woelen
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nickel carbonyl, hard to make?
I just want to tell about an experiment I did, but which did not succeed. Maybe someone else has done a similar experiment or knows about the methods,
needed to make Ni(CO)4.
I made appr. 100 ml of carbon monoxide from conc. H2SO4 and HCOOH at moderate heat (60 C or so). This can easily be done. I put the stuff in a test
tube and put a rubber stopper with a hole in the test tube and a thin PVC tube attached to it. After half a minute or so I attached a syringe to the
little tube and it slowly fills with dry and pure CO gas.
In a separate dry test tube I put a small spatula full of fine nickel powder (<= 10 um particle size). I then at once blew more than 80 ml of
CO-gas in the test tube and immediately stoppered it. I think that it was filled with almost pure CO and only little amounts of remaining air.
Then I carefully heated the test tube, but only weakly, such that it will be somewhere around 60 C or so. I also swirled the nickel powder somewhat.
No visible changes occurred.
Then I heated much stronger on another place of the test tube, hoping to get a nickel mirror, due to decomposing Ni(CO)4. This nickel mirror did not
appaer. Then I left the test tube for a few hours at its place. After that no visible changes had occurred.
Finally, I opened the test tube near a flame. The gas from the test tube burnt with a nice blue flame, just as expected. This is the color of the
flame of burning CO-gas.
This experiment was NOT intented to make Ni(CO)4 in decent quantities for keeping around. I just was curious how easy (or hard) it is to make such a
compound.
If anyone wants to repeat this experiment, be VERY careful. Ni(CO)4 is extremely toxic, much more so than CO or Ni alone. I did the experiment outside
and also opened the test tube outside when I burnt the CO-gas.
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garage chemist
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Making nickel carbonyl from nickel and carbon monoxide requires the presence of a fully reduced nickel surface.
Nickel powder that has been kept in air does not meet this requirement.
The nickel powder has to be formed in situ by reduction of nickel oxide with e.g. hydrogen and then the atmosphere changed to one of CO without ever
letting in any oxygen.
Making Ni(CO)4 is definitely not "test-tube chemistry". One has to set up an elaborate apparatus.
Instructions can be found in Brauer.
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benzylchloride1
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I have a procedure that can be used to synthesize small quantites of nickel carbonyl. This procedure was obtained from Waltons Inorganic Preparations.
This book is in the Science Madness Library. The glass apparatus will have to be constructed by a glassblower; a picture of the apparatus is in the
book. I could not copy and paste it to my post. Have fun and conduct this in a efficient fume hood as this compound is often called "Liquid Death".
13. Nickel Carbonyl 5
A number of the transition metals combine with carbon
monoxide to form compounds known as the carbonyls. These
are all more or less unstable, and most of them require high pressures of carbon monoxide for their formation. Only elements
with even atomic numbers form simple carbonyls having only one
atom of metal in the molecule; in the first long period, the simple
carbonyls known are Cr(CO)6, Fe(CO)5, and Ni(CO)4. Car-
bonyls are to be considered as coordination compounds in which
the carbon monoxide molecule, probably through the carbon,
donates a pair of electrons to the metal atom. It will be noticed
that if we add two electrons from each CO molecule to the
electrons in the metal atoms, we have 36 electrons in each case;
this is the number of electrons in the atom of the next inert gas,
krypton. The metal atoms in these carbonyls have an electronic
configuration like that of an inert gas. The bonding between the
metal and the carbon is considered to resonate between single
and double bonds.
According to this interpretation, odd-numbered elements such
as cobalt canngt form simple carbonyls M(CO), but they do
form complex carbonyls, such as Co2(CO)8. These are solids, in
contrast to the simple carbonyls, which are volatile liquids.
In all these compounds, some or all of the CO can be replaced
by nitric oxide, NO, which is believed to donate three electrons to
the metal. On this basis, the formation of the volatile cobalt
nitrosyl carbonyl, Co(CO)3NO, is easily understood.
