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Three chiral nanorods of C 14 - l -Thea, C 14 - l -Phe, and C 14 - d -Phe were first synthesized and utilized as heterogeneous nucleants to enhance the resolution of racemic Asp via direct crystallization. Through the statistical analysis from 320 batches of nucleation experiments, we found that the apparent appearance diversity of two enantiomeric crystals of Asp existed in 80 homogeneous experiments without chiral nanorods. However, in 240 heterogeneous experiments with 4.0 wt % chiral nanorods of solute mass added, the appearance of those nuclei with the same chirality as the nanorods was apparently promoted, and that with the opposite chirality was totally inhibited. Under a supersaturation level of 1.08, the maximum ee of the initial nuclei was as high as 23.51%. When the cooling rate was 0.025 K/min, the ee of the product was up to 76.85% with a yield of 14.41%. Furthermore, the simulation results from quantum mechanics (QM) and molecular dynamics (MD) revealed that the higher chiral recognition ability of C 14 - l -Thea compared to C 14 - l -Phe that originated from the interaction difference between C 14 - l -Thea and Asp enantiomers was larger than that between C 14 - l -Phe and Asp enantiomers. Moreover, the constructed nanorods exhibited good stability and recyclability.

The molar fraction solubilities of L-, D-, and DL-citrulline were first determined in aqueous solutions with different concentrations of (R)-1,3-butanediol from 283.15 to 328.15 K under 101.3 kPa using the gravimetric method. Then, based on solidstate characterizations such as powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, thermal gravity analysis (TGA), differential scanning calorimetry (DSC), and ternary phase diagram, the nature of crystalline DL-citrulline was considered to be a racemic compound. Then, the rates and parameters of primary nucleation of three species in mixtures of water and (R)-1,3-butanediol were experimentally derived through the classical nucleation theory (CNT). After that, topological electrostatic potentials and radial distribution functions were analyzed for exploring the intermolecular interactions between the molecules, and the Yasuoka−Matsumoto (YM) method was employed to simulate the nucleation process. However, the calculated nucleation rates by YM were shown to be 2 orders of magnitude greater than those derived through CNT. Finally, the effect of additives on the appearance probability (P) of racemic and enantiomeric nuclei from the same DL-citrulline solutions at a supersaturation ratio of 2.63 was statistically investigated from 140 nucleation experiments. It was interestingly found that there was only a minor difference between the appearance probabilities of both enantiomeric crystals among 20 batches of nucleations in the absence of additives; however, in the presence of additives, enantiomeric crystals with the same chirality as the additives were totally inhibited, which were utilized for the chiral enrichment of the studied racemic system. By coupling the addition of additives and seeds, L-citrulline or D-citrulline crystals with optical purity above 99% can be produced with a yield up to 25.4% through chiral enrichment from an initial ee of 88%.

Two kinds of hierarchical magnetic metal-organic framework (MOF) nanoparticles Fe3O4@PDA@UIO-66-NH-tar (mUIO-66-NH-tar) and Fe3O4@PDA@UIO-66-NH-citr (mUIO-66-NH-citr) were fabricated through post- synthetic modification. The novel nanoparticles were then characterized using SEM, FTIR, PXRD,...

Four chiral ionic liquids (CILs) of 1-hexyl-3-methylimidazolium-l-2-aminobutyrate ([Hmim][l-2-AbA]), 1-hexyl-3-methylimidazolium-d-2-aminobutyrate ([Hmim][d-2-AbA]), di-1-hexyl-3-methylimidazolium-l-malate ([Hmim]2[l-MA]), and di-1-hexyl-3-methylimidazolium-d-malate ([Hmim]2[d-MA]) were first prepared by a neutralization method and adequately characterized. In light of a gravimetric method, the molar fraction solubilities of dl- and d- together with l-threonine (Thr) were then acquired in the binary cosolvent mixtures (CM) of CILs and water, with different mass fractions (ω) of CILs under 101.3 kPa from 283.15 to 333.15 K. In CIL cosolvent mixtures (CCM), a cosolvency phenomenon was observed with the biggest solubilization and discrepant solubilities of Thr enantiomers, with ω of 0.3. Meanwhile, the asymmetry phenomenon was also found from the ternary phase diagram of Thr enantiomers and CCM, in which the enantiomeric excess values at the eutectic point (eeeut) were sensitive to temperature. Subsequently, the nucleation experiments and appearance probability statistics confirmed that CCM with ω of 0.3 (CCM-0.3) can act as excellent nucleation inhibitors which preferred to suppress the nucleation of enantiomeric crystals with the opposite chirality to them, leading to the preferential nucleation of enantiomeric crystals with the same chirality. Furthermore, by coupling seeds and CCM-0.3, the yield and yield ratio of l-Thr products through a direct antisolvent crystallization resolution were improved greatly compared with that in water, where the largest yield ratio was up to 27.47%. At the same time, isosurface diagrams and binding energy calculations by quantum mechanics (QM) revealed that the higher chiral recognition ability of [Hmim]2[l-MA] than [Hmim][l-2-AbA] stemmed from the stronger weak interactions. Particularly, the enhanced direct crystallization resolution can be feasibly recycled owing to the stability and recyclability of the CILs.