Wang Jun, Oruganti Baswanth, Durbeej Bo
Division of Theoretical Chemistry, IFM, Linköping University, SE-581 83 Linköping, Sweden.
Phys Chem Chem Phys. 2017 Mar 8;19(10):6952-6956. doi: 10.1039/c6cp08484b.
A fundamental requirement for achieving photoinduced unidirectional rotary motion about an olefinic bond in a molecular motor is that the potential energy surface of the excited state is asymmetric with respect to clockwise and counterclockwise rotations. In most available light-driven rotary molecular motors, such asymmetry is guaranteed by the presence of a stereocenter. Here, we present non-adiabatic molecular dynamics simulations based on multiconfigurational quantum chemistry to demonstrate that this chiral feature is not essential for inducing unidirectional rotary motion in molecules that incorporate a cyclohexenylidene moiety into a protonated Schiff-base framework. Rather, the simulations show that it is possible to exploit the intrinsic asymmetry of the puckered cyclohexenylidene to control the direction of photoinduced rotation.
在分子马达中，实现围绕烯烃键的光致单向旋转运动的一个基本要求是，激发态的势能面相对于顺时针和逆时针旋转是不对称的。在大多数现有的光驱动旋转分子马达中，这种不对称性是由一个立体中心的存在来保证的。在这里，我们基于多组态量子化学进行非绝热分子动力学模拟，以证明这种手性特征对于在将环己烯叉基部分纳入质子化席夫碱框架的分子中诱导单向旋转运动并非必不可少。相反，模拟表明，可以利用褶皱的环己烯叉基的固有不对称性来控制光致旋转的方向。
