Construction of curved non-alternant conjugated molecules containing heteroatoms

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05438
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 33010:Structural organic chemistry and physical organic chemistry-related
• Research Institution: Yamaguchi University
• Principal Investigator: Murafuji Toshihiro 山口大学, 大学院創成科学研究科, 教授 (40253140)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: アズレン / 非交互共役系炭化水素 / 典型元素

Outline of Final Research Achievements

We were successful in obtaining several types of substituted diazulenylborinic esters stabilized by the intramolecular coordination bond. The molecular structure of the stabilized ester was characterized by the X-ray crystallographic and NMR spectroscopic studies. The tetrahedral character (THC) of this compound was estimated to be 85%. This value was comparable to those of diphenylborinic esters possessing a tetrahedral boron center. The pi-polarization of the azulenyl groups in the borinic ester was reduced by the electron-donation from the boron functionality. The intramolecular crosslinking reactions between the azulenyl groups followed by the substitution at the boron atom with nucleophiles gave the corresponding cyclic boranes, which were fully characterized by the X-ray structural and NMR spectroscopic studies.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

ナフタレンのような２個のベンゼン環から構成される交互共役系の芳香族化合物とは異なり、アズレンは奇数の５員環と７員環が縮環した非交互共役系の芳香族炭化水素である。このような非ベンゼン系の芳香族化合物から構成される有機分子は、ベンゼン系に比べて芳香族共鳴安定化エネルギーが小さく、特異な物性の発現が期待できる。本研究では、ベンゼン系化合物に比べて合成法の開発が進んでいなかった非ベンゼノイド化合物について、その電子的な特異性を活かした新奇な分子を合成するための方法論を開発し、今後の有機エレクトロニクス分野への貢献を目指す。