Center for Biomaterials and Biopathways, Zhejiang University , Hangzhou, Zhejiang 310027, China.
Qiushi Academy for Advanced Studies, Zhejiang University , Hangzhou, Zhejiang 310027, China.
J Am Chem Soc. 2017 Jun 28;139(25):8562-8569. doi: 10.1021/jacs.7b03116. Epub 2017 Jun 15.
We herein show the chiral recognition and separation of aspartic acid (Asp) enantiomers by achiral brushite due to the asymmetries of their dynamical steps in its nonequilibrium states. Growing brushite has a higher adsorption affinity to d-Asp, while l-Asp is predominant on the dissolving brushite surface. Microstructural characterization reveals that chiral selection is mainly attributed to brushite [101] steps, which exhibit two different configurations during crystal growth and dissolution, respectively, with each preferring a distinct enantiomer due to this asymmetry. Because these transition step configurations have different stabilities, they subsequently result in asymmetric adsorption. By varying free energy barriers through solution thermodynamic driving force (i.e., supersaturation), the dominant nonequilibrium intermediate states can be switched and chiral selection regulated. This finding highlights that the dynamic steps can be vital for chiral selection, which may provide a potential pathway for chirality generation through the dynamic nature.
我们通过展示非平衡态下一水合磷酸氢钙（brushite）动力学步骤的不对称性，展示了手性 brushite 对天门冬氨酸（Asp）对映异构体的手性识别和分离。生长态的 brushite 对 d-Asp 具有更高的吸附亲和力，而 l-Asp 则在溶解态的 brushite 表面占优势。微观结构表征揭示了手性选择主要归因于 brushite [101] 台阶，它们在晶体生长和溶解过程中分别呈现出两种不同的构型，由于这种不对称性，每个构型都优先与一个特定的对映异构体结合。由于这些过渡台阶构型具有不同的稳定性，它们随后导致不对称吸附。通过改变溶液热力学驱动力（即过饱和度）来改变自由能垒，可以切换占主导地位的非平衡中间状态，并调节手性选择。这一发现强调了动态步骤对于手性选择至关重要，这可能为通过动态性质产生手性提供了一种潜在途径。
