Experimental studies help to deconvolute the driving forces for crystal growth during attrition-enhanced deracemization, demonstrating an interplay between crystal size and crystal number in the emergence of homochirality. A semiempirical population balance model is presented based on considerations of the solubility driving force, as outlined by the Gibbs–Thomson rule, and a frequency factor based on the total interfacial surface area between solid crystals and the solution phase.

The past several decades have witnessed the development of a number of different experimental approaches to help understand how the homochirality of biological molecules might have evolved in a prebiotic world. This chapter reviews chemical and physical models with a special focus on recent developments in attrition-enhanced deracemization of conglomerates, a process that combines solution phase chemical interconversion of enantiomers with thermodynamic and kinetic considerations of solubility, crystal growth, and dissolution.

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Six enantiomeric pairs of TADDOL-s gathered in two series with either methyl (series A) or phenyl (series B) substituent in 2-position of the dioxolane ring were studied by vibrational circular dichroism (VCD). Experimental IR and VCD spectra associated with density functional theory (DFT) calculations showed that the two series exhibit quite different conformations in solution. In series A, the conformer with anti C-O bonds and stabilized by intramolecular OH...OH hydrogen bonding prevails, whereas in series B the conformer with gauche C-O bonds and intramolecular OH...π hydrogen bonding is favored. The shape and sign of the VCD bands in the O-H stretching region revealing the nature of the intramolecular hydrogen bonding were clearly identified. Polarimetric measurements showed that, within the same absolute configuration, compounds in series A and in series B have opposite signs of optical rotation.