Novel Iminocoumarin Derivatives: Synthesis, Spectroscopic and Computational Studies
作者:Santosh B. Chemate、Nagaiyan Sekar
DOI:10.1007/s10895-015-1648-4
日期:2015.11
Three novel iminocoumarin derivatives with high quantum yield are synthesized from 3-benzimidazole substituted coumarin and different aromatic aldehydes. The photophysical behavior of the synthesized compounds was studied using UV-visible and fluorescence spectroscopy in polar and non-polar solvents. The compounds show absorption maxima at around 450 nm and emission maxima at around 500 nm. The quantum yields of compounds in dichloromethane and chloroform are more than 0.90. The absorption, emission and quantum yield of compounds are dependent on the polarity of solvents. Along with an intense absorption, these compounds show shoulder absorption peak in the studied solvents. The solvent polarity plots revealed the charge transfer process in the synthesized molecules from donor to acceptor. Density Functional Theory and Time Dependent Density Functional Theory computations have been used to have more understanding of the structural, molecular, electronic and photophysical parameters of the dyes. The dyes were characterized by FT-IR, 1H NMR, 13C NMR and mass spectral analysis.
Extensive Reduction in Back Electron Transfer in Twisted Intramolecular Charge-Transfer (TICT) Coumarin-Dye-Sensitized TiO<sub>2</sub>Nanoparticles/Film: A Femtosecond Transient Absorption Study
作者:Tushar Debnath、Partha Maity、Hyacintha Lobo、Balvant Singh、Ganapati S. Shankarling、Hirendra N. Ghosh
DOI:10.1002/chem.201303903
日期:2014.3.17
polarity of the solvent and the solution pH, suggest that both photoexcited dyes exist in a locally excited (LE) state in solvents of low polarity. In highly polarsolvents, however, C1 exists in an intramolecular charge‐transfer (ICT) state, whereas C2 exists in both ICT and twisted intramolecular charge‐transfer (TICT) states, their populations depending on the degree of polarity of the solvent and the pH
我们报告了两种结构相似的香豆素染料(C1和C2)的合成,表征以及光学和电化学性质。这些染料已被用作TiO 2纳米粒子和薄膜中的敏化剂,并且研究了分子结构对界面电子转移动力学的影响。在C1和C2上进行稳态光学吸收,发射和时间分辨发射的研究,改变了溶剂的极性和溶液的pH值,表明这两种光激发染料均在低极性溶剂中以局部激发(LE)状态存在。但是,在高极性溶剂中,C1以分子内电荷转移(ICT)状态存在,而C1以分子内电荷转移(ICT)状态存在。C2以ICT和扭曲的分子内电荷转移(TICT)状态存在,其数量取决于溶剂的极性程度和溶液的pH值。我们采用飞秒瞬态吸收光谱法来监测C1和C2敏化的TiO 2纳米颗粒和薄膜中的电荷转移动力学。通过直接检测TiO 2纳米粒子的导带中的电子以及瞬态吸收光谱的可见光和近红外区域中染料的自由基阳离子,已经证实了电子注入。在C1 / TiO 2和C2 / TiO 2中均进
Compounds and Method for Imaging Cancer
申请人:Vanderbilt University
公开号:US20180280543A1
公开(公告)日:2018-10-04
A compound, a method of imaging a cell, and a method of detecting a cancer, an inflammatory disease, or a neoplastic disease are provided. The compound includes a nitroxide derivative of a fluorophore that is activatable upon exposure to free radicals. The method of imaging a cell includes contacting the cell with an activatable nitroxide derivative of a fluorophore. The method of detecting a cancer, an inflammatory disease, or a neoplastic disease includes administering an activatable nitroxide derivative of a fluorophore and then imaging one or more cells contacted with the compound.
A HFIP-promoted highly selective hydroxyalkylation of aniline derivatives with arylglyoxal hydrates has been realized. The reaction produces various N,N-dialkylanilines and their derivatives with α-hydroxy carbonyl units in good to excellent yields under mild conditions. Furthermore, the synthetic potential of this method has been demonstrated by the facile synthesis of several structurally interesting