Yes, that's the idea. Some substances
separate spontaneously, and I hope Czochralski helps here as well, because it controls precisely where crystallization occurs and at what speed. The resulting big single-crystal is much purer, as the strong selectivity of crystallization produces it full effect, without crystal joints where impurities find a harbour.
For semiconductors, the growth tuned to months for 2m produces crystals with a packing perfection unseen elsewhere; supposedly not needed here.
It is my (limited!) understanding that most substances pack regularly one S molecule alternating with one R molecule in their crystal, as this is the combination that fits best, but for some other substances, S molecules pack better with S only, and R with R only, so in a plate they crystallize to a mix of separated S and R crystals.
Pasteur first sorted out the individual crystals
, then triggered the separation using two enantiomeric seeds
. This can be the method still in use now, or the industry has a better one, I don't know.
Czochralski - using two enantiomeric seeds, yes - would bring to these special substances the advantage of crystallizing only where desired and under controlled conditions. Bridgeman is one other process.
I believe to understand (do I?) that these special substances are the only entry gate for technology into chiral synthesis
. Special acids that separate spontaneously can be sorted out and then serve to purify amines that wouldn't spontaneously; special amines purify acids; and so on. Hence separating first the special substaces is useful, and I hope Czochralski helps here.
Next, when separating esters, a controlled crystallization by Czochralski can help as well - though there are other methods.
Is a chiral solvent
useful? As a drawback, it needs bigger amounts than an esterification; recycling looks possible in both cases.
It depends on the solvent's chiral selectivity. If it dissolves the S product far better, then R will crystallize first and can be harvested, and S later and can be harvested, before the solvent is reused.
Though, as I figure that a solvent molecule has few contact points with the solute, chiral selectivity is less probable than in a crystal where contact points between the molecules are numerous.