Departament de Física de la Matèria Condensada, Universitat de Barcelona, Avinguda Diagonal 647, 08028 Barcelona, Spain.
Departament de Física Aplicada, Universitat de Barcelona, Avinguda Diagonal 647, 08028 Barcelona, Spain.
Phys Chem Chem Phys. 2023 Mar 29;25(13):9238-9248. doi: 10.1039/d2cp05939h.
Spontaneous chiral symmetry breaking is observed in a wide variety of systems on very different scales, from the subatomic to the cosmological. Despite its generality and importance for a large number of applications, its origin is still a matter of debate. It has been shown that the existence of a difference between the energies of the intermediate states of optical enantiomers leads to disparate production rates and thus to symmetry breaking. However, it is still unclear why this occurs. We measured for the first time the optical rotation angle of NaClO enantiomeric crystals in solution during their formation and found that the amount of energy needed to induce the enantiomeric excess is exactly the same as the energy dissipated per mole of solid salt calculated from the entropy production obtained from the proposed model. The irreversible nature of the process leading to entropy production thus explains the chiral symmetry breaking in the salt crystals studied. The proposed method could be used to explain the formation of self-organised structures generated by self-assembly of enantiomers arising from chiral symmetry breaking, such as those emerging in the production of advanced materials and synthetic biological tissues.
自发手性对称破缺在从亚原子到宇宙学的各种不同尺度的系统中都有观察到。尽管它的普遍性和对大量应用的重要性，但它的起源仍然是一个争论的问题。已经表明，光学对映异构体中间态之间能量的差异导致了不同的产生速率，从而导致了对称破缺。然而，为什么会这样还不清楚。我们首次测量了溶液中 NaClO 对映体晶体形成过程中的旋光角度，发现诱导对映体过量所需的能量与从熵产生得到的每个摩尔固体盐的能量耗散完全相同，从所提出的模型中计算得出。导致熵产生的不可逆过程因此解释了所研究的盐晶体中的手性对称破缺。所提出的方法可用于解释由手性对称破缺引起的对映体自组装产生的自组织结构的形成，例如在先进材料和合成生物组织的生产中出现的那些结构。
