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Despite the remarkable synthetic accomplishments in creating diverse polycyclic aromatic hydrocarbons with B−N bonds (BN‐PAHs), their optoelectronic applications have been less exploited. Herein, we report the achievement of high‐mobility organic semiconductors based on existing BN‐PAHs through a "periphery engineering" strategy. Tetraphenyl‐ and diphenyl‐substituted BN‐anthracenes (TPBNA and DPBNA, respectively) are designed and synthesized. DPBNA exhibits the highest hole mobility of 1.3 cm2 V−1 s−1 in organic field‐effect transistors, significantly outperforming TPBNA and all the reported BN‐PAHs. Remarkably, this is the first BN‐PAH with mobility over 1 cm2 V−1 s−1, which is a benchmark value for practical applications as compared with amorphous silicon. Furthermore, high‐performance phototransistors based on DPBNA are also demonstrated, implying the high potential of BN‐PAHs for optoelectronic applications when the "periphery engineering" strategy is implemented. [ABSTRACT FROM AUTHOR]

Introducing BN units into polycyclic aromatic hydrocarbons expands the chemical space of conjugated materials with novel properties. However, it is challenging to achieve accurate synthesis of BN‐PAHs with specific BN positions and orientations. Here, three new parent B2N2‐perylenes with different BN orientations are synthesized with BN‐naphthalene as the building block, providing systematic insight into the effects of BN incorporation with different orientations on the structure, (anti)aromaticity, crystal packing and photophysical properties. The intermolecular dipole–dipole interaction shortens the π–π stacking distance. The crystal structure, (anti)aromaticity, and photophysical properties vary with the change of BN orientation. The revealed BN doping effects may provide a guideline for the synthesis of BN‐PAHs with specific stacking structures, and the synthetic strategy employed here can be extended toward the synthesis of larger BN‐embedded PAHs with adjustable BN patterns. [ABSTRACT FROM AUTHOR]

Considerable efforts have been devoted to achieving stable acene derivatives for electronic applications; however, the instability is still a major issue for such derivatives. To achieve higher stability with minimum structural change, CC units in the acenes were replaced with isoelectronic BN units to produce a novel BN‐embedded tetrabenzopentacene (BNTBP). BNTBP, with a planar structure, is highly stable to air, moisture, light, and heat. Compared with its carbon analogue tetrabenzopentacene (TBP), BN embedment lowered the highest occupied molecular orbital (HOMO) energy level of BNTBP, changed the orbital distribution, and decreased the HOMO orbital coefficients at the central carbon atoms, which stabilize BNTBP molecules upon exposure to oxygen and sunlight. The single‐crystal microribbons of BNTBP exhibited good performance in field‐effect transistors (FETs). The high stability and good mobility of BNTBP indicates that BN incorporation is an effective approach to afford stable large‐sized acenes with desired properties. [ABSTRACT FROM AUTHOR]

New BN-embedded, thiophene-fused, polycyclic aromatic compounds with planar geometry were designed and synthesized. The molecules showed excellent stability and chemical robustness. Postfunctionalization on this skeleton was demonstrated with a series of electrophilic bromination, palladium-catalyzed cross-coupling, and Knoevenagel condensation reactions. The π skeleton remained intact during these late-stage transformations. The optical and electronic properties have been well tuned through incorporation of electron-rich and -deficient groups on the backbone. This work shows the great advantage of the postfunctionalization strategy on BN-containing polycyclic aromatic compounds for fast diversification and materials screening. [ABSTRACT FROM AUTHOR]

Replacement of CC unit with its isoelectronic BN unit in aromatics provides a new class of molecules with appealing properties, which have attracted great attention recently. In this Concept, we focus on BN-substituted polycyclic aromatics with fused structures, and review their synthesis, photophysical, and redox properties, as well as their applications in organic electronics. We also present challenging synthetic targets, large BN- substituted polycyclic aromatics, such as regioregular BN heterosuperbenzenes, which can be viewed as BN-doped nanographenes. Finally, we propose an atomically precise bottom-up synthesis of structurally well-defined BN-doped graphenes. [ABSTRACT FROM AUTHOR]

Boron–nitrogen units were incorporated into thiophene‐fused polycyclic aromatic compounds. Organic field‐effect transistors based on these azaborine compounds were fabricated, demonstrating a novel engineering concept of organic semiconductors and providing opportunities of a broad class of BN‐containing compounds for application in future organic electronic devices (see picture; μFET=hole mobility). [ABSTRACT FROM AUTHOR]

Review: [30 refs. [ABSTRACT FROM AUTHOR]