Nickel carbonyl is prepared in this experiment, since it is the
easiest of the carbonyls to prepare, no high pressure being needed,
and is of industrial importance in the Mond process for the
purification of nickel.
The apparatus is shown in Fig. 12. The connections between
vessels A, B, and C must be all glass. No rubber may be used.
Sealed connections are best, but ground-glass joints lubricated
with a mixture of 1 part paraffin to 3 parts vaseliim may also be
used. Avoid leakage of nickel carbonyl into the room; it is extremely
poisonous, inflicting permanent damage to the body through
deposition of colloidal nickel in the organs, and the smell is not
strong enough to give due warning of its presence. The appara-
tus should therefore be set up in the hood. The gases pass out of
the reaction system through a mercury bubbler or check valve to
a glass capillary outlet inserted into the air intake of a lighted
Bunsen burner. The flame will burn up any nickel carbonyl and
will also be colored a brilliant gray by it.
Vessel A is about 25 mm in diameter, has a glass-wool plug in
the bottom, and is filled to a depth of about 7 cm with nickel
formate crystals that have been mixed with about 1 per cent by
weight of mercuric oxide. It is immmersed in an oil bath. The
tube C is loosely packed with pieces of broken glass or porcelain
for part of its length. The two stopcocks at the intake of A are
connected to sources of hydrogen and carbon monoxide. Tank
hydrogen should be freed from traces of oxygen by passing it over
red-hot copper and then through a phosphorus pentoxide tube.
First displace the air from all parts of the apparatus, including
the carbon monoxide intake, and pass hydrogen slowly. Heat
the oil bath, raising the temperature slowly from 100 ° to about
190 or 200 ° , until the green nickel formate begins to go black
because of decomposition to metallic nickel. The water of
crystalli.ation of the nickel formate is meanwhile carried away
by the hydrogen stream; to avoid condensation of this water in
B and C, this trap and tube should be kept heated during the
decomposition. Nickel formate decomposes on heating, mainly
into Ni + CO. + H2; however, a certain amount of water and
CO are formed as well. Do not heat the nickel formate or nickel
aboe 200 °, or the reactivity of the nickel will be reduced.
When the reduction to metallic nickel is complete, remove the
oil bath and let the tube A cool to room temperature, passing
hydrogen continuously. Place a Dewar vessel with dry ice and
acetone around the trap B. When A has cooled, turn off the
hydrogen and pass carbon monoxide rapidly. Watch the mer-
cury bubbler carefully; if the mercury sucks back too far, turn
on the carbon monoxide faster and nearly close the pinch clamp on the rubber tube leading from the bubbler. Do not let air suck
back into the reaction system.
Nickel carbonyl condenses in the trap B as a white solid.
When the reaction is over, reduce the carbon monoxide flow to a
very slow rate and let the contents of B thaw out. Mark the
level of the liquid in the trap with a gummed label, and afterward
measure the volume and calculate the yield. The specific
gravity of nickel carbonyl is 1.31 at room temperature.
Now warm the tube C gently with a flame until it is lust too
hot to touch--between 50 and 100°--and increase the flow of
carbon monoxide. Nickel carbonyl vapor is carried over and
decomposes in C, depositing a mirror of nickel on the surfaces.
The principle of the Mond process for purifying nickel is to pass
carbon monoxide over the metal and then to decompose the
nickel carbonyl on the surface of heated nickel balls. Cobalt,
the main impurity to be removed, does not react with carbon
monoxide under these conditions, and in any case its carbonyl i s
not volatile. Nickel completely free from cobalt is thus obtained.
Before the liquid carbonyl in B is all gone, pass some nitric
oxide into it. The nitric oxide may be prepared as in Experi-
ment 24 and stored over water, but it must be dried by sulfuric
acid before being used for this purpose. Pass it in through the
stopcock originally used for hydrogen and let it flow slowly for
about half an hour. A complex solid nickel nitrosyl carbonyl
should form in the liquid in B.
