Hi

A small organic molecule is typically crystallized from organic solvents
(or water, if soluble) by means of at least three main techniques:

1. slow evaporation of solvent leading to supersaturation and eventual
crystallization
2. supersaturation at higher temperature followed by gradual drop in
temperature causing crystallization
3. counter-diffusion of an incompatible solvent to drop solubility of the
substance and cause crystallization

Many times, just leaving an NMR tube with a tiny hole in the plastic cap
for a week or so will cause crystals to form.

Schnobviously, some substances will not crystallize easily - some form
oils, amorphous precipitates, etc. and others will form liquid hydrated
forms or just plain decompose. If you have any specific questions please
don't hesitate to contact me in person. I've spent half of my PhD
crystallizing weird small molecules for fun and profit.

As to how to solve structures of small molecules - any synchrotron is a
massive overkill. Just get in touch with a University X-ray lab, many of
which still have functional small molecule instruments. SHELX is the
software of choice - of course! (I still have the blue/white polka dot
SHELX cup, it's one of my more treasured curios).

Artem
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On Mon, Jun 1, 2020 at 6:01 PM Jiyuan Ke <jiyuan...@h3biomedicine.com>
wrote:

> Hi Everyone,
>
> I want to crystallize a small organic molecule. I have very limited
> experience in small molecule crystallography. I found that the Crystal
> Screen HT from the Hampton research is good for both small molecule and
> macromolecule crystallization. Plan to set up a sitting drop screen just
> like setting up protein crystallization. I don’t know if this is the proper
> way to do it. Is the MRC sitting drop 2-well plate (HR3-083) used for
> protein crystallization good for small molecule crystallization? Are there
> any special plates used for small molecule crystallization? Is room
> temperature ok or not?
>
> For data collection, can I use the beamline for protein crystals to
> collect data on small molecule crystals? Larger oscillation angle, shorter
> exposure, reduced beam intensity?
>
> For structure determination, is SHELXL the preferred software for solving
> small molecule structures?
>
> If anyone has experience in small molecule crystallography, please help.
> Thanks!
>
> Best Regards,
>
> --
>
> *Jiyuan Ke, Ph.D.*
>
>
> Research Investigator
>
> H3 Biomedicine Inc.
>
> 300 Technology Square, Floor 5
>
> Cambridge, MA 02139
>
> Phone: 617-252-3923
>
> Email: jiyuan...@h3biomedicine.com
>
> Website: www.h3biomedicine.com
>
>
>
>
>
>
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