

Nobody has an answer :(


Lutesium...

Title: Re: Reductions w/ HI Red Phosphorus
Post by: agrobert on March 24, 2008, 07:40:08 PM

Your question isn't very clear.  Can you clarify?

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 25, 2008, 10:48:56 AM

I have a recent interest into OrganoSulphur and OrganoPhosphorus chemistry and I've tried to visualise a reaction in which Phosphorus is used...

Can simply Al be employed instead of P??? (Whose answer is probably NO because if yes someone would - I'm not the most clever person on the world) If not why???

And Sulphur??? Can it be employed instead of P??? SI2 + H20 => HI + SO???

And take this as an extra question:
But how does HI reduce the alcoholic groups??? Is it done by the further dissasociation of HI ---Heat---> H+  +  I-

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 26, 2008, 05:53:51 PM

Or at least can someone explain me the formation of SI2 and its reaction with water???


Lutesium...

Title: Re: Reductions w/ HI Red Phosphorus
Post by: bluenote on March 26, 2008, 09:14:55 PM

Why are you asking?  That is an outdated method only used by meth cooks.  There are much better ways to accomplish this kind of transformation ie Barton-McCombie.  (If you are trying to make meth DO NOT use the Barton-McCombie reaction as the by products that are hard to remove will kill you not to mention you will probably blow up during the reaction.)  If you clarify you question (and motives) you might get a better response.

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 27, 2008, 07:53:00 PM

I don't even mind your (sorry but stupid) response bluenote!!! Why do you response??? Is it forbidden to learn??? And howcome did you come to the point that I want to synthesise illegal chemicals???

By the way I told that I gave HI/P reduction only as an example!!! The main point that I want to learn is the OrganoSulphur and OrganoPhosphorus Chemistry!!!

Can someone explain me the formation of SI2 an its reaction with water???


Lutesium...

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 27, 2008, 08:24:44 PM

Can SI2 form in an aquaeous I2 solution??? Can it react with H2O to form HI and SO???


Lutesium...

Title: Re: Reductions w/ HI Red Phosphorus
Post by: macman104 on March 27, 2008, 10:46:43 PM

According to this (http://books.google.com/books?id=LxhQPdMRfVIC&pg=PA529&lpg=PA529&dq=sulfur+diiodide&source=web&ots=Vjf9EpVgHD&sig=gwp4mQ7mDAxv5lLddNr6p-WLrGU&hl=en#PPA529,M1) book, SI₂ does not exist.  Where did you come up with this reaction?

Quote

But how does HI reduce the alcoholic groups??? Is it done by the further dissasociation of HI ---Heat---> H+  +  I-

Here's a link that might help explain:

http://designer-drugs.com/pte/12.162.180.114/dcd/chemistry/meth.hi-rp.html

Quote

Can simply Al be employed instead of P???

I don't think so.  The paper speaks of the phosphorus being oxidized to phosphoric acids, which Al wouldn't be able to form an analogous acid.  For sulfur being used instead, maybe?  I have no clue.

As far as your broader interests in organosulfur and organophosphorus chemistry, may I suggest going to your school's library and seeing if they have any books on the subject, or journals?  If all else fails, you can always purchase books on the subject.

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 28, 2008, 09:11:48 AM

At last a logical answer has come!!!  from macman10!!! Ok mac I'll do it!!!


Lutesium...

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 28, 2008, 09:25:41 AM

I also dont know if SI2 exists or not thats why I'm asking that question!!!



Lutesium...

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 28, 2008, 09:41:41 AM

If you want to you can re-read my question because I also wonder how it cleaves ethers!!!

Lutesium...

Title: Re: Phosphorus And Sulphur
Post by: AWK on March 28, 2008, 10:31:50 AM

HI exchanges OH  to form RI, then reduce RI to RH and I2

Title: Re: Phosphorus And Sulphur
Post by: lutesium on March 28, 2008, 10:37:10 AM

And the ether cleaving how does he accomplish that mission??? By bonding with R²-O-R ===> RI + R²-OH


Lutesium...

Title: Re: Phosphorus And Sulphur
Post by: AWK on March 28, 2008, 10:51:40 AM

Exactly this way

Title: Re: Phosphorus And Sulphur
Post by: lutesium on March 28, 2008, 10:59:42 AM

Which books would you reccomend???


Lutesuim...

Title: Re: Phosphorus And Sulphur
Post by: lutesium on March 28, 2008, 11:03:10 AM

Is this book a good choice???

Comprehensive Organic Chemistry : Sulphur, Selenium, Silicon, Boron, Organometallic Compounds (Comprehensive Organic Chemistry)



Lutesium...

Title: Re: Phosphorus And Sulphur
Post by: AWK on March 31, 2008, 10:20:27 AM

Quote from: lutesium on March 28, 2008, 11:03:10 AM

Is this book a good choice???

Comprehensive Organic Chemistry : Sulphur, Selenium, Silicon, Boron, Organometallic Compounds (Comprehensive Organic Chemistry)



Lutesium...

This is an advanced textbook (monograph - 6 volumes, eds D.H.R. Barton and W.D. Ollis), but price is rather for library.

Title: Re: Reductions w/ HI Red Phosphorus
Post by: lutesium on March 31, 2008, 10:29:21 AM

Quote

Can simply Al be employed instead of P???

I don't think so.  The paper speaks of the phosphorus being oxidized to phosphoric acids, which Al wouldn't be able to form an analogous acid.  For sulfur being used instead, maybe?  I have no clue.
[/quote]

But Al forms Al(OH)3 isn't this enough???

Title: Re: Phosphorus And Sulphur
Post by: AWK on March 31, 2008, 11:57:18 AM

Topick locked on request of Lutesium
Please, continue eventual discussion under:

http://www.chemicalforums.com/index.php?topic=24870.0