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SWIG's stash of red phos has run low and is weary. He waits to replenish his
supply, but until that day comes (patience is the rule) he decided to play
with a bottle of hypophospohorous
acid he had on hand, a gift from a fellow enthusiast. SWIG used TFSE to great
length, reading between what appeared to be many lines, before attemptin his
first hypo rxn.
He had ten gms of pseudo left from his last I2/red p cook (did not have
enough red p to use it all). He followed Pebble's synth as best one can in a
250 ml Erlenmeyer flask on the electric range. A little scary, but there were
three distinct stages, smells, and when it was done, it was clearly done.
Produced just shy of seven grams of finished but not recrystalized product.
The bio assay was excellent, on par with SWIG's red p product. Very smooth,
very long-legged.
Encouraged, SWIG boiled the bottle of acid to concentrate it, taking it off
the heat when the temperature reached 15 degrees C above the intital boiling
point. Being completely out of product and in need fuel for the weekend's
chores, he bought some of those clean convenience store pills and got eight
grams of pseudo. He used ten ml of hypo, and fifteen grams of iodine. He chilled his acid down
for thirty minutes before starting. He added his pseudo and his iodine to the
flask first, then the cold hypo. This gave him exactly enough time to hook his hose to
the top of the 500 ml volumentric flask he was using. The hose looped over
the top of the standard to a muffler jar-- a one litre Erlenmeyer filled 2/3
with water. The mix fumed and boiled immediately. He added heat and all went
well for about seven minutes, at which time the muffler jar suddenly and
spontaneously erupted in flames. The hose spewed out of the flask, flame
sprouting from its free end. Smoke, white and noxious, began filling the
room. SWIG calmly pulled the flask from the heating element, tossed a wet
towel over the muffler jar, and put a clamp on the hose. He then proceeded to
run like hell. Thankful that he lives well out of town, and glad that he had
that big fan running full blast, he returned shortly to find the fires out.
The flask with water in it had an orange film on the inside above the water
line. This came off easily with water. SWIG returned the flask to the heating
element, albeit at reduced temperature, and continued the cook. Within twenty
minutes of the return, the sides of the flask were clear and the contents
were golden colored. No activity going on, SWIG called the cook over, and let
the flask cool. Without filtering, he added xylene to the flask and then 20%
NaOH solution. Not enough, had to add more naOH. That done he managed 7 gms
of excellent product. Clean, very clean, and very effective.
That fire was scary as hell, though. Spontaneous combustion, no open source
of flame, no source of spark. Will reflux next time. No more of the old hose
to the jar trick for SWIG!
GMZ--long
a lurker gone public lately
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This situation is easily avoided by changing your addition sequence and
technique when everything is placed into the reaction vessel.
A beaker of Hypophosphorus
acid on it's own in any quantity that is heated and concentrated will, if not
monitored and removed from heat in time, spontaneously combust with all the
vigour and determination of red phosphorous.....smoke and all. But I am not
informing you of anything you dont already know there!
If the concentrated acid is placed in the reaction vessel first (chilling not
required as long as it is room temp and not still hot from concentrating it)
The feedstock is added and swirled and dissolved as much as it will, and it
matters not that all of it wont want to go into solution.
Then without any heat at all I2 is added to the mix in small enough portions
so all that eventuates is the fizzing reaction of the I2 as it hits and
reacts, and dissapears into the solution. If this addition is for instance in
a vessel with a stopper and hose it is simplicity itself to drop small
amounts into the neck and place the stopper on until the fizzing stops, if the
neck is smallish like a ground glass joint addition through the condensor is
favoured and this is assisted by the I2 first being ground in a mortar and
pestle to avoid clumping and blocking the tube, difficult once condensation
begins in any case so a suitable instrument to probe and clear the tube is
needed before beginning.
Once all the I2 has been added the reaction will continue for as long as it
wants to still no heat or radical anythings and very soon after will give you
a nice clear/yellow solution.
Heat is now applied in sufficient amounts only until a reaction is self
sustaining at which point it removed and the reaction allowed to take it's
course, then heat is reapplied until the point is reached when you are at
reflux of a now clearer and paler yellow solution, at which point if you have
the ratios and conentration of acid correctly pre-determined.....you are
finished.
Adding red P during any of this will only serve to nesesitate it's removal
again at some stage and I see this as an interesting but pointless step
unless one enjoys red over yellow for rxn visual stimulation.
I offer this as advice only due to my concern for the unninitiated person
getting fried in many possible ways by not being made aware of this
combustion PROBABILITY, not POSSIBILTY, and not as a synthesis for discussion
and debate at this point in time. If you dont agree with my advice I couldn't
care less so save your energies spent replying in going and proving me
incorrect as your time will be better spent and answers more forthcoming.
Regards,
Hematite.
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Hematite: Your detailed response is very much appreciated. The
procedure you suggest for a
hypophosphorous-I2 reduction makes
sense to SWIG, who now has only four hypo reactions under his belt. He will follow your
suggestions his next time around. SWIG said he is surprised that there is so
little info on hypophosphorous
acid reactions on the board, given that it is fast,
clean, and fast. And clean. And works quite well. And it is fast. And clean.
And works very well,thank you. SWIG said he’d done two more reactions since
the last post, both quite successful. He thanks you for your help!
BenWiffen: There were two separate reactions, one with ten grams of pseudo,
one with eight. The process using hypo is certainly a direct and fast method for doing a nano
style cook.
GMZ--long
a lurker gone public lately
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