
A step towards new nitrogen products - apsec112
https://news.yale.edu/2020/08/12/new-nitrogen-products-are-air
======
ttul
[https://www.nature.com/articles/s41586-020-2565-5](https://www.nature.com/articles/s41586-020-2565-5)

The activation of abundant molecules such as hydrocarbons and atmospheric
nitrogen (N2) remains a challenge because these molecules are often inert. The
formation of carbon–nitrogen bonds from N2 typically has required reactive
organic precursors that are incompatible with the reducing conditions that
promote N2 reactivity1, which has prevented catalysis. Here we report a
diketiminate-supported iron system that sequentially activates benzene and N2
to form aniline derivatives. The key to this coupling reaction is the partial
silylation of a reduced iron–dinitrogen complex, followed by migration of a
benzene-derived aryl group to the nitrogen. Further reduction releases
N2-derived aniline, and the resulting iron species can re-enter the cyclic
pathway. Specifically, we show that an easily prepared diketiminate iron
bromide complex2 mediates the one-pot conversion of several petroleum-derived
arenes into the corresponding silylated aniline derivatives, by using a
mixture of sodium powder, crown ether, trimethylsilyl bromide and N2 as the
nitrogen source. Numerous compounds along the cyclic pathway are isolated and
crystallographically characterized, and their reactivity supports a mechanism
for sequential hydrocarbon activation and N2 functionalization. This strategy
couples nitrogen atoms from N2 with abundant hydrocarbons, and maps a route
towards future catalytic systems.

~~~
burfog
It's "easily prepared", eh? Let's take a moment to appreciate the toxic,
volatile, pyrophoric nature of this concoction:

"sodium powder, crown ether, trimethylsilyl bromide and N2"

Well, the N2 is probably fine.

The pyrophoric sodium powder might even be a good thing, because it will cause
an inferno long before the crown ether has a chance to form explosive
peroxides.

~~~
dnhz
The reaction should be conducted in an oxygen-free, pure nitrogen atmosphere
where those compounds should be safe to handle.

~~~
URSpider94
When it’s boiled to dryness, crown ether can produce peroxides that are
unstable enough to explode on their own with shock or additional heat - no
oxygen needed.

It’s a not-uncommon mistake to make in a synthetic lab.

~~~
dnhz
My understanding is that evaporating solvent away doesn't form peroxides.
Rather, as an ether ages, it can peroxidize. Removing the solvent concentrates
the peroxides is all. Sure, it's a little tricky, but they're reporting
results of chemistry research, which doesn't mean immediate real world
application.

------
wcoenen
As far as I understand, the non-nitrogen atoms in the reaction are provided by
benzene.

Fun fact: benzene is so important in chemistry that it has two unicode code
points, ⌬ and ⏣.

~~~
thaumasiotes
Well, unicode doesn't have much to do with chemistry, or with importance.
Those two symbols both long predate unicode (as you'd expect given the nature
of unicode).

The reason for the second symbol is that the positioning of the double bonds
within the ring is underdetermined (and indeed, doesn't really exist) -- they
are in a state of indeterminate flux much like the bonds in a molecule of
ozone. The circle explicitly acknowledges that we can't really identify
particular bonds as being the double bonds.

~~~
EE84M3i
>Those two symbols both long predate unicode (as you'd expect given the nature
of unicode).

Yes, but notably they are not included in Unicode for compatibility with
legacy character sets.

~~~
thaumasiotes
Are they included in Unicode for any reason? They're not textual and don't
make any sense (they are actually ill-formed[1]) as independent glyphs.

[1] OK, they're not ill-formed if you really want to insert a miniature icon
of a free benzene molecule into running text, but in chemistry you're mostly
talking about benzene rings as a structural element in larger molecules, not
molecular benzene.

------
davidhyde
One of the uses of aniline is hypergolic rockets although its pretty toxic
stuff and as not used for large rockets anymore. Making test tube rockets with
aniline, pretty interesting:
[https://www.youtube.com/watch?v=OszX18NLtrY](https://www.youtube.com/watch?v=OszX18NLtrY)

------
chrisbrandow
Catalytic nitrogen fixation is one of the holy grails for chemists, so papers
that get within spitting distance often get a lot of attention.

This paper seems very interesting, but unless I’m mistaken it’s not catalytic
and that’s a big caveat.

~~~
nine_k
Apparently none of the components of the mix get used up except the nitrogen
and the benzene. It may be not one-step catalytic, but this should not be a
problem.

What am I missing?

------
michieldotv
Atmospheric nitrogen is a big source of environmental and human harm in the
Low Countries. The nitrogen deposits are literally smothering what little
nature is left.

It already led to a full-blown crisis in The Netherlands where construction
sites were ordered to shut down. In Belgium, with the lack of effective
national governance, the nitrogen problem is not being laying dormant.

This kind of innovation hopefully bodes well for Belgium which has both an
abundance of nitrogen _and_ a pervasive petrochemical industry.

~~~
isthisnametaken
Atmospheric nitrogen sounds bad.

And the Netherlands has to contend with some serious dihydrogen monoxide
issues, too.

~~~
thaumasiotes
> dihydrogen monoxide

I always wanted to know why this name was picked over "hydrogen hydroxide".

~~~
throwaway_pdp09
Because people know carbon monoxide is toxic and will quickly make the false
association.

~~~
thaumasiotes
People know chlorine is toxic and salt is half chlorine... :/

------
mkoryak
There is a book which tells the story of fixing nitrogen from air and its a
fanatic read:

[https://www.goodreads.com/book/show/3269091-the-alchemy-
of-a...](https://www.goodreads.com/book/show/3269091-the-alchemy-of-air)

its non-fiction

------
WantonQuantum
I find it interesting that I initially interpreted the headline “New nitrogen
products are in the air” as a story about pollution. I.e., new nitrogen
products (pollutants) have been detected in the atmosphere.

~~~
chrisco255
Ah well Nitrogen is the most abundant gas in the atmosphere so it's not by any
stretch a pollutant.

~~~
vikramkr
N2 isn't a pollutant but many nitrogen compounds are major pollutants, and its
not so far fetched to call something like NO2 a "nitrogen product"

------
TedShiller
> The discovery comes from a team of Yale chemists who found a way to combine
> atmospheric nitrogen with benzene to make a chemical compound called
> aniline, which is a precursor to materials used to make an assortment of
> synthetic products.

Ok, great. This is stated in a fairly neutral way. But one wonders if we are
considering the negative effects of those synthetic products. That was the
problem with plastics -- although revolutionary, there was a dearth of
discourse about its negative effects, which we are feeling now.

~~~
maxerickson
Aniline is already a widely used industrial compound (used to make
polyurethane). The novelty here is making it from atmospheric nitrogen.

~~~
MertsA
Nitrogen also makes up 2.6% of the Martian atmosphere and Nitrogen gas will
likely be an important feedstock for future Martian ISRU plans.

