タンデムヘテロフリーデルクラフツ反応を活用したヘテロ元素縮環部位を有する多環芳香族化合物群の合成

京都大学0048新制・課程博士博士(工学)甲第17584号工博第3743号新制||工||1570(附属図書館)30350京都大学大学院工学研究科物質エネルギー化学専攻(主査)教授 中村 正治, 教授 大江 浩一, 教授 村田 靖次郎学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA

Azaboradibenzo[6]helicene: Carrier Inversion Induced by Helical Homochirality

Azaboradibenzo­[6]­helicene, a new semiconductor material possessing helical chirality, has been synthesized via a tandem bora-Friedel–Crafts-type reaction. Unprecedented carrier inversion between the racemate (displaying p-type semiconductivity) and the single enantiomer (displaying n-type semiconductivity) was observed and can be explained by changes in the molecular packing induced by helical homochirality

Synthesis of BN-Fused Polycyclic Aromatics via Tandem Intramolecular Electrophilic Arene Borylation

A tandem intramolecular electrophilic arene borylation reaction has been developed for the synthesis of BN-fused polycyclic aromatic compounds such as 4b-aza-12b-boradibenzo[<i>g</i>,<i>p</i>]chrysene (<b>A</b>) and 8b,11b-diaza-19b,22b-diborahexabenzo[<i>a</i>,<i>c</i>,<i>fg</i>,<i>j</i>,<i>l</i>,<i>op</i>]tetracene. These compounds adopt a twisted conformation, which results in a tight and offset face-to-face stacking array in the solid state. Time-resolved microwave conductivity measurements prove that the intrinsic hole mobility of <b>A</b> is comparable to that of rubrene, one of the most commonly used organic semiconductors, indicating that BN-substituted PAHs are potential candidates for organic electronic materials

Azaboradibenzo[6]helicene: Carrier Inversion Induced by Helical Homochirality

Azaboradibenzo­[6]­helicene, a new semiconductor material possessing helical chirality, has been synthesized via a tandem bora-Friedel–Crafts-type reaction. Unprecedented carrier inversion between the racemate (displaying p-type semiconductivity) and the single enantiomer (displaying n-type semiconductivity) was observed and can be explained by changes in the molecular packing induced by helical homochirality

Azaboradibenzo[6]helicene: Carrier Inversion Induced by Helical Homochirality

Azaboradibenzo­[6]­helicene, a new semiconductor material possessing helical chirality, has been synthesized via a tandem bora-Friedel–Crafts-type reaction. Unprecedented carrier inversion between the racemate (displaying p-type semiconductivity) and the single enantiomer (displaying n-type semiconductivity) was observed and can be explained by changes in the molecular packing induced by helical homochirality

Triplet-Energy Control of Polycyclic Aromatic Hydrocarbons by BN Replacement: Development of Ambipolar Host Materials for Phosphorescent Organic Light-Emitting Diodes

In this work, we achieved the triplet-energy control of polycyclic aromatic hydrocarbons (PAHs) by replacing the Carbon−Carbon (CC) unit with a Boron−Nitrogen (BN) unit. Time-dependent density functional theory calculations suggested that the insertion of the BN unit may cause localization of the singly occupied molecular orbitals 1 and 2 (SOMO1/SOMO2) in the triplet state, which in turn can reduce the exchange interaction and dramatically increase the high singlet–triplet excitation energy (<i>E</i>_T). The PAH containing the BN unit, 4b-aza-12b-boradibenzo­[<i>g</i>,<i>p</i>]­chrysene, showed a large <i>E</i>_T value and ambipolar carrier-transport abilities. The introduction of a phenyl substituent on 4b-aza-12b-boradibenzo­[<i>g</i>,<i>p</i>]­chrysene slightly reduced the <i>E</i>_T values and the carrier-transport abilities, but increased the glass-transition temperatures. On the basis of these findings, we successfully built phosphorescent organic light-emitting diodes using the BN compounds as host materials, which exhibit a superior performance over the device using a representative host material, 4,4′-bis­(<i>N</i>-carbazolyl)-1,1′-biphenyl, not only in terms of efficiency but also in terms of device lifetime. This study demonstrated the potential of BN-embedded polycyclic aromatics in organic electronics and showed a novel strategy to achieve triplet-energy control of aromatic compounds