Heteroacenes, Novel Organic Semiconductors

计划合成更大的并苯类分子（杂并苯）。在杂并苯中，一些芳族C-H基团被吡啶型氮取代。该小组将探讨氮环原子数量的增加对杂并苯的光学，电化学和电学性质的影响。为了增加（所提出的并苯类型的）溶解度并加强固态芳族分子的相互重叠，它们将安装（三烷基甲硅烷基）乙炔基作为取代基。三烷基甲硅烷基促进杂并苯的液相加工。 合成部分将扩展到卤代氮杂并五苯，因为这些作为电子传输材料具有很大的电流感兴趣，并且可以容易地由途中制备的中间体制成。一个广泛的调查的薄膜形成的杂并苯固体支持物的计划。这些薄膜将通过显微镜和光谱方法进行检查;这些小组计划通过有机配体来修改底层表面，以控制所提出的杂并苯的堆叠和堆积，以优化其平行和垂直于表面的电性能，并设想在有机电子学中的潜在应用。所提出的杂并苯是用于n沟道薄膜晶体管的电子传导材料。杂并苯应该具有与并五苯（最重要的有机半导体）相似的电性质。 它们可以传输电子而不是正电荷（空穴）。 杂并苯潜在地允许构建具有相反极性和电流反向流动的有机电子器件。 这种反极性薄膜晶体管作为先进发光二极管和固态照明设备中的驱动器具有广泛的重要性。PI已经建立了与少数民族高中合作的记录，并在HBCU（克拉克亚特兰大）教授高级有机化学课程。 计划在赠款期内继续开展这些活动。

The synthesis of larger acene-like molecules (heteroacenes) is planned. In the heteroacenes, some of the aromatic C-H groups are substituted by pyridine-type nitrogens. The groups will probe the influence of an increasing number of nitrogen ring atoms on the optical, electrochemical and electrical properties of the heteroacenes. To increase the solubility (of the proposed acene-types) and enforce mutual overlap of the aromatic molecules in the solid state,they will install (trialkylsilyl)ethynyl groups as substituents. The trialkylsilyl groups facilitate the solution-phase processing of the heteroacenes. The synthesis part will be expanded towards halogenated azapentacenes as these are of great current interest as electron transport materials and can be made readily by intermediates that are prepared en route. A broad investigation of the thin film formation of the heteroacenes on solid supports is planned. These thin films will be examined by microscopy and spectroscopic methods; the groups plan to modify the underlying surfaces by organic ligands to control the stacking and packing of the proposed heteroacenes to optimize their electric properties parallel and perpendicular to the surface and envision potential applications in organic electronics. The proposed heteroacenes are electron conducting materials for n-channel thin film transistors. The heteroacenes should have similar electric properties to pentacene (the most important organic semiconductor). They can transport electrons instead of positive charges (holes). Heteroacenes potentially allow the construction of organic electronic devices with reverse polarity and reverse flow of current. Such reversed-polarity thin film transistors are of broad importance as drivers in advanced light emitting diodes and solid-state lighting devices. The PI has established a track record for working with minority high schools and has taught an advanced organic chemistry class at an HBCU (Clark Atlanta). It is planned to continue these activities during this grant period.