Lasorne Benjamin, Fihey Arnaud, Mendive-Tapia David, Jacquemin Denis
Institut Charles Gerhardt Montpellier , UMR 5253 , CNRS-UM , CTMM , Université Montpellier , CC 1501, Place Eugène Bataillon , 34095 Montpellier , France . Email:
Chimie Et Interdisciplinarité, Synthèse, Analyse, Modélisation (CEISAM) , UMR CNRS no. 6230 , BP 92208 , Université de Nantes , 2, Rue de la Houssinière , 44322 Nantes Cedex 3 , France . Email:
Chem Sci. 2015 Oct 1;6(10):5695-5702. doi: 10.1039/c5sc01960e. Epub 2015 Jun 29.
Going from photochromic compounds presenting a single switchable function to multi-addressable photochromic multimers remains an extremely difficult task notably because the interactions of several photochromic units through a linker generally result in a substantial loss of photoactivity. Due to their size and the intrinsic complexity of their electronic structure, coupled photochromes also constitute a fundamental challenge for theoretical chemistry. We present here an effective curve-crossing model that, used in connection with easily accessible data, allows a first understanding of the difficulty to obtain efficient multiphotochromes. Indeed, we demonstrate that extra crossing points, specific to multiphotochromes, have to be passed to ensure reactivity. In addition, the proposed approach allows the definition of an intuitive tilt criterion that can be used to screen a large number of substitution patterns and hence help in the design of new compounds, an aspect that is also developed here. The compatibility of this tilt criterion with previously proposed static Franck-Condon parameters is discussed as well.
从具有单一可切换功能的光致变色化合物转变为多可寻址光致变色多聚体仍然是一项极其困难的任务，尤其是因为几个光致变色单元通过连接基的相互作用通常会导致光活性大幅丧失。由于其尺寸和电子结构的固有复杂性，耦合光致变色化合物对理论化学也构成了一项基本挑战。我们在此提出一种有效的曲线交叉模型，结合易于获取的数据使用，能够初步理解获得高效多光致变色化合物的困难。实际上，我们证明，必须经过多光致变色化合物特有的额外交叉点才能确保反应活性。此外，所提出的方法允许定义一个直观的倾斜标准，该标准可用于筛选大量取代模式，从而有助于新化合物的设计，这也是本文所探讨的一个方面。本文还讨论了该倾斜标准与先前提出的静态弗兰克 - 康登参数的兼容性。
