Kleykamp Olaf A, Sharikow Eugen, Stoy Andreas, Xie Xiulan, Lichtenberg Crispin, Sundermeyer Jörg
Department of Chemistry, Philipps Universität Marburg, Hans-Meerwein-Straße 4, 35032, Marburg, Germany.
Chemistry. 2025 Feb 6;31(8):e202403929. doi: 10.1002/chem.202403929. Epub 2024 Dec 30.
Herein we report a convenient access to asymmetrically substituted, well soluble pentacene derivatives synthesized from commercially available 5,7,12,14-pentacenetetrone via reductive one step functionalization. Zinc or potassium are used as reducing agents and the reduced intermediates are trapped with electrophiles such as acetyl, triisopropylsilyl or cationic methyl synthons. The reduction allows for an unsymmetric functionalization whilst one dione moiety is maintained due to partial reduction. The resulting dyes are characterized by UV/Vis and photoluminescence spectroscopy. Their redox potentials are studied by cyclic voltammetry. The experimentally determined molecular frontier orbital energies are rationalized by density functional theory. The spatial molecular packing motive in the solid state is studied as a function of the substituent size by X-ray crystallography. Attempts of reducing the second quinone moiety towards a functionalized pentacene led to an over-reduced 6,13-dihydropentacene derivative, which by means of an XRD structural analysis surprisingly displays a planar molecular conformation and unique optoelectronic properties.
在此，我们报道了一种便捷的方法，可通过一步还原官能团化反应，从市售的5,7,12,14-并五苯四酮合成不对称取代且溶解性良好的并五苯衍生物。使用锌或钾作为还原剂，还原中间体与亲电试剂（如乙酰基、三异丙基甲硅烷基或阳离子甲基合成子）捕获。该还原反应实现了不对称官能团化，同时由于部分还原，一个二酮部分得以保留。所得染料通过紫外可见光谱和光致发光光谱进行表征。通过循环伏安法研究其氧化还原电位。通过密度泛函理论对实验测定的分子前沿轨道能量进行了合理化分析。通过X射线晶体学研究了固态下空间分子堆积模式与取代基大小的关系。将第二个醌部分还原为官能团化并五苯的尝试导致过度还原的6,13-二氢并五苯衍生物，通过XRD结构分析令人惊讶地发现其呈现平面分子构象和独特的光电性质。
