CBC: The Pretty Crystal Blog
November 4th, 2009 by excimerIf all we did from here on out is post pictures of pretty crystals we make, we would still be awesome.
Click on the above picture to the full-size pic.
There are some pretty crystals that I synthesized hydrothermally. Hydrothermal synthesis is a great way to make lots of huge, x-rayable, single crystals, assuming that your starting material is 1. insoluble in water at room temperature; 2. stable to water at ridiculous temperatures (150-200C is typical); 3. you have a way to cool the solution verrrryyyyyy slowwwwwllyyyyy. So basically it’s useless for most organic molecules, but hey, when it works, IT WORKS.
…and this is the starting material for making the above pretty crystals, which are made in a vat and also pretty.
Liveblogging: still no crystals on my end. :-Ь
Ok.ok..I try to help u….tmrw I go look up the diffuse paper for you. Let you know then. Don’t be sad.
Here you go LiqC, http://pubs.acs.org/doi/pdf/10.1021/jo900443e.
See page 1, para3, line 3 ….”slow diffusion…..”
Single crystals of 6 were obtained from a DMSO-d6 solution (2 mg/0.5 mL). Sounds like… a bis-urea.
Sounds like…a brick.
*drool*
Yes… my heart fluttered as my eyes glazed over the shinny xtals…. Hubba–hubba….
product crystals: cool lookin’ from a “i enjoy nice crystals” point of view.
starting material crystals: cool lookin’ from an “i enjoy things that belong in a fortress of solitude” point of view.
nice job all around.
While the crystals on first picture are nice (but nothing special – their habit isn’t very impressive), i bet that the crystals at the bottom are x-rayable too
1. fuck you, they are very special (to me)
2. the bottom crystals are not x-rayable, they grow quickly as disordered plates
so how did you do the gradual cooling – is this performed in some nice thermostated apparatus – or would a large oil bath with temperature control suffice ?
We have a fancy oven that can control the rate of heating and cooling. These ones were cooled at 10 °C / hr, which is actually a little fast, typically you see anywhere from 1-5 °C / hr.
Here’s to make the post complete.
http://www.youtube.com/watch?v=f3sX30NubTs
Do you lose a lot of compound just testing this method out?
May I ask what made your compound so damn insoluble?
It’s a salt, so it’s ONLY soluble in water. It’s not even soluble in methanol. It’s a lossy method (for me), but I can make this stuff on a 25+ gram scale in less than a day from cheap starting materials, so I don’t really care =)
Ah that is so an attitude I can appreciate. I am very much the same way with my compounds, whilst all around me nat. prod. chemists scrounge for every mg of compound. HAHAHAHAHA long live bulk chemistry
Colorless? heh Dope with europium. Ordinary ion coordination will give you a fat Stokes shift, near-UV absorb and red emit. Hypercoordination, especially with an anion filling the last hole, will give you brilliant red fluorescence. Gotta have a dog and pony show for the abstract graphic.
Does it dissolve in hot DEET, up to 250 C? Don’t breathe the vapors.
An undergrad lab day ought to be devoted to cute. Cyanuric acid plus melamine will obtain beautfully crystalline utter insolubles. Ditto calcium tartrate (resolved tartrate). Hydrothermal calcium tartrate doped with europium might be cute. [Tetraimidazolecopper(II)] bromide might give bitchin’ big crystals, and the terephthalate salt for polymeric linkage.
not exactly capitalizing on the Chem Blog’s demise….
wait, what? why would we do that? we like(d) the chem blog as much as everyone else and are saddened that the party there is over. since we have a nice enough site and plenty of readers, i’m not sure what we should be capitalizing on anyway…
there is a deficit of snark and cursing on chemistry blogs now. Not to worry, I’m on it.
hey, i can curse too…:P
but yes. you are clearly snarkier than i am.
someone on wordpress needs to make a curse counter for blogs. then we could compare my posts vs. yours. and then, unlike in scrabulous, i would win.
i wonder which of us would win if there were curse counters for everyday speech. i think it would be a very close competition…
I’m winning today. Large cyclic metal complexes with too many ligands and atoms suck.
two days ago I was running nearly neat large-scale reaction that begun to solidify on me – so I added 0.5L of anhydrous THF since the reagent addition was incomplete and the stirring stopped – and the mix turned into 0.75L of yogurt that still would not stir. So I said fuck it, no sense to add any more reagent and I and proceeded with quench – and that quenched sludge erupted into a mud volcano and repainted my hood. It took half a day of cleaning, taking out the manifolds, stirplates, washing everything, recycling the silicone oil from pooped-on oil baths and so on. I was the contest winner that day.
Heh… my turn…
Yesterday I had to form HBr to react with an intermediate to form a triphenylcyclopropenium cation. First (for the first time in years) I had to flame some glass tubing found in the old chem building. After tweaking with it for the best part of an hour it was just the right shape and the total equipment was spread across three heater stirrers in a six-foot hood. Any day that starts with having to make your own apparatus is a good one.
Cooled bromine drops into tetralin which is piped through the glass tubing to a second tetralin trap to catch any residual Br2. Then through another set of tubes into the reaction solution in benzene. (Displacement of the o-Bu side chain for those interested).
Naturally I wanted the bromine to stay cool and not fume, so a splash of LN2 should fix that. Alas it fixed it too well, I should have checked the melting point of bromine first.
Nevertheless “all’s well that end’s well” as the Bard used to say. After a few minutes of defrosting with a hair dryer the bromine dropped in, the HBr was formed and finally the desired product started to drop out… and out… and out! Seven grams later, I have enough cationic complex to be in business for years.
There is also no other good way of showing you still have synthetic chops to the grads and undergrads by construction monstrous glassware apparatus that actually work.
Aaah the dark art of growing crystals. I remember in my first year PhD I was doing a recrys on an early intermediate in my total synthesis and i got a crystal larger than the size of an australian 10c coin (http://en.wikipedia.org/wiki/Australian_10_cent_coin)
I like to sell my xtals at market day as fine jewels :S
Heated water gets some pretty wierd solvent behavior. Going up in temperature and under pressure, it becomes more lipophilic (one time when hydrophobic and it are not synonyms). At near critical and supercritical conditions, water is as nonpolar a solvent as iso-octane or cyclohexane, except for the oddity that its acid-base character has strengthened.
So nonpolar molecules dissolve very well, but a lot with polar moieties get chewed up by this super acid-super base mix (the pH scale os like -2 to 26 or something bizarre like that).
Your heated water is only a tiny tad towards that, but you have lots of room to play (an accelerated solvent extraction system modified just so might make a good device for crystallizing stuff).
SEXY crystals! Nice one.