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