The non-existence of a threefold aromatic conjugation in linear benzologues of triphenylene (starphenes)

Giant Polycyclic Aromatic Hydrocarbons

“…Ultralarge, unsubstituted aromatics possess an extremely high thermal stability for organic compounds; however, they have a negligible solubility in all the usual solvents, which can be attributed to the extensive planarity and the consequent packing behavior of these large aromatics. Thus it is necessary to replace the spectroscopic methods ( 1 H NMR, 13 C NMR, UV/Vis), usually carried out in solution, with solid-state analytical methods. The high thermal stability of defined graphite segments permits, for example, fractional sublimation of the arenes 20 or 21 at 550 ± 650 8C under ultrahigh vacuum conditions (Figure 4).…”

[16]Cloverphene: a Clover‐Shaped cata‐Condensed Nanographene with Sixteen Fused Benzene Rings

“…In fact, the stability of large catafused PAHs strongly depends on the mode of condensation and number of benzene rings. [10] By contrast, [14]helicene, a cata-condensed PAH with fourteen ortho-fused benzene rings, has been isolated under ambient conditions and is the largest cata-condensed PAH that had been prepared prior to this work. [9] Recently, Miller and Anthony independently succeeded at preparing stable substituted nonacene derivatives.…”

“…[14] For example, compound 2 was named [10]starphene (3.3.3). [14] For example, compound 2 was named [10]starphene (3.3.3).…”

Bottom‐up Approaches to Nanographenes through Organic Synthesis

“…In contrast, [10]phenacene (6) is expected to be a stable but extremely insoluble molecule [16]. Decastarphene (8) was prepared by Clar and Mullen from phenanthrene (19) following a five-step synthetic route based on Friedel-Crafts acylations and reductions (Scheme 11.1) [17]. Different methodologies have been employed to prepare the polyarenes displayed in Figure 11.4.…”