Alchemistry & engineerism

One step short of crazy, you're passionate.

[kemistig]

I drink copious (in my humble opinion) amounts of tea. Like 400 ml for breakfast. And I take milk in it.

Milk contains lactose, which will be the subject of this my return to posting about chemicals and engineering (in varying proportions) and the bane of many a stomachs. The image depicts beta-D-lactose, where the beta stands for the stereochemistry around the glycosidic bond that joins the two constituent sugars, glucose and galactose. Glucose is sweet and lactose is not. Milk contains around 4 % lactose which can be removed enzymatically by splitting the molecule or via a chromatographic method. The enzyme leaves glucose and galactose in the milk, and in principle it tastes sweeter than normal, lactose-y milk. In theory this also means that lactose free milk goes bad faster.

Practically, though, I've seen little or no difference. They both run out at the worst time.

[chemprentice]

Pronounced like “lapel” without the “L sound”, the Appel reaction converts alcohols into alkyl halides with inversion of stereochemistry. This reaction proceeds via SN2 for primary and secondary alcohols, and SN1 for tertiary alcohols. I had previously illustrated this reaction in one of my

[kemistig]

Reblogged for familiarity!

[kemistig]

Explosives!

Top: RDX (hexogen) and HMX (octogen), a pair of very powerful high explosives that have seen military use throughout the entire 20th century. RDX was used in the composition of early plastic explosives, and is still used in this application. It was also used for underwater applications in mixtures with TNT and aluminium such as Torpex.

Middle: PETN, pentaerythritol tetranitrate. A vasodilator as well as a high explosive, PETN also heirs from the 19th century but is still used today because of its high effectiveness. Compared to many other energetic substances it is quite non-toxic. An interesting fact is that it can also be considered biodegradable!

Bottom: The old movie star, TNT. Trinitrotoluene, as anyone with a little organic nomenclature quickly will resolve its name to, is excellent for making shells and bombs since it can easily be fused and casted into casings. TNT is the standard measure of explosive power; the nuclear weapon yield unit kiloton is just the explosive power of one thousand tons of TNT. Trinitrotoluene is relatively toxic and generally unpleasant, but very safe with regards to accidental detonation.

[rutilusstrix-deactivated2015062]

[kemistig]

Did I mention I love boats, and that tall ships are the best?

[kemistig]

What can I do with a science and engineering degree???? Ur blog is deff chem engineering no?

Yes, I'm a student of chemical engineering, although my blog posts have mostly been about chemisty so far. Engineering is advancing humanity through technology - there are as many engineering jobs as there are engineers, but in general a lot of problem solving is involved. Many chemical engineers do extensive modelling in advanced software, while others work mainly in research labs as chemists.

I myself am aiming towards a job "on the floor", i.e. the daily operation of a process plant. We'll see where I end up.

[labphoto]

A copper-amine complex at the bottom of the flask. Chemistry with transition metals is often colorful, luckily more colorful than “classical organic chemistry" where you can get 2 color: white and black :D

[kemistig]

Make those off-white bordering on piss yellow and icky gunk-brown, respectively :D

Jokes aside: transition metals are awesome.

[labphoto]

Piss yellow diazo compound dissolved in ether in the beaker. Please put away everything what can cause fire :D

[kemistig]

I can't be the only one who wants to see the mega-hyped, almost legendary, ether fire?

[fuckyeahfluiddynamics]

A drop of fluorescent dye falling into quiescent water forms fantastical structures that are a mixture of vorticity, turbulence, and molecular diffusion. The horseshoe-like shape near the front of the drop is a typical shape for two fluids strained by moving past one another. The main section of the drop billows outward like a parachute, but the turbulence of its wake stretches the dye into fine threads that quickly disperse in the water. (Photo credit: D. Quinn et al.)

[kemistig]

It's green. That's enough for me.

[kemistig]

After many long hours in the lab and by the computer we have finally turned in our thesis on carbon-carbon couplings between glycerol molecules via organometallic reactions. It has been a great project with some of the best people I know, and we actually managed to win a cash prize too!

I would like to remind you that the difference in viscosity between water and glycerol is on a 10^3 scale, while the difference between water and blood is less than a factor 10.

[kemistig]

Oh! Shiny molecule!

Potassium tert-butoxide (t-BuOK) is a convenient strong base created when potassium metal reacts with tertiary butanol. A fun thing about this compound is the cubic tetramer it forms upon sublimation - it apparently exists even in gas phase!

Due to its (quite visible) steric hindrance it is non-nucleophilic, which makes it a good choice for many syntheses, but its basicity is somewhat limited with a conjugate acid pKa of 17.

Another interesting (or annoying) property is that it tends to form the Hoffmann elimination product, contrary to the "rule" that proposes the most substituted alkene is formed. (Further reading on this blog!)

[labphoto]

Gunk, gunk, gunk and gunk. Dry distillation of furanecarboxylic acid yields furane and CO2, it’s an easy decarboxylation. The problem is that it also produces a massive amount of tarry byproduct. 

[kemistig]

Hopefully there will soon be a picture of a cool cleanup with some of the more extreme stuff :D

[labphoto]

A reaction after quenching it with some KI3. The carbon-mercury bond breaks, a carbon-iodine bond forms and this red mercury-iodide separates. 

Isn’t it pretty?

[kemistig]

Pretty and dangerous. Aren't all the best things in life?

N.B. that danger is always relative!

[kemistig]

These past few days I've gained a whole host of new followers, which of course would make any blogger happy! Big thanks to Emil at lotrproject.com (tumblr) who might've had something to do with it. Next time we work together in the lab I'll let him do all the cool operations.

The pictures depict tetrahydrofuran, a favourite solvent (complete guesswork from my side, actually) of many chemists and a polar one, at that. It acts and performs similarly to diethyl ether but is somewhat nicer to handle, in my opinion. Its main issue is its hygroscopicity - it absorbs and retains water - and its ability to form potentially explosive peroxides. It also doesn't smell as nice.

THF, as it is more often called, boils at 66 °C (151 °F) and unlike diethyl ether it's fully miscible with water; for extractions you still have to use the good old Et2O.

[labphoto]

Activation of magnesium with some subliming iodine. It has a really pretty color and it start’s the formation of Gringard reagent in no time!

[kemistig]

I suggested we'd do this when our Grignard reagent formation wouldn't start. I was practically mocked!

[labphoto]

That awesome moment when I can’t decide that wich is the worse: the mercury or the cyanide? :D

[labphoto]

We have tried out an electrochemical reaction with tungstern cathode (that spiral at the bottom) and a platinum anode (the net in the center). The result was a black gunk. 

[kemistig]

Neat setup, though! I'm a big fan of Kristof's :D

[kemistig]

Wrote an exam on chemical reaction engineering today. It went so-so, but in one of the tasks was to design a reactor for the hydrolysis of acetic anhydride, a reaction we previously examined in the laboratory (dangerously boring!)

This substance, with the IUPAC name ethanoic anhydride, can also be named acetylacetate and acetic acid anhydride, but these names are hardly ever used. It's a cheap chemical employed as an acetylating agent, for instance in the production of aspirin (http://en.wikipedia.org/wiki/File:Aspirin-skeletal.svg) and some modified starches.

It is produced by catalytic carbonylation starting from methanol via methyl acetate. As a precursor to heroine, acetic anhydride is a listed substance, but is used by many research laboratories and production plants nontheless.