Fluorination-Induced Evolution of Columnar Packing in Fluorous Triphenylenes and Benzotriphenylenes

Use of D_3h -symmetrical triphenylene (TRPH) as a substrate for high-temperature radical reactions with C₄ F₈ I₂ under varying conditions resulted in the introduction of four types of fluorinated substituents: ω-C₄ F₈ H, c-C₄ F₈ , c-C₄ F₄ , and c-C₄ HF₃ . In contrast to the previous work on direct (poly)substitutions with R_F groups in polycyclic aromatic hydrocarbons (PAHs), in this work regiospecificity, selectivity, and high yield were achieved for TRPH(C₄ F₈ ) and TRPH(C₄ F₈ )₃ . New single-crystal structural data for seven compounds combined with literature crystallographic data allowed for the first detailed and precise analysis of the effects of fluorous substituent types, their number, and their position(s) on the TRPH core on the solid-state packing, and more specifically, the degree of π-π overlap between neighboring molecules, which is linked to charge transport properties. Comparison of isostructural partially fluorinated benzotriphenylenes, 2,3-TRPH(C₄ F₄ ) and 2,3-TRPH(C₄ HF₃ ), revealed an unexpectedly large (30 %) drop of π-π overlap, when only one fluorine atom was replaced with the hydrogen atom in a C₄ F₄ moiety. Theoretical and potentially practical implications of this work may include further testing and elaboration of computational methods describing solid-state interactions and predictions of transport properties of organic semiconductors, and further advances in the molecular design of high-performing TRPH-based organic materials and supramolecular architectures for organic optoelectronics.