If pure liquid nickel carbonyl is wanted for any purpose, the
tube C is dispe/sed with and arrangements are made to transfer
the carbonyl from the trap to an appropriate receiver. Nickel
carbonyl oxidizes spontaneously in air, but if a little oxidation is
not harmful it may be poured quickly from one vessel to another
in the air, but only in a good draft. Nickel carbonyl is very
volatile at room temperature, and, as has been said, the vapor is
extremely poisonous.
Amateur NMR spectroscopist
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Jor
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It seems that this compound is much more dangerous than what i presumed to be one of the most dangerous inorganic gasses: COCl2, H2Se, AsH3, etc.
Added, it is also a carcinogen. It has a PEL (of MAC in Holland I think) of 0,001ppm.
Not recommended 
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Inorganic
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This is very very dangerous compound. I heard true story where two people working with ~100mg of Ni(CO)4 in well ventilated university lab almost they
die
Ni(CO)4 is extremely toxic !! this is thousand times more toxic then H2S or CO !!
[Edited on 2-5-2009 by Inorganic]
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DJF90
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My friend did work experience at a Nickel factory where they use purify nickel via Ni(CO)4. Despite everything being done in a sealed system they
still had to give the employees urine tests on arrival and before departure from work to make sure none of them had been exposed. It is a very nasty
chemical indeed, and as such I think it is definately something that should be a "no-go" for amatuers.
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JohnWW
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The formation using CO of Ni(CO)4, in which 4 pairs of electrons from the C atoms fill the empty 4p and 4s orbitals on the Ni atom, is used on a large
scale in the mining and smelting of Ni, in places like New Caledonia, and Sudbury, Ontario, and a new Ni mine in the West Australian outback, to
purify it. Apparently it forms more readily than the carbonyls of impurities such as Fe, Mn, V, Cr, and Co. Ni is found associated with intrusions of
ultrabasic rocks such as olivine, in which these other metals and platinum-group metals and sometimes copper-group metals are also found, and also in
metal deposits of meteoritic origin.
[Edited on 3-5-09 by JohnWW]
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woelen
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Quote: Originally posted by DJF90  | | My friend did work experience at a Nickel factory where they use purify nickel via Ni(CO)4. Despite everything being done in a sealed system they
still had to give the employees urine tests on arrival and before departure from work to make sure none of them had been exposed. It is a very nasty
chemical indeed, and as such I think it is definately something that should be a "no-go" for amatuers. |
As I
stated, I did not intend to make and isolate this compound in decent quantities, but I was just curious how easy it can be mode and whether it is
possible to make a nickel mirror from this compound on a hot surface. It turned out not to be possible as stated by garage chemist and for me this
litte excursion end here. I do not have the elaborate equipment, needed for making this compound and I certainly am not willing to make more than mg
quantities of this. In my little experiment I only used 5 mg of fine nickel powder, according to my analytical scale. It was just a tiny speck of
nickel powder at the bottom of a test tube.
Nickel carbonly is very toxic, but I do not believe that such a small scale experiment as I did really (if it did succeed) is dangerous, the more
because I did this outside. I might have made just 14.5 mg from 5 mg of nickel and this does not all end up in my lungs, not even in a closed room
 One has to see things in perspective. Keeping around a few ml of this liquid
indeed is very dangerous and is not something for the amateur chemist, but having 15 mg of this quantity, outside, no attempt to isolate it, is
another matter.
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a_bab
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I agree with this; many "extremely dangerous chemicals" can be handled safely IF in small quantities. Like, "I handle just about the lethal dose".
Just enough to actually "see" the substance. Now, the worst case scenario is to have the whole amount absorbed by the body in some way, which is not
likely unless done on purpose.
Colloidal Ni deposited in the organs? In other words, "Nickel argyria"? Now that's nasty.
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Sydenhams chorea
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Attached is Adkins and Krsek, J. Am. Chem. Soc., 70, 383 (1948), it describes the Roelen reaction which involves the addition of carbon
monoxide and hydrogen across an alkene using a cobalt catalyst. In the first stage of the process an ether-soluble cobalt compound, dicobalt
octacarbonyl, was prepared by reaction of cobalt and carbon monoxide under pressure.
