Tuning the photoinduced electron-transfer thermodynamics in 1,3,5-triaryl-2-pyrazoline fluorophores: X-ray structures, photophysical characterization, computational analysis, and in vivo evaluation
Tuning the photoinduced electron-transfer thermodynamics in 1,3,5-triaryl-2-pyrazoline fluorophores: X-ray structures, photophysical characterization, computational analysis, and in vivo evaluation
复制标题
DOI：
10.1021/ja028266o
复制
发表时间：
2003-04-02
影响因子：
15
通讯作者：
VanDerveer, DG
中科院分区：
文献类型：
--
作者：
Fahrni, CJ;Yang, LC;VanDerveer, DG
用x射线分析对一系列供体取代的1,3,5-三芳基-2-吡唑啉荧光团进行了结构表征，并用稳态吸收和发射光谱研究了它们的光物理性质。根据光谱数据和荧光团的氧化还原电位估计了衍生物的光致电子转移热力学。吡唑啉环上1位和3位的芳基取代基以不同的方式影响荧光团的光物理性质。激发态平衡能DeltaE（00）主要受1位取代基变化的影响，而荧光团的还原电位主要由3-芳基决定。利用密度泛函计算来探测发射态和电子转移态的电子结构和能量顺序。计算分析结果与实验数据定性吻合较好。此外，我们已经在体内评估了一种水溶性吡唑啉衍生物作为潜在的细胞内pH探针。膜渗透性、低毒性和高量子产率使荧光团具有生物应用的吸引力。
series of donor-substituted 1,3,5-triaryl-2-pyrazoline fluorophores were structurally characterized by X-ray analysis, and their photophysical properties studied by steady-state absorption and emission spectroscopy. The photoinduced electron-transfer thermodynamics of the derivatives was estimated on the basis of the spectroscopic data and redox potentials of the fluorophores. The aryl substituents in the 1- and 3-position of the pyrazoline ring influence the photophysical properties of the fluorophores in distinctly different ways. The excited-state equilibrium energy DeltaE(00) is primarily influenced by changes of the substituent in the 1-position, whereas the reduction potential of the fluorophore is essentially determined by the 3-aryl group. Density functional calculations were used to probe the electronic structure and energy ordering of the emissive and the electron-transfer state. The results from the computational analysis agree qualitatively well with the experimental data. In addition, we have evaluated a water soluble pyrazoline derivative in vivo as a potential intracellular pH probe. Membrane permeability, low toxicity, and high quantum yield render the fluorophore attractive for biological applications.