Extended Aromatic Materials Centred Around Tropylium

自从石墨烯被发现以来，多环芳香族材料因其良好的性质和在光电材料中的潜在应用而引起了人们的极大兴趣。虽然无缺陷的石墨烯是完全平面的，但非六角环的加入往往会导致它偏离平面性，导致测地线碎片(具有正的高斯曲率)或马鞍形碎片(具有负的高斯曲率)。通常，前者是通过包含五元环缺陷来实现的，而后者是通过较大的环缺陷(七角形、八角形等)实现的。具体地说，环庚三烯的战略包合允许氧化成三联吡喃，这导致了一类新的带电多环芳烃。然而，关于在扩展的芳香族材料中包含三联吡喃对空间和电子的影响，人们知之甚少。这个PHD项目研究了一系列高取代度联吡喃的合成、模拟和性质，它们可以被认为是合成嵌入联吡喃的翘曲纳米管的中间体。

Polycyclic aromatic materials have garnered a significant amount of interest since the discovery of graphene, due to their desirable properties and potential applications in optoelectronic materials. While defect-free graphene is entirely planar, the inclusion of non-hexagonal rings can often cause it to deviate from planarity, resulting in geodesic fragments (with positive Gaussian curvature) or saddle-shaped fragments (with negative Gaussian curvature). Typically, the former is accomplished by inclusion of five-membered ring defects, while the latter is accomplished through larger ring defects (heptagons, octagons, etc.). Specifically, the strategic inclusion of cycloheptatrienes allows for oxidation to tropyliums, which gives rise to a novel class of charged polycyclic aromatics. However, little is known about the steric and electronic impacts of including tropyliums in extended aromatic materials. This PhD project investigates the synthesis, modelling and properties of a series of highly substituted tropyliums, which can be considered intermediates towards a tropylium-embedded warped nanographene.