The hazards and a comparision to nickel carbonyl is described as follows:
| Quote: |
The use of carbon monoxide under pressure with the highly poisonous cobalt carbonyls is not without danger. The ill effect of breathing carbon
monoxide is sufficiently well known so that a warning is perhaps not necessary. According to Gilmont and Blanchard "the odor of cobalt
tetracarbonyl hydride is so intolerable that the danger from inhaling it is much less than from nickel tetracarbonyl. However, it is probably equally
poisonous, and the same precautions should be taken as with nickel tetracarbonyl."
The hydride decomposes even at room temperature, so that it will disappear rapidly from reaction mixtures held at atmospheric pressure, with the
formation of dicobalt octacarbonyl. Fortunately this latter compound has a low vapor pressure and so may be handled with much less hazard than nickel
tetracarbonyl. The dicobalt octacarbonyl also decomposes slowly in an open vessel to give carbon monoxide at room temperature. However, in an ether
solution in a closed Pyrex bottle there is no development of pressure or appreciable decomposition at room temperature. |
Attachment: ja01181a119.pdf (135kB)
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Il n'y a point de sots si incommodes que ceux qui ont de l'esprit.
François de La Rochefoucauld.
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ScienceSquirrel
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Have a look on page 5 of this reference for an interesting route to nickel carbonyl;
http://science-blogs.ucoz.com/resources/notes/msc/theory/Coo...
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12AX7
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| Quote: Originally posted by benzylchloride1 | Avoid leakage of nickel carbonyl into the room; it is extremely
poisonous, inflicting permanent damage to the body through
deposition of colloidal nickel in the organs, and the smell is not
strong enough to give due warning of its presence.
|
Presumably someone tested that at one point.
 !!!
On topic, I recall reading here a long time ago, someone had posted a story (it might be from one of the official safety pages out there on the
chemical) where a worker had been drenched in the stuff. He survived, thanks to good training: don't inhale EVER!
Tim
[Edited on 10-19-2012 by 12AX7]
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White Yeti
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I'm just wondering, is there a special reason why you tried to make nickel carbonyl instead of iron carbonyl?
The reason why I ask is because (on paper at least) iron carbonyl seems to be much safer and easier to make than its nickel counterpart. Back when I
was more foolhardy than sensible, I contemplated the synthesis of iron carbonyl. The first step would have been the synthesis of pyrophoric iron via
the decomposition of iron oxalate. The iron, while still warm and under an immobilised atmosphere of carbon dioxide, would then be treated with a
stream of carbon monoxide generated via the dehydration of formic acid with sulfuric acid.
"Ja, Kalzium, das ist alles!" -Otto Loewi
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DJF90
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Theres no need for pyrophoric iron. I was interested in Fe(CO)5 as a starting material to Fp2; thats cyclopentanyliron dicarbonyl dimer. It has a
whole array of interesting organometallic chemistry. Anyway theres a preparation in Sanshiro's book, which I've quoted here for convenience:
| Quote: | Because pure pentacarbonyliron(0) is commercially available at a reasonable price, it is not usually necessary to prepare it. However, this method is
sometimes used for the preparation of 13C or 18O labeled Fe(CO)5.
Iron powder (5.0g) is suspended in dry heptane (30ml) and is activated by shaking for 15min in an atmosphere of H2S. A slight gas evolution on the
surface of the iron particles is observed during the activation. The suspension is then store under nitrogen. After introduction of 13CO or C18O at
atmospheric pressure, the suspension is stirred at room temperature very vigorously for 20h. The solution gradually turns red during the reaction. The
solvent is then removed under reduced pressure. The title product [Fe(CO)5] is obtained by distillation at atmospheric pressure (bp 103*C).
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Hexavalent
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A chemical similar to the one discussed here was mentioned on YT: http://www.youtube.com/watch?v=u6MfZbCvPCw
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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