The nano-composites Fe3O4@SiO2@(–O3Si[(CH2)3NH])P(═O)(NH-R(+)CH(CH3)(C6H5))2 (Fe3O4@SiO2@PTA(+)) and Fe3O4@SiO2@(–O3Si[(CH2)3NH])P(═O)(NH-S(–)CH(CH3)(C6H5))2 (Fe3O4@SiO2@PTA(–)) were prepared and used for the chiral separation of five racemic mixtures (PTA = phosphoric triamide). The separation results show chiral recognition ability of these materials with respect to racemates belonging to different families of compounds (amine, acid, and amino-acid), which show their feasibility to be potential adsorbents in chiral separation. The nano-composites were characterized by FTIR, TEM, SEM, EDX, XRD, and VSM. The VSM curves of nano-composites indicate their superparamagnetic property, which is stable after their use in the separation process. Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@PTA(+) and Fe3O4@SiO2@PTA(–) are regularly spherical with uniform shape and the average sizes of 17–20, 18–23, 36–47 and 43–52 nm, respectively.

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