Departamento de Óptica, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Phys Chem Chem Phys. 2011 Oct 14;13(38):17130-4. doi: 10.1039/c1cp21729a. Epub 2011 Aug 24.
We study the tunnel dynamics of a chiral molecule between its left (L) and right (R) conformations, under the global effect of collisional decoherence together with the effect of a mean-field generated by the environment where an energetic difference, K, between homochiral and heterochiral interactions is assumed. We show that this decoherence leads unavoidably to equal populations of the L and R chiral conformations even for a high enough value of K which tends to keep localized an initial chiral state. However, we also show that K contributes to the stabilization of an initial L or R state for times that could be many orders of magnitude larger than the tunneling time, in the case the decoherence rate is much greater than the tunneling rate. In this case, an estimation of this stabilization time and a critical tunneling time is made. Even in the case in which the tunneling rate is greater than the decoherence rate, the effect of K is to keep localized the initial chiral state for times greater than the tunneling time. A possible slight chiral asymmetry is also considered.
我们研究了手性分子在其左(L)和右(R)构象之间的隧道动力学,在碰撞退相干的全局效应以及环境产生的平均场的影响下,环境中存在手性和异手性相互作用之间的能量差异 K。我们表明,这种退相干不可避免地导致 L 和 R 手性构象的种群相等,即使对于足以保持初始手性状态的足够高的 K 值。然而,我们还表明,对于退相干率远大于隧道率的情况,K 有助于稳定初始 L 或 R 状态的时间,可以比隧道时间大几个数量级。在这种情况下,对这种稳定时间和临界隧道时间进行了估计。即使在隧道率大于退相干率的情况下,K 的作用也是使初始手性状态的局域化时间大于隧道时间。还考虑了可能的轻微手性不对称。