Oliva María Moreno, Casado Juan, Raposo M Manuela M, Fonseca A Maurício C, Hartmann Horst, Hernández Víctor, López Navarrete Juan T
Department of Physical Chemistry, University of Málaga, 29071 Málaga, Spain.
J Org Chem. 2006 Sep 29;71(20):7509-20. doi: 10.1021/jo060318v.
A series of push-pull chromophores built around thiophene-based pi-conjugating spacers and bearing various types of amino donors and cyanovinyl acceptors have been analyzed by means of UV-vis-NIR, IR, and Raman spectroscopic measurements in the solid state as well as in solution. The intramolecular charge transfer (ICT) of these pi-conjugated systems has also been tested by analyzing the ability of the solute molecules to undergo shifts in their fluorescence emission maxima with increasing solvent polarity. These push-pull oligomers also display an attractive electrochemical behavior since they generate stable species both upon oxidation and reduction. Oxidation mainly involves changes in the electron-rich aminooligothienyl half-part of the molecule and leads to the formation of stable cations. On the other hand, reduction to radical anions and dianions is mainly cyanovinyl-centered but also affects the pi-conjugated electron relay. Density functional theory (DFT) calculations have been carried out to help the assignment of the most relevant electronic and vibrational features and to derive useful information about the molecular structure of these NLO-phores.
一系列围绕基于噻吩的π共轭间隔基构建、带有各种类型氨基供体和氰基乙烯基受体的推拉型发色团，已通过紫外-可见-近红外、红外和拉曼光谱测量在固态以及溶液中进行了分析。这些π共轭体系的分子内电荷转移（ICT）也通过分析溶质分子在溶剂极性增加时荧光发射最大值发生位移的能力进行了测试。这些推拉型低聚物还表现出引人注目的电化学行为，因为它们在氧化和还原时都会产生稳定的物种。氧化主要涉及分子中富电子氨基低聚噻吩部分的变化，并导致稳定阳离子的形成。另一方面，还原为自由基阴离子和二价阴离子主要以氰基乙烯基为中心，但也会影响π共轭电子传递。已进行密度泛函理论（DFT）计算，以帮助确定最相关的电子和振动特征，并得出有关这些非线性光学发色团分子结构的有用信息。
