Sciencemadness Discussion Board

Carbides

DFliyerz - 14-2-2015 at 16:12

Carbides... carbides are freakin' weird. Some make methane, some make acetylene, some make propyne... what? And they're so simple too! Anyways: are methanides, acetylides, and sesquicarbides the only types of saline carbides? What's the explanation for these strange reactions? Is it possible to make carbides at non-crazy temperatures?

blogfast25 - 14-2-2015 at 17:06

Quote:
Copper(I) acetylide can be prepared by passing acetylene through a water solution of copper(I) chloride. Silver acetylide can be obtained in a similar way from silver nitrate.

http://en.wikipedia.org/wiki/Acetylide


But apart from these it's mostly high temperature chemistry, I think.

DFliyerz - 14-2-2015 at 17:11

Quote: Originally posted by blogfast25  


But apart from these it's mostly high temperature chemistry, I think.


Actually, Wikipedia says something about making aluminum carbide from silicon carbide and aluminum, but it's unbelievably vague.

blogfast25 - 14-2-2015 at 19:11

Quote: Originally posted by DFliyerz  
Actually, Wikipedia says something about making aluminum carbide from silicon carbide and aluminum, but it's unbelievably vague.


I hope you realise just how inert SiC is. We're talking high T chemistry again, I think.

IrC - 14-2-2015 at 20:35

Since your on the subject can anyone explain why my name is unobtanium. I tried for years but Iridium will not form a carbide, only a eutectic with carbon. I have never found anyone who can explain this, even above 3,000 C it will not form a carbide. The very reason why so many years ago I chose IrC, one must always have a never ending goal.

DFliyerz - 14-2-2015 at 20:50

Quote: Originally posted by IrC  
Since your on the subject can anyone explain why my name is unobtanium. I tried for years but Iridium will not form a carbide, only a eutectic with carbon. I have never found anyone who can explain this, even above 3,000 C it will not form a carbide. The very reason why so many years ago I chose IrC, one must always have a never ending goal.


I'm guessing you've tried extremely high pressure as well?

IrC - 14-2-2015 at 22:45

No I'm not that well equipped but so far all the papers I have read by scientists that are say the same thing, only a eutectic is possible. Or at least this is all that has been accomplished in the area of Iridium - Carbon chemistry. Electronics is my real job I am not a chemist although I have studied and experimented for many years in that and other disciplines. My theory knowledge of chemistry is not on the level of so many here. But I do not see why Iridium does not bond with carbon in the same way say W does. There must be a reason yet so far I have never found a paper which explains it in detail. Likely only because it is not something many have been motivated to investigate.

Mostly Pt and Pd are discussed in the following PDF's although Ir reacts in similar ways.



Attachment: pmr-v8-i3-101-101.pdf (89kB)
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Attachment: Tempmeko 2001 HTFP at NPL Vol 1 Page 519.pdf (3MB)
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[Edited on 2-15-2015 by IrC]

DFliyerz - 15-2-2015 at 15:30

Quote: Originally posted by IrC  
No I'm not that well equipped but so far all the papers I have read by scientists that are say the same thing, only a eutectic is possible. Or at least this is all that has been accomplished in the area of Iridium - Carbon chemistry. Electronics is my real job I am not a chemist although I have studied and experimented for many years in that and other disciplines. My theory knowledge of chemistry is not on the level of so many here. But I do not see why Iridium does not bond with carbon in the same way say W does. There must be a reason yet so far I have never found a paper which explains it in detail. Likely only because it is not something many have been motivated to investigate.

Mostly Pt and Pd are discussed in the following PDF's although Ir reacts in similar ways.


I didn't look much into it, but there were some mentions of research involving the optical properties or something of iridium carbide. I also saw something about it being for sale.

Bot0nist - 15-2-2015 at 17:26

Not sure if it's legit, but there are a few listings for your unobtainium on google. I thought I had read somewhere that it was employed in hydrazine propulsion systems. I can't recall where now though.
http://www.americanelements.com/irc.html

IrC - 15-2-2015 at 20:14

Odd they list no properties for their IrC other than being crystalline. From all I have studied thus far my guess is their weight of 204.228 is merely the sum of Ir and C, and it is a mixture not a compound (chemical molecule). I would not call IrC a compound as one would say Tungsten Carbide, but merely a crystalline structure of a mechanical mix between Ir and C. This seems to be the trend with all the Platinum group elements.

From the PDF I linked above (pmr-v8-i3-101-101.pdf):

"X-ray diffraction studies showed that these eutectiferous structures were mechanical mixtures of the metals and graphite. The lattice parameter data indicated that the solid solubility of carbon in platinum, palladium, rhodium and ruthenium was vanishingly small, and prolonged heat treatment at temperatures just below the eutectic points failed to induce any of these metals to take up any carbon."