itsallgoodjames
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Questions about silver and copper acetylides
I plan to make about 2 grams of silver acetylide double salt and 500 milligrams of copper acetylide in the near-ish future, and I have two questions:
1. Is removal of impurities (NH3, PH3, AsH3, H2S, etc) from the acetylene needed for the synthesis of silver acetylide double salt and copper
acetylide? Or, would the effects of the impurities in the acetylene not be substantial enough to effect the final product too much?
2. If it is needed, how would one do it? I understand that sodium hydroxide will react with the H2S, but how would one neutralize the pnictogen
hydrides?
Thanks in advance for the help
Edit- I should clarify, I'm using technical grade calcium acetylide for the source of acetylene. Just opening it, it reeks of phosphine and hydrogen
sulfide
[Edited on 18-12-2020 by itsallgoodjames]
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
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B(a)P
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For your SADS you can try dissolving the acetylene in acetone then mixing it with a silver nitrate solution.
See this thread https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
I have no experience with copper acetylide, but the same approach may work.
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itsallgoodjames
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Huh, that's a really great idea. Thanks!
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
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aromaticfanatic
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I figured out that acetone step on semi-accident a while ago (I'm fdnjj6 with a different account) and added it to the wikipedia page for silver
acetylide. Give it a look if you want.
I have the original notes from the process on my journey to getting white and pure SADS. I started with scrubbers, heating, no heating, acid
concentrations, etc. and every variable gave different SADS. Scrubbers didn't do much at all. NaOH and baking soda scrubbers proved ineffective.
With no heating and some nitric acid it just gave a tan precipitate which was not the purity I had wanted. Performed well but I was bothered by the
ugly color.
I decided to try heating and it worked to make very white SADS... but it was always coated with very black outside layer and it formed globs rather
than a suspension of solid.
Using no nitric acid produced usable SADS but it left behind more soot which indicates less of the double salt formed. The pure silver acetylide is
actually more sensitive and less powerful so no nitric acid is not preferable.
I was frustrated at that point so I had an idea. I knew acetylene was the cause of impurities and I knew acetylene was very soluble in acetone. So I
went ahead and bubbled some into acetone. I made my usual nitric acid/AgNO3 solution and dropped some of the acetylene in acetone solution into the
other solution and it gave the most beautiful white precipitate. So I scaled up and it works great.
I did further testing and the best possible way to make SADS is by slow drop wise addition of acetylene solution into the silver nitrate solution at
room temp. Fast addition causes some discoloration. You want to swirl or stir your silver nitrate solution to prevent large crystals from forming.
Very pure SADS is known to form very sensitive larger crystals.
Wash the result with copious amounts of water to seep out the remaining acids (don't use a base as it could seep out the silver nitrate double salt)
and then washing with acetone to allow for faster drying. Work in dim light for the least amount of light degredation.
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