Question: when making new crystals what would you have to do to find out thier structure and what is the most recent one you have found and all its structural formulas

Sumit Konar answered on 5 Mar 2019:

Very good question.
I try to make as good quality crystal as possible. I will explain what do I mean by “good crystal”. All crystal has a repetitive unit cell (you can think of a match box). The match box is really tiny of the volume in the order of cubic angstrom (1 meter = 10 billion of angstrom; now you can imagine how tiny are they). Good quality crystal means, you have millions of match boxes stacked in all three directions in x, y and z. When you do not have many match boxes ordered, you will not get nice crystal or you only get in amorphous form.
Now when you have grown a nice crystal, 1st thing you do is to radiate with X-ray. X-ray radiation also have tiny wavelength (angstrom unit), therefore they can interact with the electron cloud of atoms in the crystal. They diffract from the crystal plane and produce nice spots (like stars in the sky). All spots are separated from each other and their intensity (brightness) are also different. We now use distances and intensities to solve the structure. Heavy element (like iron: Fe) will give strong intensity spot where as light element (like lithium: Li) will give weak spot. Millions of crystal-structures are now known and we have database. So when we find something new structure, we make new crystals. Sometimes same compound can have two structures; they are called polymorphs. Graphite and diamond are polymorphs.
I have found a new polymorph of a pharmaceutical drug Galunisertib; it was collaborative research with Eli Lilly. The crystal was grown under pressure. The formula is C22H19N5O.