Specific effects of water on the relation processes of excited organic molecules

水对激发有机分子关系过程的特殊影响

• 批准号: 09640594
• 负责人: TOBATA Seiji
• 金额: $ 1.79万
• 依托单位: GUNMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640594/
• 关键词: Photoionization; Laser photolysis; Fluorescence; Proton transfer; Radiationless processes; Solvent effect; Water; Aniline; 励起状態; 緩和過程; 光音響分光法; レーザー分光法

Effects of solvent water on the relaxation processes of excited organic molecules were studied by means of laser photolysis method, time-resolved thermal lensing method and fluorometry. For aniline and its derivatives, it was found that photoionization is one of the most dominant relaxation channel and that the polarization stabilization of the cation radical produced by photoionization is an important factor to determine the photoionization yield. Excited-state intramolecular proton transfer (ESIPT) reactions of 1-hydroxy-2- acetonaphthone (1H2AN) and related compounds were studied to reveal hydrogen-bonding interations in the excited state of 1-naphthole derivatives. The study showed that 1H2AN undergoes a typical ESIPT reaction, while the excited singlet state of methyl-1-hydroxy-2-naphthoate deactivates without ESIPT reactions. The effects of electronic structures on the ESIPT reaction were clarified for these compounds. Furthermore, it was found that ESIPT of 1H2AN is followed by … More cis-trans isomerization to produce an excited trans-keto form. The , 3-sigmatropic hydrogen shift in the photo-Fries rearranged intermediate of 2,4-dimethoxy-6-(p-tolyloxy)-s- triazine was investigated by using laser photolysis method. Kinetic measurements showed that water and also protic solvents accerelates the rate of the 1,3-sigmatropic hydrogen shift by mutual hydrogen exchange reactions. The electron transfer (ET) reaction from the triplet state of 1,4-dimethoxybenzene (DMB) to the hydronium ion in aqueous solution was studied to reveal effects of the hydronium ion on the photorelaxation processes of organic molecules in aqueous solution. The occurrence of the ET reaction was substantiated by formation of a DMB cation radical coinciding with disappearance of triplet DMB.From kinetic analyses, the rate constant for the ET reaction was determined to be 7.5 x 10^6M^<-1>s-1. The free energy change (DELTAG^0 = +28kJmol^<-1>) calculated for the ET reaction was consistent with the observed rate for the ET reaction from triplet DMB to the hydronium ion. Less

用激光光解法、时间分辨热透镜法和荧光光谱法研究了溶剂水对有机分子激发态弛豫过程的影响。对于苯胺及其衍生物，光电离是最主要的弛豫通道之一，光电离产生的阳离子自由基的极化稳定性是决定光电离产率的重要因素。研究了1-羟基-2-萘乙酮（1H 2AN）及其相关化合物的激发态分子内质子转移（ESIPT）反应，揭示了1-萘酚衍生物激发态的氢键相互作用.研究表明，1H 2AN发生了典型的ESIPT反应，而1-羟基-2-萘甲酸甲酯的激发单重态不发生ESIPT反应而失活。阐明了这些化合物的电子结构对ESIPT反应的影响。此外，发现1H 2AN的ESIPT之后是 ...更多信息 顺-反异构化以产生受激的反式酮形式。用激光光解法研究了2，4-二甲氧基-6-（对甲苯氧基）均三嗪的Fries重排中间体的，3 σ迁移氢位移。动力学测量表明，水和质子溶剂通过相互的氢交换反应加速1，3-σ迁移的氢转移速率。研究了水溶液中1，4-二甲氧基苯（DMB）三重态与水合氢离子的电子转移（ET）反应，揭示了水合氢离子对水溶液中有机分子光弛豫过程的影响. ET反应的发生被DMB阳离子自由基的形成和三重态DMB的消失所证实。根据动力学分析，ET反应的速率常数被确定为7.5 x 10^6M^<-1>s-1。计算的ET反应的自由能变化（Δ G ^0 =+28kJ mol ^<-1>）与观察到的从三重态DMB到水合氢离子的ET反应的速率一致。少

项目成果

Y.Kimura他: "Tunneling Effects on the 1,3-Sigmatroic Hydrogen Shift in the Photo-Fries Rearranged Intermediate of 2,4-Dimethoxy-6-(p-tolyloxy)-s-triazine." J.Chem.Soc., Faraday Trans. 94. 3077-3085 (1998)

Y. Kimura 等人：“2,4-二甲氧基-6-(对甲苯氧基)-s-三嗪光弗赖斯重排中间体中 1,3-Sigmatroic 氢位移的隧道效应。”法拉第翻译协会。94。3077-3085（1998）

S.Tobita他: "Effects of Electronic Structures on the Excited-State Intramolecular Proton Transfer of 1-Hydroxy-2-Acetonaphthone and Related Compounds." J.Phys.Chem.A. 102. 5206-5214 (1998)

S. Tobita 等人：“电子结构对 1-羟基-2-乙酰萘酮及相关化合物的激发态分子内质子转移的影响”，J.Phys.Chem.A. 102. 5206-5214 (1998)

F.Saito, S.Tobita, and H.Shizuka: "Photoionization Mechanism of Aniline Derivatives in Aqueous Solution Studied by Laser Flash Photolysis" J.Photochem.Photobiol.A : Chem.106. 119-126 (1997)

F.Saito、S.Tobita 和 H.Shizuka：“通过激光闪光光解研究水溶液中苯胺衍生物的光电离机制”J.Photochem.Photobiol.A：Chem.106。

M.Moriyama他: "Intramolecular proton-transfer cycle of 2,4-dimethoxy-6-(1-hydroxy-2-naphthyl)-s-triazine studied by laser photolysis." Chem.Phys.231. 205-214 (1998)

M.Moriyama 等人：“通过激光光解研究 2,4-二甲氧基-6-(1-羟基-2-萘基)-s-三嗪的分子内质子转移循环。”205-214。 (1998)

K.Suzuki, H.Tanabe, S.Tobita, and H.Shizuka: "Solvent-Dependent Radiationless Transitions of Excited 1-aminonaphthalene Derivatives" J.Phys.Chem.A. 101. 4496-4503 (1997)

K.Suzuki、H.Tanabe、S.Tobita 和 H.Shizuka：“激发的 1-氨基萘衍生物的溶剂依赖性无辐射转变”J.Phys.Chem.A。