We disclose a successive π‐expansion of pyracylene towards boat‐shaped polycyclic scaffolds. The unique structural features of the resulting compounds were revealed by X‐ray crystallographic analysis. Depending on the extent of π‐expansion the compounds display intense bathochromically shifted absorption bands in their UV/Vis spectra and are prone to several redox events as documented by cyclic voltammetry. The experimental observations are in line with the computational studies based on density functional theory, suggesting progressive narrowing of the HOMO–LUMO gap and distinct evolution of the electronic structure and aromaticity.

A family of fully bridged triphenylamines with embedded 5‐ and 7‐membered rings is presented. The compounds are potent electron donors capable to undergo donor/acceptor interactions with strong cyano‐based acceptors both in the solid state and solution. These interactions were evaluated by IR and UV/vis spectroscopy as well as X‐ray crystallography. The vinylene‐bridged compound was oxidized to the corresponding 1,2‐diketone which readily underwent acid‐catalyzed condensation with selected 1,2‐phenylenediamines. The resulting π‐extended quinoxaline derivatives represent valuable building blocks for the development of functional chromophores upon appropriate functionalization.

N-heterotriangulenes (N-HTAs) are promising organic semiconductors for applications in field effect transistors and solar cells. Thereby the electronic structure of organic/metal interfaces and thin films is essential for the performance of organic-molecule-based devices. Here, we studied the structural and the electronic properties of two different N-HTAs, N-HTA 550 and N-HTA 557, the latter containing an additional 7-membered ring, adsorbed on Au(111) using vibrational and electronic high-resolution electron energy loss spectroscopy in combination with state-of-the-art quantum chemical calculations. In the mono-and multilayer, both N-HTAs adopt a planar adsorption geometry with the molecular backbone oriented parallel to the gold substrate. The energies of the lowest excited electronic singlet states (S) are assigned. The optical gap (S 0 → S 1 transition) is found to be 3.4 eV for N-HTA 550 and 2.5 eV for N-HTA 557. Thus, the introduction of the −C�C− double bond in N-HTA 557 resulted in a pronounced decrease of the optical gap size by 0.9 eV due to the larger π-conjugated electron system compared to N-HTA 550. Structural variations or substitution patterns in N-HTAs foster the opportunity for tailoring their electronic properties.