The Molecular Foundry, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA.
J Am Chem Soc. 2010 Jan 27;132(3):1110-22. doi: 10.1021/ja909041g.
We describe the synthesis and characterization of a series of desymmetrized donor-acceptor [2]catenanes where different donor and acceptor units are assembled within a confined catenated geometry. Remarkable translational selectivity is maintained in all cases, including two fully desymmetrized [2]catenanes where both donors and acceptors are different, as revealed by X-ray crystallography in the solid state, and by (1)H NMR spectroscopy and electrochemistry in solution. In all desymmetrized [2]catenanes the co-conformation is dominated by the strongest donor and acceptor pairs, whose charge-transfer interactions also determine the visible absorption properties. Voltammetric and spectroelectrochemical experiments show that the catenanes can be reversibly switched among as many as seven states, characterized by distinct electronic and optical properties, by electrochemical stimulation in a relatively narrow and easily accessible potential window. Moreover in some of these compounds the oxidation of the electron donor units or the reduction of the electron acceptor ones causes the circumrotation of one molecular ring with respect to the other. These features make these compounds appealing for the development of molecular electronic devices and mechanical machines.
我们描述了一系列非对称给体-受体[2]索烃的合成和表征，其中不同的给体和受体单元在受限的索烃几何结构内组装。在所有情况下都保持了显著的平移选择性，包括两个完全非对称的[2]索烃，其中给体和受体都是不同的，这一点通过固态 X 射线晶体学、溶液中的（1）H NMR 光谱和电化学得到了揭示。在所有非对称的[2]索烃中，共构主要由最强的给体和受体对决定，它们的电荷转移相互作用也决定了可见吸收性质。伏安法和光谱电化学实验表明，通过在相对较窄且易于接近的电位窗口中电化学刺激，这些索烃可以在多达七个状态之间可逆切换，这些状态具有不同的电子和光学性质。此外，在这些化合物中的一些中，电子给体单元的氧化或电子受体单元的还原导致一个分子环相对于另一个分子环的旋转。这些特性使得这些化合物在开发分子电子器件和机械机器方面具有吸引力。
