Department of Chemistry & IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str.2, 12489 Berlin, Germany.
Chem Soc Rev. 2017 Sep 18;46(18):5536-5550. doi: 10.1039/c7cs00112f.
In order to perform chemical work, molecular systems have to be operated away from thermodynamic equilibrium and therefore require the input of energy. Light is perhaps the most abundant and advantageous energy source that in combination with photoswitches allows for a reversible and hence continuous stimulation of a system. In this review, we illustrate how photoswitchable molecules can be used to escape the global thermodynamic minimum by populating metastable states, from which energy can be transferred and transformed in a controlled fashion. We emphasize the unique feature of photodynamic equilibria, in which population of the states is dictated by the excitation wavelength (and not primarily by temperature), thereby avoiding microscopic reversibility since the photoreaction involves an electronically excited state. Thus, photoswitchable molecular systems can remotely be controlled with high spatial and temporal resolution and in addition their action can be fueled by light.
为了进行化学工作，分子系统必须远离热力学平衡状态运行，因此需要输入能量。光也许是最丰富和最有利的能源，与光开关结合使用，可以可逆地、因此可以持续地刺激一个系统。在这篇综述中，我们说明了如何通过占据亚稳态来利用光可切换分子逃离全局热力学最小值，从中可以以可控的方式转移和转化能量。我们强调光动力平衡的独特特征，其中状态的填充取决于激发波长（而不是主要取决于温度），从而避免微观可逆性，因为光反应涉及电子激发态。因此，光可切换的分子系统可以远程以高空间和时间分辨率进行控制，并且它们的作用还可以由光来提供动力。
