The synthesis of new benzothiazole push-pull systems as candidates for NLO-phores is described. Spectral (UV/VIS and solvatochromic) and theoretical studies (electronic properties based on semiempirical AM1 and PM3 methods) of the prepared compounds were carried out. The structure and physico-chemical parameters affecting the push-pull character and intramolecular charge transfer (ICT) of the studied compounds have been investigated and compounds with enhanced hyperpolarizability β have been predicted. The benzothiazolium salts were found to be much more effective NLO-phores in comparison with the corresponding neutral benzothiazoles. The 4-NPh2 group is the most effective donor. The extension of conjugated bridge improves the studied NLO characteristics. An additional acceptor group bonded to the heterocycle causes a red shift of λmax but does not increase hyperpolarizability.
描述了合成新的
苯并噻唑推-拉系统作为NLO荧光团的候选物。对所制备化合物进行了光谱(UV/VIS和溶剂致色性)和理论研究(基于半经验
AM1和PM3方法的电子性质)。研究了影响推-拉性质和分子内电荷转移(ICT)的结构和物理
化学参数,并预测了具有增强高极化率β的化合物。与相应的中性
苯并噻唑相比,
苯并噻唑盐在NLO荧光团中表现出更高的效果。4-NPh2基团是最有效的给体。共轭桥的延伸改善了研究的NLO特性。附加的受体基团与杂环相结合导致了λmax的红移,但并不增加高极化率。