Schröder Hendrik V, Hupatz Henrik, Achazi Andreas J, Sobottka Sebastian, Sarkar Biprajit, Paulus Beate, Schalley Christoph A
Institut für Chemie und Biochemie, Organische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
Institut für Chemie und Biochemie, Theoretische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
Chemistry. 2017 Feb 24;23(12):2960-2967. doi: 10.1002/chem.201605710. Epub 2017 Feb 1.
Donor-acceptor materials with small HOMO-LUMO gaps are important in molecular electronics, but are often difficult to synthesise. A simple and efficient way to position tetrathiafulvalene (TTF) as the donor and naphthalene diamide (NDI) as the acceptor in close proximity to each other in a divalent crown/ammonium pseudo[2]rotaxane is presented. The divalent design provides high chelate cooperativity and much stronger binding compared with a monovalent analogue. The pseudo[2]rotaxane was then doubly interlocked by stoppering it in a catalyst-free 1,3-dipolar cycloaddition. UV/Vis and cyclic voltammetry experiments with the resulting [2]rotaxane revealed the optoelectronic properties of an intramolecular charge transfer with a small HOMO-LUMO energy gap. Redox-switching experiments showed the rotaxane to be pentastable. DFT calculations provided insights into the electronic structures of the five redox states.
具有小的最高占据分子轨道（HOMO）-最低未占分子轨道（LUMO）能隙的给体-受体材料在分子电子学中很重要，但通常难以合成。本文提出了一种简单有效的方法，将四硫富瓦烯（TTF）作为给体，萘二酰胺（NDI）作为受体，在二价冠醚/铵假[2]轮烷中彼此紧密相邻定位。与单价类似物相比，二价设计提供了高螯合协同性和更强的结合力。然后，通过在无催化剂的1,3-偶极环加成反应中封端，使假[2]轮烷发生双重互锁。对所得[2]轮烷进行的紫外/可见光谱和循环伏安法实验揭示了具有小HOMO-LUMO能隙的分子内电荷转移的光电性质。氧化还原开关实验表明该轮烷具有五稳态。密度泛函理论（DFT）计算为五个氧化还原态的电子结构提供了深入见解。
