Design and Synthesis of Caged Compound with High Two-Photon Absorption Character in Near IR Region :Its Application to Physiological Experiments

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20539
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0501:Physical chemistry, functional solid state chemistry, organic chemistry, polymers, organic materials, biomolecular chemistry, and related fields
• Research Institution: Kyushu University (2022); Hiroshima University (2021)
• Principal Investigator: Chitose Youhei 九州大学, 工学研究院, 助教 (60911534)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 2光子吸収 / ケージド化合物 / 光解離性保護基 / 反応中間体

Outline of Final Research Achievements

In this study, we developed a Donor-π-Donor (D-π-D) based coumarin derivative. Its two-photon absorption (TPA) cross-section was determined to be 498 GM at 700 nm by two-photon excited fluorescence method. The two-photon uncaging efficiency of D-π-D based caged benzoic acid was also determined to be 134 GM at 700 nm, which indicates relatively high two-photon responsive chromophore. In addition, we investigated the detail mechanism of bond cleavage steps in the uncaging reaction of caged benzoic acid. The laser flash photolysis experiments and product analysis suggested the presence of methyl cation intermediate which indicated the heterolysis of C-O bond.

Free Research Field

有機光化学

Academic Significance and Societal Importance of the Research Achievements

既存の7-ジエチルアミノクマリン骨格の3位に２重結合を持つ電子供与基部位を導入することで、比較的高い2光子吸収断面積を付与することができた。今後、D-π-D型クマリン誘導体を基盤骨格とする光解離性保護基を用いたケージド化合物を開発することで、低毒性かつ生体透過性の高い近赤外領域の2光子励起を用いて生物活性物質の濃度上昇を時空間的に制御することができる。こうした技術を応用することによって、生体深部における疾患部位の回復や、脳内における神経伝達物質の機能解明に繋がると期待される。