Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.
J Am Chem Soc. 2012 Aug 1;134(30):12418-21. doi: 10.1021/ja3055029. Epub 2012 Jul 20.
The synthesis and photophysical properties of a series of naphthalene-containing solvatochromic fluorophores are described within. These novel fluorophores are prepared using a microwave-assisted dehydrogenative Diels-Alder reaction of styrene, followed by a palladium-catalyzed cross coupling reaction to install an electron donating amine group. The new fluorophores are structurally related to Prodan. Photophysical properties of the new fluorophores were studied and intriguing solvatochromic behavior was observed. For most of these fluorophores, high quantum yields (60-99%) were observed in methylene chloride in addition to large Stokes shifts (95-226 nm) in this same solvent. As the solvent polarity increased, so did the observed Stokes shift with one derivative displaying a Stokes shift of ~300 nm in ethanol. All fluorophore emission maxima, and nearly all absorption maxima were significantly red-shifted when compared to Prodan. Shifting the absorption and emission maxima of a fluorophore into the visible region increases its utility in biological applications. Moreover, the cyclopentane portion of the fluorophore structure provides an attachment point for biomolecules that will minimize disruptions of the photophysical properties.
本文描述了一系列含萘的溶剂化变色荧光团的合成和光物理性质。这些新型荧光团是通过微波辅助的脱氢 Diels-Alder 反应合成的，然后通过钯催化的交叉偶联反应引入供电子胺基团。这些新的荧光团与 Prodan 结构相关。研究了新荧光团的光物理性质，观察到了有趣的溶剂化变色行为。对于大多数这些荧光团，在二氯甲烷中观察到高量子产率（60-99%），此外在相同溶剂中观察到大的斯托克斯位移（95-226nm）。随着溶剂极性的增加，观察到的斯托克斯位移也增加，其中一个衍生物在乙醇中显示出约 300nm 的斯托克斯位移。与 Prodan 相比，所有荧光团的荧光发射最大值和几乎所有吸收最大值都明显红移。将荧光团的吸收和发射最大值移至可见光区域可增加其在生物应用中的实用性。此外，荧光团结构的环戊烷部分为生物分子提供了附着点，可最大程度地减少对光物理性质的干扰。
