Synthesis and anatiaromatic character of a dianionic ccompound bearing a heavier group 14 element

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K14203
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 33010:Structural organic chemistry and physical organic chemistry-related
• Research Institution: Chuo University
• Principal Investigator: Kuwabara Takuya 中央大学, 理工学部, 助教 (60768654)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 反芳香族性 / 非芳香族性 / 高周期14族元素 / ジアニオン

Outline of Final Research Achievements

We synthesized a tin analogue of cycloheptatrienyl anion from the reduction of the corresponding diphenyl derivative with lithium under low temperatures. A lithium salt of diphenylstannepinyl anion has been successfully isolated and characterized by NMR and X-ray diffraction studies, which indicates its non-aromatic character. In contrast, a similar reaction with a longer reaction time resulted in the formation of a further reduced species, dilithiostannepin, the formation of which was confirmed by a quenching reaction using iodomethane. Although isolation of this compound is unsuccessful so far due to its thermal instability, our theoretical studies indicate its global antiaromatic nature.

Free Research Field

有機元素化学

Academic Significance and Societal Importance of the Research Achievements

本研究では、スズのジアニオン種という高周期元素の特異な電子状態を組み込んだ新たな反芳香族化合物の合成に成功した。本成果は、既存の反芳香族化合物が炭素や窒素などの第二周期の元素で構成される、という一般常識を覆し、スズのような第５周期の元素をもつ4nπ電子系化合物でも反芳香族化合物が発現する、ということを見いだした、基礎化学的に重要な成果である。