Time-resolved infrared spectroscopy with multivariate analysis on photoinduced proton transfer in aromatic urea-acetate anion complex
Time-resolved infrared spectroscopy with multivariate analysis on photoinduced proton transfer in aromatic urea-acetate anion complex
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时间分辨红外光谱与芳香脲-乙酸根阴离子复合物中光诱导质子转移的多变量分析
DOI：
10.1021/acs.jpcb.1c09526
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Taka-ak Ishibashi*
中科院分区：
文献类型：
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作者：
Masato Kondoh;Hayato Honda;Kei Togasaki;Yoshinobu Nishimura;Tatsuro Arai;Taka-ak Ishibashi*
1-蒽-2-基-3-苯基脲（2 PUA）是一种芳香族脲类化合物，与乙酸根阴离子（AcO-）形成氢键复合物，称为2 PUA-AcO-复合物。利用纳秒时间分辨红外光谱研究了2 PUA-AcO-复合物在二甲基亚砜（DMSO）中的光诱导反应。用等浓度的AcO-光激发2 PUA后得到的TR-IR光谱一致地用光诱导质子转移模型解释。TR-IR光谱的光谱和时间轮廓在很大程度上取决于2 PUA和AcO-的浓度条件。在过量AcO-存在的条件下，TR-IR光谱包含一个意外的信号，其幅度与溶液中游离AcO-的浓度有关。使用奇异值分解分析的浓度依赖的TR-IR光谱，我们提取的光谱分量，反映光诱导反应的2 PUA-AcO-复合物。提取的光谱类似于在等浓度条件下获得的TR-IR光谱，表明在2 PUA-AcO-络合物的光诱导反应期间发生相同的质子转移，而与浓度条件无关。通过比较2 PUA与AcO-在DMSO中的稳态和瞬态红外光谱与密度泛函理论的计算表明，2 PUA-AcO-复合物和互变异构体物种在很大程度上与溶剂DMSO分子在其电子基态相互作用。
1-Anthracen-2-yl-3-phenylurea (2PUA) is an aromatic urea compound, which forms a hydrogen-bonded complex with an acetate anion (AcO–), 2PUA–AcO–complex. We investigated the photoinduced reaction of the 2PUA–AcO–complex in dimethyl sulfoxide (DMSO) by nanosecond time-resolved infrared (TR-IR) spectroscopy. TR-IR spectra obtained after the photoexcitation of 2PUA with the equal concentration of AcO–were consistently explained by a photoinduced proton transfer model. The spectral and temporal profiles of the TR-IR spectra largely depended on concentration conditions of 2PUA and AcO–. Under the condition where excessive amounts of AcO–existed, the TR-IR spectra contained an unexpected signal whose amplitude was related to the concentration of free AcO–in the solution. Using singular value decomposition analysis of the concentration-dependent TR-IR spectra, we extracted the spectral component that reflects the photoinduced reaction of the 2PUA–AcO–complex. The extracted spectrum resembled the TR-IR spectrum obtained under the equal concentration condition, indicating that the same proton transfer occurs during the photoinduced reaction of the 2PUA–AcO–complex irrespective of the concentration conditions. Comparing the steady-state and transient IR spectra of the 2PUA with AcO–in DMSO with density functional theory calculations suggests that both 2PUA–AcO–complex and tautomer species interact with solvent DMSO molecules in their electronic ground states to a large extent.