| There are a lot of reasons to grow | | | | dissolve and diffuse in there. As the |
| crystals in research, but none of them | | | | polarity SLOWLY changes, the |
| are more important than the journal bump | | | | thermodynamic wonders of crystallization |
| they cause. As it turns out, even | | | | occur. In the case to the left, I've put |
| collecting a crystal can be its own | | | | some of my new synthetic target, |
| publication, albeit in a less than | | | | Tiklemaitaint A, into a vial filled with |
| interesting journal. Therefore, it is | | | | dichloromethane and I've allowed pentane |
| with great efforts that we try to grow | | | | to slowly diffuse into it. If you look |
| crystals. | | | | closely you'll see some pretty crystals. |
| For those of us in the natural products | | | | Another method that's very popular is to |
| game, crystals all but remove the | | | | simply allow for slow diffusion. This |
| ambiguity with any relative | | | | method is more straight forward. You |
| stereochemistry. This way, we only have | | | | simply layer one solvent on top of |
| two possible molecules to make. SURE, | | | | another and the slow diffusion process |
| you can say you've made heptacene and | | | | causes crystals to form in the middle. |
| stabilized it by various things, but | | | | So, that's pretty easy. Then again, the |
| you're assured a JACS or Angew paper if | | | | easiest way is to just keep some of your |
| you can give 'em a cif file. And since | | | | crap in an NMR tube and forget about it |
| blogs are useless (imho) if they fail to | | | | and then one day look over and discover |
| inform, I'll show you how 'ol Kyle grows | | | | amazing crystals. That's possibly the |
| up his crystals. | | | | best way to do it, since there's no |
| I do my own data collection at our world | | | | effort and it's always a surprise. |
| famous crystal structure facility, mount | | | | You can also cap your NMR tube (or any |
| my own crystals, solve my own | | | | vial, really) and drop it into a (really |
| diffractions and whatnot, so I've vested | | | | good) dewar with some hot solvent. Cap |
| a lot of interest in this sort of stuff. | | | | that baby tight and put it in the |
| That isn't to say I'm an expert, of | | | | freezer. Hopefully, it will take a few |
| course. Now, all I do is organic | | | | days for the solvent to get down to |
| crystals that aren't air or moisture | | | | zero, at which point you can extract |
| sensitive. So this isn't an exhaustive | | | | your vial and MAYBE see some crystals. |
| review by any means. For a more in depth | | | | If you're lucky enough to work where |
| guide, I suggest you look at this. | | | | there is a -72 chill room (or -20 or |
| First thing I usually try is to do a | | | | -50) (a deep freezer works too, if you |
| vial-in-vial vapor diffusion. This is a | | | | have the space) where you can just plop |
| simple little ditty in which one places | | | | it in. (If it's owned by the asshole |
| their compound inside of a small vial in | | | | biochemists, tell them it's DI/DI sugar |
| a solvent it is reasonably soluble in | | | | water. It's alright to lie to |
| and putting it in a larger vial filled | | | | biochemists. They'll believe anything if |
| with volatile solvent that it is not | | | | you tell them entropy made you do it.) |
| soluble in at all. Overtime the volatile | | | | I've never tried to make crystals at the |
| solvent will evaporate up and into the | | | | low temperature. I can't imagine |
| less volatile solvent and slowly | | | | mounting them would be that fun. |